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Sample records for externally applied compression

  1. An unusual case: right proximal ureteral compression by the ovarian vein and distal ureteral compression by the external iliac vein

    Directory of Open Access Journals (Sweden)

    Halil Ibrahim Serin

    2015-12-01

    Full Text Available A 32-years old woman presented to the emergency room of Bozok University Research Hospital with right renal colic. Multidetector computed tomography (MDCT showed compression of the proximal ureter by the right ovarian vein and compression of the right distal ureter by the right external iliac vein. To the best of our knowledge, right proximal ureteral compression by the ovarian vein together with distal ureteral compression by the external iliac vein have not been reported in the literature. Ovarian vein and external iliac vein compression should be considered in patients presenting to the emergency room with renal colic or low back pain and a dilated collecting system.

  2. External pneumatic intermittent compression for treatment of dependent pregnancy edema.

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    Jacobs, M K; McCance, K L; Stewart, M L

    1982-01-01

    A portable external pneumatic intermittent compression (EPIC) device has been successful in reducing peripheral edema. This study explored the effectiveness of EPIC for treating dependent pregnancy edema. In the study, 42 healthy pregnant women received EPIC for 30 minutes at 40 torr while in the left lateral recumbent position: Group One with mid-thigh boots, and Group Two with below-knee boots. Prior to compression, descriptive data were gathered, leg circumference measurements made, and surface skin temperatures recorded for three sites per leg. Vital signs were taken and pedal edema subjectively indexed. Following compression, circumferences, skin temperatures, vital signs, and edema indices were rerecorded. Three volumes were calculated for each leg using a mathematical model of leg segments as conical frustum units. Mean volume reductions for each leg were significant. The mid-thigh-length boots produced greater mean volume decreases. The volume decrease for calf, lower leg, and foot frustum units were significant. EPIC holds promise as a useful treatment for dependent pregnancy edema.

  3. Compression garments and exercise: no influence of pressure applied.

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    Beliard, Samuel; Chauveau, Michel; Moscatiello, Timothée; Cros, François; Ecarnot, Fiona; Becker, François

    2015-03-01

    Compression garments on the lower limbs are increasingly popular among athletes who wish to improve performance, reduce exercise-induced discomfort, and reduce the risk of injury. However, the beneficial effects of compression garments have not been clearly established. We performed a review of the literature for prospective, randomized, controlled studies, using quantified lower limb compression in order to (1) describe the beneficial effects that have been identified with compression garments, and in which conditions; and (2) investigate whether there is a relation between the pressure applied and the reported effects. The pressure delivered were measured either in laboratory conditions on garments identical to those used in the studies, or derived from publication data. Twenty three original articles were selected for inclusion in this review. The effects of wearing compression garments during exercise are controversial, as most studies failed to demonstrate a beneficial effect on immediate or performance recovery, or on delayed onset of muscle soreness. There was a trend towards a beneficial effect of compression garments worn during recovery, with performance recovery found to be improved in the five studies in which this was investigated, and delayed-onset muscle soreness was reportedly reduced in three of these five studies. There is no apparent relation between the effects of compression garments worn during or after exercise and the pressures applied, since beneficial effects were obtained with both low and high pressures. Wearing compression garments during recovery from exercise seems to be beneficial for performance recovery and delayed-onset muscle soreness, but the factors explaining this efficacy remain to be elucidated. Key pointsWe observed no relationship between the effects of compression and the pressures applied.The pressure applied at the level of the lower limb by compression garments destined for use by athletes varies widely between

  4. A review of the hemodynamic effects of external leg and lower body compression.

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    Helmi, M; Gommers, D; Groeneveld, A B J

    2014-03-01

    External leg and lower body compression (ELC) has been used for decades in the prevention of deep vein thrombosis and the treatment of leg ischemia. Because of systemic effects, the methods have regained interest in anesthesia, surgery and critical care. This review intends to summarize hemodynamic effects and their mechanisms. Compilation of relevant literature published in English as full paper and retrieved from Medline. By compressing veins, venous stasis is diminished and venous return and arterial blood flow are increased. ELC has been suggested to improve systemic hemodynamics, in different clinical settings, such as postural hypotension, anesthesia, surgery, shock, cardiopulmonary resuscitation and mechanical ventilation. However, the hemodynamic alterations depend upon the magnitude, extent, cycle, duration and thus the modality of ELC, when applied in a static or intermittent fashion (by pneumatic inflation), respectively. ELC may help future research and optimizing treatment of hemodynamically unstable, surgical or critically ill patients, independent of plasma volume expansion.

  5. Cellular automata codebooks applied to compact image compression

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    Radu DOGARU

    2006-12-01

    Full Text Available Emergent computation in semi-totalistic cellular automata (CA is used to generate a set of basis (or codebook. Such codebooks are convenient for simple and circuit efficient compression schemes based on binary vector quantization, applied to the bitplanes of any monochrome or color image. Encryption is also naturally included using these codebooks. Natural images would require less than 0.5 bits per pixel (bpp while the quality of the reconstructed images is comparable with traditional compression schemes. The proposed scheme is attractive for low power, sensor integrated applications.

  6. The mechanical vapour compression process applied to seawater desalination

    International Nuclear Information System (INIS)

    Murat, F.; Tabourier, B.

    1984-01-01

    The authors present the mechanical vapour compression process applied to sea water desalination. As an example, the paper presents the largest unit so far constructed by SIDEM using this process : a 1,500 m3/day unit installed in the Nuclear Power Plant of Flamanville in France which supplies a high quality process water to that plant. The authors outline the advantages of this process and present also the serie of mechanical vapour compression unit that SIDEM has developed in a size range in between 25 m3/day and 2,500 m3/day

  7. Biomechanical Comparison of External Fixation and Compression Screws for Transverse Tarsal Joint Arthrodesis.

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    Latt, L Daniel; Glisson, Richard R; Adams, Samuel B; Schuh, Reinhard; Narron, John A; Easley, Mark E

    2015-10-01

    Transverse tarsal joint arthrodesis is commonly performed in the operative treatment of hindfoot arthritis and acquired flatfoot deformity. While fixation is typically achieved using screws, failure to obtain and maintain joint compression sometimes occurs, potentially leading to nonunion. External fixation is an alternate method of achieving arthrodesis site compression and has the advantage of allowing postoperative compression adjustment when necessary. However, its performance relative to standard screw fixation has not been quantified in this application. We hypothesized that external fixation could provide transverse tarsal joint compression exceeding that possible with screw fixation. Transverse tarsal joint fixation was performed sequentially, first with a circular external fixator and then with compression screws, on 9 fresh-frozen cadaveric legs. The external fixator was attached in abutting rings fixed to the tibia and the hindfoot and a third anterior ring parallel to the hindfoot ring using transverse wires and half-pins in the tibial diaphysis, calcaneus, and metatarsals. Screw fixation comprised two 4.3 mm headless compression screws traversing the talonavicular joint and 1 across the calcaneocuboid joint. Compressive forces generated during incremental fixator foot ring displacement to 20 mm and incremental screw tightening were measured using a custom-fabricated instrumented miniature external fixator spanning the transverse tarsal joint. The maximum compressive force generated by the external fixator averaged 186% of that produced by the screws (range, 104%-391%). Fixator compression surpassed that obtainable with screws at 12 mm of ring displacement and decreased when the tibial ring was detached. No correlation was found between bone density and the compressive force achievable by either fusion method. The compression across the transverse tarsal joint that can be obtained with a circular external fixator including a tibial ring exceeds that

  8. Interaction of externally-driven acoustic waves with compressible convection

    International Nuclear Information System (INIS)

    Jones, P.; Merryfield, W.

    1992-01-01

    Two-dimensional numerical simulations are used to examine the interaction of acoustic waves with a compressible convecting fluid. Acoustic waves are forced at the lower boundary of the computational domain and propagate through a three-layer system undergoing vigorous penetrative convection. Energy exchange between the wave and the fluid is analyzed using a work integral formulation

  9. External radiation in spinal cord compression in multiple myeloma

    International Nuclear Information System (INIS)

    Rao, G.H.; Ayyagiri, S.; Dutta, T.K.; Gupta, B.D.; Gulati, D.R.

    1978-01-01

    The place of radiotherapy in 14 cases of spinal cord compression in multiple myeloma is outlined. The modalities of treatment and the role of surgery and radiation as decompression methods are emphasised. Complete recovery is seen in 50 percent of the patients in this small group with judicious combination of surgical and/or radiation decompression. Chemotherapy as systematic treatment must be given in all the cases after decompression procedures. It is suggested that reactive oedema after irradiation is only speculative and radiation alone as primary treatment may be recommended in selected cases. (author)

  10. External radiation in spinal cord compression in multiple myeloma

    Energy Technology Data Exchange (ETDEWEB)

    Rao, G H; Ayyagiri, S; Dutta, T K; Gupta, B D; Gulati, D R [Post-Graduate Inst. of Medical Education and Research, Chandigarh (India). Dept. of Radiotherapy

    1978-02-01

    The place of radiotherapy in 14 cases of spinal cord compression in multiple myeloma is outlined. The modalities of treatment and the role of surgery and radiation as decompression methods are emphasised. Complete recovery is seen in 50 percent of the patients in this small group with judicious combination of surgical and/or radiation decompression. Chemotherapy as systematic treatment must be given in all the cases after decompression procedures. It is suggested that reactive oedema after irradiation is only speculative and radiation alone as primary treatment may be recommended in selected cases.

  11. The influence of external compression on muscle blood flow during exercise

    International Nuclear Information System (INIS)

    Styf, J.

    1990-01-01

    Intramuscular pressures and muscle blood flow were measured in the anterior tibial muscle during dynamic concentric exercise in 14 subjects. Pressures were recorded by the microcapillary infusion method and muscle blood flow by the 133-Xenon clearance technique. Muscle blood flow during constant exercise decreased from 34.5 (SD = 10.3) to 10.6 (SD = 4.9) ml/100 g/min (P less than 0.001) when muscle relaxation pressure was increased from 13.5 (SD = 2.7) to 39.9 (SD = 9.0) mm Hg by external compression. Muscle relaxation pressure during exercise is the intramuscular pressure between contractions. External compression of the lower limb during exercise impedes muscle blood flow by increasing muscle relaxation pressure. The experimental model seems suitable to study the influence of external compression by knee braces on intramuscular pressure during exercise

  12. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

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    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient's cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  13. External cardiac compression may be harmful in some scenarios of pulseless electrical activity.

    LENUS (Irish Health Repository)

    Hogan, T S

    2012-10-01

    Pulseless electrical activity occurs when organised or semi-organised electrical activity of the heart persists but the product of systemic vascular resistance and the increase in systemic arterial flow generated by the ejection of the left venticular stroke volume is not sufficient to produce a clinically detectable pulse. Pulseless electrical activity encompasses a very heterogeneous variety of severe circulatory shock states ranging in severity from pseudo-cardiac arrest to effective cardiac arrest. Outcomes of cardiopulmonary resuscitation for pulseless electrical activity are generally poor. Impairment of cardiac filling is the limiting factor to cardiac output in many scenarios of pulseless electrical activity, including extreme vasodilatory shock states. There is no evidence that external cardiac compression can increase cardiac output when impaired cardiac filling is the limiting factor to cardiac output. If impaired cardiac filling is the limiting factor to cardiac output and the heart is effectively ejecting all the blood returning to it, then external cardiac compression can only increase cardiac output if it increases venous return and cardiac filling. Repeated cardiac compression asynchronous with the patient\\'s cardiac cycle and raised mean intrathoracic pressure due to chest compression can be expected to reduce rather than to increase cardiac filling and therefore to reduce rather than to increase cardiac output in such circumstances. The hypothesis is proposed that the performance of external cardiac compression will have zero or negative effect on cardiac output in pulseless electrical activity when impaired cardiac filling is the limiting factor to cardiac output. External cardiac compression may be both directly and indirectly harmful to significant sub-groups of patients with pulseless electrical activity. We have neither evidence nor theory to provide comfort that external cardiac compression is not harmful in many scenarios of pulseless

  14. Calculation of external-internal flow fields for mixed-compression inlets

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    Chyu, W. J.; Kawamura, T.; Bencze, D. P.

    1987-01-01

    Supersonic inlet flows with mixed external-internal compressions were computed using a combined implicit-explicit (Beam-Warming-Steger/MacCormack) method for solving the three-dimensional unsteady, compressible Navier-Stokes equations in conservation form. Numerical calculations were made of various flows related to such inlet operations as the shock-wave intersections, subsonic spillage around the cowl lip, and inlet started versus unstarted conditions. Some of the computed results were compared with wind tunnel data.

  15. Review of external ocular compression: clinical applications of the ocular pressure estimator

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    Korenfeld MS

    2016-02-01

    Full Text Available Michael S Korenfeld,1,2 David K Dueker3 1Comprehensive Eye Care, Ltd. Washington, MO, USA; 2Washington University Department of Ophthalmology and Visual Sciences, St Louis, MO, USA; 3Ophthalmology, Hamad Medical Corporation, Doha, Qatar Purpose: The authors have previously validated an Ocular Pressure Estimator (OPE that can estimate the intraocular pressure (IOP during external ocular compression (EOC. The authors now apply the OPE in clinical states where EOC is clinically important. The original work is described for two periods of risk: during sleep and during the digital ocular massage (DOM maneuver used by surgeons after trabeculectomy to keep the operation functional. Other periods of risk for external ocular compression are then reviewed.Methods: The first protocol estimated the IOP in the dependent eye during simulated sleep. Subjects had their IOPs initially measured in an upright-seated position, immediately upon assuming a right eye dependent side sleeping position (with nothing contacting the eye, and then 5 minutes later while still in this position. While maintaining this position, the fluid filled bladder of the OPE was then placed between the subject’s closed eye and a pillow during simulated sleep. The IOP was continuously estimated in this position for 5 minutes. The subjects then had the IOP measured in both eyes in an upright-seated position. The second protocol determined if a larger vertical cup-to-disc ratio was more common on the side that patients reported they preferred to sleep on. The hypothesis was that chronic asymmetric, compression induced, elevations of IOP during sleep would be associated with otherwise unexplained asymmetry of the vertical cup-to-disc ratio. The third protocol assessed the IOP during DOM. The OPE was used to characterize the IOP produced during the DOM maneuver of five glaucoma surgeons. After this, 90 mmHg was chosen as a target pressure for DOM. The surgeons were then verbally coached

  16. Magnetic response to applied electrostatic field in external magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, T.C. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318, Sao Paulo, SP (Brazil); University of Florida, Department of Physics, Gainesville, FL (United States); Gitman, D.M. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318, Sao Paulo, SP (Brazil); Tomsk State University, Department of Physics, Tomsk (Russian Federation); Shabad, A.E. [P. N. Lebedev Physics Institute, Moscow (Russian Federation)

    2014-04-15

    We show, within QED and other possible nonlinear theories, that a static charge localized in a finite domain of space becomes a magnetic dipole, if it is placed in an external (constant and homogeneous) magnetic field in the vacuum. The magnetic moment is quadratic in the charge, depends on its size and is parallel to the external field, provided the charge distribution is at least cylindrically symmetric. This magneto-electric effect is a nonlinear response of the magnetized vacuum to an applied electrostatic field. Referring to the simple example of a spherically symmetric applied field, the nonlinearly induced current and its magnetic field are found explicitly throughout the space; the pattern of the lines of force is depicted, both inside and outside the charge, which resembles that of a standard solenoid of classical magnetostatics. (orig.)

  17. DISTRACTION EXTERNAL FIXATIONS OF PELVIC FRACTURES CAUSED BY A LATERAL COMPRESSION.

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    Pavlin Apostolov

    2011-11-01

    Full Text Available The authors represent a distraction external pelvic fixation technique, which they use in pelvic fractures caused by a lateral compression. They consider the indications and mounting techniques. The authors recommend the early movement activities (on the 3rd - 5th day after the external fixator placement. This method had been used in 8 patients and 3 cases are analyzed in details. The priority of this technique over open reduction and internal fixation (ORIF mainly are: (1 the implementation of good reduction of the fracture preventing the risk of ORIF; (2 the possibility for early movement activities for the patient.

  18. Endovascular treatment of external iliac vein stenosis caused by graft compression after kidney transplantation

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    Willamax Oliveira de Sousa

    2013-06-01

    Full Text Available A 57-year old patient presented with approximately 80% stenosis of the left external iliac vein due to compression by the renal graft after kidney transplantation. The initial clinical manifestation of this vascular complication was progressive edema of the left lower limb, starting in the foot during the immediate postoperative period and reaching the thigh. Renal function also deteriorated during the first four months after transplantation. Venous Doppler ultrasound findings were suggestive of a diagnosis of extrinsic compression by the kidney graft and so phlebography was ordered, confirming stenosis of the left external iliac vein. The patient was initially treated with balloon angioplasty, but there was still residual stenosis so a stent was inserted, eliminating the stenosis. The edema reduced over time and the patient's renal function improved. While vascular complications are rare, and potentially severe, events, success rates are good if treatment is started early.

  19. Predicted VO2max and effectiveness of external chest compression by Chinese nurses.

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    Ho, Leo S T; Jones, Alice Y M; Rainer, Timothy H

    2017-08-01

    The aims of this study were to assess the influence of sex and body position on external chest compression (ECC) to a manikin by Chinese nurses and to determine the relationship between rescuer's predicted VO2max and ECC depth. A total of 40 nurses performed ECC on a manikin for 5 min in the standing (S) and bed-mount kneeling (K) position, then completed a Chester step-test, in 3 separate days. The rate and depth of compressions and oxygen consumption during ECC were measured. Mean compression rate recorded was above 100/min in both positions throughout ECC. Mean compression depth for male participants was more than 38 mm for 5 min in the K-position but only 3 min in the S-position. Female participants achieved this compression depth for less than 90 s in the K-position but not at all in the S-position. Irrespective of sex, the K-position appears to facilitate effective ECC. The relationship between aerobic fitness of female nurses and their ability to perform effective cardiopulmonary resuscitation warrants further investigation.

  20. Wavelet compression algorithm applied to abdominal ultrasound images

    International Nuclear Information System (INIS)

    Lin, Cheng-Hsun; Pan, Su-Feng; LU, Chin-Yuan; Lee, Ming-Che

    2006-01-01

    We sought to investigate acceptable compression ratios of lossy wavelet compression on 640 x 480 x 8 abdominal ultrasound (US) images. We acquired 100 abdominal US images with normal and abnormal findings from the view station of a 932-bed teaching hospital. The US images were then compressed at quality factors (QFs) of 3, 10, 30, and 50 followed outcomes of a pilot study. This was equal to the average compression ratios of 4.3:1, 8.5:1, 20:1 and 36.6:1, respectively. Four objective measurements were carried out to examine and compare the image degradation between original and compressed images. Receiver operating characteristic (ROC) analysis was also introduced for subjective assessment. Five experienced and qualified radiologists as reviewers blinded to corresponding pathological findings, analysed paired 400 randomly ordered images with two 17-inch thin film transistor/liquid crystal display (TFT/LCD) monitors. At ROC analysis, the average area under curve (Az) for US abdominal image was 0.874 at the ratio of 36.6:1. The compressed image size was only 2.7% for US original at this ratio. The objective parameters showed the higher the mean squared error (MSE) or root mean squared error (RMSE) values, the poorer the image quality. The higher signal-to-noise ratio (SNR) or peak signal-to-noise ratio (PSNR) values indicated better image quality. The average RMSE, PSNR at 36.6:1 for US were 4.84 ± 0.14, 35.45 dB, respectively. This finding suggests that, on the basis of the patient sample, wavelet compression of abdominal US to a ratio of 36.6:1 did not adversely affect diagnostic performance or evaluation error for radiologists' interpretation so as to risk affecting diagnosis

  1. Applying environmental externalities to US Clean Coal Technologies for Asia

    International Nuclear Information System (INIS)

    Szpunar, C.B.; Gillette, J.L.

    1993-01-01

    The United States is well positioned to play an expanding role in meeting the energy technology demands of the Asian Pacific Basin, including Indonesia, Thailand, and the Republic of China (ROC-Taiwan). The US Department of Energy Clean Coal Technology (CCT) Demonstration Program provides a proving ground for innovative coal-related technologies that can be applied domestically and abroad. These innovative US CCTs are expected to satisfy increasingly stringent environmental requirements while substantially improving power generation efficiencies. They should also provide distinct advantages over conventional pulverized coal-fired combustors. Finally, they are expected to be competitive with other energy options currently being considered in the region. This paper presents potential technology scenarios for Indonesia, Thailand, and the ROC-Taiwan and considers an environmental cost-benefit approach employing a newly developed method of applying environmental externalities. Results suggest that the economic benefits from increased emission control can indeed be quantified and used in cost-benefit comparisons, and that US CCTs can be very cost effective in reducing emissions

  2. Vortex Generators in a Streamline-Traced, External-Compression Supersonic Inlet

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    Baydar, Ezgihan; Lu, Frank K.; Slater, John W.; Trefny, Charles J.

    2017-01-01

    Vortex generators within a streamline-traced, external-compression supersonic inlet for Mach 1.66 were investigated to determine their ability to increase total pressure recovery and reduce total pressure distortion. The vortex generators studied were rectangular vanes arranged in counter-rotating and co-rotating arrays. The vane geometric factors of interest included height, length, spacing, angle-of-incidence, and positions upstream and downstream of the inlet terminal shock. The flow through the inlet was simulated numerically through the solution of the steady-state, Reynolds-averaged Navier-Stokes equations on multi-block, structured grids using the Wind-US flow solver. The vanes were simulated using a vortex generator model. The inlet performance was characterized by the inlet total pressure recovery and the radial and circumferential total pressure distortion indices at the engine face. Design of experiments and statistical analysis methods were applied to quantify the effect of the geometric factors of the vanes and search for optimal vane arrays. Co-rotating vane arrays with negative angles-of-incidence positioned on the supersonic diffuser were effective in sweeping low-momentum flow from the top toward the sides of the subsonic diffuser. This distributed the low-momentum flow more evenly about the circumference of the subsonic diffuser and reduced distortion. Co-rotating vane arrays with negative angles-of-incidence or counter-rotating vane arrays positioned downstream of the terminal shock were effective in mixing higher-momentum flow with lower-momentum flow to increase recovery and decrease distortion. A strategy of combining a co-rotating vane array on the supersonic diffuser with a counter-rotating vane array on the subsonic diffuser was effective in increasing recovery and reducing distortion.

  3. Olfactory Neuroblastoma: A Rare Cause of External Ophthalmoplegia, Proptosis and Compressive Optic Neuropathy.

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    Kartı, Ömer; Zengin, Mehmet Özgür; Çelik, Ozan; Tokat, Taşkın; Küsbeci, Tuncay

    2018-04-01

    Olfactory neuroblastoma (ONB), which is a neuroectodermal tumor of the nasal cavity, is a rare and locally aggressive malignancy that may invade the orbit via local destruction. In this study, we report a patient with proptosis, external ophthalmoplegia, and compressive optic neuropathy caused by ONB. A detailed clinical examination including ocular imaging and histopathological studies were performed. The 62-year-old female patient presented to our clinic with complaints of proptosis and visual deterioration in the left eye. Her complaints started 2 months prior to admission. Visual acuity in the left eye was counting fingers from 2 meters. There was relative afferent pupillary defect. She had 6 mm of proptosis and limitation of motility. Fundus examination was normal in the right eye, but there was a hyperemic disc, and increased vascular tortuosity and dilation of the retinal veins in the left eye. Computerized tomography and magnetic resonance imaging of the brain and orbits demonstrated a large heterogeneous mass in the left superior nasal cavity with extensions into the ethmoidal sinuses as well as into the left orbit, compressing the medial rectus muscle and optic nerve. Endoscopic biopsy of the lesion was consistent with an ONB (Hyams' grade III). Orbital invasion may occur in patients with ONB. Therefore, it is important to be aware of this malignancy because some patients present with ophthalmic signs such as external ophthalmoplegia, proptosis, or compressive optic neuropathy.

  4. External carotid compression: a novel technique to improve cerebral perfusion during selective antegrade cerebral perfusion for aortic arch surgery.

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    Grocott, Hilary P; Ambrose, Emma; Moon, Mike

    2016-10-01

    Selective antegrade cerebral perfusion (SACP) involving cannulation of either the axillary or innominate artery is a commonly used technique for maintaining cerebral blood flow (CBF) during the use of hypothermic cardiac arrest (HCA) for operations on the aortic arch. Nevertheless, asymmetrical CBF with hypoperfusion of the left cerebral hemisphere is a common occurrence during SACP. The purpose of this report is to describe an adjunctive maneuver to improve left hemispheric CBF during SACP by applying extrinsic compression to the left carotid artery. A 77-yr-old male patient with a history of aortic valve replacement presented for emergent surgical repair of an acute type A aortic dissection of a previously known ascending aortic aneurysm. His intraoperative course included cannulation of the right axillary artery, which was used as the aortic inflow during cardiopulmonary bypass and also allowed for subsequent SACP during HCA. After the onset of HCA, the innominate artery was clamped at its origin to allow for SACP. Shortly thereafter, however, the left-sided cerebral oxygen saturation (SrO2) began to decrease. Augmenting the PaO2, PaCO2 and both SACP pressure and flow failed to increase left hemispheric SrO2. Following the use of ultrasound guidance to confirm the absence of atherosclerotic disease in the carotid artery, external pressure was applied partially compressing the artery. With the carotid compression, the left cerebral saturation abruptly increased, suggesting pressurization of the left cerebral hemispheric circulation and augmentation of CBF. Direct ultrasound visualization and cautious partial compression of the left carotid artery may address asymmetrical CBF that occurs with SACP during HCA for aortic arch surgery. This strategy may lead to improved symmetry of CBF and corresponding cerebral oximetry measurements during aortic arch surgery.

  5. Optimization of the multilinear compression function applied to calorimetry

    International Nuclear Information System (INIS)

    Cattaneo, P.W.Paolo Walter

    2002-01-01

    The energy dynamic range required by a calorimeter with high speed readout may exceed existing ADC capability. A solution may be a dynamic compressor matching the energy span to the ADC range, such as to contribute at most a predefinite amount to the calorimeter resolution. A multilinear compression function is the easiest to implement, therefore it is interesting to optimize the input to output relation and fix the break points

  6. [Comparison study on locking compress plate external fixator and standard external fixator for treatment of tibial open fractures].

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    Wu, Gang; Luo, Xiaozhong; Tan, Lun; Lin, Xu; Wu, Chao; Guo, Yong; Zhong, Zewei

    2013-11-01

    To compare the clinical results of locking compress plate (LCP) as an external fixator and standard external fixator for treatment of tibial open fractures. Between May 2009 and June 2012, 59 patients with tibial open fractures were treated with LCP as an external fixator in 36 patients (group A), and with standard external fixator in 23 patients (group B). There was no significant difference in gender, age, cause of injury, affected side, type of fracture, location, and interval between injury and surgery between 2 groups (P > 0.05). The time of fracture healing and incision healing, the time of partial weight-bearing, the range of motion (ROM) of knee and ankle, and complications were compared between 2 groups. The incidence of pin-track infection in group A (0) was significantly lower than that in group B (21.7%) (P=0.007). No significant difference was found in the incidence of superficial infection and deep infection of incision, and the time of incision healing between 2 groups (P > 0.05). Deep vein thrombosis occurred in 5 cases of group A and 2 cases of group B, showing no significant difference (Chi(2)=0.036, P=0.085). All patients were followed up 15.2 months on average (range, 9-28 months) in group A, and 18.6 months on average (range, 9-47 months) in group B. The malunion rate and nonunion rate showed no significant difference between groups A and B (0 versus 13.0% and 0 versus 8.7%, P > 0.05); the delayed union rate of group A (2.8%) was significantly lower than that of group B (21.7%) (Chi(2)=5.573, P=0.018). Group A had shorter time of fracture healing, quicker partial weight-bearing, greater ROM of the knee and ankle than group B (P fracture, and has good patients' compliance, so it is helpful to do functional exercise, improve fracture healing and function recovery, and reduce the complication incidence.

  7. [Treatment type C fracture of the distal radius with locking compression plate and external fixators].

    Science.gov (United States)

    Yang, Xiang; Zhao, You-ming; Chen, Lin; Ye, Cong-cong; Guo, Wei-jun; Wang, Bo

    2013-12-01

    To compare efficacy of unilateral external fixators and locking compression plates in treating type C fractures of the distal radius. From January 2009 to June 2010, 76 patients with distal radius fracture were treated with LCP and external fixators, 54 patients were followed up. Among them, 29 cases were male and 25 cases were female with an average age of 45.31 (ranged, 24 to 68) years old. There were 29 patients in LCP group. According to AO classification, 8 cases were type C1, 7 cases were type C2 and 14 cases were type C3. There were 25 cases in external fixators group. According to AO classification, 6 cases were type C1, 8 cases were type C2 and 11 cases were type C3. Radial height, volar tilt and radial inclination were compared, advanced Gartland-Werley scoring were used to assessed wrist joint function after 6 and 12 months' following up. Two cases were suffered from nail infection in external fixators group. Fifty-four patients were followed up from 12 to 24 months with an average of 21.3 months. Radial height was (9.60 +/- 0.72) mm, volar tilt was (9.55 +/- 0.80) degrees and radial inclination was (21.40 +/- 0.78) degrees in LCP group,while those were (9.40 +/- 0.70) mm, (9.47 +/- 0.71) degrees and (21.20 +/- 0.73) degrees in external fixtors group, and with no statistical significance (P>0.05). Advanced Gartland-Werley score after 6 months' following up was 3.31 +/- 1.17 in LCP group, 5.56 +/- 1.58 in external fixtors group, and with significant difference (t=-5.99,Pmeaning (t=-1.55, P>0.05). LCP and external fixtors can receive good curative effects in treating type C distal radius fracture, and LCP can obtain obviously short-term efficacy, while there is no significant difference between two groups in long-term results. For serious distal radius comminuted fracture which unable to plate internal fixation, external fixators is a better choice.

  8. Compressed Sensing Techniques Applied to Ultrasonic Imaging of Cargo Containers

    Directory of Open Access Journals (Sweden)

    Yuri Álvarez López

    2017-01-01

    Full Text Available One of the key issues in the fight against the smuggling of goods has been the development of scanners for cargo inspection. X-ray-based radiographic system scanners are the most developed sensing modality. However, they are costly and use bulky sources that emit hazardous, ionizing radiation. Aiming to improve the probability of threat detection, an ultrasonic-based technique, capable of detecting the footprint of metallic containers or compartments concealed within the metallic structure of the inspected cargo, has been proposed. The system consists of an array of acoustic transceivers that is attached to the metallic structure-under-inspection, creating a guided acoustic Lamb wave. Reflections due to discontinuities are detected in the images, provided by an imaging algorithm. Taking into consideration that the majority of those images are sparse, this contribution analyzes the application of Compressed Sensing (CS techniques in order to reduce the amount of measurements needed, thus achieving faster scanning, without compromising the detection capabilities of the system. A parametric study of the image quality, as a function of the samples needed in spatial and frequency domains, is presented, as well as the dependence on the sampling pattern. For this purpose, realistic cargo inspection scenarios have been simulated.

  9. Applied physics of external radiation exposure dosimetry and radiation protection

    CERN Document Server

    Antoni, Rodolphe

    2017-01-01

    This book describes the interaction of living matter with photons, neutrons, charged particles, electrons and ions. The authors are specialists in the field of radiation protection. The book synthesizes many years of experiments with external radiation exposure in the fields of dosimetry and radiation shielding in medical, industrial and research fields. It presents the basic physical concepts including dosimetry and offers a number of tools to be used by students, engineers and technicians to assess the radiological risk and the means to avoid them by calculating the appropriate shields. The theory of radiation interaction in matter is presented together with empirical formulas and abacus. Numerous numerical applications are treated to illustrate the different topics. The state of the art in radiation protection and dosimetry is presented in detail, especially in the field of simulation codes for external exposure to radiation, medical projects and advanced research. Moreover, important data spread in differ...

  10. Modeling external constraints: Applying expert systems to nuclear plants

    International Nuclear Information System (INIS)

    Beck, C.E.; Behera, A.K.

    1993-01-01

    Artificial Intelligence (AI) applications in nuclear plants have received much attention over the past decade. Specific applications that have been addressed include development of models and knowledge-bases, plant maintenance, operations, procedural guidance, risk assessment, and design tools. This paper examines the issue of external constraints, with a focus on the use of Al and expert systems as design tools. It also provides several suggested methods for addressing these constraints within the Al framework. These methods include a State Matrix scheme, a layered structure for the knowledge base, and application of the dynamic parameter concept

  11. External chest compressions using a mechanical feedback device : cross-over simulation study.

    Science.gov (United States)

    Skorning, M; Derwall, M; Brokmann, J C; Rörtgen, D; Bergrath, S; Pflipsen, J; Beuerlein, S; Rossaint, R; Beckers, S K

    2011-08-01

    External chest compressions (ECC) are essential components of resuscitation and are usually performed without any adjuncts in professional healthcare. Even for healthcare professionals during in-hospital and out-of-hospital resuscitation poor performance in ECC has been reported in recent years. Although several stand-alone devices have been developed none has been implemented as a standard in patient care. The aim of this study was to examine if the use of a mechanical device providing visual feedback and audible assistance during ECC improves performance of healthcare professionals following minimal and simplified instructions. In a prospective, randomized cross-over study 81 healthcare professionals performed ECC for 3 min (in the assumed setting of a secured airway) twice on a manikin (Skillreporter ResusciAnne®, with PC-Skillreporting System Version 1.3.0, Laerdal, Stavanger, Norway) in a mock cardiac arrest scenario. Group 1 (n=40) performed ECC with the device first followed by classic ECC and group 2 (n=41) in the opposite order. Minimal instructions were standardized and provided by video instruction (1 min 38 s). Endpoints were achievement of a mean compression rate between 90 and 110/min and a mean compression depth of 40-50 mm. In addition participants had to answer questionnaires about demographic data, professional experience and recent recommendations for ECC as well as their impression of the device concerning the ease of use and their personal level of confidence. Data were analyzed for group-related and inter-group differences using SAS (Version 9.1.3, SAS Institute, Cary, NC). A total of 81 healthcare professionals regularly involved in resuscitation attempts in pre-hospital or in-hospital settings took part in the study with no differences between the groups: females 35.8% (n=52), emergency medical technicians 32.1% (n=26), anesthesia nurses 32.1% (n=26), physicians (anesthesiology) 45% (n=29). In group 1 33 out of 40 (82.5%; 99.7±4

  12. Hormonal therapy with external radiation therapy for metastatic spinal cord compression from newly diagnosed prostate cancer

    International Nuclear Information System (INIS)

    Kato, So; Hozumi, Takahiro; Yamakawa, Kiyofumi; Higashikawa, Akiro; Goto, Takahiro; Shinohara, Mitsuru; Kondo, Taiji

    2013-01-01

    Although hormonal therapy is effective for treatment of prostate cancer, its effect in the treatment of metastatic spinal cord compression (MSCC) has not been established. The objective of this study was to clarify the efficacy of conservative treatment of MSCC-induced paralysis resulting from prostate cancer for patients without a previous treatment history. We reviewed data from 38 patients with MSCC-induced paralysis from newly diagnosed prostate cancer who presented to our service between 1984 and 2010. Conservative treatment consisted of hormonal therapy with external radiation therapy (ERT). Patient demographic data, treatment details, involved spine MRI images, complications, and the course of neurologic recovery were investigated. Twenty-five patients were treated conservatively. Mean follow-up period was 36.8 months. Sixteen patients (two with Frankel B, 14 with Frankel C) were unable to walk at initial presentation. After initiating conservative treatment, 75% (12 of 16) of these patients regained the ability to walk within 1 month, 88% (14 in 16) did so within 3 months, and all non-ambulatory patients did so within 6 months. No one had morbid complications. Four patients who did not regain the ability to walk at 1 month were found to have progressed to paraplegia rapidly, and tended to have severe compression as visualized on MRI, with a delay in the start of treatment in comparison with those who did so within 1 month (21.0 vs. 7.8 days). Hormonal therapy associated with ERT is an important option for treatment of MSCC resulting from newly diagnosed prostate cancer. (author)

  13. The evaluation of upper body muscle activity during the performance of external chest compressions in simulated hypogravity

    Science.gov (United States)

    Krygiel, Rebecca G.; Waye, Abigail B.; Baptista, Rafael Reimann; Heidner, Gustavo Sandri; Rehnberg, Lucas; Russomano, Thais

    2014-04-01

    BACKGROUND: This original study evaluated the electromyograph (EMG) activity of four upper body muscles: triceps brachii, erector spinae, upper rectus abdominis, and pectoralis major, while external chest compressions (ECCs) were performed in simulated Martian hypogravity using a Body Suspension Device, counterweight system, and standard full body cardiopulmonary resuscitation (CPR) mannequin. METHOD: 20 young, healthy male subjects were recruited. One hundred compressions divided into four sets, with roughly six seconds between each set to indicate 'ventilation', were performed within approximately a 1.5 minute protocol. Chest compression rate, depth and number were measured along with the subject's heart rate (HR) and rating of perceived exertion (RPE). RESULTS: All mean values were used in two-tailed t-tests using SPSS to compare +1 Gz values (control) versus simulated hypogravity values. The AHA (2005) compression standards were maintained in hypogravity. RPE and HR increased by 32% (p training regimes in case of a serious cardiac event in hypogravity.

  14. [Ambulant compression therapy for crural ulcers; an effective treatment when applied skilfully].

    Science.gov (United States)

    de Boer, Edith M; Geerkens, Maud; Mooij, Michael C

    2015-01-01

    The incidence of crural ulcers is high. They reduce quality of life considerably and create a burden on the healthcare budget. The key treatment is ambulant compression therapy (ACT). We describe two patients with crural ulcers whose ambulant compression treatment was suboptimal and did not result in healing. When the bandages were applied correctly healing was achieved. If correctly applied ACT should provide sufficient pressure to eliminate oedema, whilst taking local circumstances such as bony structures and arterial qualities into consideration. To provide pressure-to-measure regular practical training, skills and regular quality checks are needed. Knowledge of the properties of bandages and the proper use of materials for padding under the bandage enables good personalised ACT. In trained hands adequate compression and making use of simple bandages and dressings provides good care for patients suffering from crural ulcers in contrast to inadequate ACT using the same materials.

  15. Effect of applied stress on the compressive residual stress introduced by laser peening

    International Nuclear Information System (INIS)

    Sumiya, Rie; Tazawa, Toshiyuki; Narazaki, Chihiro; Saito, Toshiyuki; Kishimoto, Kikuo

    2016-01-01

    Peening is the process which is able to be generated compressive residual stress and is known to be effective for preventing SCC initiation and improvement of fatigue strength. Laser peening is used for the nuclear power plant components in order to prevent SCC initiation. Although it is reported that the compressive residual stress decreases due to applied stresses under general operating condition, the change of residual stress might be large under excessive loading such as an earthquake. The objectives of this study are to evaluate the relaxation behavior of the compressive residual stress due to laser peening and to confirm the surface residual stress after loading. Therefore laser peened round bar test specimens of SUS316L which is used for the reactor internals of nuclear power plant were loaded at room temperature and elevated temperature and then surface residual stresses were measured by X-ray diffraction method. In the results of this test, it was confirmed that the compressive residual stress remained after applying uniform stress larger than 0.2% proof stress, and the effect of cyclic loading on the residual stress was small. The effect of applying compressive stress on the residual stress relaxation was confirmed to be less than that of applying tensile stress. Plastic deformation through a whole cross section causes the change in the residual stress distribution. As a result, the surface compressive residual stress is released. It was shown that the effect of specimen size on residual stress relaxation and the residual stress relaxation behavior in the stress concentration region can be explained by assumed stress relaxation mechanism. (author)

  16. Peyton's 4-Steps-Approach in comparison: Medium-term effects on learning external chest compression – a pilot study

    Directory of Open Access Journals (Sweden)

    Münster, Tobias

    2016-08-01

    Full Text Available Introduction: The external chest compression is a very important skill required to maintain a minimum of circulation during cardiac arrest until further medical procedures can be taken. Peyton’s 4-Steps-Approach is one method of skill training, the four steps being:Based on CPR skill training, this method is widely, allegedly predominantly used, although there are insufficient studies on Peyton’s 4-Steps-Approach for skill training in CPR in comparison with other methods of skill training. In our study, we compared the medium- term effects on learning external chest compression with a CPR training device in three different groups: PEY (Peyton’s 4-Steps-Approach, PMOD (Peyton’s 4-Steps-Approach without Step 3 and STDM, the standard model, according to the widely spread method “see one, do one” (this is equal to Peyton’s step 1 and 3.Material and Methods: This prospective and randomised pilot study took place during the summer semester of 2009 at the SkillsLab and Simulation Centre of the University of Cologne (Kölner interprofessionelles Skills Lab und Simulationszentrum - KISS. The subjects were medical students (2 and 3 semester. They volunteered for the study and were randomised in three parallel groups, each receiving one of the teaching methods mentioned above. One week and 5/6 months after the intervention, an objective, structured single assessment was taken. Compression rate, compression depth, correct compressions, and the sum of correct checklist items were recorded. Additionally, we compared cumulative percentages between the groups based on the correct implementation of the resuscitation guidelines during that time.Results: The examined sample consisted of 134 subjects (68% female; age 22±4; PEY: n=62; PMOD: n=31; STDM: n=41. There was no difference between the groups concerning age, gender, pre-existing experience in CPR or time of last CPR course. The only significant difference between the groups was the mean

  17. Peyton's 4-Steps-Approach in comparison: Medium-term effects on learning external chest compression - a pilot study.

    Science.gov (United States)

    Münster, Tobias; Stosch, Christoph; Hindrichs, Nina; Franklin, Jeremy; Matthes, Jan

    2016-01-01

    The external chest compression is a very important skill required to maintain a minimum of circulation during cardiac arrest until further medical procedures can be taken. Peyton's 4-Steps-Approach is one method of skill training, the four steps being: Demonstration, Deconstruction, Comprehension and Execution. Based on CPR skill training, this method is widely, allegedly predominantly used, although there are insufficient studies on Peyton's 4-Steps-Approach for skill training in CPR in comparison with other methods of skill training. In our study, we compared the medium- term effects on learning external chest compression with a CPR training device in three different groups: PEY (Peyton's 4-Steps-Approach), PMOD (Peyton's 4-Steps-Approach without Step 3) and STDM, the standard model, according to the widely spread method "see one, do one" (this is equal to Peyton's step 1 and 3). This prospective and randomised pilot study took place during the summer semester of 2009 at the SkillsLab and Simulation Centre of the University of Cologne (Kölner interprofessionelles Skills Lab und Simulationszentrum - KISS). The subjects were medical students (2(nd) and 3(rd) semester). They volunteered for the study and were randomised in three parallel groups, each receiving one of the teaching methods mentioned above. One week and 5/6 months after the intervention, an objective, structured single assessment was taken. Compression rate, compression depth, correct compressions, and the sum of correct checklist items were recorded. Additionally, we compared cumulative percentages between the groups based on the correct implementation of the resuscitation guidelines during that time. The examined sample consisted of 134 subjects (68% female; age 22±4; PEY: n=62; PMOD: n=31; STDM: n=41). There was no difference between the groups concerning age, gender, pre-existing experience in CPR or time of last CPR course. The only significant difference between the groups was the mean

  18. Effects of selected design variables on three ramp, external compression inlet performance. [boundary layer control bypasses, and mass flow rate

    Science.gov (United States)

    Kamman, J. H.; Hall, C. L.

    1975-01-01

    Two inlet performance tests and one inlet/airframe drag test were conducted in 1969 at the NASA-Ames Research Center. The basic inlet system was two-dimensional, three ramp (overhead), external compression, with variable capture area. The data from these tests were analyzed to show the effects of selected design variables on the performance of this type of inlet system. The inlet design variables investigated include inlet bleed, bypass, operating mass flow ratio, inlet geometry, and variable capture area.

  19. Internal (Annular) and Compressible External (Flat Plate) Turbulent Flow Heat Transfer Correlations.

    Energy Technology Data Exchange (ETDEWEB)

    Dechant, Lawrence [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Smith, Justin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-01

    Here we provide a discussion regarding the applicability of a family of traditional heat transfer correlation based models for several (unit level) heat transfer problems associated with flight heat transfer estimates and internal flow heat transfer associated with an experimental simulation design (Dobranich 2014). Variability between semi-empirical free-flight models suggests relative differences for heat transfer coefficients on the order of 10%, while the internal annular flow behavior is larger with differences on the order of 20%. We emphasize that these expressions are strictly valid only for the geometries they have been derived for e.g. the fully developed annular flow or simple external flow problems. Though, the application of flat plate skin friction estimate to cylindrical bodies is a traditional procedure to estimate skin friction and heat transfer, an over-prediction bias is often observed using these approximations for missile type bodies. As a correction for this over-estimate trend, we discuss a simple scaling reduction factor for flat plate turbulent skin friction and heat transfer solutions (correlations) applied to blunt bodies of revolution at zero angle of attack. The method estimates the ratio between axisymmetric and 2-d stagnation point heat transfer skin friction and Stanton number solution expressions for sub-turbulent Reynolds numbers %3C1x10 4 . This factor is assumed to also directly influence the flat plate results applied to the cylindrical portion of the flow and the flat plate correlations are modified by

  20. New trends in applied harmonic analysis sparse representations, compressed sensing, and multifractal analysis

    CERN Document Server

    Cabrelli, Carlos; Jaffard, Stephane; Molter, Ursula

    2016-01-01

    This volume is a selection of written notes corresponding to courses taught at the CIMPA School: "New Trends in Applied Harmonic Analysis: Sparse Representations, Compressed Sensing and Multifractal Analysis". New interactions between harmonic analysis and signal and image processing have seen striking development in the last 10 years, and several technological deadlocks have been solved through the resolution of deep theoretical problems in harmonic analysis. New Trends in Applied Harmonic Analysis focuses on two particularly active areas that are representative of such advances: multifractal analysis, and sparse representation and compressed sensing. The contributions are written by leaders in these areas, and covers both theoretical aspects and applications. This work should prove useful not only to PhD students and postdocs in mathematics and signal and image processing, but also to researchers working in related topics.

  1. Opportunities and challenges in applying the compressive sensing framework to nuclear science and engineering

    International Nuclear Information System (INIS)

    Mille, Matthew; Su, Lin; Yazici, Birsen; Xu, X. George

    2011-01-01

    Compressive sensing is a 5-year old theory that has already resulted in an extremely large number of publications in the literature and that has the potential to impact every field of engineering and applied science that has to do with data acquisition and processing. This paper introduces the mathematics, presents a simple demonstration of radiation dose reduction in x-ray CT imaging, and discusses potential application in nuclear science and engineering. (author)

  2. Sensitivity of total stress to changes in externally applied water pressure in KBS-3 buffer bentonite

    International Nuclear Information System (INIS)

    Harrington, J.F.; Birchall, D.J.

    2007-04-01

    In the current Swedish repository design concept, composite copper and steel canisters containing spent nuclear fuel will be placed in large diameter disposal boreholes drilled into the floor of the repository tunnels. The space around each canister will be filled with pre-compacted bentonite which over time will draw in the surrounding ground water and swell, closing up any construction joints. However, for the purposes of performance assessment, it is necessary to consider the effect of glacial loading of a future repository and its impact on the mechanical behaviour of the bentonite, in particular, the sensitivity of total stress to changes in porewater pressure (backpressure). Two experimental histories have been undertaken using a custom-designed constant volume and radial flow (CVRF) apparatus. In both tests backpressure was varied in a number of incremental and decremental cycles while total stress, porewater pressure and volumetric flow rate were continuously monitored. The swelling pressure of the buffer clay at dry densities of 1.8 Mg/m 3 and 1.61 Mg/m 3 was determined to be around 5.5 MPa and 7.2 MPa respectively. For initial ascending porewater pressure histories the average proportionality factor α ranged from 0.86 and 0.92. Data exhibited a general trend of increasing α with increasing backpressure. In test Mx80-11 this was supported by analysis of the water inflow data which indicated a reduction in system compressibility. Asymptotic values of porewater pressure within the clay are in good agreement with externally applied backpressure values. Inspection of data provides no evidence for the development of hydraulic thresholds within the clay, subject to the boundary conditions of this test geometry. Analysis of the stress data demonstrates significant hysteresis between ascending and descending porewater pressure histories. The amount of hysteresis appears to be linked to the magnitude of the backpressure applied to the specimen, suggesting some

  3. Sensitivity of total stress to changes in externally applied water pressure in KBS-3 buffer bentonite

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, J.F.; Birchall, D.J. [British Geological Survey, Chemical and Biological Hazards Programme, Kingsley Dunham Centre (United Kingdom)

    2007-04-15

    In the current Swedish repository design concept, composite copper and steel canisters containing spent nuclear fuel will be placed in large diameter disposal boreholes drilled into the floor of the repository tunnels. The space around each canister will be filled with pre-compacted bentonite which over time will draw in the surrounding ground water and swell, closing up any construction joints. However, for the purposes of performance assessment, it is necessary to consider the effect of glacial loading of a future repository and its impact on the mechanical behaviour of the bentonite, in particular, the sensitivity of total stress to changes in porewater pressure (backpressure). Two experimental histories have been undertaken using a custom-designed constant volume and radial flow (CVRF) apparatus. In both tests backpressure was varied in a number of incremental and decremental cycles while total stress, porewater pressure and volumetric flow rate were continuously monitored. The swelling pressure of the buffer clay at dry densities of 1.8 Mg/m{sup 3} and 1.61 Mg/m{sup 3} was determined to be around 5.5 MPa and 7.2 MPa respectively. For initial ascending porewater pressure histories the average proportionality factor {alpha} ranged from 0.86 and 0.92. Data exhibited a general trend of increasing {alpha} with increasing backpressure. In test Mx80-11 this was supported by analysis of the water inflow data which indicated a reduction in system compressibility. Asymptotic values of porewater pressure within the clay are in good agreement with externally applied backpressure values. Inspection of data provides no evidence for the development of hydraulic thresholds within the clay, subject to the boundary conditions of this test geometry. Analysis of the stress data demonstrates significant hysteresis between ascending and descending porewater pressure histories. The amount of hysteresis appears to be linked to the magnitude of the backpressure applied to the specimen

  4. Use of a biodegradable, oversized stent in a child with tracheomalacia secondary to vascular external compression.

    Science.gov (United States)

    Di Dedda, Giovanni; Mirabile, Cristian

    2017-01-01

    We describe the implantation of an absorbable, custom-made stent of polydioxanone to treat tracheomalacia in a 5-month-old patient with extrinsic compression by a double aortic arch. The use of an absorbable, oversized stent treated the tracheal collapse caused by vascular compression, avoided removal procedures, and allowed the infant's growth. The use of an oversized stent prevented stent migration and gave minimal problems of granulation.

  5. Effect of externally applied periodic force on ion acoustic waves in superthermal plasmas

    Science.gov (United States)

    Chowdhury, Snigdha; Mandi, Laxmikanta; Chatterjee, Prasanta

    2018-04-01

    Ion acoustic solitary waves in superthermal plasmas are investigated in the presence of trapped electrons. The reductive perturbation technique is employed to obtain a forced Korteweg-de Vries-like Schamel equation. An analytical solution is obtained in the presence of externally applied force. The effect of the external applied periodic force is also observed. The effect of the spectral index (κ), the strength ( f 0 ) , and the frequency ( ω ) on the amplitude and width of the solitary wave is obtained. The result may be useful in laboratory plasma as well as space environments.

  6. [Surgical treatment for talar neck fracture of Hawkins III, IV type with compression hollow screws combined with external fixator].

    Science.gov (United States)

    Wang, Xian-Xun; Wan, Chang-Tao; Yu, Li

    2017-05-25

    To investigate the clinical effects of compression hollow screws combined with external fixator in treating talar neck fracture of Hawkins III, IV type. From March 2010 to August 2014, 15 patients with talar neck fractures of Hawkins III, IV type were treated by open reduction and compression hollow screws fixation complicated with external fixator fixation. Including 9 males and 6 females, aged from 17 to 65 years old with an average of 37.5 years old. There were 9 cases of Hawkins III and 6 cases of Hawkins IV type. Postoperative radiographs and CT of ankle were used to evaluate the fracture healing and talar necrosis. The function of ankle and foot were evaluated by American Society of Ankle and Foot Surgery(AOFAS). All the patients were followed up for 8 to 55 months with an average of 23.5 months and all fractures got bone healing from 13 to 38 weeks with an average of (17.99±6.81) weeks. Traumatic arthritis occurred in 7 cases and talar necrosis in 6 cases (2 cases of type III and 4 cases of type IV) after operation. The average AOFAS score was 61.80±18.75, including excellent in 4 cases, good in 2 cases, fair in 4 cases and poor in 5 cases. Talar neck fracture with Hawkins III, IV type has large possibility to develop avascular necrosis. Hollow compression screw combined with external fixation may late weight-bearing for ankle and can sufficiently guarantee bone healing time, and achieve good results for the treatment of talar neck fracture.

  7. Impact of physical fitness and biometric data on the quality of external chest compression: a randomised, crossover trial

    Directory of Open Access Journals (Sweden)

    Russo Sebastian G

    2011-11-01

    Full Text Available Abstract Background During circulatory arrest, effective external chest compression (ECC is a key element for patient survival. In 2005, international emergency medical organisations changed their recommended compression-ventilation ratio (CVR from 15:2 to 30:2 to acknowledge the vital importance of ECC. We hypothesised that physical fitness, biometric data and gender can influence the quality of ECC. Furthermore, we aimed to determine objective parameters of physical fitness that can reliably predict the quality of ECC. Methods The physical fitness of 30 male and 10 female healthcare professionals was assessed by cycling and rowing ergometry (focussing on lower and upper body, respectively. During ergometry, continuous breath-by-breath ergospirometric measurements and heart rate (HR were recorded. All participants performed two nine-minute sequences of ECC on a manikin using CVRs of 30:2 and 15:2. We measured the compression and decompression depths, compression rates and assessed the participants' perception of exhaustion and comfort. The median body mass index (BMI; male 25.4 kg/m2 and female 20.4 kg/m2 was used as the threshold for subgroup analyses of participants with higher and lower BMI. Results HR during rowing ergometry at 75 watts (HR75 correlated best with the quality of ECC (r = -0.57, p 75, the compression depth decreased over time, beginning after four minutes for the 15:2 CVR and after three minutes for the 30:2 CVR. Although found to be more exhausting, a CVR of 30:2 was rated as being more comfortable. Conclusion The quality of the ECC and fatigue can both be predicted by BMI and physical fitness. An evaluation focussing on the upper body may be a more valid predictor of ECC quality than cycling based tests. Our data strongly support the recommendation to relieve ECC providers after two minutes.

  8. Mechanical evaluation of external skeletal fixator-intramedullary pin tie-in configurations applied to cadaveral humeri from red-tailed hawks (Buteo jamaicensis).

    Science.gov (United States)

    Van Wettere, Arnaud J; Redig, Patrick T; Wallace, Larry J; Bourgeault, Craig A; Bechtold, Joan E

    2009-12-01

    Use of external skeletal fixator-intramedullary pin (ESF-IM) tie-in fixators is an adjustable and effective method of fracture fixation in birds. The objective of this study was to determine the contribution of each of the following parameters to the compressive and torsional rigidity of an ESF-IM pin tie-in applied to avian bones with an osteotomy gap: (1) varying the fixation pin position in the proximal bone segment and (2) increasing the number of fixation pins in one or both bone segments. ESF-IM pin tie-in constructs were applied to humeri harvested from red-tailed hawks (Buteo jamaicensis) (n=24) that had been euthanatized for clinical reasons. Constructs with a variation in the placement of the proximal fixation pin and with 2, 3, or 4 fixation pins applied to avian bone with an osteotomy gap were loaded to a defined displacement in torque and axial compression. Response variables were determined from resulting load-displacement curves (construct stiffness, load at 1-mm displacement). Increasing the number of fixation pins from 1 to 2 per bone segment significantly increased the stiffness in torque (110%) and compression (60%), and the safe load in torque (107%) and compression (50%). Adding a fixation pin to the distal bone segment to form a 3-pin fixator significantly increased the stiffness (27%) and safe load (20%) in torque but not in axial compression. In the configuration with 2 fixation pins, placing the proximal pin distally in the proximal bone segment significantly increased the stiffness in torque (28%), and the safe load in torque (23%) and in axial compression (32%). Results quantified the relative importance of specific parameters affecting the rigidity of ESF-IM pin tie-in constructs as applied to unstable bone fracture models in birds.

  9. Integrated processing for the treatment of materials applied to thermal compression of hydrogen

    International Nuclear Information System (INIS)

    Rodriguez, M.G; Esquivel, M. R

    2009-01-01

    In this work, AB 5 intermetallics are synthesized by low energy mechanical alloying according to: AB 5 + AB 5 = AB 5 . The obtained intermetallics are annealed at 600 oC to optimize both the microstructural and hydrogen sorption properties. Then, the material is applied to the design of schemes for thermal compression of hydrogen (TCH). These results are obtained within the frame of a research project related to Energy and Environment and focused on the replacement on fossil supply systems by a hydrogen based one. [es

  10. Compressive Strength Prediction of Square Concrete Columns Retrofitted with External Steel Collars

    Directory of Open Access Journals (Sweden)

    Pudjisuryadi, P.

    2013-01-01

    Full Text Available Transverse confining stress in concrete members, commonly provided by transverse reinforcement, has been recognized to enhance strength and ductility. Nowadays, the confining method has been further developed to external confinement approach. This type of confinement can be used for retrofitting existing concrete columns. Many external confining techniques have been proven to be successful in retrofitting circular columns. However, for square or rectangular columns, providing effective confining stress by external retrofitting method is not a simple task due to high stress concentration at column’s corners. This paper proposes an analytical model to predict the peak strength of square concrete columns confined by external steel collars. Comparison with the experimental results showed that the model can predict the peak strength reasonably well. However, it should be noted that relatively larger amount of steel is needed to achieve comparable column strength enhancement when it is compared with those of conve tional internally-confined columns.

  11. External injection systems applied in modern cyclotrons designed and manufactured in NIIEFA

    International Nuclear Information System (INIS)

    Bogdanov, P.V.; Vasilchenko, I.N.; Veresov, O.L.; Gavrish, Yu.N.; Grigorenko, S.V.; Zuev, Yu.V.; Kozienko, M.T.; Mudrolyubov, V.G.; Strokach, A.P.; Tsygankov, S.S.

    2012-01-01

    The main parameters and design features of the external injection systems applied in modern cyclotrons designed and manufactured in NIIEFA and intended for production of radionuclides for medicine are presented. The use of these external injection systems instead of a traditional internal source allows the current of the accelerated beam to be significantly increased and the in-leakage of the working gas to the acceleration chamber to be reduced, which results in reduced beam losses in the process of acceleration and lower equipment activation.

  12. Effects of humeral head compression taping on the isokinetic strength of the shoulder external rotator muscle in patients with rotator cuff tendinitis

    OpenAIRE

    Kim, Moon-Hwan; Oh, Jae-Seop

    2015-01-01

    [Purpose] The purpose of this study was to examine the effects of humeral head compression taping (HHCT) on the strength of the shoulder external rotator muscle in patients with rotator cuff tendinitis. [Subjects and Methods] Twenty patients with rotator cuff tendinitis were recruited. The shoulder external rotator strength was measured using a Biodex isokinetic dynamometer system. A paired t-test was performed to evaluate within-group differences in the strength of the shoulder external rota...

  13. Does peroperative external pneumatic leg muscle compression prevent post-operative venous thrombosis in neurosurgery?

    Science.gov (United States)

    Bynke, O; Hillman, J; Lassvik, C

    1987-01-01

    Post-operative deep venous thrombosis (DVT) is a frequent and potentially life-threatening complication in neurosurgery. In this field of surgery, with its special demands for exact haemostasis, prophylaxis against deep venous thrombosis with anticoagulant drugs has been utilized only reluctantly. Postoperative pneumatic muscle compression (EPC) has been shown to be effective, although there are several practical considerations involved with this method which limit its clinical applicability. In the present study per-operative EPC was evaluated and was found to provide good protection against DVT in patients with increased risk from this complication. This method has the advantage of being effective, safe, inexpensive and readily practicable.

  14. Environmental externalities: Applying the concept to Asian coal-based power generation

    Energy Technology Data Exchange (ETDEWEB)

    Szpunar, C.B.; Gillette, J.L.

    1993-03-01

    This report examines the concept of environmental externality. It discusses various factors -- the atmospheric transformations, relationship of point-source emissions to ambient air quality, dose-response relationships, applicable cause-and-effect principles, and risk and valuation research -- that are considered by a number of state utilities when they apply the environmental externality concept to energy resource planning. It describes a methodology developed by Argonne National Laboratory for general use in resource planning, in combination with traditional methods that consider the cost of electricity production. Finally, it shows how the methodology can be applied in Indonesia, Thailand, and Taiwan to potential coal-fired power plant projects that will make use of clean coal technologies.

  15. Environmental externalities: Applying the concept to Asian coal-based power generation

    International Nuclear Information System (INIS)

    Szpunar, C.B.; Gillette, J.L.

    1993-03-01

    This report examines the concept of environmental externality. It discusses various factors -- the atmospheric transformations, relationship of point-source emissions to ambient air quality, dose-response relationships, applicable cause-and-effect principles, and risk and valuation research -- that are considered by a number of state utilities when they apply the environmental externality concept to energy resource planning. It describes a methodology developed by Argonne National Laboratory for general use in resource planning, in combination with traditional methods that consider the cost of electricity production. Finally, it shows how the methodology can be applied in Indonesia, Thailand, and Taiwan to potential coal-fired power plant projects that will make use of clean coal technologies

  16. Stabilisation of ballooning modes in torsatrons with an externally applied toroidal current

    International Nuclear Information System (INIS)

    Cooper, W.A.

    1996-01-01

    It has been found that ideal ballooning modes can impose very restrictive volume average β limits in torsatrons much below the typical values close to 5% that are required to be economically realisable as reactor systems and it has been shown that externally applied toroidal currents that are peaked can destabilise the Mercier criterion in this type of configuration. We will show here that if the applied currents are hollow, they can stabilise the ballooning modes without triggering Mercier instabilities and as a result raise the limiting β* from 2% to 5%. (author) 3 figs., 10 refs

  17. ICD lead extraction: Not a benign procedure. External chest compression: Not a benign manoeuvre

    Directory of Open Access Journals (Sweden)

    Federico Sertic

    2017-09-01

    Full Text Available This is the case of a 45-year-old man who was electively admitted to our hospital for revision and extraction of his faulty implantable cardioverter–defibrillator lead and box. The procedure was complicated by cardiac tamponade requiring pericardiocentisis (unsuccessful and cardiopulmonary resuscitation. The patient was then rushed to theatre for emergency sternotomy and institution of cardiopulmonary bypass. A tear in the superior vena cava was identified and repaired. Unfortunately, the patient suffered of a liver laceration, due to chest compression, which required emergency laparotomy. The aim of this report is to highlight the combination and management of two rare life-threatening complications that occurred in a single case.

  18. Subcutaneous emphysema, pneumomediastinum, pneumothorax, pneumoperitoneum, and pneumoretroperitoneum by insufflation of compressed air at the external genitalia in a child.

    Science.gov (United States)

    Muramori, Katsumi; Takahashi, Yukiko; Handa, Noritoshi; Aikawa, Hisayuki

    2009-04-01

    A 7-year-old girl with concurrent subcutaneous emphysema, pneumomediastinum, pneumothorax, pneumoperitoneum, and pneumoretroperitoneum arrived at our facility. Compressed air at 5 atm of pressure was insufflated through the nozzle of a spray gun over her external genitalia. She was admitted for a small amount of genital bleeding and significant subcutaneous emphysema extending from the cheek to the upper body. Radiographic examination of the abdomen was suggestive of a visceral perforation, but she was managed conservatively and discharged in satisfactory condition without surgical intervention. The female genitalia possibly served as the entry point for air into the retroperitoneum and peritoneal cavity, with subsequent migration of air through the esophageal hiatus that resulted in pneumomediastinum, pneumothorax, and extensive subcutaneous emphysema.

  19. Rabbit model of intervertebral disc degeneration by external compression device characterized by X-ray, MRI, histology, and cell viability

    Directory of Open Access Journals (Sweden)

    Ismail Ismail

    2006-12-01

    Full Text Available Appropriate experimental animal models, which mimic the degenerative process occurring in human intervertebral disc (IVD breakdown and can be used for new treatment studies such as tissue engineering or disc distraction are lacking. We studied the external compression device that used by Kroeber et al to create intervertebral disc degeneration in rabbit model characterized by X-ray, MRI, Histology, and Cell Viability. Ten NZW rabbit were randomly assigned to one of five groups. Intervertebral disc VL4-L5 are compressed using an external loading device, 1.9 MPa. First group rabbit are loaded for 14 days, second loaded for 28 days, thirth group are loaded for 14 days, and unloaded for 14 days, fourth group loaded for 28 days and unloaded for 28 days. The fifth group, rabbits underwent a sham operation. Additional, rabbits were used as sample for cell viability study. In disc height : sample in group one have biggest decreasing of disc height, that is 23.9 unit. In MRI assessment, the worst grade is grade 3. In histological score, the worst group is group three (58.69, and the best is group 4 (45.69. Group one have the largest dead cell, that are 403.5, and the smallest is group four (124.75. Trypan blue staining showed that group four have better viable cell (91.1 compare than group three (86.4. The study conclude disc degeneration can be created by external axial loading for 14 days in rabbit intervertebral disc. Duration of 28 days unloading gave better result for cells to recover. (Med J Indones 2006; 15:199-207  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Keywords: Rabbit model –intervertebral disc degeneration- external compression device-X-ray, MRI, Histology, and Cell viabilty /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso

  20. Three dimensional numerical study of different parameters effect on the external magnetic field applied to center the arc of the horizontal mercury discharge lamp

    Directory of Open Access Journals (Sweden)

    Mohamed Bechir Ben Hamida

    2015-10-01

    Full Text Available The aim of this paper is to evaluate the magnitude of the external magnetic field to be applied to a horizontal mercury discharge lamp such that the Lorentz forces counterbalance buoyancy forces and the hot region of the arc remains centered inside the lamp with the variation of six parameters of the lamp such as the external temperature of the lamp, envelope thickness, convective loss, Interelectrodeslength, pressure and current supply pointing to the influence of the parameters to the compensating magnetic field value. To achieve this objective, a commercial numerical software “Comsol Multiphysics” is used to implement the model that solves the equations of mass, energy and momentum for laminar compressible flow combined with the Laplace equation for the plasma in a three dimensional.

  1. Noise-spectroscopy of multiqubit systems: Determining all their parameters by applying an external classical noise

    Energy Technology Data Exchange (ETDEWEB)

    Savel' ev, S., E-mail: S.Saveliev@lboro.ac.uk [Department of Physics, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Zagoskin, A.M. [Department of Physics, Loughborough University, Leicestershire LE11 3TU (United Kingdom); Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Omelyanchouk, A.N. [Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); B. Verkin Institute for Low Temperature Physics and Engineering, 61103 Kharkov (Ukraine); Nori, Franco [Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Physics Department, University of Michigan, Ann Arbor, MI 48109-1040 (United States)

    2010-10-05

    Imagine that you have several sets of two coupled qubits, but you do not know the parameters of their Hamitonians. How to determine these without resorting to the usual spectroscopy approach to the problem? Based on numerical modeling, we show that all the parameters of a system of two coupled qubits can be determined by applying to it an external classical noise and analyzing the Fourier spectrum of the elements of the system's density matrix. In particular, the interlevel spacings as well as the strength and sign of the qubit-qubit coupling can be determined this way.

  2. Laser generated hot electron transport in an externally applied magnetic field

    International Nuclear Information System (INIS)

    Burnett, N.H.; Enright, G.D.

    1986-01-01

    The authors have investigated the effect of an externally applied DC magnetic field on the generation and transport of hot electrons in CO/sub 2/ laser irradiation of cylindrical targets. The targets used in these studies were 6.3 mm diameter metal rods through which a pulsed current was driven from an external capacitor. Magnetic fields up to 150 kgauss were produced at the target surface. The CO/sub 2/ laser was focused with an f/5 lens resulting in a laser intensity of ≅3 x 10/sup 14/ W/cm/sup 2/ in a 100 μm diameter focal spot. The effect of the external magnetic field on the generation and inward transport of superhot (≥ 100 keV) electrons was studied. Principal diagnostics included a six channel hard x-ray spectrometer, a high energy x-ray pinhole camera, a LiF Laue x-ray spectrograph and a Ross-filtered (W-Ta) pair of x-ray detectors. The latter two diagnostics were designed to detect Au Kα /sub emission at 68.2 keV

  3. Effects of humeral head compression taping on the isokinetic strength of the shoulder external rotator muscle in patients with rotator cuff tendinitis.

    Science.gov (United States)

    Kim, Moon-Hwan; Oh, Jae-Seop

    2015-01-01

    [Purpose] The purpose of this study was to examine the effects of humeral head compression taping (HHCT) on the strength of the shoulder external rotator muscle in patients with rotator cuff tendinitis. [Subjects and Methods] Twenty patients with rotator cuff tendinitis were recruited. The shoulder external rotator strength was measured using a Biodex isokinetic dynamometer system. A paired t-test was performed to evaluate within-group differences in the strength of the shoulder external rotator muscle. [Results] Significantly higher shoulder external rotator peak torque and peak torque per body weight were found in the HHCT condition than in the no-taping condition. [Conclusion] HHCT may effectively increase the shoulder external rotator muscle strength in patients with rotator cuff tendinitis.

  4. Experimental investigation of homogeneous charge compression ignition combustion of biodiesel fuel with external mixture formation in a CI engine.

    Science.gov (United States)

    Ganesh, D; Nagarajan, G; Ganesan, S

    2014-01-01

    In parallel to the interest in renewable fuels, there has also been increased interest in homogeneous charge compression ignition (HCCI) combustion. HCCI engines are being actively developed because they have the potential to be highly efficient and to produce low emissions. Even though HCCI has been researched extensively, few challenges still exist. These include controlling the combustion at higher loads and the formation of a homogeneous mixture. To obtain better homogeneity, in the present investigation external mixture formation method was adopted, in which the fuel vaporiser was used to achieve excellent HCCI combustion in a single cylinder air-cooled direct injection diesel engine. In continuation of our previous works, in the current study a vaporised jatropha methyl ester (JME) was mixed with air to form a homogeneous mixture and inducted into the cylinder during the intake stroke to analyze the combustion, emission and performance characteristics. To control the early ignition of JME vapor-air mixture, cooled (30 °C) Exhaust gas recirculation (EGR) technique was adopted. The experimental result shows 81% reduction in NOx and 72% reduction in smoke emission.

  5. Fuzzy Relational Compression Applied on Feature Vectors for Infant Cry Recognition

    Science.gov (United States)

    Reyes-Galaviz, Orion Fausto; Reyes-García, Carlos Alberto

    Data compression is always advisable when it comes to handling and processing information quickly and efficiently. There are two main problems that need to be solved when it comes to handling data; store information in smaller spaces and processes it in the shortest possible time. When it comes to infant cry analysis (ICA), there is always the need to construct large sound repositories from crying babies. Samples that have to be analyzed and be used to train and test pattern recognition algorithms; making this a time consuming task when working with uncompressed feature vectors. In this work, we show a simple, but efficient, method that uses Fuzzy Relational Product (FRP) to compresses the information inside a feature vector, building with this a compressed matrix that will help us recognize two kinds of pathologies in infants; Asphyxia and Deafness. We describe the sound analysis, which consists on the extraction of Mel Frequency Cepstral Coefficients that generate vectors which will later be compressed by using FRP. There is also a description of the infant cry database used in this work, along with the training and testing of a Time Delay Neural Network with the compressed features, which shows a performance of 96.44% with our proposed feature vector compression.

  6. Photovoltaic dependence of photorefractive grating on the externally applied dc electric field

    Science.gov (United States)

    Maurya, M. K.; Yadav, R. A.

    2013-04-01

    Photovoltaic dependence of photorefractive grating (i.e., space-charge field and phase-shift of the index grating) on the externally applied dc electric field in photovoltaic-photorefractive materials has been investigated. The influence of photovoltaic field (EPhN), diffusion field and carrier concentration ratio r (donor/acceptor impurity concentration ratio) on the space-charge field (SCF) and phase-shift of the index grating in the presence and absence of the externally applied dc electric field have also been studied in details. Our results show that, for a given value of EPhN and r, the magnitude of the SCF and phase-shift of the index grating can be enhanced significantly by employing the lower dc electric field (EONphotovoltaic-photorefractive crystal and higher value of diffusion field (EDN>40). Such an enhancement in the magnitude of the SCF and phase-shift of the index grating are responsible for the strongest beam coupling in photovoltaic-photorefractive materials. This sufficiently strong beam coupling increases the two-beam coupling gain that may be exceed the absorption and reflection losses of the photovoltaic-photorefractive sample, and optical amplification can occur. The higher value of optical amplification in photovoltaic-photorefractive sample is required for the every applications of photorefractive effect so that technology based on the photorefractive effect such as holographic storage devices, optical information processing, acousto-optic tunable filters, gyro-sensors, optical modulators, optical switches, photorefractive-photovoltaic solitons, biomedical applications, and frequency converters could be improved.

  7. External Compression Headaches

    Science.gov (United States)

    ... comfortable options. Also, if possible, remove headwear frequently to give yourself a break from the ... is a not-for-profit organization and proceeds from Web advertising help support our mission. Mayo Clinic does ...

  8. A Comparison of Compressed Sensing and Sparse Recovery Algorithms Applied to Simulation Data

    Directory of Open Access Journals (Sweden)

    Ya Ju Fan

    2016-08-01

    Full Text Available The move toward exascale computing for scientific simulations is placing new demands on compression techniques. It is expected that the I/O system will not be able to support the volume of data that is expected to be written out. To enable quantitative analysis and scientific discovery, we are interested in techniques that compress high-dimensional simulation data and can provide perfect or near-perfect reconstruction.  In this paper, we explore the use of compressed sensing (CS techniques to reduce the size of the data before they are written out. Using large-scale simulation data, we investigate how the sufficient sparsity condition and the contrast in the data affect the quality of reconstruction and the degree of compression.  We provide suggestions for the practical implementation of CS techniques and compare them with other sparse recovery methods. Our results show that despite longer times for reconstruction, compressed sensing techniques can provide near perfect reconstruction over a range of data with varying sparsity.

  9. SBS pulse compression applied to a commercial Q-switch Nd-YAG laser

    International Nuclear Information System (INIS)

    Aliaga-Rossel, R.; Bayley, J.; Mamin, A.; Nizienko, Y.

    1997-01-01

    In optical diagnosis of dense Z-pinches, sub-nanosecond laser pulses are required in order to freeze the movement of the plasma during the probing. Commercial lasers can provide such type of pulses but they are either very expensive, or they have a very low energy per pulse. A technique that uses Stimulated Brillouin Scattering (SBS) to compress a 8 ns pulse of a commercial Q-switched Nd-YAG laser is reported here. To carry out this passive compression technique, a frequency doubled laser pulse of 10 ns was focused into a single SBS gas cell, 2 m long, filled with a mixture of argon and sulphurhexafluoride (SF 6 ) at a total pressure of 40 bar. A shorter and high intensity pulse was reflected from the cell (created by SBS) and it travelled back along its original path until it was separated from its original direction by using a dichroic polariser. The pumping volume of the SBS cell, the convergence of the incident beam and the pressure of the gas cell, were optimised to maximise both temporal compression and the output energy. Pulses of 10 ns were compressed to less than 400 ps with a conversion efficiency of 80%. This SBS pulse compression system has been used to make most of the optical measurements of a dense fibre pinch plasma produced in the MAGPIE generator

  10. A single 60-min bout of peristaltic pulse external pneumatic compression transiently upregulates phosphorylated ribosomal protein s6.

    Science.gov (United States)

    Martin, J S; Kephart, W C; Mobley, C B; Wilson, T J; Goodlett, M D; Roberts, M D

    2017-11-01

    We investigated whether a single 60-min bout of whole leg, peristaltic pulse external pneumatic compression (EPC) altered select growth factor-related mRNAs and/or various phospho(p)-proteins related to cell growth, proliferation, inflammation and apoptosis signalling (e.g. Akt-mTOR, Jak-Stat). Ten participants (8 males, 2 females; aged 22·2 ± 0·4 years) reported to the laboratory 4 h post-prandial, and vastus lateralis muscle biopsies were obtained prior to (PRE), 1 h and 4 h post-EPC treatment. mRNA expression was analysed using real-time RT-PCR and phosphophorylated and cleaved proteins were analysed using an antibody array. No changes in selected growth factor-related mRNAs were observed following EPC. All p-proteins significantly altered by EPC decreased, except for p-rps6 (Ser235/236) which increased 31% 1 h post-EPC compared to PRE levels (P = 0·016). Notable decreases also included p-BAD (Ser112; -28%, P = 0·004) at 4 h post-EPC compared to PRE levels. In summary, an acute bout of EPC transiently upregulates p-rps6 as well as affecting other markers in the Akt-mTOR signalling cascade. Future research should characterize whether chronic EPC application promotes alterations in lower-limb musculature and/or enhances exercise-induced training adaptations. © 2016 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  11. Finite Strain Analysis of Shock Compression of Brittle Solids Applied to Titanium Diboride

    Science.gov (United States)

    2014-07-01

    dislocation motion [18,19] may take place at high pressures. Multiple investigations have discovered that tita - nium diboride demonstrates a rather unique...mean stress under shock compression. It has been suggested [5] that pore collapse may be an important source of inelasticity in tita - nium diboride

  12. Environmental externalities: Applying the concept to Asian coal-based power generation. [Includes external environmental and societal costs and methods of evaluating them

    Energy Technology Data Exchange (ETDEWEB)

    Szpunar, C.B.; Gillette, J.L.

    1993-03-01

    This report examines the concept of environmental externality. It discusses various factors -- the atmospheric transformations, relationship of point-source emissions to ambient air quality, dose-response relationships, applicable cause-and-effect principles, and risk and valuation research -- that are considered by a number of state utilities when they apply the environmental externality concept to energy resource planning. It describes a methodology developed by Argonne National Laboratory for general use in resource planning, in combination with traditional methods that consider the cost of electricity production. Finally, it shows how the methodology can be applied in Indonesia, Thailand, and Taiwan to potential coal-fired power plant projects that will make use of clean coal technologies.

  13. Impact of external pneumatic compression target inflation pressure on transcriptome-wide RNA expression in skeletal muscle.

    Science.gov (United States)

    Martin, Jeffrey S; Kephart, Wesley C; Haun, Cody T; McCloskey, Anna E; Shake, Joshua J; Mobley, Christopher B; Goodlett, Michael D; Kavazis, Andreas; Pascoe, David D; Zhang, Lee; Roberts, Michael D

    2016-11-01

    Next-generation RNA sequencing was employed to determine the acute and subchronic impact of peristaltic pulse external pneumatic compression (PEPC) of different target inflation pressures on global gene expression in human vastus lateralis skeletal muscle biopsy samples. Eighteen (N = 18) male participants were randomly assigned to one of the three groups: (1) sham (n = 6), 2) EPC at 30-40 mmHg (LP-EPC; n = 6), and 3) EPC at 70-80 mmHg (MP-EPC; n = 6). One hour treatment with sham/EPC occurred for seven consecutive days. Vastus lateralis skeletal muscle biopsies were performed at baseline (before first treatment; PRE), 1 h following the first treatment (POST1), and 24 h following the last (7th) treatment (POST2). Changes from PRE in gene expression were analyzed via paired comparisons within each group. Genes were filtered to include only those that had an RPKM ≥ 1.0, a fold-change of ≥1.5 and a paired t-test value of <0.01. For the sham condition, two genes at POST1 and one gene at POST2 were significantly altered. For the LP-EPC condition, nine genes were up-regulated and 0 genes were down-regulated at POST1 while 39 genes were up-regulated and one gene down-regulated at POST2. For the MP-EPC condition, two genes were significantly up-regulated and 21 genes were down-regulated at POST1 and 0 genes were altered at POST2. Both LP-EPC and MP-EPC acutely alter skeletal muscle gene expression, though only LP-EPC appeared to affect gene expression with subchronic application. Moreover, the transcriptome response to EPC demonstrated marked heterogeneity (i.e., genes and directionality) with different target inflation pressures. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  14. Concomitant external pneumatic compression treatment with consecutive days of high intensity interval training reduces markers of proteolysis.

    Science.gov (United States)

    Haun, Cody T; Roberts, Michael D; Romero, Matthew A; Osburn, Shelby C; Healy, James C; Moore, Angelique N; Mobley, Christopher B; Roberson, Paul A; Kephart, Wesley C; Mumford, Petey W; Goodlett, Michael D; Pascoe, David D; Martin, Jeffrey S

    2017-12-01

    To compare the effects of external pneumatic compression (EPC) and sham when used concurrently with high intensity interval training (HIIT) on performance-related outcomes and recovery-related molecular measures. Eighteen recreationally endurance-trained male participants (age: 21.6 ± 2.4 years, BMI: 25.7 ± 0.5 kg/m 2 , VO 2peak : 51.3 ± 0.9 mL/kg/min) were randomized to balanced sham and EPC treatment groups. Three consecutive days of HIIT followed by EPC/sham treatment (Days 2-4) and 3 consecutive days of recovery (Days 5-7) with EPC/sham only on Days 5-6 were employed. Venipuncture, flexibility and pressure-to-pain threshold (PPT) measurements were made throughout. Vastus lateralis muscle was biopsied at PRE (i.e., Day 1), 1-h post-EPC/sham treatment on Day 2 (POST1), and 24-h post-EPC/sham treatment on Day 7 (POST2). 6-km run time trial performance was tested at PRE and POST2. No group × time interaction was observed for flexibility, PPT, or serum measures of creatine kinase (CK), hsCRP, and 8-isoprostane. However, there was a main effect of time for serum CK (p = 0.005). Change from PRE in 6-km run times at POST2 were not significantly different between groups. Significant between-groups differences existed for change from PRE in atrogin-1 mRNA (p = 0.018) at the POST1 time point (EPC: - 19.7 ± 8.1%, sham: + 7.7 ± 5.9%) and atrogin-1 protein concentration (p = 0.013) at the POST2 time point (EPC: - 31.8 ± 7.5%, sham: + 96.0 ± 34.7%). In addition, change from PRE in poly-Ub proteins was significantly different between groups at both the POST1 (EPC: - 26.0 ± 10.3%, sham: + 34.8 ± 28.5%; p = 0.046) and POST2 (EPC: - 33.7 ± 17.2%, sham: + 21.4 ± 14.9%; p = 0.037) time points. EPC when used concurrently with HIIT and in subsequent recovery days reduces skeletal muscle markers of proteolysis.

  15. Edge-Localized mode control and transport generated by externally applied magnetic perturbations

    International Nuclear Information System (INIS)

    Joseph, I.

    2012-01-01

    This article reviews the subject of edge localized mode (ELM) control using externally applied magnetic perturbations and proposes theoretical mechanisms that may be responsible for the induced transport changes. The first question that must be addressed is: what is the structure of magnetic field within the plasma? Although initial hypotheses focused on the possibility of the creation of a region of stochastic field lines at the tokamak edge, drift magnetohydrodynamics theory predicts that magnetic reconnection is strongly suppressed over the region of the pedestal with steep gradients and fast perpendicular rotation. Reconnection can only occur near the location where the perpendicular electron velocity vanishes, and hence the electron impedance nearly vanishes, or near the foot of the pedestal, where the plasma is sufficiently cold and resistive. The next question that must be addressed is: which processes are responsible for the observed transport changes, nonlinearity, turbulence, or stochasticity? Over the pedestal region where ions and electrons rotate in opposite directions relative to the perturbation, the quasilinear Lorentz force decelerates the electron fluid and accelerates the ion fluid. The quasilinear magnetic flutter flux is proportional to the force and produces an outward convective transport that can be significant. Over the pedestal region where the E x B flow and the electrons rotate in opposite directions relative to the perturbation, magnetic islands with a width on the order of the ion gyroradius can directly radiate drift waves. In addition, the combination of quasilinear electron transport and ion viscous transport can lead to a large net particle flux. Since there are many transport mechanisms that may be active simultaneously, it is important to determine which physical mechanisms are responsible for ELM control and to predict the scaling to future devices (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Performance of Ruecking's Word-compression Method When Applied to Machine Retrieval from a Library Catalog

    Directory of Open Access Journals (Sweden)

    Ben-Ami Lipetz

    1969-12-01

    Full Text Available F. H. Ruecking's word-compression algorithm for retrieval of bibliographic data from computer stores was tested for performance in matching user-supplied, unedited bibliographic data to the bibliographic data contained in a library catalog. The algorithm was tested by manual simulation, using data derived from 126 case studies of successful manual searches of the card catalog at Sterling Memorial Library, Yale University. The algorithm achieved 70% recall in comparison to conventional searching. Its accepta- bility as a substitute for conventional catalog searching methods is ques- tioned unless recall performance can be improved, either by use of the algorithm alone or in combination with other algorithms.

  17. [Quality of self-applied compression bandages in patients with chronic venous ulcers : Results of a prospective clinical study].

    Science.gov (United States)

    Stoffels-Weindorf, M; Stoffels, I; Jockenhöfer, F; Dissemond, J

    2018-04-01

    For effective compression therapy in patients with venous leg ulcers, sufficient pressure is essential. In everyday life, it is often the patients themselves who apply the compression bandages. Many of these patients have restriction in their movement and had been rarely trained adequately. Hence, there was the question of how efficient are the autonomously applied compression bandages of those patients. In all, 100 consecutive patients with venous leg ulcer were asked to apply compression bandages on their own leg. We documented both the achieved compression and formal criteria of correct performance. A total of 59 women and 41 men with an average age of 70.3 years were included in the study. Overall 43 patients were not able to applycompression bandage because of physical limitations. The measured pressure values in the remaining 57 patients ranged between 6 and 93 mm Hg (mean 28.3 mm Hg). Eleven patients reached the prescribed effective compression pressure. Of these, formal errors were found in 6 patients, so that only 5 patients had correctly applied the compression bandages. Our data show that most patients with venous leg ulcers are not able to apply effective compression therapy with short-stretch bandages to themselves. Multilayer systems, adaptive compression bandages, and ulcer stocking systems today are possibly easier and more effective therapy options. Alternatively short-stretch bandages could be applied by trained persons but only under the control with pressure measuring probes.

  18. GLYCOHEMOGLOBIN - COMPARISON OF 12 ANALYTICAL METHODS, APPLIED TO LYOPHILIZED HEMOLYSATES BY 101 LABORATORIES IN AN EXTERNAL QUALITY ASSURANCE PROGRAM

    NARCIS (Netherlands)

    WEYKAMP, CW; PENDERS, TJ; MUSKIET, FAJ; VANDERSLIK, W

    Stable lyophilized ethylenediaminetetra-acetic acid (EDTA)-blood haemolysates were applied in an external quality assurance programme (SKZL, The Netherlands) for glycohaemoglobin assays in 101 laboratories using 12 methods. The mean intralaboratory day-to-day coefficient of variation (CV),

  19. The influence of applied internal and external rotation on the pivot shift phenomenon.

    Science.gov (United States)

    Kopf, Sebastian; Musahl, Volker; Perka, Carsten; Kauert, Ralf; Hoburg, Arnd; Becker, Roland

    2017-04-01

    The pivot shift test is performed in different techniques and the rotation of the tibia seems to have a significant impact on the amount of the pivot shift phenomenon. It has been hypothesised that external rotation will increase the phenomenon due to less tension at the iliotibial band in knee extension. Twenty-four patients with unilateral anterior cruciate ligament insufficiency were included prospectively. The pivot shift test was performed bilaterally in internal and external tibial rotation under general anaesthesia. Knee motion was captured using a femoral and a tibial inertial sensor. The difference between positive and negative peak values in Euclidean norm of acceleration was calculated to evaluate the amount of the pivot shift phenomenon. The pivot shift phenomenon was significantly increased in patients with ACL insufficiency when the test was performed in external [mean 5.2 ms - 2 (95% CI 4.3-6.0)] compared to internal tibial rotation [mean 4.4 ms - 2 (95% CI 3.5-5.4)] (p = 0.002). In healthy, contralateral knees did not show any difference between external [mean 4.0 ms - 2 (95% CI 3.3-4.7)] and internal tibial rotation [mean 4.0 ms - 2 (95% CI 3.4-4.6)] (ns). The pivot shift phenomenon was increased with external rotation in ACL-insufficient knees, and therefore, one should perform the pivot shift test, rather, in external rotation to easily evoke the, sometimes difficult to detect, pivot shift phenomenon. I (diagnostic study).

  20. A Conceptual Framework for Error Remediation with Multiple External Representations Applied to Learning Objects

    Science.gov (United States)

    Leite, Maici Duarte; Marczal, Diego; Pimentel, Andrey Ricardo; Direne, Alexandre Ibrahim

    2014-01-01

    This paper presents the application of some concepts of Intelligent Tutoring Systems (ITS) to elaborate a conceptual framework that uses the remediation of errors with Multiple External Representations (MERs) in Learning Objects (LO). To this is demonstrated a development of LO for teaching the Pythagorean Theorem through this framework. This…

  1. Effects of augmented trunk stabilization with external compression support on shoulder and scapular muscle activity and maximum strength during isometric shoulder abduction.

    Science.gov (United States)

    Jang, Hyun-jeong; Kim, Suhn-yeop; Oh, Duck-won

    2015-04-01

    The aim of the present study was to investigate the effects of augmented trunk stabilization with external compression support (ECS) on the electromyography (EMG) activity of shoulder and scapular muscles and shoulder abductor strength during isometric shoulder abduction. Twenty-six women volunteered for the study. Surface EMG was used to monitor the activity of the upper trapezius (UT), lower trapezius (LT), serratus anterior (SA), and middle deltoid (MD), and shoulder abductor strength was measured using a dynamometer during three experimental conditions: (1) no external support (condition-1), (2) pelvic support (condition-2), and (3) pelvic and thoracic supports (condition-3) in an active therapeutic movement device. EMG activities were significantly lower for UT and higher for MD during condition 3 than during condition 1 (p strength was significantly higher during condition 3 than during condition 1 (p isometric shoulder abduction and increasing shoulder abductor strength. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Possibilities and conditions of applying PIXE analysis with external proton beam

    International Nuclear Information System (INIS)

    Potocek, V.

    1989-01-01

    The technical and methodological prerequisites are summed up for the use of the PIXE method with an external proton beam. The method is suitable for the preliminary analysis of unknown samples prior to the choice of the best suited analytical method, for the nondestructive analysis of rare samples such as unique works of art, of small amounts of materials which are difficult to access, etc., as well as for calibration and comparing analyses. As for the operators the application of the PIXE method with external proton beam assumes the availability of accelerator operating time, minimization of the length of exposure of the targets, optimization of parameters of the exciting beam and automation of the whole process. Attention is also devoted to technical provisions and organization of laboratory work. The design is described of an analytical unit using the PIXE method with external proton beam, and it is stated that the Van de Graaff accelerator at the Institute of Nuclear Physics in Rez near Prague could be used for the purpose. (Z.M.). 6 refs

  3. Impacts Of External Price Shocks On Malaysian Macro Economy-An Applied General Equilibrium Analysis

    Directory of Open Access Journals (Sweden)

    Abul Quasem Al-Amin

    2008-10-01

    Full Text Available This paper examines the impacts of external price shocks in the Malaysian economy. There are three simulations are carried out with different degrees of external shocks using Malaysian Social Accounting Matrix (SAM and Computable General Equilibrium (CGE analysis. The model results indicate that the import price shocks, better known as external price shocks by 15% decreases the domestic production of building and construction sector by 25.87%, hotels, restaurants and entertainment sector by 12.04%, industry sector by 12.02%, agriculture sector by 11.01%, and electricity and gas sector by 9.55% from the baseline. On the import side, our simulation results illustrate that as a result of the import price shocks by 15%, imports decreases significantly in all sectors from base level. Among the scenarios, the largest negative impacts goes on industry sectors by 29.67% followed by building and construction sector by 22.42%, hotels, restaurants and entertainment sector by 19.45%, electricity and gas sector by 13.%, agriculture sector by 12.63% and other service sectors by 11.17%. However significant negative impact goes to the investment and fixed capital investment. It also causes the household income, household consumption and household savings down and increases the cost of livings in the economy results in downward social welfare.

  4. An atomic resolution scanning tunneling microscope that applies external tensile stress and strain in an ultrahigh vacuum

    International Nuclear Information System (INIS)

    Fujita, D; Kitahara, M; Onishi, K; Sagisaka, K

    2008-01-01

    We have developed an ultrahigh vacuum scanning tunneling microscope with an in situ external stress application capability in order to determine the effects of stress and strain on surface atomistic structures. It is necessary to understand these effects because controlling them will be a key technology that will very likely be used in future nanometer-scale fabrication processes. We used our microscope to demonstrate atomic resolution imaging under external tensile stress and strain on the surfaces of wafers of Si(111) and Si(001). We also successfully observed domain redistribution induced by applying uniaxial stress at an elevated temperature on the surface of a wafer of vicinal Si(100). We confirmed that domains for which an applied tensile stress is directed along the dimer bond become less stable and shrink. This suggests that it may be feasible to fabricate single domain surfaces in a process that controls surface stress and strain

  5. Scalable Methods for Eulerian-Lagrangian Simulation Applied to Compressible Multiphase Flows

    Science.gov (United States)

    Zwick, David; Hackl, Jason; Balachandar, S.

    2017-11-01

    Multiphase flows can be found in countless areas of physics and engineering. Many of these flows can be classified as dispersed two-phase flows, meaning that there are solid particles dispersed in a continuous fluid phase. A common technique for simulating such flow is the Eulerian-Lagrangian method. While useful, this method can suffer from scaling issues on larger problem sizes that are typical of many realistic geometries. Here we present scalable techniques for Eulerian-Lagrangian simulations and apply it to the simulation of a particle bed subjected to expansion waves in a shock tube. The results show that the methods presented here are viable for simulation of larger problems on modern supercomputers. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1315138. This work was supported in part by the U.S. Department of Energy under Contract No. DE-NA0002378.

  6. Lessons learned from applying external input to DOE policy decision making

    International Nuclear Information System (INIS)

    Imholz, R.M.; Hindman, T.B. Jr.; Brubaker, D.M.

    1990-01-01

    Our nation has entered an era in which the public is demanding clean up and restoration of its environment, understandable information, and participation in decision making. The US Department of Energy's (DOE's) culture, which grew out of the Atomic Energy Commission (AEC) culture of classification, compartmentalization, and strict-need-to-know dissemination of information, was in direct conflict with this demand for public involvement. The DOE recognized this and committed to changing their culture into one of openness and public involvement in decision making and policy direction. This paper reports that as a result, DOE created a number of external review groups, one of them being the State and Tribal Government Working Group (STGWG). The STGWG was created to review the first Environmental Restoration and Waste Management Five-Year Plan. The Five-Year Plan establishes an agenda for compliance and cleanup of DOE installations against which progress can be measured

  7. Suppression of beam-excited electron waves by an externally applied RF signal

    International Nuclear Information System (INIS)

    Fukumasa, Osamu; Itatani, Ryohei

    1980-11-01

    Suppression of the beam-excited electron wave in a bounded system is investigated in connection with the beam distribution function. Wave suppression has two different processes depending on whether injected beams are reflected at the other end or not. In the absence of reflected beam electrons, deformation of the beam distribution function is observed in relation to the suppression of the electron wave. However, when beam electrons are reflected, the external wave suppresses the electron wave but distribution function shows no appreciable change. These experimental results show that nonlinear behaviors of beam electrons, namely behaviors of reflected beams, are quite important for wave suppression. By using the method of partial simulation, interaction between two waves in the bounded system including nonlinear motions of beam electrons is studied numerically. Qualitative agreement between experimental and numerical results is obtained. (author)

  8. External Resistances Applied to MFC Affect Core Microbiome and Swine Manure Treatment Efficiencies

    Science.gov (United States)

    Vilajeliu-Pons, Anna; Bañeras, Lluis; Puig, Sebastià; Molognoni, Daniele; Vilà-Rovira, Albert; Hernández-del Amo, Elena; Balaguer, Maria D.; Colprim, Jesús

    2016-01-01

    Microbial fuel cells (MFCs) can be designed to combine water treatment with concomitant electricity production. Animal manure treatment has been poorly explored using MFCs, and its implementation at full-scale primarily relies on the bacterial distribution and activity within the treatment cell. This study reports the bacterial community changes at four positions within the anode of two almost identically operated MFCs fed swine manure. Changes in the microbiome structure are described according to the MFC fluid dynamics and the application of a maximum power point tracking system (MPPT) compared to a fixed resistance system (Ref-MFC). Both external resistance and cell hydrodynamics are thought to heavily influence MFC performance. The microbiome was characterised both quantitatively (qPCR) and qualitatively (454-pyrosequencing) by targeting bacterial 16S rRNA genes. The diversity of the microbial community in the MFC biofilm was reduced and differed from the influent swine manure. The adopted electric condition (MPPT vs fixed resistance) was more relevant than the fluid dynamics in shaping the MFC microbiome. MPPT control positively affected bacterial abundance and promoted the selection of putatively exoelectrogenic bacteria in the MFC core microbiome (Sedimentibacter sp. and gammaproteobacteria). These differences in the microbiome may be responsible for the two-fold increase in power production achieved by the MPPT-MFC compared to the Ref-MFC. PMID:27701451

  9. Case report of deep vein thrombosis caused by artificial urinary sphincter reservoir compressing right external iliac vein

    Directory of Open Access Journals (Sweden)

    Marcus J Yip

    2015-01-01

    Full Text Available Artificial urinary sphincters (AUSs are commonly used after radical prostatectomy for those who are incontinent of urine. However, they are associated with complications, the most common being reservoir uprising or migration. We present a unique case of occlusive external iliac and femoral vein obstruction by the AUS reservoir causing thrombosis. Deflation of the reservoir and anticoagulation has, thus far, not been successful at decreasing thrombus burden. We present this case as a rare, but significant surgical complication; explore the risk factors that may have contributed, and other potential endovascular therapies to address this previously unreported AUS complication.

  10. Unsteady flow of two-phase fluid in circular pipes under applied external magnetic and electrical fields

    International Nuclear Information System (INIS)

    Gedik, Engin; Recebli, Ziyaddin; Kurt, Hueseyin; Kecebas, Ali

    2012-01-01

    The unsteady viscous incompressible and electrically conducting of two-phase fluid flow in circular pipes with external magnetic and electrical field is considered in this present study. Effects of both uniform transverse external magnetic and electrical fields applied perpendicular to the fluid and each other on the two-phase (solid/liquid) unsteady flow is investigated numerically. While iron powders are being used as the first phase of two-phase fluid, pure water was used as the second phase. The system of the derived governing equations, which are based on the Navier-Stokes equations including Maxwell equations, are solved numerically by using Pdex4 function on the Matlab for both phases. The originality of this study is that, in addition to magnetic field, the effect of electrical field on two-phase unsteady fluids is being examined. The magnetic field which is applied on flow decreases the velocity of both phases, whereas the electrical field applied along with magnetic field acted to increase and decrease the velocity values depending on the direction of electrical field. Electrical field alone did not display any impact on two-phase flow. On the other hand, analytical and numerical results are compared and favorable agreements have been obtained. (authors)

  11. Evaluation of a wavelet-based compression algorithm applied to the silicon drift detectors data of the ALICE experiment at CERN

    International Nuclear Information System (INIS)

    Falchieri, Davide; Gandolfi, Enzo; Masotti, Matteo

    2004-01-01

    This paper evaluates the performances of a wavelet-based compression algorithm applied to the data produced by the silicon drift detectors of the ALICE experiment at CERN. This compression algorithm is a general purpose lossy technique, in other words, its application could prove useful even on a wide range of other data reduction's problems. In particular the design targets relevant for our wavelet-based compression algorithm are the following ones: a high-compression coefficient, a reconstruction error as small as possible and a very limited execution time. Interestingly, the results obtained are quite close to the ones achieved by the algorithm implemented in the first prototype of the chip CARLOS, the chip that will be used in the silicon drift detectors readout chain

  12. Effects of applied stress ratio on the fatigue behavior of additively manufactured porous biomaterials under compressive loading.

    Science.gov (United States)

    de Krijger, Joep; Rans, Calvin; Van Hooreweder, Brecht; Lietaert, Karel; Pouran, Behdad; Zadpoor, Amir A

    2017-06-01

    Additively manufactured (AM) porous metallic biomaterials are considered promising candidates for bone substitution. In particular, AM porous titanium can be designed to exhibit mechanical properties similar to bone. There is some experimental data available in the literature regarding the fatigue behavior of AM porous titanium, but the effect of stress ratio on the fatigue behavior of those materials has not been studied before. In this paper, we study the effect of applied stress ratio on the compression-compression fatigue behavior of selective laser melted porous titanium (Ti-6Al-4V) based on the diamond unit cell. The porous titanium biomaterial is treated as a meta-material in the context of this work, meaning that R-ratios are calculated based on the applied stresses acting on a homogenized volume. After morphological characterization using micro computed tomography and quasi-static mechanical testing, the porous structures were tested under cyclic loading using five different stress ratios, i.e. R = 0.1, 0.3, 0.5, 0.7 and 0.8, to determine their S-N curves. Feature tracking algorithms were used for full-field deformation measurements during the fatigue tests. It was observed that the S-N curves of the porous structures shift upwards as the stress ratio increases. The stress amplitude was the most important factor determining the fatigue life. Constant fatigue life diagrams were constructed and compared with similar diagrams for bulk Ti-6Al-4V. Contrary to the bulk material, there was limited dependency of the constant life diagrams to mean stress. The notches present in the AM biomaterials were the sites of crack initiation. This observation and other evidence suggest that the notches created by the AM process cause the insensitivity of the fatigue life diagrams to mean stress. Feature tracking algorithms visualized the deformation during fatigue tests and demonstrated the root cause of inclined (45°) planes of specimen failure. In conclusion, the R

  13. Conduction band structure and electron mobility in uniaxially strained Si via externally applied strain in nanomembranes

    Energy Technology Data Exchange (ETDEWEB)

    Chen Feng [Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Euaruksakul, Chanan; Himpsel, F J; Lagally, Max G [University of Wisconsin-Madison, Madison, WI 53706 (United States); Liu Zheng; Liu Feng, E-mail: lagally@engr.wisc.edu [University of Utah, Salt Lake City, UT 84112 (United States)

    2011-08-17

    Strain changes the band structure of semiconductors. We use x-ray absorption spectroscopy to study the change in the density of conduction band (CB) states when silicon is uniaxially strained along the [1 0 0] and [1 1 0] directions. High stress can be applied to silicon nanomembranes, because their thinness allows high levels of strain without fracture. Strain-induced changes in both the sixfold degenerate {Delta} valleys and the eightfold degenerate L valleys are determined quantitatively. The uniaxial deformation potentials of both {Delta} and L valleys are directly extracted using a strain tensor appropriate to the boundary conditions, i.e., confinement in the plane in the direction orthogonal to the straining direction, which correspond to those of strained CMOS in commercial applications. The experimentally determined deformation potentials match the theoretical predictions well. We predict electron mobility enhancement created by strain-induced CB modifications.

  14. Electromagnetic response of non-trivially shaped superconductors in external magnetic fields and with applied currents

    International Nuclear Information System (INIS)

    Cabral, Leonardo Ribeiro Eulalio; Aguiar, Jose Albino Oliveira de

    2002-01-01

    Full text: The study of the electromagnetic response of high-T c superconductors is essential for future technological applications. Such materials are hard type II superconductors, where the mixed state (a state characterized by quantized normal flux tubes - also called vortices - immersed in a superconductor phase) occupies most of the phase diagram. Therefore, the electromagnetic properties are dictated by the vortex dynamics in these materials. One has also to consider the presence of structural defects and thermal effects, which turn the vortex dynamics very complex. These difficulties may be overcome throughout a macroscopic description, also known as continuum approximation, of the electromagnetic fields in superconductors, obtained from critical state models and constitutive relations E = E(j) and H = H(B) (where E is the electric field generated by moving vortices, j the current density, B the induction - related to the local density of vortices - and H the reversible magnetic field that is in equilibrium with B). In superconductors with negligible demagnetization factors, such as long cylinders and bars with applied magnetic fields and/or currents along their longer dimensions, the Meissner state and the flux penetration is quite well understood. However, the actual specimen shape plays an important role on the electromagnetic behavior of superconductors. Numerical methods are often employed, since such cases are hard to treat analytically. In this work we studied the electromagnetic response of superconductors with various shapes. The Meissner state is obtained for thin curved strips and long cylinders with arbitrary cross-section, in perpendicular field and with applied currents. The flux penetration is numerically calculated for thin curved strips for the Bean (j c =const.) and the Kim (j c (B) = j c0 /(1 + βB)) models. (author)

  15. Compression of an Applied Bz field by a z-pinch onto a Tamped DT Fiber for Inertial Confinement Fusion

    Science.gov (United States)

    Nash, Tom

    2009-11-01

    Simulations of a z-pinch compressing an applied 100 kG Bz field onto an on-axis DT fiber tamped with beryllium show the field reaching over 100 MG in the tamp, sufficient to confine DT alpha particles and to form a thermal barrier. The barrier allows the DT plasma to burn at a rho*r value as low as 0.045 g/cm^2, and at temperatures over 50 keV for a 63 MA drive current. Driving currents between 21 and 63 MA are considered with cryogenic DT fiber diameters between 600 μm and 1.6 mm. Pinch implosion times are 120 ns with a peak implosion velocity of 35 cm/μs. 1D simulations are of a foil pinch, but for improved stability we propose a nested wire-array. Simulated fusion yields with this system scale as the sixth power of the current, with burn fractions scaling as the fourth power of the current. At 63 MA the simulated yield is 521 MJ from 4.2 mg/cm of DT with a 37% burn fraction at a rho*r of only 0.18 g/cm^2.

  16. Development of Ground Coils with Low Eddy Current Loss by Applying the Compression Molding Method after the Coil Winding

    Science.gov (United States)

    Suzuki, Masao; Aiba, Masayuki; Takahashi, Noriyuki; Ota, Satoru; Okada, Shigenori

    In a magnetically levitated transportation (MAGLEV) system, a huge number of ground coils will be required because they must be laid for the whole line. Therefore, stable performance and reduced cost are essential requirements for the ground coil development. On the other hand, because the magnetic field changes when the superconducting magnet passes by, an eddy current will be generated in the conductor of the ground coil and will result in energy loss. The loss not only increases the magnetic resistance for the train running but also brings an increase in the ground coil temperature. Therefore, the reduction of the eddy current loss is extremely important. This study examined ground coils in which both the eddy current loss and temperature increase were small. Furthermore, quantitative comparison for the eddy current loss of various magnet wire samples was performed by bench test. On the basis of the comparison, a round twisted wire having low eddy current loss was selected as an effective ground coil material. In addition, the ground coils were manufactured on trial. A favorable outlook to improve the size accuracy of the winding coil and uneven thickness of molded resin was obtained without reducing the insulation strength between the coil layers by applying a compression molding after winding.

  17. Fast-ion losses induced by ELMs and externally applied magnetic perturbations in the ASDEX Upgrade tokamak

    International Nuclear Information System (INIS)

    Garcia-Munoz, M; Rodriguez-Ramos, M; Äkäslompolo, S; De Marne, P; Dunne, M G; Dux, R; Fietz, S; Fuchs, C; Geiger, B; Herrmann, A; Hoelzl, M; Kurzan, B; McDermott, R M; Strumberger, E; Evans, T E; Ferraro, N M; Pace, D C; Lazanyi, N; Nocente, M; Shinohara, K

    2013-01-01

    Phase-space time-resolved measurements of fast-ion losses induced by edge localized modes (ELMs) and ELM mitigation coils have been obtained in the ASDEX Upgrade tokamak by means of multiple fast-ion loss detectors (FILDs). Filament-like bursts of fast-ion losses are measured during ELMs by several FILDs at different toroidal and poloidal positions. Externally applied magnetic perturbations (MPs) have little effect on plasma profiles, including fast-ions, in high collisionality plasmas with mitigated ELMs. A strong impact on plasma density, rotation and fast-ions is observed, however, in low density/collisionality and q 95 plasmas with externally applied MPs. During the mitigation/suppression of type-I ELMs by externally applied MPs, the large fast-ion bursts observed during ELMs are replaced by a steady loss of fast-ions with a broad-band frequency and an amplitude of up to an order of magnitude higher than the neutral beam injection (NBI) prompt loss signal without MPs. Multiple FILD measurements at different positions, indicate that the fast-ion losses due to static 3D fields are localized on certain parts of the first wall rather than being toroidally/poloidally homogeneously distributed. Measured fast-ion losses show a broad energy and pitch-angle range and are typically on banana orbits that explore the entire pedestal/scrape-off-layer (SOL). Infra-red measurements are used to estimate the heat load associated with the MP-induced fast-ion losses. The heat load on the FILD detector head and surrounding wall can be up to six times higher with MPs than without 3D fields. When 3D fields are applied and density pump-out is observed, an enhancement of the fast-ion content in the plasma is typically measured by fast-ion D-alpha (FIDA) spectroscopy. The lower density during the MP phase also leads to a deeper beam deposition with an inward radial displacement of ≈2 cm in the maximum of the beam emission. Orbit simulations are used to test different models for 3D

  18. Histomorphometric study and three-dimensional reconstruction of the osteocyte lacuno-canalicular network one hour after applying tensile and compressive forces.

    Science.gov (United States)

    Bozal, Carola B; Sánchez, Luciana M; Mandalunis, Patricia M; Ubios, Ángela M

    2013-01-01

    The occurrence of very early morphological changes in the osteocyte lacuno-canalicular network following application of tensile and/or compressive forces remains unknown to date. Thus, the aim of this study was to perform a morphological and morphometric evaluation of the changes in the three-dimensional structure of the lacuno-canalicular network and the osteocyte network of alveolar bone that take place very early after applying tensile and compressive forces in vivo, conducting static histomorphometry on bright-field microscopy and confocal laser scanning microscopy images. Our results showed that both the tensile and compressive forces induced early changes in osteocytes and their lacunae, which manifested as an increase in lacunar volume and changes in lacunar shape and orientation. An increase in canalicular width and a decrease in the width and an increase in the length of cytoplasmic processes were also observed. The morphological changes in the lacuno-canalicular and osteocyte networks that occur in vivo very early after application of tensile and compressive forces would be an indication of an increase in permeability within the system. Thus, both compressive and tensile forces would cause fluid displacement very soon after being applied; the latter would in turn rapidly activate alveolar bone osteocytes, enhancing transmission of the signals to the entire osteocyte network and the effector cells located at the bone surface. Copyright © 2013 S. Karger AG, Basel.

  19. Sistemas distribuídos aplicados à compressão e recuperação de imagens = Distributed systems applied to image compression and recovery

    Directory of Open Access Journals (Sweden)

    Fabio Jorge Assad Gostaldon

    2008-01-01

    Full Text Available Processamento digital de imagens é uma área que demanda grande capacidade de processamento. Sob este fato, torna-se interessante a implementação de softwares que estejam baseados na distribuição do processamento em vários nós ou máquinas da rede de computadores. Especificamente neste trabalho são abordados algoritmos distribuídos de compressão e expansão de imagens que utilizam a imagem transformada discreta de cosseno. Os resultados mostram que a economia de tempo conseguida com os algoritmos paralelos, em relação aos seus equivalentes seqüenciais, é função da resolução da imagem eda complexidade dos cálculos envolvidos, ou seja, maior a eficiência quanto maior o tempo de processamento em relação ao tempo de comunicação entre os nós.Digital image processing is a field that demands great processing capacity. As such, it becomes relevant to implement software that is based on the distribution of the processing into several nodes divided by computers belonging to the same network. Specificallydiscussed in this work are distributed algorithms of compression and expansion of images using the discrete cosine transform. The results show that the savings in processing time obtained due to the parallel algorithms, in comparison to its sequential equivalents, is afunction that depends on the resolution of the image and the complexity of the involved calculation; that is, efficiency is greater the longer the processing period is in terms of thetime involved for the communication between the network points.

  20. Hemostatic Agents for Control of Intracavitary Non-Compressible Hemorrhage: An Overview of Current Results

    National Research Council Canada - National Science Library

    Kheirabadi, Bijan; Klemcke, Harold G

    2004-01-01

    The majority (̃80%) of hemorrhagic deaths on the battlefield are due to intracavitary hemorrhage that is not accessible for direct compression and cannot be treated with externally applied hemostatic agents...

  1. A framework for data compression and damage detection in structural health monitoring applied on a laboratory three-story structure

    Directory of Open Access Journals (Sweden)

    Manoel Afonso Pereira de Lima

    2016-09-01

    Full Text Available Structural Health Monitoring (SHM is an important technique used to preserve many types of structures in the short and long run, using sensor networks to continuously gather the desired data. However, this causes a strong impact in the data size to be stored and processed. A common solution to this is using compression algorithms, where the level of data compression should be adequate enough to allow the correct damage identification. In this work, we use the data sets from a laboratory three-story structure to evaluate the performance of common compression algorithms which, then, are combined with damage detection algorithms used in SHM. We also analyze how the use of Independent Component Analysis, a common technique to reduce noise in raw data, can assist the detection performance. The results showed that Piecewise Linear Histogram combined with Nonlinear PCA have the best trade-off between compression and detection for small error thresholds while Adaptive PCA with Principal Component Analysis perform better with higher values.

  2. Luminous flux improvement of xenon fluorescent lamps by applying synchronized high-voltage pulse to the auxiliary external electrode

    Energy Technology Data Exchange (ETDEWEB)

    Motomura, Hideki; Oka, Kojiro; Sogabe, Toru; Jinno, Masafumi, E-mail: hmoto@mayu.ee.ehime-u.ac.jp [Department of Electrical and Electronic Engineering, Ehime University 3 Bunkyo-cho, Matsuyama, Ehime 790-8577 (Japan)

    2011-06-08

    As the environmental awareness of people becomes stronger, the demand for mercury-free light sources also becomes stronger. The authors have been developing cold cathode fluorescent lamps in which xenon gas is filled as an ultraviolet radiator instead of mercury. Previously the authors reported the luminous flux enhancement method using a grounded auxiliary external electrode (AEE). In this paper, in order to improve the luminous flux much more, a positive voltage pulse which was synchronized to the main driving negative voltage pulse was applied to the AEE. As a result, the maximum input power increased under which the positive column did not constrict and the luminous flux improved by 70% at the xenon filling pressure of 6.7 kPa. It is proved that the positive voltage pulse application to the AEE with the amplitude of more than 2 kV expands the positive column in the radial direction. It is attributed to the phenomenon that the residual ions and electrons, which are generated by dielectric barrier discharge between the AEE and the anode during the falling edge of the negative pulse to the cathode, spread the discharge path from the anode towards the AEE during the cold cathode discharge mode. By increasing the xenon filling pressure, luminous efficacy was improved to 25 lm W{sup -1}.

  3. Band gap opening of bilayer graphene by F4-TCNQ molecular doping and externally applied electric field.

    Science.gov (United States)

    Tian, Xiaoqing; Xu, Jianbin; Wang, Xiaomu

    2010-09-09

    The band gap opening of bilayer graphene with one side surface adsorption of F4-TCNQ is reported. F4-TCNQ doped bilayer graphene shows p-type semiconductor characteristics. With a F4-TCNQ concentration of 1.3 x 10(-10) mol/cm(2), the charge transfer between each F4-TCNQ molecule and graphene is 0.45e, and the built-in electric field, E(bi), between the graphene layers could reach 0.070 V/A. The charge transfer and band gap opening of the F4-TCNQ-doped graphene can be further modulated by an externally applied electric field (E(ext)). At 0.077 V/A, the gap opening at the Dirac point (K), DeltaE(K) = 306 meV, and the band gap, E(g) = 253 meV, are around 71% and 49% larger than those of the pristine bilayer under the same E(ext).

  4. Maximum-principle-satisfying space-time conservation element and solution element scheme applied to compressible multifluids

    KAUST Repository

    Shen, Hua

    2016-10-19

    A maximum-principle-satisfying space-time conservation element and solution element (CE/SE) scheme is constructed to solve a reduced five-equation model coupled with the stiffened equation of state for compressible multifluids. We first derive a sufficient condition for CE/SE schemes to satisfy maximum-principle when solving a general conservation law. And then we introduce a slope limiter to ensure the sufficient condition which is applicative for both central and upwind CE/SE schemes. Finally, we implement the upwind maximum-principle-satisfying CE/SE scheme to solve the volume-fraction-based five-equation model for compressible multifluids. Several numerical examples are carried out to carefully examine the accuracy, efficiency, conservativeness and maximum-principle-satisfying property of the proposed approach.

  5. Maximum-principle-satisfying space-time conservation element and solution element scheme applied to compressible multifluids

    KAUST Repository

    Shen, Hua; Wen, Chih-Yung; Parsani, Matteo; Shu, Chi-Wang

    2016-01-01

    A maximum-principle-satisfying space-time conservation element and solution element (CE/SE) scheme is constructed to solve a reduced five-equation model coupled with the stiffened equation of state for compressible multifluids. We first derive a sufficient condition for CE/SE schemes to satisfy maximum-principle when solving a general conservation law. And then we introduce a slope limiter to ensure the sufficient condition which is applicative for both central and upwind CE/SE schemes. Finally, we implement the upwind maximum-principle-satisfying CE/SE scheme to solve the volume-fraction-based five-equation model for compressible multifluids. Several numerical examples are carried out to carefully examine the accuracy, efficiency, conservativeness and maximum-principle-satisfying property of the proposed approach.

  6. 76 FR 55384 - External Peer Review Meeting for the Draft Guidance of Applying Quantitative Data To Develop Data...

    Science.gov (United States)

    2011-09-07

    ... ENVIRONMENTAL PROTECTION AGENCY [EPA/100/J-11/001; FRL-9460-1] External Peer Review Meeting for... attend this peer review meeting as observers. Time will be set aside for observers to give brief oral... the draft document, EPA intends to consider the comments from the external peer review meeting along...

  7. FRC translation into a compression coil

    International Nuclear Information System (INIS)

    Chrien, R.E.

    1985-01-01

    Several features of the problem of FRC translation into a compression coil are considered. First, the magnitude of the guide field is calculated and found to exceed that which would be applied to a flux conserver. Second, energy conservation is applied to FRC translation from a flux conserver into a compression coil. It is found that a significant temperature decrease is required for translation to be energetically possible. The temperature change depends on the external inductance in the compression circuit. An analogous case is that of a compression region composed of a compound magnet; in this case the temperature change depends on the ratio of inner and outer coil radii. Finally, the kinematics of intermediate translation states are calculated using an ''abrupt transition'' model. It is found, in this model, that the FRC must overcome a potential hill during translation, which requires a small initial velocity

  8. Evaluating health inequity interventions: applying a contextual (external) validity framework to programs funded by the Canadian Health Services Research Foundation.

    Science.gov (United States)

    Phillips, Kaye; Müller-Clemm, Werner; Ysselstein, Margaretha; Sachs, Jonathan

    2013-02-01

    Including context in the measurement and evaluation of health in equity interventions is critical to understanding how events that occur in an intervention's environment might contribute to or impede its success. This study adapted and piloted a contextual validity assessment framework on a selection of health inequity-related programs funded by the Canadian Health Services Research Foundation (CHSRF) between 1998 and 2006. The two overarching objectives of this study were (1) to determine the relative amount and quality of attention given to conceptualizing, measuring and validating context within CHSRF funded research final reports related to health-inequity; and (2) to contribute evaluative evidence towards the incorporation of context into the assessment and measurement of health inequity interventions. The study found that of the 42/146 CHSRF programs and projects, judged to be related to health inequity 20 adequately reported on the conceptualization, measurement and validation of context. Amongst these health-inequity related project reports, greatest emphasis was placed on describing the socio-political and economical context over actually measuring and validating contextual evidence. Applying a contextual validity assessment framework was useful for distinguishing between the descriptive (conceptual) versus empirical (measurement and validation) inclusion of documented contextual evidence. Although contextual validity measurement frameworks needs further development, this study contributes insight into identifying funded research related to health inequities and preliminary criteria for assessing interventions targeted at specific populations and jurisdictions. This study also feeds a larger critical dialogue (albeit beyond the scope of this study) regarding the relevance and utility of using evaluative techniques for understanding how specific external conditions support or impede the successful implementation of health inequity interventions. Copyright

  9. An Applied Method for Predicting the Load-Carrying Capacity in Compression of Thin-Wall Composite Structures with Impact Damage

    Science.gov (United States)

    Mitrofanov, O.; Pavelko, I.; Varickis, S.; Vagele, A.

    2018-03-01

    The necessity for considering both strength criteria and postbuckling effects in calculating the load-carrying capacity in compression of thin-wall composite structures with impact damage is substantiated. An original applied method ensuring solution of these problems with an accuracy sufficient for practical design tasks is developed. The main advantage of the method is its applicability in terms of computing resources and the set of initial data required. The results of application of the method to solution of the problem of compression of fragments of thin-wall honeycomb panel damaged by impacts of various energies are presented. After a comparison of calculation results with experimental data, a working algorithm for calculating the reduction in the load-carrying capacity of a composite object with impact damage is adopted.

  10. Currency crisis and external fragility: a Minskyan interpretation applied to the Brazilian economy between 1999 and 2013

    Directory of Open Access Journals (Sweden)

    Victor Hugo Rocha Sarto

    2016-12-01

    Full Text Available This work has two goals. The first one is to develop an interpretation for open economies founded on Minsky’s financial fragility hypothesis about the process of a currency crisis and its determinants. The deterioration of an economy’s external financial structure is identified as the reason for the increase of its crisis susceptibility. With this approach, we create external fragility indexes intending to measure an economy’s crisis susceptibility. Our second objective is to evaluate the Brazilian external fragility between 1999 and 2013 using the index and the interpretation previously developed. The results suggest that Brazilian’s external fragility suffered a gradual and significant decrease and tends to follow stable trend in the coming years.

  11. Trunk muscle activation and associated lumbar spine joint shear forces under different levels of external forward force applied to the trunk

    NARCIS (Netherlands)

    Kingma, I.; Staudenmann, D.; van Dieen, J.H.

    2007-01-01

    High anterior intervertebral shear loads could cause low back injuries and therefore the neuromuscular system may actively counteract these forces. This study investigated whether, under constant moment loading relative to L3L4, an increased externally applied forward force on the trunk results in a

  12. Proposal of a methodology to be applied for the characterization of external exposure risk of employees in nuclear medicine services

    International Nuclear Information System (INIS)

    Simoes, Rafael Figueiredo Pohlmann

    2010-01-01

    Nuclear medicine procedure requires the administration of radioactive material by injection, ingestion or inhalation. After incorporation, the patient becomes a mobile source of radiation and, after their examination; they can irradiate everyone on their way out of the Nuclear Medicine Service (NMS). A group of workers in this path is considered a critical group, but there are no conviction on this classification, because there are not measurements available. Thus, workers claiming for occupationally exposed individual's (OEI) rights are common. Employers are always in a complex situation, because if they decided to undertake the individual external monitoring of the critical working groups, the Court considers all as OEI and employers are taxed. On the other hand, if they do not provide monitoring, it is impossible to prove that these workers were not exposed to effective doses higher than individual annual public's limit and they lose the actions, too. This work proposes a methodology to evaluate, using TLD environmental monitors, air kerma rate at critical staff points in a NMS. This method provides relevant information about critical groups' exposure. From these results, the clinic or hospital may prove technically, without individual monitoring of employees, the classification of areas and can estimate the maximum flow of patients in the free areas which guarantees exposures below the public individual dose limit. This methodology has been applied successfully to a private clinic in Rio de Janeiro, which operates a NMS. The only critical group that received exposure statistically different from clinic background radiation was that on the antechamber of the NMS. This is a site that should be characterized as a supervised area and the group of workers in this environment as OEI, as the estimated extrapolated annual effective dose in this position was 1.2 +- 0.7 mSv/year, above the public annual limit (1,0 mSv/year). Normalizing by the number of patients, it can

  13. A Direct Approach to Determine the External Disturbing Gravity Field by Applying Green Integral with the Ground Boundary Value

    Directory of Open Access Journals (Sweden)

    TIAN Jialei

    2015-11-01

    Full Text Available By using the ground as the boundary, Molodensky problem usually gets the solution in form of series. Higher order terms reflect the correction between a smooth surface and the ground boundary. Application difficulties arise from not only computational complexity and stability maintenance, but also data-intensiveness. Therefore, in this paper, starting from the application of external gravity disturbance, Green formula is used on digital terrain surface. In the case of ignoring the influence of horizontal component of the integral, the expression formula of external disturbance potential determined by boundary value consisted of ground gravity anomalies and height anomaly difference are obtained, whose kernel function is reciprocal of distance and Poisson core respectively. With this method, there is no need of continuation of ground data. And kernel function is concise, and suitable for the stochastic computation of external disturbing gravity field.

  14. Mining compressing sequential problems

    NARCIS (Netherlands)

    Hoang, T.L.; Mörchen, F.; Fradkin, D.; Calders, T.G.K.

    2012-01-01

    Compression based pattern mining has been successfully applied to many data mining tasks. We propose an approach based on the minimum description length principle to extract sequential patterns that compress a database of sequences well. We show that mining compressing patterns is NP-Hard and

  15. Compressions of electrorheological fluids under different initial gap distances.

    Science.gov (United States)

    Tian, Yu; Wen, Shizhu; Meng, Yonggang

    2003-05-01

    Compressions of electrorheological (ER) fluids have been carried out under different initial gap distances and different applied voltages. The nominal yield stresses of the compressed ER fluid under different conditions, according to the mechanics of compressing continuous fluids considering the yield stress of the plastic fluid, have been calculated. Curves of nominal yield stress under different applied voltages at an initial gap distance of 4 mm overlapped well and were shown to be proportional to the square of the external electric field and agree well with the traditional description. With the decrease of the initial gap distance, the difference between the nominal yield stress curves increased. The gap distance effect on the compression of ER fluids could not be explained by the traditional description based on the Bingham model and the continuous media theory. An explanation based on the mechanics of particle chain is proposed to describe the gap distance effect on the compression of ER fluids.

  16. A SURVEY OF THE PARAMETER SPACE OF THE COMPRESSIBLE LIQUID DROP MODEL AS APPLIED TO THE NEUTRON STAR INNER CRUST

    International Nuclear Information System (INIS)

    Newton, W. G.; Gearheart, M.; Li Baoan

    2013-01-01

    We present a systematic survey of the range of predictions of the neutron star inner crust composition, crust-core transition densities and pressures, and density range of the nuclear 'pasta' phases at the bottom of the crust provided by the compressible liquid drop model in light of the current experimental and theoretical constraints on model parameters. Using a Skyrme-like model for nuclear matter, we construct baseline sequences of crust models by consistently varying the density dependence of the bulk symmetry energy at nuclear saturation density, L, under two conditions: (1) that the magnitude of the symmetry energy at saturation density J is held constant, and (2) J correlates with L under the constraint that the pure neutron matter (PNM) equation of state (EoS) satisfies the results of ab initio calculations at low densities. Such baseline crust models facilitate consistent exploration of the L dependence of crustal properties. The remaining surface energy and symmetric nuclear matter parameters are systematically varied around the baseline, and different functional forms of the PNM EoS at sub-saturation densities implemented, to estimate theoretical 'error bars' for the baseline predictions. Inner crust composition and transition densities are shown to be most sensitive to the surface energy at very low proton fractions and to the behavior of the sub-saturation PNM EoS. Recent calculations of the energies of neutron drops suggest that the low-proton-fraction surface energy might be higher than predicted in Skyrme-like models, which our study suggests may result in a greatly reduced volume of pasta in the crust than conventionally predicted.

  17. A SURVEY OF THE PARAMETER SPACE OF THE COMPRESSIBLE LIQUID DROP MODEL AS APPLIED TO THE NEUTRON STAR INNER CRUST

    Energy Technology Data Exchange (ETDEWEB)

    Newton, W. G.; Gearheart, M.; Li Baoan, E-mail: william.newton@tamuc.edu [Department of Physics and Astronomy, Texas A and M University-Commerce, Commerce, TX 75429-3011 (United States)

    2013-01-15

    We present a systematic survey of the range of predictions of the neutron star inner crust composition, crust-core transition densities and pressures, and density range of the nuclear 'pasta' phases at the bottom of the crust provided by the compressible liquid drop model in light of the current experimental and theoretical constraints on model parameters. Using a Skyrme-like model for nuclear matter, we construct baseline sequences of crust models by consistently varying the density dependence of the bulk symmetry energy at nuclear saturation density, L, under two conditions: (1) that the magnitude of the symmetry energy at saturation density J is held constant, and (2) J correlates with L under the constraint that the pure neutron matter (PNM) equation of state (EoS) satisfies the results of ab initio calculations at low densities. Such baseline crust models facilitate consistent exploration of the L dependence of crustal properties. The remaining surface energy and symmetric nuclear matter parameters are systematically varied around the baseline, and different functional forms of the PNM EoS at sub-saturation densities implemented, to estimate theoretical 'error bars' for the baseline predictions. Inner crust composition and transition densities are shown to be most sensitive to the surface energy at very low proton fractions and to the behavior of the sub-saturation PNM EoS. Recent calculations of the energies of neutron drops suggest that the low-proton-fraction surface energy might be higher than predicted in Skyrme-like models, which our study suggests may result in a greatly reduced volume of pasta in the crust than conventionally predicted.

  18. Theoretical analysis of multiple quantum-well, slow-light devices under applied external fields using a fully analytical model in fractional dimension

    Energy Technology Data Exchange (ETDEWEB)

    Kohandani, R; Kaatuzian, H [Photonics Research Laboratory, Electrical Engineering Department, AmirKabir University of Technology, Hafez Ave., Tehran (Iran, Islamic Republic of)

    2015-01-31

    We report a theoretical study of optical properties of AlGaAs/GaAs multiple quantum-well (MQW), slow-light devices based on excitonic population oscillations under applied external magnetic and electric fields using an analytical model for complex dielectric constant of Wannier excitons in fractional dimension. The results are shown for quantum wells (QWs) of different width. The significant characteristics of the exciton in QWs such as exciton energy and exciton oscillator strength (EOS) can be varied by application of external magnetic and electric fields. It is found that a higher bandwidth and an appropriate slow-down factor (SDF) can be achieved by changing the QW width during the fabrication process and by applying magnetic and electric fields during device functioning, respectively. It is shown that a SDF of 10{sup 5} is obtained at best. (slowing of light)

  19. Left ventricular outflow obstruction as a result of external cardiac compression by a mediastinal tumor; Zwezenie drogi odplywu lewej komory wywolane uciskiem przeez guz srodpiersia

    Energy Technology Data Exchange (ETDEWEB)

    Rydlewska-Sadowska, W.; Kowalski, M.; Borowiecka, E.; Polkowski, J.; Szaroszyk, W. [Klinika Szybkiej Diagnostyki, Zaklad Radiologii, Instytut Kardiologii, Warsaw (Poland)

    1993-12-31

    A case of left ventricular outflow tract stenosis resulted from compression of the heart is presented. This symptomatic cardiovascular lesion was produced by extensive growth of mediastinal tumour. Numerous noninvasive methods were necessary to establish this difficult diagnosis. The patient underwent surgery that disclosed a benign process (of neurofibroma). After tumour`s resection marked hemodynamic signs subsided. (author) 12 refs, 6 figs

  20. Influence of applied compressive stress on the hysteresis curves and magnetic domain structure of grain-oriented transverse Fe-3%Si steel

    International Nuclear Information System (INIS)

    Perevertov, O; Schäfer, R

    2012-01-01

    The influence of an applied compressive stress on the hysteresis curve and domain structure in conventional (1 1 0) [0 0 1] Fe-3%Si steel cut transverse to the rolling direction is studied. Quasistatic hysteresis loops under compressive stress up to 75 MPa were measured. The magnetic domains and magnetization processes were observed by longitudinal Kerr microscopy at different levels of stress. It is shown that the bulk hysteresis loop can be described with a good accuracy by the action of an effective field, which is the product of the stress and a function of magnetization. Domain observations have shown that the reasons for the effective field are demagnetizing fields due to the disappearance of supplementary domains along [0 1 0] and [1 0 0] at low fields and different domain systems in different grains at moderate fields. The latter are caused by differences in grain sensitivity to stress depending on the degree of misorientation. A decrease in the effective field above 1 T is connected with a transformation of all grains into the same domain system—the column pattern. (paper)

  1. Compression and reswelling of microgel particles after an osmotic shock

    NARCIS (Netherlands)

    Sleeboom, J.F.; Voudouris, P.; Punter, M.T.J.J.M.; Aangenendt, F.J.; Florea, D.; van der Schoot, P.P.A.M.; Wyss, H.M.

    2016-01-01

    We use dedicated microfluidic devices to expose soft hydrogel particles to a rapid change in the externally applied osmotic pressure and observe a non-monotonic response: After an initial rapid compression the particle slowly reswells to approximately its original size. Using a simple

  2. Numerical simulation of plasma response to externally applied resonant magnetic perturbation on the J-TEXT tokamak

    Science.gov (United States)

    Bicheng, LI; Zhonghe, JIANG; Jian, LV; Xiang, LI; Bo, RAO; Yonghua, DING

    2018-05-01

    Nonlinear magnetohydrodynamic (MHD) simulations of an equilibrium on the J-TEXT tokamak with applied resonant magnetic perturbations (RMPs) are performed with NIMROD (non-ideal MHD with rotation, open discussion). Numerical simulation of plasma response to RMPs has been developed to investigate magnetic topology, plasma density and rotation profile. The results indicate that the pure applied RMPs can stimulate 2/1 mode as well as 3/1 mode by the toroidal mode coupling, and finally change density profile by particle transport. At the same time, plasma rotation plays an important role during the entire evolution process.

  3. Collapse of the balloon-expandable stent in the common iliac artery due to minor external compression in a lean patient

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Eun; Choi, Ho Cheol; Choi, Dae Seob; Lee, Sang Min; Lee, Jung Eun [Gyeongsang National University School of Medicine and Gyeongsang National University Hospital, Jinju (Korea, Republic of); Cho, Su Beom; Ahn, Jong Hwa [Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Changwon (Korea, Republic of)

    2017-08-15

    A 60-year-old lean man with claudication due to severe stenosis of the right common iliac artery (CIA) underwent balloon-expandable stent deployment. Nineteen months later, claudication and lower limb ischemia in the patient recurred after minor external pressure and computed tomography indicated collapse of the right CIA stent. We performed balloon angioplasty again and self-expandable stent deployment was performed, and the patient's symptoms were relieved. We suggest that the CIA in a lean person could be susceptible to external pressure.

  4. Collapse of the balloon-expandable stent in the common iliac artery due to minor external compression in a lean patient

    International Nuclear Information System (INIS)

    Park, Sung Eun; Choi, Ho Cheol; Choi, Dae Seob; Lee, Sang Min; Lee, Jung Eun; Cho, Su Beom; Ahn, Jong Hwa

    2017-01-01

    A 60-year-old lean man with claudication due to severe stenosis of the right common iliac artery (CIA) underwent balloon-expandable stent deployment. Nineteen months later, claudication and lower limb ischemia in the patient recurred after minor external pressure and computed tomography indicated collapse of the right CIA stent. We performed balloon angioplasty again and self-expandable stent deployment was performed, and the patient's symptoms were relieved. We suggest that the CIA in a lean person could be susceptible to external pressure

  5. Hybrid instrument applied to human reliability study in event of loss of external electric power in a nuclear power plant

    International Nuclear Information System (INIS)

    Martins, Eduardo Ferraz

    2015-01-01

    The study projects in highly complex installations involves robust modeling, supported by conceptual and mathematical tools, to carry out systematic research and structured the different risk scenarios that can lead to unwanted events from occurring equipment failures or human errors. In the context of classical modeling, the Probabilistic Safety Analysis (PSA) seeks to provide qualitative and quantitative information about the project particularity and their operational facilities, including the identification of factors or scenarios that contribute to the risk and consequent comparison options for increasing safety. In this context, the aim of the thesis is to develop a hybrid instrument (CPP-HI) innovative, from the integrated modeling techniques of Failure Mode and Effect Analysis (FMEA), concepts of Human Reliability Analysis and Probabilistic Composition of Preferences (PCP). In support of modeling and validation of the CPP-HI, a simulation was performed on a triggering event 'Loss of External Electric Power' - PEEE, in a Nuclear Power plant. The results were simulated in a virtual environment (sensitivity analysis) and are robust to the study of Human Reliability Analysis (HRA) in the context of the PSA. (author)

  6. Peripheral arterial volume distensibility: significant differences with age and blood pressure measured using an applied external pressure

    International Nuclear Information System (INIS)

    Zheng, Dingchang; Murray, Alan

    2011-01-01

    A new arterial distensibility measurement technique was assessed in 100 healthy normotensive subjects. Arterial transmural pressures on the whole right arm were reduced with a 50 cm long cuff inflated to 10, 20, 30 and 40 mmHg. The electrocardiogram, and finger and ear photoplethysmograms were recorded simultaneously. Arm pulse propagation time, pulse wave velocity (PWV) and arterial volume distensibility were determined. With a 40 mmHg reduction in transmural pressure, arm pulse propagation time increased from 61 to 83 ms, PWV decreased from 12 to 8 m s −1 and arterial distensibility increased from 0.102% to 0.232% per mmHg (all P < 0.0001). At all cuff pressures, arterial distensibility was significantly related to resting mean arterial pressure (MAP), diastolic blood pressure (DBP) and age, and for systolic blood pressure at 30 and 40 mmHg (all P < 0.05). At 40 mmHg cuff pressure, arterial distensibility fell by 54% for a MAP increase from 75 to 105 mmHg, 57% for a DBP increase from 60 to 90 mmHg and 47% for an age increase from 20 to 70 years. These changes were more than double than those without cuff pressure. Our technique showed that systemic volume distensibility of the peripheral arm artery reduced with age, with a greater effect at higher external and lower transmural pressures

  7. Phase-matched light amplification by three-wave mixing process in a birefringent fiber due to externally applied stress

    International Nuclear Information System (INIS)

    Ohashi, M.; Kitayama, K.; Ishida, Y.; Uchida, N.

    1982-01-01

    A novel method to achieve phase-matched light amplification in a birefringent fiber via the three-wave mixing is proposed by using frequency shift change due to the stress applied to the fiber. It is confirmed that the signal power from a cw laser diode at lambda = 1.292 μm is amplified by 6.1 x 10 3 times in the birefringent fiber pumped with a Q-switched Nd: yttrium aluminum garnet laser at lambda = 1.064 μm. This will provide a new fiber-optic light signal amplifier having a good tolerance for variation of signal wavelengths

  8. Using LDR as Sensing Element for an External Fuzzy Controller Applied in Photovoltaic Pumping Systems with Variable-Speed Drives.

    Science.gov (United States)

    Maranhão, Geraldo Neves De A; Brito, Alaan Ubaiara; Leal, Anderson Marques; Fonseca, Jéssica Kelly Silva; Macêdo, Wilson Negrão

    2015-09-22

    In the present paper, a fuzzy controller applied to a Variable-Speed Drive (VSD) for use in Photovoltaic Pumping Systems (PVPS) is proposed. The fuzzy logic system (FLS) used is embedded in a microcontroller and corresponds to a proportional-derivative controller. A Light-Dependent Resistor (LDR) is used to measure, approximately, the irradiance incident on the PV array. Experimental tests are executed using an Arduino board. The experimental results show that the fuzzy controller is capable of operating the system continuously throughout the day and controlling the direct current (DC) voltage level in the VSD with a good performance.

  9. Using LDR as Sensing Element for an External Fuzzy Controller Applied in Photovoltaic Pumping Systems with Variable-Speed Drives

    Directory of Open Access Journals (Sweden)

    Geraldo Neves De A. Maranhão

    2015-09-01

    Full Text Available In the present paper, a fuzzy controller applied to a Variable-Speed Drive (VSD for use in Photovoltaic Pumping Systems (PVPS is proposed. The fuzzy logic system (FLS used is embedded in a microcontroller and corresponds to a proportional-derivative controller. A Light-Dependent Resistor (LDR is used to measure, approximately, the irradiance incident on the PV array. Experimental tests are executed using an Arduino board. The experimental results show that the fuzzy controller is capable of operating the system continuously throughout the day and controlling the direct current (DC voltage level in the VSD with a good performance.

  10. Operation of an extraction, applied-B diode using an externally-driven, metallic foil anode plasma source

    International Nuclear Information System (INIS)

    Hinshelwood, D.D.; Fisher, R.C.; Greenly, J.B.; Neri, J.M.; Oliver, B.V.; Ottinger, P.F.; Rose, D.V.; Stephanakis, S.J.; Young, F.C.

    1995-01-01

    The authors are developing an extraction, applied-B ion diode, on the Gamble II generator at NRL, for ion-beam-transport research in support of the SNL light-ion ICF program. An ion beam with a voltage above 1 MV and a proton current of 150--200 kA is required for transport experiments. At present they are using hardware which allows a maximum anode area of ∼60 cm 2 . These parameters result in enhancement factors 2--3 times greater than those in similar experiments at Cornell, SNL, and KfK. In addition, the early, high-impedance phase of the diode must be minimized to prevent insulator flashover. Transport experiments with beam focusing also preclude ion beam angular momentum. A version of the EMFAP source, developed at Cornell and improved at KfK, is used to provide prompt turn-on of the ion current. To date the authors have obtained ion beams with rapid turn-on, high currents and current densities, high ion efficiencies (80%), relatively stable impedance behavior, and negligible angular momentum. Unfortunately, these have not all been obtained on the same shot. Electron loss current flowing through the anode foil is seen to play an important role in evolution of the anode plasma. Under the conditions of this experiment, the diode self-magnetic field is also important. Work at present centers on viewing the existing data in light of the refined field measurements, coupled with PIC modeling, to identify an operating regime that will provide the required electrical behavior without beam angular momentum

  11. Neutron scattering techniques for betaine calcium chloride dihydrate under applied external field (temperature, electric field and hydrostatic pressure)

    International Nuclear Information System (INIS)

    Hernandez, O.

    1997-01-01

    We have studied with neutron scattering techniques betaine calcium chloride dihydrate (BCCD), a dielectric aperiodic crystal which displays a Devil's staircase type phase diagram made up of several incommensurate and commensurate phases, having a range of stability very sensitive to temperature, electric field and hydrostatic pressure. We have measured a global hysteresis of δ(T) of about 2-3 K in the two incommensurate phases. A structural study of the modulated commensurate phases 1/4 and 1/5 allows us to evidence that the atomic modulation functions are anharmonic. The relevance of the modelization of the modulated structure by polar Ising pseudo-spins is then directly established. On the basis of group theory calculation in the four dimensional super-space, we interpret this anharmonic modulation as a soliton regime with respect to the lowest-temperature non modulated ferroelectric phase. The continuous character of the transition to the lowest-temperature non modulated phase and the diffuse scattering observed in this phase are accounted for the presence of ferroelectric domains separated by discommensurations. Furthermore, we have shown that X-rays induce in BCCD a strong variation with time of irradiation of the intensity of satellite peaks, and more specifically for third order ones. This is why the 'X-rays' structural model is found more harmonic than the 'neutron' one. Under electric field applied along the vector b axis, we confirm that commensurate phases with δ = even/odd are favoured and hence are polar along this direction. We have evidenced at 10 kV / cm two new higher order commensurate phases in the phase INC2, corroborating the idea of a 'complete' Devil's air-case phase diagram. A phenomenon of generalized coexistence of phases occurs above 5 kV / cm. We have characterized at high field phase transitions between 'coexisting' phases, which are distinguishable from classical lock-in transitions. Under hydrostatic pressure, our results contradict

  12. Knee joint passive stiffness and moment in sagittal and frontal planes markedly increase with compression.

    Science.gov (United States)

    Marouane, H; Shirazi-Adl, A; Adouni, M

    2015-01-01

    Knee joints are subject to large compression forces in daily activities. Due to artefact moments and instability under large compression loads, biomechanical studies impose additional constraints to circumvent the compression position-dependency in response. To quantify the effect of compression on passive knee moment resistance and stiffness, two validated finite element models of the tibiofemoral (TF) joint, one refined with depth-dependent fibril-reinforced cartilage and the other less refined with homogeneous isotropic cartilage, are used. The unconstrained TF joint response in sagittal and frontal planes is investigated at different flexion angles (0°, 15°, 30° and 45°) up to 1800 N compression preloads. The compression is applied at a novel joint mechanical balance point (MBP) identified as a point at which the compression does not cause any coupled rotations in sagittal and frontal planes. The MBP of the unconstrained joint is located at the lateral plateau in small compressions and shifts medially towards the inter-compartmental area at larger compression forces. The compression force substantially increases the joint moment-bearing capacities and instantaneous angular rigidities in both frontal and sagittal planes. The varus-valgus laxities diminish with compression preloads despite concomitant substantial reductions in collateral ligament forces. While the angular rigidity would enhance the joint stability, the augmented passive moment resistance under compression preloads plays a role in supporting external moments and should as such be considered in the knee joint musculoskeletal models.

  13. Effects of external pelvic compression on electromyographic activity of the hamstring muscles during unipedal stance in sportsmen with and without hamstring injuries.

    Science.gov (United States)

    Arumugam, Ashokan; Milosavljevic, Stephan; Woodley, Stephanie; Sole, Gisela

    2015-06-01

    There is some evidence that hamstring function can be influenced by interventions focusing on the pelvis via an anatomic and neurophysiologic link between these two segments. Previous research demonstrated increased electromyographic activity from injured hamstrings during transition from bipedal to unipedal stance (BUS). The aim of this study was to investigate the effects of a pelvic compression belt (PCB) on electromyographic activity of selected muscles during BUS in sportsmen with and without hamstring injury. Electromyographic amplitudes (normalised to maximum voluntary isometric contraction [MVIC]) of the hamstrings, gluteus maximus, gluteus medius and lumbar multifidus were obtained during BUS from 20 hamstring-injured participants (both sides) and 30 healthy participants (one side, randomly selected). There was an increase in biceps femoris (by 1.23 ± 2.87 %MVIC; p = 0.027) and gluteus maximus (by 0.63 ± 1.13 %MVIC; p = 0.023) electromyographic activity for the hamstring-injured side but no significant differences other than a decrease in multifidus activity (by 1.36 ± 2.92 %MVIC; p = 0.023) were evident for healthy participants while wearing the PCB. However, the effect sizes for these findings were small. Wearing the PCB did not significantly change electromyographic activity of other muscles in either participant group (p > 0.050). Moreover, the magnitude of change induced by the PCB was not significantly different between groups (p > 0.050) for the investigated muscles. Thus, application of a PCB to decrease electromyographic activity of injured hamstrings during BUS is likely to have little effect. Similar research is warranted in participants with acute hamstring injury. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. DNABIT Compress - Genome compression algorithm.

    Science.gov (United States)

    Rajarajeswari, Pothuraju; Apparao, Allam

    2011-01-22

    Data compression is concerned with how information is organized in data. Efficient storage means removal of redundancy from the data being stored in the DNA molecule. Data compression algorithms remove redundancy and are used to understand biologically important molecules. We present a compression algorithm, "DNABIT Compress" for DNA sequences based on a novel algorithm of assigning binary bits for smaller segments of DNA bases to compress both repetitive and non repetitive DNA sequence. Our proposed algorithm achieves the best compression ratio for DNA sequences for larger genome. Significantly better compression results show that "DNABIT Compress" algorithm is the best among the remaining compression algorithms. While achieving the best compression ratios for DNA sequences (Genomes),our new DNABIT Compress algorithm significantly improves the running time of all previous DNA compression programs. Assigning binary bits (Unique BIT CODE) for (Exact Repeats, Reverse Repeats) fragments of DNA sequence is also a unique concept introduced in this algorithm for the first time in DNA compression. This proposed new algorithm could achieve the best compression ratio as much as 1.58 bits/bases where the existing best methods could not achieve a ratio less than 1.72 bits/bases.

  15. Effects of applying an external magnetic field during the deep cryogenic heat treatment on the corrosion resistance and wear behavior of 1.2080 tool steel

    International Nuclear Information System (INIS)

    Akhbarizadeh, Amin; Amini, Kamran; Javadpour, Sirus

    2012-01-01

    Highlights: ► Deep cryogenic increases the carbide percentage and make a more homogenous distribution. ► Deep cryogenic improve the wear resistance and corrosion behavior of 1.2080 tool steel. ► Applying the magnetic field weaker the carbide distribution and decreases the carbides percentage. ► Magnetized samples showed weaker corrosion and wear behavior. -- Abstract: This work concerns with the effect of applying an external magnetic field on the corrosion behavior, wear resistance and microstructure of 1.2080 (D2) tool steel during the deep cryogenic heat treatment. These analyses were performed via scanning electron microscope (SEM), optical microscope (OM), transmission electron microscope (TEM) and X-ay diffraction (XRD) to study the microstructure, a pin-on-disk wear testing machine to study the wear behavior, and linear sweep voltammetry to study the corrosion behavior of the samples. It was shown that the deep cryogenic heat treatment eliminates retained austenite and makes a more uniform carbide distribution with higher percentage. It was also observed that the deep cryogenic heat treatment improves the wear behavior and corrosion resistance of 1.2080 tool steel. In comparison between the magnetized and non-magnetized samples, the carbide percentage decreases and the carbide distribution weakened in the magnetized samples; subsequently, the wear behavior and corrosion resistance attenuated compared in the magnetized samples.

  16. Compression stockings

    Science.gov (United States)

    Call your health insurance or prescription plan: Find out if they pay for compression stockings. Ask if your durable medical equipment benefit pays for compression stockings. Get a prescription from your doctor. Find a medical equipment store where they can ...

  17. A single bout of whole-leg, peristaltic pulse external pneumatic compression upregulates PGC-1α mRNA and endothelial nitric oxide sythase protein in human skeletal muscle tissue.

    Science.gov (United States)

    Kephart, Wesley C; Mobley, C Brooks; Fox, Carlton D; Pascoe, David D; Sefton, JoEllen M; Wilson, Trent J; Goodlett, Michael D; Kavazis, Andreas N; Roberts, Michael D; Martin, Jeffrey S

    2015-07-01

    What is the central question of this study? Does 60 min of peristaltic pulse external pneumatic compression (EPC) alter gene and protein expression patterns related to metabolism, vascular biology, redox balance and inflammation in vastus lateralis biopsy samples? What is the main finding and its importance? A single bout of EPC transiently upregulates PGC-1α mRNA, while also upregulating endothelial nitric oxide synthase protein and nitric oxide metabolite concentrations in vastus lateralis biopsy samples. We investigated whether a single 60 min bout of whole-leg, lower pressure external pneumatic compression (EPC) altered select vascular, metabolic, antioxidant and inflammation-related mRNAs. Ten participants (eight male, two female; aged 22.0 ± 0.4 years) reported to the laboratory 4 h postprandial, and vastus lateralis muscle biopsies were obtained before (PRE) and 1 and 4 h after EPC treatment. Messenger RNA expression was analysed using real-time RT-PCR, and significant mRNA findings were investigated further by Western blot analysis of respective protein concentrations. Peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) mRNA increased by 77% 1 h following EPC compared with PRE levels (P = 0.005), but no change in protein concentration 1 or 4 h post-EPC was observed. Increases in endothelial nitric oxide sythase (eNOS) mRNA (+44%) and superoxide dismutase 2 (SOD2) mRNA (+57%) 1 h post-EPC as well as an increase in interleukin-10 mRNA (+132%) 4 h post-EPC compared with PRE levels were observed, but only approached significance (P = 0.076, 0.077 and 0.074, respectively). Interestingly, eNOS protein (+40%, P = 0.025) and nitrate and nitrite (NOx) concentrations (+69%, P = 0.025) increased 1-4 h post-EPC. Moreover, SOD2 protein tended to increase from PRE to 4 h post-EPC (+43%, P = 0.074), although no changes in tissue 4-hydroxnonenal levels was observed. An acute bout of EPC transiently upregulates PGC-1α mRNA, while also upregulating e

  18. FRC translation into a compression coil

    International Nuclear Information System (INIS)

    Chrien, R.E.

    1986-01-01

    The equilibrium and translational kinematics of Field-Reversed Configurations (FRCs) in a cylindrical coil which does not conserve flux are problems that arise in connection with adiabatic compressional heating. In this paper, they consider several features of the problem of FRC translation into a compression coil. First, the magnitude of the guide field is calculated and found to exceed that which would be applied to a flux conserver. Second, energy conservation is applied to FRC translation from a flux conserver into a compression coil. It is found that a significant temperature decrease is required for translation to be energetically possible. The temperature change depends on the external inductance in the compression circuit. An analogous case is that of a compression region composed of a compound magnet; in this case the temperature change depends on the ratio of inner and outer coil radii. Finally, the kinematics of intermediate translation states are calculated using an abrupt transition model. It is found, in this model, that the FRC must overcome a potential hill during translation, which requires a small initial velocity

  19. Compression and Reswelling of Microgel Particles after an Osmotic Shock

    Science.gov (United States)

    Sleeboom, Jelle J. F.; Voudouris, Panayiotis; Punter, Melle T. J. J. M.; Aangenendt, Frank J.; Florea, Daniel; van der Schoot, Paul; Wyss, Hans M.

    2017-09-01

    We use dedicated microfluidic devices to expose soft hydrogel particles to a rapid change in the externally applied osmotic pressure and observe a surprising, nonmonotonic response: After an initial rapid compression, the particle slowly reswells to approximately its original size. We theoretically account for this behavior, enabling us to extract important material properties from a single microfluidic experiment, including the compressive modulus, the gel permeability, and the diffusivity of the osmolyte inside the gel. We expect our approach to be relevant to applications such as controlled release, chromatography, and responsive materials.

  20. Influence of applied compressive stress on the hysteresis curves and magnetic domain structure of grain-oriented transverse Fe–3%Si steel

    Czech Academy of Sciences Publication Activity Database

    Perevertov, Oleksiy; Schäfer, R.

    2012-01-01

    Roč. 45, č. 13 (2012), "135001-1"-"135001-11" ISSN 0022-3727 Grant - others:GA AV ČR(CZ) M100100906 Institutional research plan: CEZ:AV0Z10100520 Keywords : hysteresis curve * magnetic domains * compressive stress * goss steel * effective field Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.528, year: 2012

  1. Regional Externalities

    NARCIS (Netherlands)

    Heijman, W.J.M.

    2007-01-01

    The book offers practical and theoretical insights in regional externalities. Regional externalities are a specific subset of externalities that can be defined as externalities where space plays a dominant role. This class of externalities can be divided into three categories: (1) externalities

  2. Most effective way to improve the hydrogen storage abilities of Na-decorated BN sheets: applying external biaxial strain and an electric field.

    Science.gov (United States)

    Tang, Chunmei; Zhang, Xue; Zhou, Xiaofeng

    2017-02-15

    Density functional calculations were used to investigate the hydrogen storage abilities of Na-atoms-decorated BN sheets under both external biaxial strain and a vertical electric field. The Na atom generally has the weakest binding strength to a given substrate compared with the other elements in the periodic table [PANS, 2016, 113, 3735]. Consequently, it is understudied in comparison to other elements and there are few reports about the hydrogen storage abilities of Na-decorated nanomaterials. We calculated that the average binding energy (E b ) of Na atoms to the pure BN sheet is 1.08 eV, which is smaller than the cohesive energy of bulk Na (1.11 eV). However, the E b can be increased to 1.15 eV under 15% biaxial strain, and further up to 1.53 eV with the control of both 15% biaxial strain and a 5.14 V nm -1 electric field (E-field). Therefore, the application of biaxial strain and an external upward E-field can prevent clustering of the Na atoms on the surface of a BN sheet, which is crucial for the hydrogen storage. Each Na atom on the surface of a BN sheet can adsorb only one H 2 molecule when no strain or E-field is applied; however, the absorption increases to five H 2 molecules under 15% biaxial strain and six H 2 molecules under both 15% biaxial strain combined with a 5.14 V nm -1 E-field. The average adsorption energies for H 2 of BN-(Na-mH 2 ) (m = 1-6) are within the range of practical applications (0.2-0.6 eV). The hydrogen gravimetric density of the periodic BN-(Na-6H 2 ) 4 structure is 9 wt%, which exceeds the 5.5 wt% value that should be met by 2017 as specified by the US Department of Energy. On the other side, removal of the biaxial strain and E-field can help to desorb the H 2 molecule. These findings suggest a new route to design hydrogen storage materials under near-ambient conditions.

  3. The force applied to successfully turn a foetus during reattempts of external cephalic version is substantially reduced when performed under spinal analgesia.

    Science.gov (United States)

    Suen, Stephen Sik Hung; Khaw, Kim S; Law, Lai Wa; Sahota, Daljit Singh; Lee, Shara Wee Yee; Lau, Tze Kin; Leung, Tak Yeung

    2012-06-01

    To compare the forces exerted during external cephalic version (ECV) on the maternal abdomen between ( 1 ) the primary attempts performed without spinal analgesia (SA), which failed and ( 2 ) the subsequent reattempts performed under SA. Patients with an uncomplicated singleton breech-presenting pregnancy suitable for ECV were recruited. During ECV, the operator wore a pair of gloves, which had thin piezo-resistive pressure sensors measuring the contact pressure between the operator's hands and maternal abdomen. For patients who had failed ECV, reattempts by the same operator was made with patients under SA, and the applied force was measured in the same manner. The profile of the exerted forces over time during each attempt was analyzed and denoted by pressure-time integral (PTI: mmHg sec). Pain score was also graded by patients using visual analogue scale. Both PTI and pain score before and after the use of SA were then compared. Overall, eight patients who had a failed ECV without SA underwent a reattempt with SA. All of them had successful version and the median PTI of the successful attempts under SA were lower than that of the previous failed attempts performed without SA (127 386 mmHg sec vs. 298,424 mmHg sec; p = 0.017). All of them also reported a 0 pain score, which was significantly lower than that of before (median 7.5; p = 0.016). SA improves the success rate of ECV as well as reduces the force required for successful version.

  4. A Proposal of a Method to Measure and Evaluate the Effect to Apply External Support Measures for Owners by Construction Management Method, etc

    Science.gov (United States)

    Tada, Hiroshi; Miyatake, Ichiro; Mouri, Junji; Ajiki, Norihiko; Fueta, Toshiharu

    In Japan, various approaches have been taken to ensure the quality of public works or to support the procurement regime of the governmental agencies, as a means to utilize external resources, which include the procurement support service or the construction management (CM) method. Although discussions on these measures to utilize external resources (hereinafter referred to as external support measure) have been going on, as well as the follow-up surveys showing the positive effects of such measures have been conducted, the surveys only deal with the matters concerning the overall effects of the external support measure on the whole, meaning that the effect of each item of the tasks have not been addressed, and that the extent it dealt with the expectations of the client is unknown. However, the effective use of the external support measure in future cannot be achieved without knowing what was the purpose to introduce the external support measure, and what effect was expected on each task item, and what extent the expectation fulfilled. Furthermore, it is important to clarify not only the effect as compared to the client's expectation (performance), but also the public benefit of this measure (value improvement). From this point of view, there is not an established method to figure out the effect of the client's measure to utilize external resources. In view of this background, this study takes the CM method as an example of the external support measure, and proposes a method to measure and evaluate the effect by each task item, and suggests the future issues and possible responses, in the aim of contributing the promotion, improvement, and proper implementation of the external support measures in future.

  5. Does external pneumatic compression treatment between bouts of overreaching resistance training sessions exert differential effects on molecular signaling and performance-related variables compared to passive recovery? An exploratory study.

    Science.gov (United States)

    Haun, Cody T; Roberts, Michael D; Romero, Matthew A; Osburn, Shelby C; Mobley, Christopher B; Anderson, Richard G; Goodlett, Michael D; Pascoe, David D; Martin, Jeffrey S

    2017-01-01

    We sought to compare the effects of external pneumatic compression (EPC) and sham when used concurrently with resistance training on performance-related outcomes and molecular measures related to recovery. Twenty (N = 20) resistance-trained male participants (aged 21.6±2.4 years) were randomized to balanced sham or EPC intervention groups. The protocol consisted of 3 consecutive days of heavy, voluminous back squat exercise followed by EPC/sham treatment (Days2-4) and 3 consecutive days of recovery (Days5-7) with EPC/sham only on Days5-6. On Day1 (PRE), and Days3-7, venipuncture, flexibility and pressure-to-pain threshold (PPT) measures were performed. Vastsus lateralis muscle tissue was biopsied at PRE, 1-h post-EPC/sham treatment on Day2 (POST1) and 24-h post-EPC/sham treatment on Day7 (POST2). Isokinetic peak torque was assessed at PRE and POST2. Peak isokinetic strength did not change from PRE to POST2 in either group. The PPT was significantly lower on Days3-6 with sham, indicating greater muscle soreness, though this was largely abolished in the EPC group. A significant decrease in flexibility with sham was observed on Day3 (+16.2±4.6% knee joint angle; P0.01). Vastus lateralis poly-ubiquitinated proteins significantly increased at the POST2 time point relative to PRE with sham (+66.6±24.6%; Pmuscle oxidative stress and proteolysis markers during recovery from heavy resistance exercise.

  6. Temperature Development on the External Root Surface During Laser-Assisted Endodontic Treatment Applying a Microchopped Mode of a 980 nm Diode Laser.

    Science.gov (United States)

    Beer, Franziska; Farmakis, Eleftherios Terry R; Kopic, Josip; Kurzmann, Christoph; Moritz, Andreas

    2017-04-01

    The aim of this article was to investigate the temperature increase of the external root surface during laser-assisted endodontic treatment using a diode laser (980 nm) in a microchopped mode. Ten freshly extracted, human maxillary incisors with mature apices were collected, prepared to size F4 at working length (ProTaper; Dentsply Maillefer, Ballaigues, Switzerland), mounted to a holder, and irradiated (using spiral movements in coronal direction) with a diode laser (GENTLEray 980 Classic Plus; KaVo, Biberach, Germany) with a 200 μm fiber in four different treatment groups: Group 1 (control group) was irradiated in six cycles of 5-sec irradiation/20-sec pause with 2.5 W in the pulse mode. Groups 2 to 4 were irradiated at six cycles of 5-sec irradiation/20-sec pause in the microchopped mode (Group 2-1.6 W; Group 3-2.0 W; Group 4-2.5 W). The applied mode was 25 ms on/25 ms off. Within the on period, the laser delivered an intermittent sequence of energy complexes and the maximum output was equal to the nominated output of the device (12 W). Canals were kept moist by sterile saline irrigation in between irradiations, and temperature changes were continuously measured using a thermal imaging camera. Recordings were analyzed by a mixed model (analysis of variance [ANOVA] for repeated measurements). The highest mean of temperature rise, 1.94°C ± 1.07°C, was measured in Group 4, followed by Group 3 (1.74°C ± 1.22°C) and Group 2 (1.58°C ± 1.18°C). The lowest increase occurred in Group 1 (1.06°C ± 1.20°C). There was a significant difference (p = 0.041) between the groups. Significant differences were found between Groups 1 and 4 (p = 0.007) and 1 and 2 (p = 0.035). In addition, a marginally significant difference between Groups 1 and 2 (p = 0.052) was noted. There was no significant difference between Groups 2, 3, and 4. Despite the low mean values reported, the highest temperature increase (+5.7°C) was

  7. Estudo experimental da aplicação das forças de compressão ou distração sobre o sistema de fixação pedicular Compression or distraction forces applied on a pedicular fixation system: an experimental study

    Directory of Open Access Journals (Sweden)

    Helton Luiz Aparecido Defino

    2006-01-01

    Full Text Available Foi realizado estudo experimental com o objetivo de avaliar os efeitos da aplicação da força de compressão e distração (aproximação e afastamento sobre os implantes colocados nos pedículos vertebrais. Foram utilizados no estudo os segmentos vertebrais T8-T9, T10-T11, T12-L1, L2-L3 e L4-L5 de suínos da raça Landsark. Cada segmento vertebral foi fixado com implantes pediculares, tendo sido aplicada força de compressão ou distração com deslocamento que variou de 5,1 mm a 9,35 mm. O deslocamento provocado pela aplicação das forças foi mensurado em quatro pontos do segmento vertebral: A (porção anterior do corpo vertebral, B (porção média do corpo vertebral, C (porção posterior do corpo vertebral e D (processo articular siperior. A força de compressão produziu o afastamento dos pontos localizados nas regiões A e B, e aproximação dos pontos da região D. A força de distração produziu a aproximação dos pontos da região A e B e o afastamento dos pontos da região D.An experimental study was conducted with the objective of evaluating the effects of compression and distraction (approach and deviation forces applied on implants placed at vertebral pedicles. The vertebral segments T8-T9, T10-T11, T12-L1, L2-L3 and L4-L5 of Landsark pigs were used in the study. Each vertebral segment was fixed with pedicular implants, with compression or distraction forces being applied with a displacement that ranged from 5.1 mm to 9.35 mm. Displacement caused by forces application was measured in four points of the vertebral segment: A (anterior portion of the vertebral segment, B (medial portion of the vertebral segment, C (posterior portion of the vertebral segment and D (superior joint process. Compression forces caused the deviation of points located at regions A and B, and the approach of points at region D. Distraction forces caused the approach of points at regions A and B and deviation of the points at region D.

  8. Externally guided target for inertial fusion

    International Nuclear Information System (INIS)

    Martinez-Val, J.M.; Piera, M.

    1996-01-01

    A totally new concept is proposed to reach fusion conditions by externally guided inertial confinement. The acceleration and compression of the fuel is guided by a cannon-like external duct with a conical section ending in a small-size cavity around the central point of the tube. The fuel pellets coming from each cannon mouth collide in the central cavity where the implosion and final compression of the fuel take place. Both the tube material density and its areal density must be much higher than the initial density and areal density of the fuel. The external tube will explode into pieces as a consequence of the inner pressures achieved after the fuel central collision. If the collision is suitably driven, a fusion burst can take place before the tube disassembly. because of the features of the central collision needed to trigger ignition, this concept could be considered as tamped impact fusion. Both the fusion products and the debris from the guide tube are caught by a liquid-lithium curtain surrounding the target. Only two driving beams are necessary. The system can be applied to any type of driver and could use a solid pellet at room temperature as the initial target. 54 refs., 24 figs., 1 tab

  9. Does external pneumatic compression treatment between bouts of overreaching resistance training sessions exert differential effects on molecular signaling and performance-related variables compared to passive recovery? An exploratory study.

    Directory of Open Access Journals (Sweden)

    Cody T Haun

    Full Text Available We sought to compare the effects of external pneumatic compression (EPC and sham when used concurrently with resistance training on performance-related outcomes and molecular measures related to recovery.Twenty (N = 20 resistance-trained male participants (aged 21.6±2.4 years were randomized to balanced sham or EPC intervention groups. The protocol consisted of 3 consecutive days of heavy, voluminous back squat exercise followed by EPC/sham treatment (Days2-4 and 3 consecutive days of recovery (Days5-7 with EPC/sham only on Days5-6. On Day1 (PRE, and Days3-7, venipuncture, flexibility and pressure-to-pain threshold (PPT measures were performed. Vastsus lateralis muscle tissue was biopsied at PRE, 1-h post-EPC/sham treatment on Day2 (POST1 and 24-h post-EPC/sham treatment on Day7 (POST2. Isokinetic peak torque was assessed at PRE and POST2.Peak isokinetic strength did not change from PRE to POST2 in either group. The PPT was significantly lower on Days3-6 with sham, indicating greater muscle soreness, though this was largely abolished in the EPC group. A significant decrease in flexibility with sham was observed on Day3 (+16.2±4.6% knee joint angle; P0.01. Vastus lateralis poly-ubiquitinated proteins significantly increased at the POST2 time point relative to PRE with sham (+66.6±24.6%; P<0.025 and were significantly greater (P<0.025 than those observed with EPC at the same time point (-18.6±8.5%. 4-hydroxynonenal values were significantly lower at POST2 relative to PRE with EPC (-16.2±5.6%; P<0.025 and were significantly lower (P<0.025 than those observed with sham at the same time point (+11.8±5.9%.EPC mitigated a reduction in flexibility and PPT that occurred with sham. Moreover, EPC reduced select skeletal muscle oxidative stress and proteolysis markers during recovery from heavy resistance exercise.

  10. Graph Compression by BFS

    Directory of Open Access Journals (Sweden)

    Alberto Apostolico

    2009-08-01

    Full Text Available The Web Graph is a large-scale graph that does not fit in main memory, so that lossless compression methods have been proposed for it. This paper introduces a compression scheme that combines efficient storage with fast retrieval for the information in a node. The scheme exploits the properties of the Web Graph without assuming an ordering of the URLs, so that it may be applied to more general graphs. Tests on some datasets of use achieve space savings of about 10% over existing methods.

  11. An alternative noninvasive technique for the treatment of iatrogenic femoral pseudoaneurysms: stethoscope-guided compression.

    Science.gov (United States)

    Korkmaz, Ahmet; Duyuler, Serkan; Kalayci, Süleyman; Türker, Pinar; Sahan, Ekrem; Maden, Orhan; Selçuk, Mehmet Timur

    2013-06-01

    latrogenic femoral pseudoaneurysm is a well-known vascular access site complication. Many invasive and noninvasive techniques have been proposed for the management of this relatively common complication. In this study, we aimed to evaluate efficiency and safety of stethoscope-guided compression as a novel noninvasive technique in the femoral pseudoaneurysm treatment. We prospectively included 29 consecutive patients with the diagnosis of femoral pseudoaneurysm who underwent coronary angiography. Patients with a clinical suspicion of femoral pseudoaneurysm were referred to colour Doppler ultrasound evaluation. The adult (large) side of the stethoscope was used to determine the location where the bruit was best heard. Then compression with the paediatric (small) side of the stethoscope was applied until the bruit could no longer be heard and compression was maintained for at least two sessions. Once the bruit disappeared, a 12-hour bed rest with external elastic compression was advised to the patients, in order to prevent disintegration of newly formed thrombosis. Mean pseudoaneurysm size was 1.7 +/- 0.4 cmx 3.0 +/- 0.9 cm and the mean duration of compression was 36.2 +/- 8.5 minutes.Twenty-six (89.6%) of these 29 patients were successfully treated with stethoscope-guided compression. In 18 patients (62%), the pseuodoaneurysms were successfully closed after 2 sessions of 15-minute compression. No severe complication was observed. Stethoscope-guided compression of femoral pseudoaneurysms is a safe and effective novel technique which requires less equipment and expertise than other contemporary methods.

  12. Wellhead compression

    Energy Technology Data Exchange (ETDEWEB)

    Harrington, Joe [Sertco Industries, Inc., Okemah, OK (United States); Vazquez, Daniel [Hoerbiger Service Latin America Inc., Deerfield Beach, FL (United States); Jacobs, Denis Richard [Hoerbiger do Brasil Industria de Equipamentos, Cajamar, SP (Brazil)

    2012-07-01

    Over time, all wells experience a natural decline in oil and gas production. In gas wells, the major problems are liquid loading and low downhole differential pressures which negatively impact total gas production. As a form of artificial lift, wellhead compressors help reduce the tubing pressure resulting in gas velocities above the critical velocity needed to surface water, oil and condensate regaining lost production and increasing recoverable reserves. Best results come from reservoirs with high porosity, high permeability, high initial flow rates, low decline rates and high total cumulative production. In oil wells, excessive annulus gas pressure tends to inhibit both oil and gas production. Wellhead compression packages can provide a cost effective solution to these problems by reducing the system pressure in the tubing or annulus, allowing for an immediate increase in production rates. Wells furthest from the gathering compressor typically benefit the most from wellhead compression due to system pressure drops. Downstream compressors also benefit from higher suction pressures reducing overall compression horsepower requirements. Special care must be taken in selecting the best equipment for these applications. The successful implementation of wellhead compression from an economical standpoint hinges on the testing, installation and operation of the equipment. Key challenges and suggested equipment features designed to combat those challenges and successful case histories throughout Latin America are discussed below.(author)

  13. The effect of externally applied oscillating electric fields on the l=1 and l=2 diocotron modes in non-neutral plasmas

    International Nuclear Information System (INIS)

    Spencer, R.L.

    1990-01-01

    A high-frequency oscillating electric field can change the properties of diocotron modes in non-neutral plasmas. The effect depends crucially on the azimuthal mode number, m, of the applied field. For m=0,±1 there is no effect, and for applied standing waves there is also no effect. But if the applied field has the form of a traveling wave with |m|≥2, the frequency of stable diocotron modes can be modified and for |m|≥3, the l=2 instability of hollow density profiles can be stabilized. The analytic results are verified with a nonlinear fluid simulation of an infinitely long non-neutral plasma

  14. Application specific compression : final report.

    Energy Technology Data Exchange (ETDEWEB)

    Melgaard, David Kennett; Byrne, Raymond Harry; Myers, Daniel S.; Harrison, Carol D.; Lee, David S.; Lewis, Phillip J.; Carlson, Jeffrey J.

    2008-12-01

    With the continuing development of more capable data gathering sensors, comes an increased demand on the bandwidth for transmitting larger quantities of data. To help counteract that trend, a study was undertaken to determine appropriate lossy data compression strategies for minimizing their impact on target detection and characterization. The survey of current compression techniques led us to the conclusion that wavelet compression was well suited for this purpose. Wavelet analysis essentially applies a low-pass and high-pass filter to the data, converting the data into the related coefficients that maintain spatial information as well as frequency information. Wavelet compression is achieved by zeroing the coefficients that pertain to the noise in the signal, i.e. the high frequency, low amplitude portion. This approach is well suited for our goal because it reduces the noise in the signal with only minimal impact on the larger, lower frequency target signatures. The resulting coefficients can then be encoded using lossless techniques with higher compression levels because of the lower entropy and significant number of zeros. No significant signal degradation or difficulties in target characterization or detection were observed or measured when wavelet compression was applied to simulated and real data, even when over 80% of the coefficients were zeroed. While the exact level of compression will be data set dependent, for the data sets we studied, compression factors over 10 were found to be satisfactory where conventional lossless techniques achieved levels of less than 3.

  15. Micro-/nanosized cantilever beams and mass sensors under applied axial tensile/compressive force vibrating in vacuum and viscous fluid

    Directory of Open Access Journals (Sweden)

    Ivo Stachiv

    2015-11-01

    Full Text Available Vibrating micro-/nanosized cantilever beams under an applied axial force are the key components of various devices used in nanotechnology. In this study, we perform a complete theoretical investigation of the cantilever beams under an arbitrary value of the axial force vibrating in a specific environment such as vacuum, air or viscous fluid. Based on the results easy accessible expressions enabling one the fast and highly accurate estimations of changes in the Q-factor and resonant frequencies of beam oscillating in viscous fluid caused by the applied axial force are derived and analyzed. It has been also shown that for beam-to-string and string vibrational regimes the mode shape starts to significantly deviate from the one known for a beam without axial force. Moreover, a linear dependency of the vibrational amplitude in resonance on the dimensionless tension parameter has been found. We revealed that only a large axial force, i.e. the string vibrational regime, significantly improves the Q-factor of beams submerged in fluid, while an increase of the axial force in beam and beam-to-string transition regimes has a negligibly small impact on the Q-factor enhancement. Experiments carried out on the carbon nanotubes and nanowires are in a good agreement with present theoretical predictions.

  16. Speech Compression

    Directory of Open Access Journals (Sweden)

    Jerry D. Gibson

    2016-06-01

    Full Text Available Speech compression is a key technology underlying digital cellular communications, VoIP, voicemail, and voice response systems. We trace the evolution of speech coding based on the linear prediction model, highlight the key milestones in speech coding, and outline the structures of the most important speech coding standards. Current challenges, future research directions, fundamental limits on performance, and the critical open problem of speech coding for emergency first responders are all discussed.

  17. Proposal of requirements for performance in Brazil for systems of external individual monitoring for neutrons applying the TLD-albedo technique

    International Nuclear Information System (INIS)

    Martins, Marcelo M.; Mauricio, Claudia L.P.; Pereira, Walsan W.; Fonseca, Evaldo S. da; Silva, Ademir X.

    2009-01-01

    This work presents a criteria and conditions proposal for the regulations in Brazil of individual monitoring systems for neutrons applying the albedo technique with thermoluminescent detectors. Tests are proposed for the characterization performance of the system based on the Regulation ISO 21909 and on the experience of the authors

  18. Liquid-solid phase transition of physical hydrogels subject to an externally applied electro-chemo-mechanical coupled field with mobile ionic species.

    Science.gov (United States)

    Wu, Tao; Li, Hua

    2017-08-09

    In this study, a model was multiphysically developed for the simulation of the phase transition of physical hydrogels between liquid solution and solid gel states, subject to an electro-chemo-mechanically coupled field, with the effect of the mobile ionic species in the solution. The present model consists of the governing equations for the equilibrium of forces and the conservation of mass, Maxwell's equations, and an evolution equation for the interface. Based on the second law of thermodynamics, the constitutive equations are formulated from the energy viewpoint, including a novel formulation of free energy with the effect of crosslink density. The present model may be reduced to Suo's non-equilibrium thermodynamic theory if the interface is ignored when only a single phase exists. It may also be reduced to Dolbow's model for gel-gel phase transition when the electric field is ignored. Therefore, the present model becomes more generalized since it is able to represent both the bulk phase and the interface behaviors, and the mechanical field is simultaneously coupled with both the electric and chemical fields. In the first case study, the system at equilibrium state was numerically investigated for analysis of the influences of the electrical and chemical potentials as well as the mechanical pressure externally imposed on the boundary of the system domain. The second case study presents a spherically symmetrical solution-gel phase transition at non-equilibrium states, with the emphasis on the evolution of both the interface and electrochemical potentials.

  19. Improvement of fatigue resistance for multilayer lead zirconate titanate (PZT)-based ceramic actuators by external mechanical loads

    Science.gov (United States)

    Yang, Gang; Yue, Zhenxing; Ji, Ye; Chu, Xiangcheng; Li, Longtu

    2008-12-01

    The influence of external compressive loads, applied along a direction perpendicular to polarization, on fatigue behaviors of multilayer lead zirconate titanate (PZT)-based ceramic actuators was investigated. Under no external mechanical load, a normal fatigue behavior was observed, demonstrating that both switching polarization (Pswitching) and remnant polarization (Pr) progressively decreased with increasing switching cycles due to domain pinning by charge point defects. However, an anomalous enhancement in both switching and remnant polarizations was observed upon application of the external compressive loads. After 5×106 cycles of polarization switching, Pswitching and Pr increase by about 13% and 6% at 40 MPa, respectively, while Pswitching and Pr increase by about 11% and 21% at 60 MPa, respectively. The improvement of fatigue resistance can be attributed to non-180° domain switching and suppression of microcracking, triggered by external mechanical loads.

  20. Dual compression is not an uncommon type of iliac vein compression syndrome.

    Science.gov (United States)

    Shi, Wan-Yin; Gu, Jian-Ping; Liu, Chang-Jian; Lou, Wen-Sheng; He, Xu

    2017-09-01

    Typical iliac vein compression syndrome (IVCS) is characterized by compression of left common iliac vein (LCIV) by the overlying right common iliac artery (RCIA). We described an underestimated type of IVCS with dual compression by right and left common iliac arteries (LCIA) simultaneously. Thirty-one patients with IVCS were retrospectively included. All patients received trans-catheter venography and computed tomography (CT) examinations for diagnosing and evaluating IVCS. Late venography and reconstructed CT were used for evaluating the anatomical relationship among LCIV, RCIA and LCIA. Imaging manifestations as well as demographic data were collected and evaluated by two experienced radiologists. Sole and dual compression were found in 32.3% (n = 10) and 67.7% (n = 21) of 31 patients respectively. No statistical differences existed between them in terms of age, gender, LCIV diameter at the maximum compression point, pressure gradient across stenosis, and the percentage of compression level. On CT and venography, sole compression was commonly presented with a longitudinal compression at the orifice of LCIV while dual compression was usually presented as two types: one had a lengthy stenosis along the upper side of LCIV and the other was manifested by a longitudinal compression near to the orifice of external iliac vein. The presence of dual compression seemed significantly correlated with the tortuous LCIA (p = 0.006). Left common iliac vein can be presented by dual compression. This type of compression has typical manifestations on late venography and CT.

  1. Effect of the wire geometry and an externally applied magnetic field on the detection efficiency of superconducting nanowire single-photon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lusche, Robert; Semenov, Alexey; Huebers, Heinz-Willhelm [DLR, Institut fuer Planetenforschung, Berlin (Germany); Ilin, Konstantin; Siegel, Michael [Karlsruher Institut fuer Technologie (Germany); Korneeva, Yuliya; Trifonov, Andrey; Korneev, Alexander; Goltsman, Gregory [Moscow State Pedagogical University (Russian Federation)

    2013-07-01

    The interest in single-photon detectors in the near-infrared wavelength regime for applications, e.g. in quantum cryptography has immensely increased in the last years. Superconducting nanowire single-photon detectors (SNSPD) already show quite reasonable detection efficiencies in the NIR which can even be further improved. Novel theoretical approaches including vortex-assisted photon counting state that the detection efficiency in the long wavelength region can be enhanced by the detector geometry and an applied magnetic field. We present spectral measurements in the wavelength range from 350-2500 nm of the detection efficiency of meander-type TaN and NbN SNSPD with varying nanowire line width from 80 to 250 nm. Due to the used experimental setup we can accurately normalize the measured spectra and are able to extract the intrinsic detection efficiency (IDE) of our detectors. The results clearly indicate an improvement of the IDE depending on the wire width according to the theoretic models. Furthermore we experimentally found that the smallest detectable photon-flux can be increased by applying a small magnetic field to the detectors.

  2. Effect of combined external uniaxial stress and dc bias on the dielectric property of BaTiO3-based dielectrics in multilayer ceramic capacitor: thermodynamics and experiments

    International Nuclear Information System (INIS)

    Yang Gang; Yue Zhenxing; Sun Tieyu; Gou Huanlin; Li Longtu

    2008-01-01

    The dielectric properties of (Nb, Y)-doped BaTiO 3 in a multilayer ceramic capacitor (MLCC) under combined external uniaxial compressive stress and dc bias field were investigated at room temperature by using a modified Ginsburg-Landau-Devonshire thermodynamic theory and the dielectric measurement. It is found that although dc bias decreases the dielectric properties dominantly, the influence of the external uniaixial compressive stress should not be neglected. When applied along a direction perpendicular to the internal electrode layer in the MLCC, the external uniaixal compressive stress will strengthen the negative effect of dc bias. In contrast, the external uniaxial compressive stress along a direction parallel to the internal electrode layer in the MLCC will increase the dielectric permittivity under dc bias field, i.e. improve the ε-V response of the MLCC. Furthermore, although there is a difference between the calculated permittivity and the measured permittivity, the effects of the combined external uniaxial compressive stress and dc bias field on the dielectric permittivity described through two approaches are in good agreement

  3. Neuroprotective effects and UPLC-Q-TOF/MS-based active components identification of external applied a novel Wen-Luo-Tong microemulsion.

    Science.gov (United States)

    Lin, Hong-Mei; Lin, Long-Fei; Xia, Zhen-Zhen; Mao, Yong; Liu, Jia; Xu, Ling-Yan; Wu, Qing

    2017-11-13

    Chemotherapy induced neuropathy causes excruciating pain to cancer patients. Wen-Luo-Tong (WLT), a traditional Chinese medicinal compound, has been used to alleviate anti-cancer drug such as oxaliplatin-induced neuropathic pain for many years. However, the current route of administration of WLT is inconvenient and the active ingredients and mechanism of action of WLT are still unclear. To address these issues, we developed a novel formulation of WLT (W/O microemulsion) for the ease of application. New ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) methods were employed for analysis of the ingredients. We identified seven ingredients that penetrated through the skin into the Franz cell receptor solution and four of those ingredients were retained in skin tissue when WLT microemulsion was applied. We tested the microemulsion formulation on an oxaliplatin-induced neuropathy rat model and showed that this formulation significantly decreased oxaliplatin-induced mechanical hyperalgesia responses. Schwann cells (SCs) viability experiment in vitro was studied to test the protective effect of the identified seven ingredients. The result showed that Hydroxysafflor Yellow A, icariin, epimedin B and 4-dihydroxybenzoic acid significantly increased the viability of SCs after injured by Oxaliplatin. Our report presents the first novel formulation of WLT with neuroprotective effect and ease of use, which has potential for clinical applications.

  4. FRESCO: Referential compression of highly similar sequences.

    Science.gov (United States)

    Wandelt, Sebastian; Leser, Ulf

    2013-01-01

    In many applications, sets of similar texts or sequences are of high importance. Prominent examples are revision histories of documents or genomic sequences. Modern high-throughput sequencing technologies are able to generate DNA sequences at an ever-increasing rate. In parallel to the decreasing experimental time and cost necessary to produce DNA sequences, computational requirements for analysis and storage of the sequences are steeply increasing. Compression is a key technology to deal with this challenge. Recently, referential compression schemes, storing only the differences between a to-be-compressed input and a known reference sequence, gained a lot of interest in this field. In this paper, we propose a general open-source framework to compress large amounts of biological sequence data called Framework for REferential Sequence COmpression (FRESCO). Our basic compression algorithm is shown to be one to two orders of magnitudes faster than comparable related work, while achieving similar compression ratios. We also propose several techniques to further increase compression ratios, while still retaining the advantage in speed: 1) selecting a good reference sequence; and 2) rewriting a reference sequence to allow for better compression. In addition,we propose a new way of further boosting the compression ratios by applying referential compression to already referentially compressed files (second-order compression). This technique allows for compression ratios way beyond state of the art, for instance,4,000:1 and higher for human genomes. We evaluate our algorithms on a large data set from three different species (more than 1,000 genomes, more than 3 TB) and on a collection of versions of Wikipedia pages. Our results show that real-time compression of highly similar sequences at high compression ratios is possible on modern hardware.

  5. Efficient Lossy Compression for Compressive Sensing Acquisition of Images in Compressive Sensing Imaging Systems

    Directory of Open Access Journals (Sweden)

    Xiangwei Li

    2014-12-01

    Full Text Available Compressive Sensing Imaging (CSI is a new framework for image acquisition, which enables the simultaneous acquisition and compression of a scene. Since the characteristics of Compressive Sensing (CS acquisition are very different from traditional image acquisition, the general image compression solution may not work well. In this paper, we propose an efficient lossy compression solution for CS acquisition of images by considering the distinctive features of the CSI. First, we design an adaptive compressive sensing acquisition method for images according to the sampling rate, which could achieve better CS reconstruction quality for the acquired image. Second, we develop a universal quantization for the obtained CS measurements from CS acquisition without knowing any a priori information about the captured image. Finally, we apply these two methods in the CSI system for efficient lossy compression of CS acquisition. Simulation results demonstrate that the proposed solution improves the rate-distortion performance by 0.4~2 dB comparing with current state-of-the-art, while maintaining a low computational complexity.

  6. DNABIT Compress – Genome compression algorithm

    OpenAIRE

    Rajarajeswari, Pothuraju; Apparao, Allam

    2011-01-01

    Data compression is concerned with how information is organized in data. Efficient storage means removal of redundancy from the data being stored in the DNA molecule. Data compression algorithms remove redundancy and are used to understand biologically important molecules. We present a compression algorithm, “DNABIT Compress” for DNA sequences based on a novel algorithm of assigning binary bits for smaller segments of DNA bases to compress both repetitive and non repetitive DNA sequence. Our ...

  7. DNABIT Compress – Genome compression algorithm

    Science.gov (United States)

    Rajarajeswari, Pothuraju; Apparao, Allam

    2011-01-01

    Data compression is concerned with how information is organized in data. Efficient storage means removal of redundancy from the data being stored in the DNA molecule. Data compression algorithms remove redundancy and are used to understand biologically important molecules. We present a compression algorithm, “DNABIT Compress” for DNA sequences based on a novel algorithm of assigning binary bits for smaller segments of DNA bases to compress both repetitive and non repetitive DNA sequence. Our proposed algorithm achieves the best compression ratio for DNA sequences for larger genome. Significantly better compression results show that “DNABIT Compress” algorithm is the best among the remaining compression algorithms. While achieving the best compression ratios for DNA sequences (Genomes),our new DNABIT Compress algorithm significantly improves the running time of all previous DNA compression programs. Assigning binary bits (Unique BIT CODE) for (Exact Repeats, Reverse Repeats) fragments of DNA sequence is also a unique concept introduced in this algorithm for the first time in DNA compression. This proposed new algorithm could achieve the best compression ratio as much as 1.58 bits/bases where the existing best methods could not achieve a ratio less than 1.72 bits/bases. PMID:21383923

  8. SU-F-T-91: Development of Real Time Abdominal Compression Force (ACF) Monitoring System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T; Kim, D; Kang, S; Cho, M; Kim, K; Shin, D; Noh, Y; Suh, T [Department of Biomedical Engineering and Research Institute of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of); Kim, S [Virginia Commonwealth University, Richmond, VA (United States)

    2016-06-15

    Purpose: Hard-plate based abdominal compression is known to be effective, but no explicit method exists to quantify abdominal compression force (ACF) and maintain the proper ACF through the whole procedure. In addition, even with compression, it is necessary to do 4D CT to manage residual motion but, 4D CT is often not possible due to reduced surrogating sensitivity. In this study, we developed and evaluated a system that both monitors ACF in real time and provides surrogating signal even under compression. The system can also provide visual-biofeedback. Methods: The system developed consists of a compression plate, an ACF monitoring unit and a visual-biofeedback device. The ACF monitoring unit contains a thin air balloon in the size of compression plate and a gas pressure sensor. The unit is attached to the bottom of the plate thus, placed between the plate and the patient when compression is applied, and detects compression pressure. For reliability test, 3 volunteers were directed to take several different breathing patterns and the ACF variation was compared with the respiratory flow and external respiratory signal to assure that the system provides corresponding behavior. In addition, guiding waveform were generated based on free breathing, and then applied for evaluating the effectiveness of visual-biofeedback. Results: We could monitor ACF variation in real time and confirmed that the data was correlated with both respiratory flow data and external respiratory signal. Even under abdominal compression, in addition, it was possible to make the subjects successfully follow the guide patterns using the visual biofeedback system. Conclusion: The developed real time ACF monitoring system was found to be functional as intended and consistent. With the capability of both providing real time surrogating signal under compression and enabling visual-biofeedback, it is considered that the system would improve the quality of respiratory motion management in radiation

  9. SU-F-T-91: Development of Real Time Abdominal Compression Force (ACF) Monitoring System

    International Nuclear Information System (INIS)

    Kim, T; Kim, D; Kang, S; Cho, M; Kim, K; Shin, D; Noh, Y; Suh, T; Kim, S

    2016-01-01

    Purpose: Hard-plate based abdominal compression is known to be effective, but no explicit method exists to quantify abdominal compression force (ACF) and maintain the proper ACF through the whole procedure. In addition, even with compression, it is necessary to do 4D CT to manage residual motion but, 4D CT is often not possible due to reduced surrogating sensitivity. In this study, we developed and evaluated a system that both monitors ACF in real time and provides surrogating signal even under compression. The system can also provide visual-biofeedback. Methods: The system developed consists of a compression plate, an ACF monitoring unit and a visual-biofeedback device. The ACF monitoring unit contains a thin air balloon in the size of compression plate and a gas pressure sensor. The unit is attached to the bottom of the plate thus, placed between the plate and the patient when compression is applied, and detects compression pressure. For reliability test, 3 volunteers were directed to take several different breathing patterns and the ACF variation was compared with the respiratory flow and external respiratory signal to assure that the system provides corresponding behavior. In addition, guiding waveform were generated based on free breathing, and then applied for evaluating the effectiveness of visual-biofeedback. Results: We could monitor ACF variation in real time and confirmed that the data was correlated with both respiratory flow data and external respiratory signal. Even under abdominal compression, in addition, it was possible to make the subjects successfully follow the guide patterns using the visual biofeedback system. Conclusion: The developed real time ACF monitoring system was found to be functional as intended and consistent. With the capability of both providing real time surrogating signal under compression and enabling visual-biofeedback, it is considered that the system would improve the quality of respiratory motion management in radiation

  10. Interactive computer graphics applications for compressible aerodynamics

    Science.gov (United States)

    Benson, Thomas J.

    1994-01-01

    Three computer applications have been developed to solve inviscid compressible fluids problems using interactive computer graphics. The first application is a compressible flow calculator which solves for isentropic flow, normal shocks, and oblique shocks or centered expansions produced by two dimensional ramps. The second application couples the solutions generated by the first application to a more graphical presentation of the results to produce a desk top simulator of three compressible flow problems: 1) flow past a single compression ramp; 2) flow past two ramps in series; and 3) flow past two opposed ramps. The third application extends the results of the second to produce a design tool which solves for the flow through supersonic external or mixed compression inlets. The applications were originally developed to run on SGI or IBM workstations running GL graphics. They are currently being extended to solve additional types of flow problems and modified to operate on any X-based workstation.

  11. Radial and axial compression of pure electron

    International Nuclear Information System (INIS)

    Park, Y.; Soga, Y.; Mihara, Y.; Takeda, M.; Kamada, K.

    2013-01-01

    Experimental studies are carried out on compression of the density distribution of a pure electron plasma confined in a Malmberg-Penning Trap in Kanazawa University. More than six times increase of the on-axis density is observed under application of an external rotating electric field that couples to low-order Trivelpiece-Gould modes. Axial compression of the density distribution with the axial length of a factor of two is achieved by controlling the confining potential at both ends of the plasma. Substantial increase of the axial kinetic energy is observed during the axial compression. (author)

  12. Thermal compression modulus of polarized neutron matter

    International Nuclear Information System (INIS)

    Abd-Alla, M.

    1990-05-01

    We applied the equation of state for pure polarized neutron matter at finite temperature, calculated previously, to calculate the compression modulus. The compression modulus of pure neutron matter at zero temperature is very large and reflects the stiffness of the equation of state. It has a little temperature dependence. Introducing the spin excess parameter in the equation of state calculations is important because it has a significant effect on the compression modulus. (author). 25 refs, 2 tabs

  13. Comparing biological networks via graph compression

    Directory of Open Access Journals (Sweden)

    Hayashida Morihiro

    2010-09-01

    Full Text Available Abstract Background Comparison of various kinds of biological data is one of the main problems in bioinformatics and systems biology. Data compression methods have been applied to comparison of large sequence data and protein structure data. Since it is still difficult to compare global structures of large biological networks, it is reasonable to try to apply data compression methods to comparison of biological networks. In existing compression methods, the uniqueness of compression results is not guaranteed because there is some ambiguity in selection of overlapping edges. Results This paper proposes novel efficient methods, CompressEdge and CompressVertices, for comparing large biological networks. In the proposed methods, an original network structure is compressed by iteratively contracting identical edges and sets of connected edges. Then, the similarity of two networks is measured by a compression ratio of the concatenated networks. The proposed methods are applied to comparison of metabolic networks of several organisms, H. sapiens, M. musculus, A. thaliana, D. melanogaster, C. elegans, E. coli, S. cerevisiae, and B. subtilis, and are compared with an existing method. These results suggest that our methods can efficiently measure the similarities between metabolic networks. Conclusions Our proposed algorithms, which compress node-labeled networks, are useful for measuring the similarity of large biological networks.

  14. Compressed Sensing with Rank Deficient Dictionaries

    DEFF Research Database (Denmark)

    Hansen, Thomas Lundgaard; Johansen, Daniel Højrup; Jørgensen, Peter Bjørn

    2012-01-01

    In compressed sensing it is generally assumed that the dictionary matrix constitutes a (possibly overcomplete) basis of the signal space. In this paper we consider dictionaries that do not span the signal space, i.e. rank deficient dictionaries. We show that in this case the signal-to-noise ratio...... (SNR) in the compressed samples can be increased by selecting the rows of the measurement matrix from the column space of the dictionary. As an example application of compressed sensing with a rank deficient dictionary, we present a case study of compressed sensing applied to the Coarse Acquisition (C...

  15. Atomic effect algebras with compression bases

    International Nuclear Information System (INIS)

    Caragheorgheopol, Dan; Tkadlec, Josef

    2011-01-01

    Compression base effect algebras were recently introduced by Gudder [Demonstr. Math. 39, 43 (2006)]. They generalize sequential effect algebras [Rep. Math. Phys. 49, 87 (2002)] and compressible effect algebras [Rep. Math. Phys. 54, 93 (2004)]. The present paper focuses on atomic compression base effect algebras and the consequences of atoms being foci (so-called projections) of the compressions in the compression base. Part of our work generalizes results obtained in atomic sequential effect algebras by Tkadlec [Int. J. Theor. Phys. 47, 185 (2008)]. The notion of projection-atomicity is introduced and studied, and several conditions that force a compression base effect algebra or the set of its projections to be Boolean are found. Finally, we apply some of these results to sequential effect algebras and strengthen a previously established result concerning a sufficient condition for them to be Boolean.

  16. ExternE: Externalities of energy Vol. 1. Summary

    International Nuclear Information System (INIS)

    Holland, M.; Berry, J.

    1995-01-01

    There is a growing requirement for policy analysts to take account of the environment in their decision making and to undertake the specified cost-benefit analysis. Within the European Union this is reflected in the 5th Environmental Action Programme, and the Commission's White Paper entitled 'Growth, competitiveness, employment and the ways forward to the 21st century'. This has led to a need for evaluation of environmental externalities. The ExternE Project commenced in 1991 as the European part of a collaborative study between the European Commission and the US Department of Energy. It aims to be the first systematic approach to the evaluation of external costs of a wide range of different fuel cycles. The project will result in an operational accounting framework for the quantification and monetarisation of priority environmental and other externalities. This framework will allow the calculation of the marginal external costs and benefits for specific power plants, at specific sites using specified technologies. There are three major phases in the project. Phase 1 was undertaken in collaboration with the US Department of Energy. In this phase the teams jointly developed the conceptual approach and methodology and shared scientific information for application to a number of fuel cycles. On the European side work concentrated on the nuclear and coal fuel cycles which together were expected to raise many of the fundamental issues in fuel cycle analysis. The project is currently nearing completion of Phase 2. During this phase the methodology has been applied to a wide range of different fossil, nuclear and renewable fuel cycles for power generation and energy conservation options. Also a series of National Implementation Programmes is underway in which the methodology and accounting framework are being applied to reference sites throughout Europe. In addition the general methodology is being extended to address the evaluation of externalities associated with

  17. Externalities of fuel cycles 'ExternE' project. Summary report

    International Nuclear Information System (INIS)

    Holland, M.; Berry, J.

    1994-01-01

    There is a growing requirement for policy analysts to take account of the environment in their decision making and to undertake the specified cost-benefit analysis. Within the European Union this is reflected in the 5th Environmental Action Programme, and the Commission's White Paper entitled 'Growth, competitiveness, employment and the ways forward to the 21st century'. This has led to a need for evaluation of environmental externalities. The ExternE Project commenced in 1991 as the European part of a collaborative study between the European Commission and the US Department of Energy. It aims to be the first systematic approach to the evaluation of external costs of a wide range of different fuel cycles. The project will result in an operational accounting framework for the quantification and monetarisation of priority environmental and other externalities. This framework will allow the calculation of the marginal external costs and benefits for specific power plants, at specific sites using specified technologies. There are three major phases in the project. Phase I was undertaken in collaboration with the US Department of Energy. In this phase the teams jointly developed the conceptual approach and methodology and shared scientific information for application to a number of fuel cycles. On the European side work concentrated on the nuclear and coal fuel cycles which together were expected to raise many of the fundamental issues in fuel cycle analysis. The project is currently nearing completion of Phase 2. During this phase the methodology has been applied to a wide range of different fossil, nuclear and renewable fuel cycles for power generation and energy conservation options. Also a series of National Implementation Programmes are underway in which the methodology and accounting framework are being applied to reference sites throughout Europe. In addition the general methodology is being extended to address the evaluation of externalities associated with

  18. Compressibility of the protein-water interface

    Science.gov (United States)

    Persson, Filip; Halle, Bertil

    2018-06-01

    The compressibility of a protein relates to its stability, flexibility, and hydrophobic interactions, but the measurement, interpretation, and computation of this important thermodynamic parameter present technical and conceptual challenges. Here, we present a theoretical analysis of protein compressibility and apply it to molecular dynamics simulations of four globular proteins. Using additively weighted Voronoi tessellation, we decompose the solution compressibility into contributions from the protein and its hydration shells. We find that positively cross-correlated protein-water volume fluctuations account for more than half of the protein compressibility that governs the protein's pressure response, while the self correlations correspond to small (˜0.7%) fluctuations of the protein volume. The self compressibility is nearly the same as for ice, whereas the total protein compressibility, including cross correlations, is ˜45% of the bulk-water value. Taking the inhomogeneous solvent density into account, we decompose the experimentally accessible protein partial compressibility into intrinsic, hydration, and molecular exchange contributions and show how they can be computed with good statistical accuracy despite the dominant bulk-water contribution. The exchange contribution describes how the protein solution responds to an applied pressure by redistributing water molecules from lower to higher density; it is negligibly small for native proteins, but potentially important for non-native states. Because the hydration shell is an open system, the conventional closed-system compressibility definitions yield a pseudo-compressibility. We define an intrinsic shell compressibility, unaffected by occupation number fluctuations, and show that it approaches the bulk-water value exponentially with a decay "length" of one shell, less than the bulk-water compressibility correlation length. In the first hydration shell, the intrinsic compressibility is 25%-30% lower than in

  19. Compressibility of the protein-water interface.

    Science.gov (United States)

    Persson, Filip; Halle, Bertil

    2018-06-07

    The compressibility of a protein relates to its stability, flexibility, and hydrophobic interactions, but the measurement, interpretation, and computation of this important thermodynamic parameter present technical and conceptual challenges. Here, we present a theoretical analysis of protein compressibility and apply it to molecular dynamics simulations of four globular proteins. Using additively weighted Voronoi tessellation, we decompose the solution compressibility into contributions from the protein and its hydration shells. We find that positively cross-correlated protein-water volume fluctuations account for more than half of the protein compressibility that governs the protein's pressure response, while the self correlations correspond to small (∼0.7%) fluctuations of the protein volume. The self compressibility is nearly the same as for ice, whereas the total protein compressibility, including cross correlations, is ∼45% of the bulk-water value. Taking the inhomogeneous solvent density into account, we decompose the experimentally accessible protein partial compressibility into intrinsic, hydration, and molecular exchange contributions and show how they can be computed with good statistical accuracy despite the dominant bulk-water contribution. The exchange contribution describes how the protein solution responds to an applied pressure by redistributing water molecules from lower to higher density; it is negligibly small for native proteins, but potentially important for non-native states. Because the hydration shell is an open system, the conventional closed-system compressibility definitions yield a pseudo-compressibility. We define an intrinsic shell compressibility, unaffected by occupation number fluctuations, and show that it approaches the bulk-water value exponentially with a decay "length" of one shell, less than the bulk-water compressibility correlation length. In the first hydration shell, the intrinsic compressibility is 25%-30% lower than

  20. Efficient access of compressed data

    International Nuclear Information System (INIS)

    Eggers, S.J.; Shoshani, A.

    1980-06-01

    A compression technique is presented that allows a high degree of compression but requires only logarithmic access time. The technique is a constant suppression scheme, and is most applicable to stable databases whose distribution of constants is fairly clustered. Furthermore, the repeated use of the technique permits the suppression of a multiple number of different constants. Of particular interest is the application of the constant suppression technique to databases the composite key of which is made up of an incomplete cross product of several attribute domains. The scheme for compressing the full cross product composite key is well known. This paper, however, also handles the general, incomplete case by applying the constant suppression technique in conjunction with a composite key suppression scheme

  1. Compression of Probabilistic XML Documents

    Science.gov (United States)

    Veldman, Irma; de Keijzer, Ander; van Keulen, Maurice

    Database techniques to store, query and manipulate data that contains uncertainty receives increasing research interest. Such UDBMSs can be classified according to their underlying data model: relational, XML, or RDF. We focus on uncertain XML DBMS with as representative example the Probabilistic XML model (PXML) of [10,9]. The size of a PXML document is obviously a factor in performance. There are PXML-specific techniques to reduce the size, such as a push down mechanism, that produces equivalent but more compact PXML documents. It can only be applied, however, where possibilities are dependent. For normal XML documents there also exist several techniques for compressing a document. Since Probabilistic XML is (a special form of) normal XML, it might benefit from these methods even more. In this paper, we show that existing compression mechanisms can be combined with PXML-specific compression techniques. We also show that best compression rates are obtained with a combination of PXML-specific technique with a rather simple generic DAG-compression technique.

  2. Adiabatic compression of ion rings

    International Nuclear Information System (INIS)

    Larrabee, D.A.; Lovelace, R.V.

    1982-01-01

    A study has been made of the compression of collisionless ion rings in an increasing external magnetic field, B/sub e/ = zB/sub e/(t), by numerically implementing a previously developed kinetic theory of ring compression. The theory is general in that there is no limitation on the ring geometry or the compression ratio, lambdaequivalentB/sub e/ (final)/B/sub e/ (initial)> or =1. However, the motion of a single particle in an equilibrium is assumed to be completely characterized by its energy H and canonical angular momentum P/sub theta/ with the absence of a third constant of the motion. The present computational work assumes that plasma currents are negligible, as is appropriate for a low-temperature collisional plasma. For a variety of initial ring geometries and initial distribution functions (having a single value of P/sub theta/), it is found that the parameters for ''fat'', small aspect ratio rings follow general scaling laws over a large range of compression ratios, 1 3 : The ring radius varies as lambda/sup -1/2/; the average single particle energy as lambda/sup 0.72/; the root mean square energy spread as lambda/sup 1.1/; and the total current as lambda/sup 0.79/. The field reversal parameter is found to saturate at values typically between 2 and 3. For large compression ratios the current density is found to ''hollow out''. This hollowing tends to improve the interchange stability of an embedded low β plasma. The implications of these scaling laws for fusion reactor systems are discussed

  3. Limiting density ratios in piston-driven compressions

    International Nuclear Information System (INIS)

    Lee, S.

    1985-07-01

    By using global energy and pressure balance applied to a shock model it is shown that for a piston-driven fast compression, the maximum compression ratio is not dependent on the absolute magnitude of the piston power, but rather on the power pulse shape. Specific cases are considered and a maximum density compression ratio of 27 is obtained for a square-pulse power compressing a spherical pellet with specific heat ratio of 5/3. Double pulsing enhances the density compression ratio to 1750 in the case of linearly rising compression pulses. Using this method further enhancement by multiple pulsing becomes obvious. (author)

  4. [Application value of magnetic compression anastomosis in digestive tract reconstruction].

    Science.gov (United States)

    Du, Xilin; Fan, Chao; Zhang, Hongke; Lu, Jianguo

    2014-05-01

    Magnetic compression anastomosis can compress tissues together and restore the continuity. Magnetic compression anastomosis mainly experienced three stages: magnetic ring, magnetic ring and column, and smart self-assembling magnets for endoscopy (SAMSEN). Nowadays, the magnetic compression anastomosis has been applied in vascular and different digestive tract surgeries, especially for complex surgery, such as anastomotic stenosis of biliary ducts after liver transplantation or congenital esophageal stenosis. Although only case reports are available at present, the advantages of the magnetic compression anastomosis includes lower cost, simplicity, individualization, good efficacy, safety, and minimally invasiveness. We are building a better technical platform to make magnetic compression anastomosis more advanced and popularized.

  5. A Compressive Superresolution Display

    KAUST Repository

    Heide, Felix; Gregson, James; Wetzstein, Gordon; Raskar, Ramesh; Heidrich, Wolfgang

    2014-01-01

    In this paper, we introduce a new compressive display architecture for superresolution image presentation that exploits co-design of the optical device configuration and compressive computation. Our display allows for superresolution, HDR, or glasses-free 3D presentation.

  6. A Compressive Superresolution Display

    KAUST Repository

    Heide, Felix

    2014-06-22

    In this paper, we introduce a new compressive display architecture for superresolution image presentation that exploits co-design of the optical device configuration and compressive computation. Our display allows for superresolution, HDR, or glasses-free 3D presentation.

  7. Waves and compressible flow

    CERN Document Server

    Ockendon, Hilary

    2016-01-01

    Now in its second edition, this book continues to give readers a broad mathematical basis for modelling and understanding the wide range of wave phenomena encountered in modern applications.  New and expanded material includes topics such as elastoplastic waves and waves in plasmas, as well as new exercises.  Comprehensive collections of models are used to illustrate the underpinning mathematical methodologies, which include the basic ideas of the relevant partial differential equations, characteristics, ray theory, asymptotic analysis, dispersion, shock waves, and weak solutions. Although the main focus is on compressible fluid flow, the authors show how intimately gasdynamic waves are related to wave phenomena in many other areas of physical science.   Special emphasis is placed on the development of physical intuition to supplement and reinforce analytical thinking. Each chapter includes a complete set of carefully prepared exercises, making this a suitable textbook for students in applied mathematics, ...

  8. Microbunching and RF Compression

    International Nuclear Information System (INIS)

    Venturini, M.; Migliorati, M.; Ronsivalle, C.; Ferrario, M.; Vaccarezza, C.

    2010-01-01

    Velocity bunching (or RF compression) represents a promising technique complementary to magnetic compression to achieve the high peak current required in the linac drivers for FELs. Here we report on recent progress aimed at characterizing the RF compression from the point of view of the microbunching instability. We emphasize the development of a linear theory for the gain function of the instability and its validation against macroparticle simulations that represents a useful tool in the evaluation of the compression schemes for FEL sources.

  9. The Evaluating of the possibility and adopting and applying of the international external auditing standards and it's suitability with the professional and legal environment in the State of Iraq

    Directory of Open Access Journals (Sweden)

    Fedaa Abd Almajid Sabbar Alaraji

    2017-12-01

    Full Text Available The external audit profession in Iraq suffers from problems and weakness in the profession, the most important of which is the of the profession of auditing system and monitoring auditing (external audit which is utilized in Iraq a now. And the failure to keep pace with developments and economic changes in the countries of the world, including Iraq, The current our study is aim to diagnosis and determine of most important of problems and Barriers which is suffer for it profession of external audit in Iraq. Our study is achieve many conclusions the most important,the suffering of the profession of external auditing in Iraq of many problems such as government intervention in the management of the profession, Also the study reached several recommendation and the most important work to develop the profession in Iraq based on international standards of external auditing which are considered guide for development.

  10. Compression for radiological images

    Science.gov (United States)

    Wilson, Dennis L.

    1992-07-01

    The viewing of radiological images has peculiarities that must be taken into account in the design of a compression technique. The images may be manipulated on a workstation to change the contrast, to change the center of the brightness levels that are viewed, and even to invert the images. Because of the possible consequences of losing information in a medical application, bit preserving compression is used for the images used for diagnosis. However, for archiving the images may be compressed to 10 of their original size. A compression technique based on the Discrete Cosine Transform (DCT) takes the viewing factors into account by compressing the changes in the local brightness levels. The compression technique is a variation of the CCITT JPEG compression that suppresses the blocking of the DCT except in areas of very high contrast.

  11. Limpeza da superfície de corte de rebolos por um sistema de ar comprimido na retificação cilíndrica externa de mergulho de materiais cerâmicos refrigerados com a técnica da mínima quantidade de lubrificante (MQL Grinding wheel surface cleaning using a compressed air system, in external plunge grinding of ceramics using the minimum quantity lubricant (MQL technique

    Directory of Open Access Journals (Sweden)

    E. C. Bianchi

    2012-06-01

    to diminish the amounts applied, due to some problems it may cause. The cost of the final product enhances considerably with the application of cutting fluids; they are environmentally hazardous substances, and the cause of many illnesses to the people involved. In this case, industries, universities and research centers are prompted to research alternative methods which are less harmful to the environment. Between these arises the minimum quantity lubricant (MQL technique, however having also its disadvantages, like the formation of a grout on wheel surface, which generates higher surface roughness on the workpiece. Aiming to minimize the problems concerning this grout, compressed air jets can be applied in order to clean the abrasive tool, which is the subject of the present work. This study aims to analyze some output variables of the external plunge grinding as surface roughness and roundness errors. Using the obtained results, it is intended to study MQL technique, aiming its improvement through the surface cleaning of the grinding wheel by compressed air jets.

  12. Optimisation algorithms for ECG data compression.

    Science.gov (United States)

    Haugland, D; Heber, J G; Husøy, J H

    1997-07-01

    The use of exact optimisation algorithms for compressing digital electrocardiograms (ECGs) is demonstrated. As opposed to traditional time-domain methods, which use heuristics to select a small subset of representative signal samples, the problem of selecting the subset is formulated in rigorous mathematical terms. This approach makes it possible to derive algorithms guaranteeing the smallest possible reconstruction error when a bounded selection of signal samples is interpolated. The proposed model resembles well-known network models and is solved by a cubic dynamic programming algorithm. When applied to standard test problems, the algorithm produces a compressed representation for which the distortion is about one-half of that obtained by traditional time-domain compression techniques at reasonable compression ratios. This illustrates that, in terms of the accuracy of decoded signals, existing time-domain heuristics for ECG compression may be far from what is theoretically achievable. The paper is an attempt to bridge this gap.

  13. Stress analysis of shear/compression test

    International Nuclear Information System (INIS)

    Nishijima, S.; Okada, T.; Ueno, S.

    1997-01-01

    Stress analysis has been made on the glass fiber reinforced plastics (GFRP) subjected to the combined shear and compression stresses by means of finite element method. The two types of experimental set up were analyzed, that is parallel and series method where the specimen were compressed by tilted jigs which enable to apply the combined stresses, to the specimen. Modified Tsai-Hill criterion was employed to judge the failure under the combined stresses that is the shear strength under the compressive stress. The different failure envelopes were obtained between the two set ups. In the parallel system the shear strength once increased with compressive stress then decreased. On the contrary in the series system the shear strength decreased monotonicly with compressive stress. The difference is caused by the different stress distribution due to the different constraint conditions. The basic parameters which control the failure under the combined stresses will be discussed

  14. Radiological Image Compression

    Science.gov (United States)

    Lo, Shih-Chung Benedict

    The movement toward digital images in radiology presents the problem of how to conveniently and economically store, retrieve, and transmit the volume of digital images. Basic research into image data compression is necessary in order to move from a film-based department to an efficient digital -based department. Digital data compression technology consists of two types of compression technique: error-free and irreversible. Error -free image compression is desired; however, present techniques can only achieve compression ratio of from 1.5:1 to 3:1, depending upon the image characteristics. Irreversible image compression can achieve a much higher compression ratio; however, the image reconstructed from the compressed data shows some difference from the original image. This dissertation studies both error-free and irreversible image compression techniques. In particular, some modified error-free techniques have been tested and the recommended strategies for various radiological images are discussed. A full-frame bit-allocation irreversible compression technique has been derived. A total of 76 images which include CT head and body, and radiographs digitized to 2048 x 2048, 1024 x 1024, and 512 x 512 have been used to test this algorithm. The normalized mean -square-error (NMSE) on the difference image, defined as the difference between the original and the reconstructed image from a given compression ratio, is used as a global measurement on the quality of the reconstructed image. The NMSE's of total of 380 reconstructed and 380 difference images are measured and the results tabulated. Three complex compression methods are also suggested to compress images with special characteristics. Finally, various parameters which would effect the quality of the reconstructed images are discussed. A proposed hardware compression module is given in the last chapter.

  15. Computer simulation of fatigue under diametrical compression

    International Nuclear Information System (INIS)

    Carmona, H. A.; Kun, F.; Andrade, J. S. Jr.; Herrmann, H. J.

    2007-01-01

    We study the fatigue fracture of disordered materials by means of computer simulations of a discrete element model. We extend a two-dimensional fracture model to capture the microscopic mechanisms relevant for fatigue and we simulate the diametric compression of a disc shape specimen under a constant external force. The model allows us to follow the development of the fracture process on the macrolevel and microlevel varying the relative influence of the mechanisms of damage accumulation over the load history and healing of microcracks. As a specific example we consider recent experimental results on the fatigue fracture of asphalt. Our numerical simulations show that for intermediate applied loads the lifetime of the specimen presents a power law behavior. Under the effect of healing, more prominent for small loads compared to the tensile strength of the material, the lifetime of the sample increases and a fatigue limit emerges below which no macroscopic failure occurs. The numerical results are in a good qualitative agreement with the experimental findings

  16. Force balancing in mammographic compression

    International Nuclear Information System (INIS)

    Branderhorst, W.; Groot, J. E. de; Lier, M. G. J. T. B. van; Grimbergen, C. A.; Neeter, L. M. F. H.; Heeten, G. J. den; Neeleman, C.

    2016-01-01

    Purpose: In mammography, the height of the image receptor is adjusted to the patient before compressing the breast. An inadequate height setting can result in an imbalance between the forces applied by the image receptor and the paddle, causing the clamped breast to be pushed up or down relative to the body during compression. This leads to unnecessary stretching of the skin and other tissues around the breast, which can make the imaging procedure more painful for the patient. The goal of this study was to implement a method to measure and minimize the force imbalance, and to assess its feasibility as an objective and reproducible method of setting the image receptor height. Methods: A trial was conducted consisting of 13 craniocaudal mammographic compressions on a silicone breast phantom, each with the image receptor positioned at a different height. The image receptor height was varied over a range of 12 cm. In each compression, the force exerted by the compression paddle was increased up to 140 N in steps of 10 N. In addition to the paddle force, the authors measured the force exerted by the image receptor and the reaction force exerted on the patient body by the ground. The trial was repeated 8 times, with the phantom remounted at a slightly different orientation and position between the trials. Results: For a given paddle force, the obtained results showed that there is always exactly one image receptor height that leads to a balance of the forces on the breast. For the breast phantom, deviating from this specific height increased the force imbalance by 9.4 ± 1.9 N/cm (6.7%) for 140 N paddle force, and by 7.1 ± 1.6 N/cm (17.8%) for 40 N paddle force. The results also show that in situations where the force exerted by the image receptor is not measured, the craniocaudal force imbalance can still be determined by positioning the patient on a weighing scale and observing the changes in displayed weight during the procedure. Conclusions: In mammographic breast

  17. A new device to noninvasively estimate the intraocular pressure produced during ocular compression

    Directory of Open Access Journals (Sweden)

    Korenfeld MS

    2016-01-01

    Full Text Available Michael S Korenfeld,1,2 David K Dueker3 1Comprehensive Eye Care, Ltd., 2Department of Ophthalmology and Visual Sciences, Washington University, Washington, MO, USA; 3Hamad Medical Corporation, Doha, Qatar Purpose: To describe a noninvasive instrument that estimates intraocular pressure during episodes of external globe compression and to demonstrate the accuracy and reliability of this device by comparing it to the intraocular pressures simultaneously and manometrically measured in cannulated eyes. Methods: A thin fluid-filled bladder was constructed from flexible and inelastic plastic sheeting and was connected to a pressure transducer with high pressure tubing. The output of the pressure transducer was sent to an amplifier and recorded. This device was validated by measuring induced pressure in the fluid-filled bladder while digital pressure was applied to one surface, and the other surface was placed directly against a human cadaver eye or in vivo pig eye. The human cadaver and in vivo pig eyes were each cannulated to provide a manometric intraocular pressure control. Results: The measurements obtained with the newly described device were within ~5% of simultaneously measured manometric intraocular pressures in both a human cadaver and in vivo pig eye model for a pressure range of ~15–100 mmHg. Conclusion: This novel noninvasive device is useful for estimating the intraocular pressure transients induced during any form of external globe compression; this is a clinical setting where no other devices can be used to estimate intraocular pressure. Keywords: glaucoma, intraocular pressure, tonometer, ocular compression

  18. Proposal of a methodology to be applied for the characterization of external exposure risk of employees in nuclear medicine services; Proposta de uma metodologia para caracterizacao de risco de exposicao externa de funcionarios de servicos de medicina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Simoes, Rafael Figueiredo Pohlmann

    2010-07-01

    Nuclear medicine procedure requires the administration of radioactive material by injection, ingestion or inhalation. After incorporation, the patient becomes a mobile source of radiation and, after their examination; they can irradiate everyone on their way out of the Nuclear Medicine Service (NMS). A group of workers in this path is considered a critical group, but there are no conviction on this classification, because there are not measurements available. Thus, workers claiming for occupationally exposed individual's (OEI) rights are common. Employers are always in a complex situation, because if they decided to undertake the individual external monitoring of the critical working groups, the Court considers all as OEI and employers are taxed. On the other hand, if they do not provide monitoring, it is impossible to prove that these workers were not exposed to effective doses higher than individual annual public's limit and they lose the actions, too. This work proposes a methodology to evaluate, using TLD environmental monitors, air kerma rate at critical staff points in a NMS. This method provides relevant information about critical groups' exposure. From these results, the clinic or hospital may prove technically, without individual monitoring of employees, the classification of areas and can estimate the maximum flow of patients in the free areas which guarantees exposures below the public individual dose limit. This methodology has been applied successfully to a private clinic in Rio de Janeiro, which operates a NMS. The only critical group that received exposure statistically different from clinic background radiation was that on the antechamber of the NMS. This is a site that should be characterized as a supervised area and the group of workers in this environment as OEI, as the estimated extrapolated annual effective dose in this position was 1.2 +- 0.7 mSv/year, above the public annual limit (1,0 mSv/year). Normalizing by the number of

  19. Compressed sensing & sparse filtering

    CERN Document Server

    Carmi, Avishy Y; Godsill, Simon J

    2013-01-01

    This book is aimed at presenting concepts, methods and algorithms ableto cope with undersampled and limited data. One such trend that recently gained popularity and to some extent revolutionised signal processing is compressed sensing. Compressed sensing builds upon the observation that many signals in nature are nearly sparse (or compressible, as they are normally referred to) in some domain, and consequently they can be reconstructed to within high accuracy from far fewer observations than traditionally held to be necessary. Apart from compressed sensing this book contains other related app

  20. The FRX-C/LSM compression experiment

    International Nuclear Information System (INIS)

    Rej, D.J.; Siemon, R.E.; Taggart, D.P.

    1989-01-01

    After two years of preparation, hardware for high-power FRC compression heating studies is now being installed onto FRX-C/LSM. FRCs will be formed and translated out of the θ-pinch source, and into a compressor where the external B-field will be increased from 0.4 to 2 T in 55 μs. The compressed FRC can then be translated into a third stage for further study. A principal experimental goal is to study FRC confinement at the high energy density, n(T/sub e/ + T/sub i/) ≤ 1.0 /times/ 10 22 keV/m 3 , associated with the large external field. Experiments are scheduled to begin in April. 11 refs., 5 figs

  1. Computer simulation of fatigue under diametrical compression

    OpenAIRE

    Carmona, H. A.; Kun, F.; Andrade Jr., J. S.; Herrmann, H. J.

    2006-01-01

    We study the fatigue fracture of disordered materials by means of computer simulations of a discrete element model. We extend a two-dimensional fracture model to capture the microscopic mechanisms relevant for fatigue, and we simulate the diametric compression of a disc shape specimen under a constant external force. The model allows to follow the development of the fracture process on the macro- and micro-level varying the relative influence of the mechanisms of damage accumulation over the ...

  2. Anisotropic Concrete Compressive Strength

    DEFF Research Database (Denmark)

    Gustenhoff Hansen, Søren; Jørgensen, Henrik Brøner; Hoang, Linh Cao

    2017-01-01

    When the load carrying capacity of existing concrete structures is (re-)assessed it is often based on compressive strength of cores drilled out from the structure. Existing studies show that the core compressive strength is anisotropic; i.e. it depends on whether the cores are drilled parallel...

  3. Experiments with automata compression

    NARCIS (Netherlands)

    Daciuk, J.; Yu, S; Daley, M; Eramian, M G

    2001-01-01

    Several compression methods of finite-state automata are presented and evaluated. Most compression methods used here are already described in the literature. However, their impact on the size of automata has not been described yet. We fill that gap, presenting results of experiments carried out on

  4. Tailoring of in-plane magnetic anisotropy in polycrystalline cobalt thin films by external stress

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Dileep, E-mail: dkumar@csr.res.in [UGC-DAE Consortium for Scientic Research, Khandwa Road, Indore 452001 (India); Singh, Sadhana [UGC-DAE Consortium for Scientic Research, Khandwa Road, Indore 452001 (India); Vishawakarma, Pramod [School of Nanotechnology, RGPV, Bhopal 462036 (India); Dev, Arun Singh; Reddy, V.R. [UGC-DAE Consortium for Scientic Research, Khandwa Road, Indore 452001 (India); Gupta, Ajay [Amity Center for Spintronic Materials, Amity University, Sector 125, Noida 201303 (India)

    2016-11-15

    Polycrystalline Co films of nominal thickness ~180 Å were deposited on intentionally curved Si substrates. Tensile and compressive stresses of 100 MPa and 150 MPa were induced in the films by relieving the curvature. It has been found that, within the elastic limit, presence of stress leads to an in-plane magnetic anisotropy in the film and its strength increases with increasing stress. Easy axis of magnetization in the films is found to be parallel/ transverse to the compressive /tensile stresses respectively. The origin of magnetic anisotropy in the stressed films is understood in terms of magneto- elastic coupling, where the stress try to align the magnetic moments in order to minimize the magneto-elastic as well as anisotropy energy. Tensile stress is also found to be responsible for the surface smoothening of the films, which is attributed to the movement of the atoms associated with the applied stress. The present work provides a possible way to tailor the magnetic anisotropy and its direction in polycrystalline and amorphous films using external stress. - Highlights: • Tensile and compressive stresses were induced in Co films by removing the bending force from the substrates after film deposition. • Controlled external mechanical stress is found to be responsible for magnetic anisotropies in amorphous and polycrystalline thin films, where crystalline anisotropy is absent. • Tensile stress leads to surface smoothening of the polycrystalline Co films.

  5. Effects of prolonged compression on the variations of haemoglobin oxygenation-assessment by spectral analysis of reflectance spectrophotometry signals

    International Nuclear Information System (INIS)

    Li, Zengyong; Tam, Eric W C; Mak, Arthur F T; Lau, Roy Y C

    2006-01-01

    The consequences of rhythmical flow motion for nutrition and the oxygen supply to tissue are largely unknown. In this study, the periodic variations of haemoglobin oxygenation in compressed and uncompressed skin were evaluated with a reflection spectrometer using an in vivo Sprague-Dawley rat model. Skin compression was induced over the trochanter area by a locally applied external pressure of 13.3 kPa (100 mmHg) via a specifically designed pneumatic indentor. A total of 19 rats were used in this study. The loading duration is 6 h per day for four consecutive days. Haemoglobin oxygenation variations were quantified using spectral analysis based on wavelets' transformation. The results found that in both compressed and uncompressed skin, periodic variations of the haemoglobin oxygenation were characterized by two frequencies in the range of 0.01-0.05 Hz and 0.15-0.4 Hz. These frequency ranges coincide with those of the frequency range of the endothelial-related metabolic and myogenic activities found in the flow motion respectively. Tissue compression following the above loading schedule induced a significant decrease in the spectral amplitudes of frequency interval 0.01-0.05 Hz during the pre-occlusion period on day 3 and day 4 as compared to that on day 1 (p 2 consumption rates of arteriolar walls. The modification of vessel wall oxygen consumption might substantially affect the available oxygen supply to the compressed tissue. This mechanism might be involved in the process leading to pressure ulcer formation

  6. Effect of Compression Garments on Physiological Responses After Uphill Running.

    Science.gov (United States)

    Struhár, Ivan; Kumstát, Michal; Králová, Dagmar Moc

    2018-03-01

    Limited practical recommendations related to wearing compression garments for athletes can be drawn from the literature at the present time. We aimed to identify the effects of compression garments on physiological and perceptual measures of performance and recovery after uphill running with different pressure and distributions of applied compression. In a random, double blinded study, 10 trained male runners undertook three 8 km treadmill runs at a 6% elevation rate, with the intensity of 75% VO2max while wearing low, medium grade compression garments and high reverse grade compression. In all the trials, compression garments were worn during 4 hours post run. Creatine kinase, measurements of muscle soreness, ankle strength of plantar/dorsal flexors and mean performance time were then measured. The best mean performance time was observed in the medium grade compression garments with the time difference being: medium grade compression garments vs. high reverse grade compression garments. A positive trend in increasing peak torque of plantar flexion (60º·s-1, 120º·s-1) was found in the medium grade compression garments: a difference between 24 and 48 hours post run. The highest pain tolerance shift in the gastrocnemius muscle was the medium grade compression garments, 24 hour post run, with the shift being +11.37% for the lateral head and 6.63% for the medial head. In conclusion, a beneficial trend in the promotion of running performance and decreasing muscle soreness within 24 hour post exercise was apparent in medium grade compression garments.

  7. Application of content-based image compression to telepathology

    Science.gov (United States)

    Varga, Margaret J.; Ducksbury, Paul G.; Callagy, Grace

    2002-05-01

    Telepathology is a means of practicing pathology at a distance, viewing images on a computer display rather than directly through a microscope. Without compression, images take too long to transmit to a remote location and are very expensive to store for future examination. However, to date the use of compressed images in pathology remains controversial. This is because commercial image compression algorithms such as JPEG achieve data compression without knowledge of the diagnostic content. Often images are lossily compressed at the expense of corrupting informative content. None of the currently available lossy compression techniques are concerned with what information has been preserved and what data has been discarded. Their sole objective is to compress and transmit the images as fast as possible. By contrast, this paper presents a novel image compression technique, which exploits knowledge of the slide diagnostic content. This 'content based' approach combines visually lossless and lossy compression techniques, judiciously applying each in the appropriate context across an image so as to maintain 'diagnostic' information while still maximising the possible compression. Standard compression algorithms, e.g. wavelets, can still be used, but their use in a context sensitive manner can offer high compression ratios and preservation of diagnostically important information. When compared with lossless compression the novel content-based approach can potentially provide the same degree of information with a smaller amount of data. When compared with lossy compression it can provide more information for a given amount of compression. The precise gain in the compression performance depends on the application (e.g. database archive or second opinion consultation) and the diagnostic content of the images.

  8. Wavelet-based audio embedding and audio/video compression

    Science.gov (United States)

    Mendenhall, Michael J.; Claypoole, Roger L., Jr.

    2001-12-01

    Watermarking, traditionally used for copyright protection, is used in a new and exciting way. An efficient wavelet-based watermarking technique embeds audio information into a video signal. Several effective compression techniques are applied to compress the resulting audio/video signal in an embedded fashion. This wavelet-based compression algorithm incorporates bit-plane coding, index coding, and Huffman coding. To demonstrate the potential of this audio embedding and audio/video compression algorithm, we embed an audio signal into a video signal and then compress. Results show that overall compression rates of 15:1 can be achieved. The video signal is reconstructed with a median PSNR of nearly 33 dB. Finally, the audio signal is extracted from the compressed audio/video signal without error.

  9. Influence of breast compression pressure on the performance of population-based mammography screening

    NARCIS (Netherlands)

    Holland, Katharina; Sechopoulos, Ioannis; Mann, Ritse M.; Den Heeten, Gerard J.; van Gils, Carla H.; Karssemeijer, Nico

    2017-01-01

    Background: In mammography, breast compression is applied to reduce the thickness of the breast. While it is widely accepted that firm breast compression is needed to ensure acceptable image quality, guidelines remain vague about how much compression should be applied during mammogram acquisition. A

  10. Capillary waves of compressible fluids

    International Nuclear Information System (INIS)

    Falk, Kerstin; Mecke, Klaus

    2011-01-01

    The interplay of thermal noise and molecular forces is responsible for surprising features of liquids on sub-micrometer lengths-in particular at interfaces. Not only does the surface tension depend on the size of an applied distortion and nanoscopic thin liquid films dewet faster than would be expected from hydrodynamics, but also the dispersion relation of capillary waves differ at the nanoscale from the familiar macroscopic behavior. Starting with the stochastic Navier-Stokes equation we study the coupling of capillary waves to acoustic surface waves which is possible in compressible fluids. We find propagating 'acoustic-capillary waves' at nanometer wavelengths where in incompressible fluids capillary waves are overdamped.

  11. Externalities of energy. Swedish implementation of the ExternE methodology

    International Nuclear Information System (INIS)

    Nilsson, Maans; Gullberg, M.

    1998-01-01

    The growing interest for developing economic instruments for efficient environmental policies has opened up a large area of multi-disciplinary research. ExternE is an example of this research, combining disciplines such as engineering, ecology, immunology and economics expertise to create new knowledge about how environmental pressures from energy production affect our nature and society. The ExternE Project aims to identify and, as far as possible quantify the externalities of energy production in Europe. The Stockholm Environment Institute has carried out a preliminary aggregation: -Coal Fuel Cycle: centred around Vaesteraas Kraftvaermeverk, Vaesteraas. This is the largest co-generation plant in Sweden, with four blocks and a maximum co-generation output of 520 MW electricity and 950 MW heat. The analysis is carried out on boiler B4. -Biomass Fuel Cycle: centred around Haendeloeverket, Norrkoeping. This plant predominately burns forestry residues, but a variety of fuels are combusted. Haendeloeverket has an installed capacity of 100 MW electricity and 375 MW heat, in a total of three boilers and two back-pressure turbines. The analysis is carried out on boiler P13. -Hydro Fuel Cycle: Klippens Kraftstation, Storuman. Built in 1990-1994, it is the youngest hydro power station in Sweden. It has been designed and built with significant efforts to account for and protect environmental values. Installed capacity is 28 MW. The environmental impact assessment from the construction of this plant is carried out, but the evaluation is still not finalized. The preliminary aggregation aimed to test whether ExternE results could be used to make estimates for the entire Swedish electricity production system. Hence, national results as well as results from other partner countries in ExternE has been applied

  12. 49 CFR 192.461 - External corrosion control: Protective coating.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Protective coating... for Corrosion Control § 192.461 External corrosion control: Protective coating. (a) Each external protective coating, whether conductive or insulating, applied for the purpose of external corrosion control...

  13. External effects and social costs of road transport

    NARCIS (Netherlands)

    Verhoef, E.T.

    1994-01-01

    The article contains a welfare economic analysis of road transport's external effects. First, we discuss the definition of external effects. Applying this definition, it is concluded that road transport activities give rise to a wide range of external costs. However, there are no external benefits

  14. Nuclear data compression and reconstruction via discrete wavelet transform

    Energy Technology Data Exchange (ETDEWEB)

    Park, Young Ryong; Cho, Nam Zin [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    Discrete Wavelet Transforms (DWTs) are recent mathematics, and begin to be used in various fields. The wavelet transform can be used to compress the signal and image due to its inherent properties. We applied the wavelet transform compression and reconstruction to the neutron cross section data. Numerical tests illustrate that the signal compression using wavelet is very effective to reduce the data saving spaces. 7 refs., 4 figs., 3 tabs. (Author)

  15. Nuclear data compression and reconstruction via discrete wavelet transform

    Energy Technology Data Exchange (ETDEWEB)

    Park, Young Ryong; Cho, Nam Zin [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1998-12-31

    Discrete Wavelet Transforms (DWTs) are recent mathematics, and begin to be used in various fields. The wavelet transform can be used to compress the signal and image due to its inherent properties. We applied the wavelet transform compression and reconstruction to the neutron cross section data. Numerical tests illustrate that the signal compression using wavelet is very effective to reduce the data saving spaces. 7 refs., 4 figs., 3 tabs. (Author)

  16. Application of Compressive Sensing to Gravitational Microlensing Experiments

    Science.gov (United States)

    Korde-Patel, Asmita; Barry, Richard K.; Mohsenin, Tinoosh

    2016-01-01

    Compressive Sensing is an emerging technology for data compression and simultaneous data acquisition. This is an enabling technique for significant reduction in data bandwidth, and transmission power and hence, can greatly benefit spaceflight instruments. We apply this process to detect exoplanets via gravitational microlensing. We experiment with various impact parameters that describe microlensing curves to determine the effectiveness and uncertainty caused by Compressive Sensing. Finally, we describe implications for spaceflight missions.

  17. Compressive laser ranging.

    Science.gov (United States)

    Babbitt, Wm Randall; Barber, Zeb W; Renner, Christoffer

    2011-12-15

    Compressive sampling has been previously proposed as a technique for sampling radar returns and determining sparse range profiles with a reduced number of measurements compared to conventional techniques. By employing modulation on both transmission and reception, compressive sensing in ranging is extended to the direct measurement of range profiles without intermediate measurement of the return waveform. This compressive ranging approach enables the use of pseudorandom binary transmit waveforms and return modulation, along with low-bandwidth optical detectors to yield high-resolution ranging information. A proof-of-concept experiment is presented. With currently available compact, off-the-shelf electronics and photonics, such as high data rate binary pattern generators and high-bandwidth digital optical modulators, compressive laser ranging can readily achieve subcentimeter resolution in a compact, lightweight package.

  18. Dynamical mechanisms for sensitive response of aperiodic firing cells to external stimulation

    International Nuclear Information System (INIS)

    Xie Yong; Xu Jianxue; Hu Sanjue; Kang Yanmei; Yang Hongjun; Duan Yubin

    2004-01-01

    An interesting phenomenon that aperiodic firing neurons have a higher sensitivity to drugs than periodic firing neurons have been reported for the chronically compressed dorsal root ganglion neurons in rats. In this study, the dynamical mechanisms for such a phenomenon are uncovered from the viewpoint of dynamical systems theory. We use the Rose-Hindmarsh neuron model to illustrate our opinions. Periodic orbit theory is introduced to characterize the dynamical behavior of aperiodic firing neurons. It is considered that bifurcations, crises and sensitive dependence of chaotic motions on control parameters can be the underlying mechanisms. And then, a similar analysis is applied to the modified Chay model describing the firing behavior of pancreatic beta cells. The same dynamical mechanisms can be obtained underlying that aperiodic firing cells are more sensitive to external stimulation than periodic firing ones. As a result, we conjecture that sensitive response of aperiodic firing cells to external stimulation is a universal property of excitable cells

  19. Hanford External Dosimetry Program

    International Nuclear Information System (INIS)

    Fix, J.J.

    1990-10-01

    This document describes the Hanford External Dosimetry Program as it is administered by Pacific Northwest Laboratory (PNL) in support of the US Department of Energy (DOE) and its Hanford contractors. Program services include administrating the Hanford personnel dosimeter processing program and ensuring that the related dosimeter data accurately reflect occupational dose received by Hanford personnel or visitors. Specific chapters of this report deal with the following subjects: personnel dosimetry organizations at Hanford and the associated DOE and contractor exposure guidelines; types, characteristics, and procurement of personnel dosimeters used at Hanford; personnel dosimeter identification, acceptance testing, accountability, and exchange; dosimeter processing and data recording practices; standard sources, calibration factors, and calibration processes (including algorithms) used for calibrating Hanford personnel dosimeters; system operating parameters required for assurance of dosimeter processing quality control; special dose evaluation methods applied for individuals under abnormal circumstances (i.e., lost results, etc.); and methods for evaluating personnel doses from nuclear accidents. 1 ref., 14 figs., 5 tabs

  20. Comparison of the effectiveness of compression stockings and layer compression systems in venous ulceration treatment

    Science.gov (United States)

    Jawień, Arkadiusz; Cierzniakowska, Katarzyna; Cwajda-Białasik, Justyna; Mościcka, Paulina

    2010-01-01

    Introduction The aim of the research was to compare the dynamics of venous ulcer healing when treated with the use of compression stockings as well as original two- and four-layer bandage systems. Material and methods A group of 46 patients suffering from venous ulcers was studied. This group consisted of 36 (78.3%) women and 10 (21.70%) men aged between 41 and 88 years (the average age was 66.6 years and the median was 67). Patients were randomized into three groups, for treatment with the ProGuide two-layer system, Profore four-layer compression, and with the use of compression stockings class II. In the case of multi-layer compression, compression ensuring 40 mmHg blood pressure at ankle level was used. Results In all patients, independently of the type of compression therapy, a few significant statistical changes of ulceration area in time were observed (Student’s t test for matched pairs, p ulceration area in each of the successive measurements was observed in patients treated with the four-layer system – on average 0.63 cm2/per week. The smallest loss of ulceration area was observed in patients using compression stockings – on average 0.44 cm2/per week. However, the observed differences were not statistically significant (Kruskal-Wallis test H = 4.45, p > 0.05). Conclusions A systematic compression therapy, applied with preliminary blood pressure of 40 mmHg, is an effective method of conservative treatment of venous ulcers. Compression stockings and prepared systems of multi-layer compression were characterized by similar clinical effectiveness. PMID:22419941

  1. Regulating multiple externalities

    DEFF Research Database (Denmark)

    Waldo, Staffan; Jensen, Frank; Nielsen, Max

    2016-01-01

    Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory instrume......Open access is a well-known externality problem in fisheries causing excess capacity and overfishing. Due to global warming, externality problems from CO2 emissions have gained increased interest. With two externality problems, a first-best optimum can be achieved by using two regulatory...

  2. Video Coding Technique using MPEG Compression Standards

    African Journals Online (AJOL)

    Akorede

    The two dimensional discrete cosine transform (2-D DCT) is an integral part of video and image compression ... solution for the optimum trade-off by applying rate-distortion theory has been ..... Int. J. the computer, the internet and management,.

  3. Transversely Compressed- and Restrained Shear Joints

    DEFF Research Database (Denmark)

    Schmidt, Jacob Wittrup; Hansen, Christian Skodborg

    2013-01-01

    Anchorage of FRP strengthening systems where the deformation perpendicular to the FRP material is restrained or a compressive force is applied on the strengthening, seems to provide ductility, increased utilization of the FRP and failure modes which can be controlled through the anchorage method....

  4. Strain-effect transistors: Theoretical study on the effects of external strain on III-nitride high-electron-mobility transistors on flexible substrates

    Energy Technology Data Exchange (ETDEWEB)

    Shervin, Shahab; Asadirad, Mojtaba [Department of Mechanical Engineering, University of Houston, Houston, Texas 77204-4006 (United States); Materials Science and Engineering Program, University of Houston, Houston, Texas 77204 (United States); Kim, Seung-Hwan; Ravipati, Srikanth; Lee, Keon-Hwa [Department of Mechanical Engineering, University of Houston, Houston, Texas 77204-4006 (United States); Bulashevich, Kirill [STR Group, Inc., Engels av. 27, P.O. Box 89, 194156, St. Petersburg (Russian Federation); Ryou, Jae-Hyun, E-mail: jryou@uh.edu [Department of Mechanical Engineering, University of Houston, Houston, Texas 77204-4006 (United States); Materials Science and Engineering Program, University of Houston, Houston, Texas 77204 (United States); Texas Center for Superconductivity at the University of Houston (TcSUH), University of Houston, Houston, Texas 77204 (United States)

    2015-11-09

    This paper presents strain-effect transistors (SETs) based on flexible III-nitride high-electron-mobility transistors (HEMTs) through theoretical calculations. We show that the electronic band structures of InAlGaN/GaN thin-film heterostructures on flexible substrates can be modified by external bending with a high degree of freedom using polarization properties of the polar semiconductor materials. Transfer characteristics of the HEMT devices, including threshold voltage and transconductance, are controlled by varied external strain. Equilibrium 2-dimensional electron gas (2DEG) is enhanced with applied tensile strain by bending the flexible structure with the concave-side down (bend-down condition). 2DEG density is reduced and eventually depleted with increasing compressive strain in bend-up conditions. The operation mode of different HEMT structures changes from depletion- to enchantment-mode or vice versa depending on the type and magnitude of external strain. The results suggest that the operation modes and transfer characteristics of HEMTs can be engineered with an optimum external bending strain applied in the device structure, which is expected to be beneficial for both radio frequency and switching applications. In addition, we show that drain currents of transistors based on flexible InAlGaN/GaN can be modulated only by external strain without applying electric field in the gate. The channel conductivity modulation that is obtained by only external strain proposes an extended functional device, gate-free SETs, which can be used in electro-mechanical applications.

  5. Comparison of changes in tidal volume associated with expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation.

    Science.gov (United States)

    Morino, Akira; Shida, Masahiro; Tanaka, Masashi; Sato, Kimihiro; Seko, Toshiaki; Ito, Shunsuke; Ogawa, Shunichi; Takahashi, Naoaki

    2015-07-01

    [Purpose] This study was designed to compare and clarify the relationship between expiratory rib cage compression and expiratory abdominal compression in patients on prolonged mechanical ventilation, with a focus on tidal volume. [Subjects and Methods] The subjects were 18 patients on prolonged mechanical ventilation, who had undergone tracheostomy. Each patient received expiratory rib cage compression and expiratory abdominal compression; the order of implementation was randomized. Subjects were positioned in a 30° lateral recumbent position, and a 2-kgf compression was applied. For expiratory rib cage compression, the rib cage was compressed unilaterally; for expiratory abdominal compression, the area directly above the navel was compressed. Tidal volume values were the actual measured values divided by body weight. [Results] Tidal volume values were as follows: at rest, 7.2 ± 1.7 mL/kg; during expiratory rib cage compression, 8.3 ± 2.1 mL/kg; during expiratory abdominal compression, 9.1 ± 2.2 mL/kg. There was a significant difference between the tidal volume during expiratory abdominal compression and that at rest. The tidal volume in expiratory rib cage compression was strongly correlated with that in expiratory abdominal compression. [Conclusion] These results indicate that expiratory abdominal compression may be an effective alternative to the manual breathing assist procedure.

  6. Breast compression in mammography: how much is enough?

    Science.gov (United States)

    Poulos, Ann; McLean, Donald; Rickard, Mary; Heard, Robert

    2003-06-01

    The amount of breast compression that is applied during mammography potentially influences image quality and the discomfort experienced. The aim of this study was to determine the relationship between applied compression force, breast thickness, reported discomfort and image quality. Participants were women attending routine breast screening by mammography at BreastScreen New South Wales Central and Eastern Sydney. During the mammographic procedure, an 'extra' craniocaudal (CC) film was taken at a reduced level of compression ranging from 10 to 30 Newtons. Breast thickness measurements were recorded for both the normal and the extra CC film. Details of discomfort experienced, cup size, menstrual status, existing breast pain and breast problems were also recorded. Radiologists were asked to compare the image quality of the normal and manipulated film. The results indicated that 24% of women did not experience a difference in thickness when the compression was reduced. This is an important new finding because the aim of breast compression is to reduce breast thickness. If breast thickness is not reduced when compression force is applied then discomfort is increased with no benefit in image quality. This has implications for mammographic practice when determining how much breast compression is sufficient. Radiologists found a decrease in contrast resolution within the fatty area of the breast between the normal and the extra CC film, confirming a decrease in image quality due to insufficient applied compression force.

  7. Deterministic Differential Properties of the Compression Function of BMW

    DEFF Research Database (Denmark)

    Guo, Jian; Thomsen, Søren Steffen

    2011-01-01

    In this paper, we give some determinstic differential properties for the compression function of SHA-3 candidate Blue Midnight Wish (tweaked version for round 2). The computational complexity is about 20 compression function calls. This applies to security parameters 0/16, 1/15, and 2/14. The eff...

  8. ExternE National Implementation Finland

    Energy Technology Data Exchange (ETDEWEB)

    Pingoud, K; Maelkki, H; Wihersaari, M; Pirilae, P [VTT Energy, Espoo (Finland); Hongisto, M [Imatran Voima Oy, Vantaa (Finland); Siitonen, S [Ekono Energy Ltd, Espoo (Finland); Johansson, M [Finnish Environment Institute, Helsinki (Finland)

    1999-07-01

    ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

  9. ExternE National Implementation Finland

    International Nuclear Information System (INIS)

    Pingoud, K.; Maelkki, H.; Wihersaari, M.; Pirilae, P.; Hongisto, M.; Siitonen, S.; Johansson, M.

    1999-01-01

    ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

  10. ExternE National Implementation Finland

    Energy Technology Data Exchange (ETDEWEB)

    Pingoud, K.; Maelkki, H.; Wihersaari, M.; Pirilae, P. [VTT Energy, Espoo (Finland); Hongisto, M. [Imatran Voima Oy, Vantaa (Finland); Siitonen, S. [Ekono Energy Ltd, Espoo (Finland); Johansson, M. [Finnish Environment Institute, Helsinki (Finland)

    1999-07-01

    ExternE National Implementation is a continuation of the ExternE Project, funded in part by the European Commission's Joule III Programme. This study is the result of the ExternE National Implementation Project for Finland. Three fuel cycles were selected for the Finnish study: coal, peat and wood-derived biomass, which together are responsible for about 40% of total electricity generation in Finland and about 75% of the non-nuclear fuel based generation. The estimated external costs or damages were dominated by the global warming (GW) impacts in the coal and peat fuel cycles, but knowledge of the true GW impacts is still uncertain. From among other impacts that were valued in monetary terms the human health damages due to airborne emissions dominated in all the three fuel cycles. Monetary valuation for ecosystem impacts is not possible using the ExternE methodology at present. The Meri-Pori power station representing the coal fuel cycle is one of the world's cleanest and most efficient coal-fired power plants with a condensing turbine. The coal is imported mainly from Poland. The estimated health damages were about 4 mECU/kWh, crop damages an order of magnitude lower and damages caused to building materials two orders of magnitude lower. The power stations of the peat and biomass fuel cycles are of CHP type, generating electricity and heat for the district heating systems of two cities. Their fuels are of domestic origin. The estimated health damages allocated to electricity generation were about 5 and 6 mECU/kWh, respectively. The estimates were case-specific and thus an generalisation of the results to the whole electricity generation in Finland is unrealistic. Despite the uncertainties and limitations of the methodology, it is a promising tool in the comparison of similar kinds of fuel cycles, new power plants and pollution abatement technologies and different plant locations with each other. (orig.)

  11. Optical pulse compression

    International Nuclear Information System (INIS)

    Glass, A.J.

    1975-01-01

    The interest in using large lasers to achieve a very short and intense pulse for generating fusion plasma has provided a strong impetus to reexamine the possibilities of optical pulse compression at high energy. Pulse compression allows one to generate pulses of long duration (minimizing damage problems) and subsequently compress optical pulses to achieve the short pulse duration required for specific applications. The ideal device for carrying out this program has not been developed. Of the two approaches considered, the Gires--Tournois approach is limited by the fact that the bandwidth and compression are intimately related, so that the group delay dispersion times the square of the bandwidth is about unity for all simple Gires--Tournois interferometers. The Treacy grating pair does not suffer from this limitation, but is inefficient because diffraction generally occurs in several orders and is limited by the problem of optical damage to the grating surfaces themselves. Nonlinear and parametric processes were explored. Some pulse compression was achieved by these techniques; however, they are generally difficult to control and are not very efficient. (U.S.)

  12. Application of digital compression techniques to optical surveillance systems

    International Nuclear Information System (INIS)

    Johnson, C.S.

    1991-01-01

    There are many benefits to handling video images electronically, however, the amount of digital data in a normal video image is a major obstacle. The solution is to remove the high frequency and redundant information in a process that is referred to as compression. Compression allows the number of digital bits required for a given image to be reduced for more efficient storage or transmission of images. The next question is how much compression can be done without impairing the image quality beyond its usefulness for a given application. This paper discusses image compression that might be applied to provide useful images in unattended nuclear facility surveillance applications

  13. External Otitis (Swimmer's Ear)

    Science.gov (United States)

    ... otitis. Fungal external otitis (otomycosis), typically caused by Aspergillus niger or Candida albicans, is less common. Boils are ... in the ear. Fungal external otitis caused by Aspergillus niger usually causes grayish black or yellow dots (called ...

  14. ExternE: Externalities of energy Vol. 2. Methodology

    International Nuclear Information System (INIS)

    Berry, J.; Holland, M.; Watkiss, P.

    1995-01-01

    This report describes the methodology used by the ExternE Project of the European Commission (DGXII) JOULE Programme for assessment of the external costs of energy. It is one of a series of reports describing analysis of nuclear, fossil and renewable fuel cycles for assessment of the externalities associated with electricity generation. Part I of the report deals with analysis of impacts, and Part II with the economic valuation of those impacts. Analysis is conducted on a marginal basis, to allow the effect of an incremental investment in a given technology to be quantified. Attention has been paid to the specificity of results with respect to the location of fuel cycle activities, the precise technologies used, and the type and source of fuel. The main advantages of this detailed approach are as follows: It takes full and proper account of the variability of impacts that might result from different power projects; It is more transparent than analysis based on hypothetically 'representative' cases for each of the different fuel cycles; It provides a framework for consistent comparison between fuel cycles. A wide variety of impacts have been considered. These include the effects of air pollution on the natural and human environment, consequences of accidents in the workplace, impacts of noise and visual intrusion on amenity, and the effects of climate change arising from the release of greenhouse gases. Wherever possible we have used the 'impact pathway' or 'damage function' approach to follow the analysis from identification of burdens (e.g. emissions) through to impact assessment and then valuation in monetary terms. This has required a detailed knowledge of the technologies involved, pollutant dispersion, analysis of effects on human and environmental health, and economics. In view of this the project brought together a multi-disciplinary team with experts from many European countries and the USA. The spatial and temporal ranges considered in the analysis are

  15. ASH External Web Portal (External Portal) -

    Data.gov (United States)

    Department of Transportation — The ASH External Web Portal is a web-based portal that provides single sign-on functionality, making the web portal a single location from which to be authenticated...

  16. Isentropic Compression of Argon

    International Nuclear Information System (INIS)

    Oona, H.; Solem, J.C.; Veeser, L.R.; Ekdahl, C.A.; Rodriquez, P.J.; Younger, S.M.; Lewis, W.; Turley, W.D.

    1997-01-01

    We are studying the transition of argon from an insulator to a conductor by compressing the frozen gas isentropically to pressures at which neighboring atomic orbitals overlap sufficiently to allow some electron motion between atoms. Argon and the other rare gases have closed electron shells and therefore remain montomic, even when they solidify. Their simple structure makes it likely that any measured change in conductivity is due to changes in the atomic structure, not in molecular configuration. As the crystal is compressed the band gap closes, allowing increased conductivity. We have begun research to determine the conductivity at high pressures, and it is our intention to determine the compression at which the crystal becomes a metal

  17. Pulsed Compression Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Roestenberg, T. [University of Twente, Enschede (Netherlands)

    2012-06-07

    The advantages of the Pulsed Compression Reactor (PCR) over the internal combustion engine-type chemical reactors are briefly discussed. Over the last four years a project concerning the fundamentals of the PCR technology has been performed by the University of Twente, Enschede, Netherlands. In order to assess the feasibility of the application of the PCR principle for the conversion methane to syngas, several fundamental questions needed to be answered. Two important questions that relate to the applicability of the PCR for any process are: how large is the heat transfer rate from a rapidly compressed and expanded volume of gas, and how does this heat transfer rate compare to energy contained in the compressed gas? And: can stable operation with a completely free piston as it is intended with the PCR be achieved?.

  18. Medullary compression syndrome

    International Nuclear Information System (INIS)

    Barriga T, L.; Echegaray, A.; Zaharia, M.; Pinillos A, L.; Moscol, A.; Barriga T, O.; Heredia Z, A.

    1994-01-01

    The authors made a retrospective study in 105 patients treated in the Radiotherapy Department of the National Institute of Neoplasmic Diseases from 1973 to 1992. The objective of this evaluation was to determine the influence of radiotherapy in patients with medullary compression syndrome in aspects concerning pain palliation and improvement of functional impairment. Treatment sheets of patients with medullary compression were revised: 32 out of 39 of patients (82%) came to hospital by their own means and continued walking after treatment, 8 out of 66 patients (12%) who came in a wheelchair or were bedridden, could mobilize by their own after treatment, 41 patients (64%) had partial alleviation of pain after treatment. In those who came by their own means and did not change their characteristics, functional improvement was observed. It is concluded that radiotherapy offers palliative benefit in patients with medullary compression syndrome. (authors). 20 refs., 5 figs., 6 tabs

  19. Stationary solution of the compressible magnetohydrodynamic equation and its stability with respect to initial disturbance

    Directory of Open Access Journals (Sweden)

    WU Renchao

    2016-06-01

    Full Text Available In this paper, we consider three dimensional compressible viscous magnetohydro dynamic equations(MHD with external potentialforce. We first derive the corresponding non-constantstationary solutions. Then we show global well-posedness of the initial value problem for the three dimensional compressible viscous magnetohydrodynamic equations, provided that rescribed initial data is close to the stationary solution.

  20. Mechanical response of common millet (Panicum miliaceum) seeds under quasi-static compression: Experiments and modeling.

    Science.gov (United States)

    Hasseldine, Benjamin P J; Gao, Chao; Collins, Joseph M; Jung, Hyun-Do; Jang, Tae-Sik; Song, Juha; Li, Yaning

    2017-09-01

    The common millet (Panicum miliaceum) seedcoat has a fascinating complex microstructure, with jigsaw puzzle-like epidermis cells articulated via wavy intercellular sutures to form a compact layer to protect the kernel inside. However, little research has been conducted on linking the microstructure details with the overall mechanical response of this interesting biological composite. To this end, an integrated experimental-numerical-analytical investigation was conducted to both characterize the microstructure and ascertain the microscale mechanical properties and to test the overall response of kernels and full seeds under macroscale quasi-static compression. Scanning electron microscopy (SEM) was utilized to examine the microstructure of the outer seedcoat and nanoindentation was performed to obtain the material properties of the seedcoat hard phase material. A multiscale computational strategy was applied to link the microstructure to the macroscale response of the seed. First, the effective anisotropic mechanical properties of the seedcoat were obtained from finite element (FE) simulations of a microscale representative volume element (RVE), which were further verified from sophisticated analytical models. Then, macroscale FE models of the individual kernel and full seed were developed. Good agreement between the compression experiments and FE simulations were obtained for both the kernel and the full seed. The results revealed the anisotropic property and the protective function of the seedcoat, and showed that the sutures of the seedcoat play an important role in transmitting and distributing loads in responding to external compression. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Generation of intense, high-energy ion pulses by magnetic compression of ion rings

    International Nuclear Information System (INIS)

    Kapetanakos, C.A.

    1981-01-01

    A system based on the magnetic compression of ion rings, for generating intense (High-current), high-energy ion pulses that are guided to a target without a metallic wall or an applied external magnetic field includes a vacuum chamber; an inverse reflex tetrode for producing a hollow ion beam within the chamber; magnetic coils for producing a magnetic field, bo, along the axis of the chamber; a disc that sharpens a magnetic cusp for providing a rotational velocity to the beam and causing the beam to rotate; first and second gate coils for producing fast-rising magnetic field gates, the gates being spaced apart, each gate modifying a corresponding magnetic mirror peak (Near and far peaks) for trapping or extracting the ions from the magnetic mirror, the ions forming a ring or layer having rotational energy; a metal liner for generating by magnetic flux compression a high, time-varying magnetic field, the time-varying magnetic field progressively increasing the kinetic energy of the ions, the magnetic field from the second gate coil decreasing the far mirror peak at the end of the compression for extracting the trapped rotating ions from the confining mirror; and a disc that sharpens a magnetic half-cusp for increasing the translational velocity of the ion beam. The system utilizes the self-magnetic field of the rotating, propagating ion beam to prevent the beam from expanding radially upon extraction

  2. MGR External Events Hazards Analysis

    International Nuclear Information System (INIS)

    Booth, L.

    1999-01-01

    The purpose and objective of this analysis is to apply an external events Hazards Analysis (HA) to the License Application Design Selection Enhanced Design Alternative 11 [(LADS EDA II design (Reference 8.32))]. The output of the HA is called a Hazards List (HL). This analysis supersedes the external hazards portion of Rev. 00 of the PHA (Reference 8.1). The PHA for internal events will also be updated to the LADS EDA II design but under a separate analysis. Like the PHA methodology, the HA methodology provides a systematic method to identify potential hazards during the 100-year Monitored Geologic Repository (MGR) operating period updated to reflect the EDA II design. The resulting events on the HL are candidates that may have potential radiological consequences as determined during Design Basis Events (DBEs) analyses. Therefore, the HL that results from this analysis will undergo further screening and analysis based on the criteria that apply during the performance of DBE analyses

  3. Internal and External Readings of Same

    DEFF Research Database (Denmark)

    Hardt, Daniel

    2016-01-01

    Same is an anaphoric element that performs a comparison, which can either be external or internal to a sentence. Hardt and Mikkelsen (2015) show that same, unlike other anaphoric expressions, imposes a parallelism constraint, and they present three types of examples showing that same...... is infelicitous in the absence of parallelism. Hardt and Mikkelsen propose an account that applies uniformly to internal and external readings; however, the evidence they present largely targets external readings – they don’t offer empirical evidence that clearly supports the uniform approach. Furthermore, Barker...... (2007) argues that internal readings must be treated differently than external readings. In this paper, I show that the parallelism effects observed by Hardt and Mikkelsen in fact apply to internal readings as well. This provides support for a uniform treatment of internal and external readings of same...

  4. Relationship between pore structure and compressive strength of ...

    Indian Academy of Sciences (India)

    J BU

    compressive strength relationship in ... He applied this equation to experimental data on gypsum plasters and ... Popovics [15] observes that this is true even for different types of ... proportions and curing ages of concrete samples are listed in table 1.

  5. Huffman-based code compression techniques for embedded processors

    KAUST Repository

    Bonny, Mohamed Talal; Henkel, Jö rg

    2010-01-01

    % for ARM and MIPS, respectively. In our compression technique, we have conducted evaluations using a representative set of applications and we have applied each technique to two major embedded processor architectures, namely ARM and MIPS. © 2010 ACM.

  6. Data compression considerations for detectors with local intelligence

    International Nuclear Information System (INIS)

    Garcia-Sciveres, M; Wang, X

    2014-01-01

    This note summarizes the outcome of discussions about how data compression considerations apply to tracking detectors with local intelligence. The method for analyzing data compression efficiency is taken from a previous publication and applied to module characteristics from the WIT2014 workshop. We explore local intelligence and coupled layer structures in the language of data compression. In this context the original intelligent tracker concept of correlating hits to find matches of interest and discard others is just a form of lossy data compression. We now explore how these features (intelligence and coupled layers) can be exploited for lossless compression, which could enable full readout at higher trigger rates than previously envisioned, or even triggerless

  7. Hybrid instrument applied to human reliability study in event of loss of external electric power in a nuclear power plant; Instrumento hibrido aplicado ao estudo da confiabilidade humana em evento de perda de energia eletrica externa em usina nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Eduardo Ferraz

    2015-04-01

    The study projects in highly complex installations involves robust modeling, supported by conceptual and mathematical tools, to carry out systematic research and structured the different risk scenarios that can lead to unwanted events from occurring equipment failures or human errors. In the context of classical modeling, the Probabilistic Safety Analysis (PSA) seeks to provide qualitative and quantitative information about the project particularity and their operational facilities, including the identification of factors or scenarios that contribute to the risk and consequent comparison options for increasing safety. In this context, the aim of the thesis is to develop a hybrid instrument (CPP-HI) innovative, from the integrated modeling techniques of Failure Mode and Effect Analysis (FMEA), concepts of Human Reliability Analysis and Probabilistic Composition of Preferences (PCP). In support of modeling and validation of the CPP-HI, a simulation was performed on a triggering event 'Loss of External Electric Power' - PEEE, in a Nuclear Power plant. The results were simulated in a virtual environment (sensitivity analysis) and are robust to the study of Human Reliability Analysis (HRA) in the context of the PSA. (author)

  8. Metastatic tumor of thoracic and lumbar spine: prospective study comparing the surgery and radiotherapy vs external immobilization with radiotherapy

    International Nuclear Information System (INIS)

    Falavigna, Asdrubal; Ioppi, Ana Elisa Empinotti; Grasselli, Juliana

    2007-01-01

    Bone metastases at the thoracic and lumbar segment of the spine are usually presented with painful sensation and medullar compression. The treatment is based on the clinical and neurological conditions of the patient and the degree of tumor invasion. In the present study, 32 patients with spinal metastasis of thoracic and lumbar segment were prospectively analyzed. These patients were treated by decompression and internal stabilization followed by radiotherapy or irradiation with external immobilization. The election of the groups was in accordance with the tumor radiotherapy sensitivity, clinical conditions, spinal stability, medullar or nerve compression and patient's decision. The Frankel scale and pain visual test were applied at the moment of diagnosis and after 1 and 6 months. The surgical group had better results with preserving the ambulation longer and significant reduction of pain.(author)

  9. The possibilities of compressed sensing based migration

    KAUST Repository

    Aldawood, Ali; Hoteit, Ibrahim; Alkhalifah, Tariq Ali

    2013-01-01

    Linearized waveform inversion or Least-square migration helps reduce migration artifacts caused by limited acquisition aperture, coarse sampling of sources and receivers, and low subsurface illumination. However, leastsquare migration, based on L2-norm minimization of the misfit function, tends to produce a smeared (smoothed) depiction of the true subsurface reflectivity. Assuming that the subsurface reflectivity distribution is a sparse signal, we use a compressed-sensing (Basis Pursuit) algorithm to retrieve this sparse distribution from a small number of linear measurements. We applied a compressed-sensing algorithm to image a synthetic fault model using dense and sparse acquisition geometries. Tests on synthetic data demonstrate the ability of compressed-sensing to produce highly resolved migrated images. We, also, studied the robustness of the Basis Pursuit algorithm in the presence of Gaussian random noise.

  10. The possibilities of compressed sensing based migration

    KAUST Repository

    Aldawood, Ali

    2013-09-22

    Linearized waveform inversion or Least-square migration helps reduce migration artifacts caused by limited acquisition aperture, coarse sampling of sources and receivers, and low subsurface illumination. However, leastsquare migration, based on L2-norm minimization of the misfit function, tends to produce a smeared (smoothed) depiction of the true subsurface reflectivity. Assuming that the subsurface reflectivity distribution is a sparse signal, we use a compressed-sensing (Basis Pursuit) algorithm to retrieve this sparse distribution from a small number of linear measurements. We applied a compressed-sensing algorithm to image a synthetic fault model using dense and sparse acquisition geometries. Tests on synthetic data demonstrate the ability of compressed-sensing to produce highly resolved migrated images. We, also, studied the robustness of the Basis Pursuit algorithm in the presence of Gaussian random noise.

  11. Compressible generalized Newtonian fluids

    Czech Academy of Sciences Publication Activity Database

    Málek, Josef; Rajagopal, K.R.

    2010-01-01

    Roč. 61, č. 6 (2010), s. 1097-1110 ISSN 0044-2275 Institutional research plan: CEZ:AV0Z20760514 Keywords : power law fluid * uniform temperature * compressible fluid Subject RIV: BJ - Thermodynamics Impact factor: 1.290, year: 2010

  12. Temporal compressive sensing systems

    Science.gov (United States)

    Reed, Bryan W.

    2017-12-12

    Methods and systems for temporal compressive sensing are disclosed, where within each of one or more sensor array data acquisition periods, one or more sensor array measurement datasets comprising distinct linear combinations of time slice data are acquired, and where mathematical reconstruction allows for calculation of accurate representations of the individual time slice datasets.

  13. Compression of Infrared images

    DEFF Research Database (Denmark)

    Mantel, Claire; Forchhammer, Søren

    2017-01-01

    best for bits-per-pixel rates below 1.4 bpp, while HEVC obtains best performance in the range 1.4 to 6.5 bpp. The compression performance is also evaluated based on maximum errors. These results also show that HEVC can achieve a precision of 1°C with an average of 1.3 bpp....

  14. Gas compression infrared generator

    International Nuclear Information System (INIS)

    Hug, W.F.

    1980-01-01

    A molecular gas is compressed in a quasi-adiabatic manner to produce pulsed radiation during each compressor cycle when the pressure and temperature are sufficiently high, and part of the energy is recovered during the expansion phase, as defined in U.S. Pat. No. 3,751,666; characterized by use of a cylinder with a reciprocating piston as a compressor

  15. Compression force behaviours: An exploration of the beliefs and values influencing the application of breast compression during screening mammography

    International Nuclear Information System (INIS)

    Murphy, Fred; Nightingale, Julie; Hogg, Peter; Robinson, Leslie; Seddon, Doreen; Mackay, Stuart

    2015-01-01

    This research project investigated the compression behaviours of practitioners during screening mammography. The study sought to provide a qualitative understanding of ‘how’ and ‘why’ practitioners apply compression force. With a clear conflict in the existing literature and little scientific evidence base to support the reasoning behind the application of compression force, this research project investigated the application of compression using a phenomenological approach. Following ethical approval, six focus group interviews were conducted at six different breast screening centres in England. A sample of 41 practitioners were interviewed within the focus groups together with six one-to-one interviews of mammography educators or clinical placement co-ordinators. The findings revealed two broad humanistic and technological categories consisting of 10 themes. The themes included client empowerment, white-lies, time for interactions, uncertainty of own practice, culture, power, compression controls, digital technology, dose audit-safety nets, numerical scales. All of these themes were derived from 28 units of significant meaning (USM). The results demonstrate a wide variation in the application of compression force, thus offering a possible explanation for the difference between practitioner compression forces found in quantitative studies. Compression force was applied in many different ways due to individual practitioner experiences and behaviour. Furthermore, the culture and the practice of the units themselves influenced beliefs and attitudes of practitioners in compression force application. The strongest recommendation to emerge from this study was the need for peer observation to enable practitioners to observe and compare their own compression force practice to that of their colleagues. The findings are significant for clinical practice in order to understand how and why compression force is applied

  16. Advances in applied mechanics

    CERN Document Server

    Wu, Theodore Y; Wu, Theodore Y

    2000-01-01

    This highly acclaimed series provides survey articles on the present state and future direction of research in important branches of applied solid and fluid mechanics. Mechanics is defined as a branch of physics that focuses on motion and on the reaction of physical systems to internal and external forces.

  17. Halftoning processing on a JPEG-compressed image

    Science.gov (United States)

    Sibade, Cedric; Barizien, Stephane; Akil, Mohamed; Perroton, Laurent

    2003-12-01

    Digital image processing algorithms are usually designed for the raw format, that is on an uncompressed representation of the image. Therefore prior to transforming or processing a compressed format, decompression is applied; then, the result of the processing application is finally re-compressed for further transfer or storage. The change of data representation is resource-consuming in terms of computation, time and memory usage. In the wide format printing industry, this problem becomes an important issue: e.g. a 1 m2 input color image, scanned at 600 dpi exceeds 1.6 GB in its raw representation. However, some image processing algorithms can be performed in the compressed-domain, by applying an equivalent operation on the compressed format. This paper is presenting an innovative application of the halftoning processing operation by screening, to be applied on JPEG-compressed image. This compressed-domain transform is performed by computing the threshold operation of the screening algorithm in the DCT domain. This algorithm is illustrated by examples for different halftone masks. A pre-sharpening operation, applied on a JPEG-compressed low quality image is also described; it allows to de-noise and to enhance the contours of this image.

  18. Lightweight, compressible and electrically conductive polyurethane sponges coated with synergistic multiwalled carbon nanotubes and graphene for piezoresistive sensors.

    Science.gov (United States)

    Ma, Zhonglei; Wei, Ajing; Ma, Jianzhong; Shao, Liang; Jiang, Huie; Dong, Diandian; Ji, Zhanyou; Wang, Qian; Kang, Songlei

    2018-04-19

    Lightweight, compressible and highly sensitive pressure/strain sensing materials are highly desirable for the development of health monitoring, wearable devices and artificial intelligence. Herein, a very simple, low-cost and solution-based approach is presented to fabricate versatile piezoresistive sensors based on conductive polyurethane (PU) sponges coated with synergistic multiwalled carbon nanotubes (MWCNTs) and graphene. These sensor materials are fabricated by convenient dip-coating layer-by-layer (LBL) electrostatic assembly followed by in situ reduction without using any complicated microfabrication processes. The resultant conductive MWCNT/RGO@PU sponges exhibit very low densities (0.027-0.064 g cm-3), outstanding compressibility (up to 75%) and high electrical conductivity benefiting from the porous PU sponges and synergistic conductive MWCNT/RGO structures. In addition, the MWCNT/RGO@PU sponges present larger relative resistance changes and superior sensing performances under external applied pressures (0-5.6 kPa) and a wide range of strains (0-75%) compared with the RGO@PU and MWCNT@PU sponges, due to the synergistic effect of multiple mechanisms: "disconnect-connect" transition of nanogaps, microcracks and fractured skeletons at low compression strain and compressive contact of the conductive skeletons at high compression strain. The electrical and piezoresistive properties of MWCNT/RGO@PU sponges are strongly associated with the dip-coating cycle, suspension concentration, and the applied pressure and strain. Fully functional applications of MWCNT/RGO@PU sponge-based piezoresistive sensors in lighting LED lamps and detecting human body movements are demonstrated, indicating their excellent potential for emerging applications such as health monitoring, wearable devices and artificial intelligence.

  19. Light-weight reference-based compression of FASTQ data.

    Science.gov (United States)

    Zhang, Yongpeng; Li, Linsen; Yang, Yanli; Yang, Xiao; He, Shan; Zhu, Zexuan

    2015-06-09

    The exponential growth of next generation sequencing (NGS) data has posed big challenges to data storage, management and archive. Data compression is one of the effective solutions, where reference-based compression strategies can typically achieve superior compression ratios compared to the ones not relying on any reference. This paper presents a lossless light-weight reference-based compression algorithm namely LW-FQZip to compress FASTQ data. The three components of any given input, i.e., metadata, short reads and quality score strings, are first parsed into three data streams in which the redundancy information are identified and eliminated independently. Particularly, well-designed incremental and run-length-limited encoding schemes are utilized to compress the metadata and quality score streams, respectively. To handle the short reads, LW-FQZip uses a novel light-weight mapping model to fast map them against external reference sequence(s) and produce concise alignment results for storage. The three processed data streams are then packed together with some general purpose compression algorithms like LZMA. LW-FQZip was evaluated on eight real-world NGS data sets and achieved compression ratios in the range of 0.111-0.201. This is comparable or superior to other state-of-the-art lossless NGS data compression algorithms. LW-FQZip is a program that enables efficient lossless FASTQ data compression. It contributes to the state of art applications for NGS data storage and transmission. LW-FQZip is freely available online at: http://csse.szu.edu.cn/staff/zhuzx/LWFQZip.

  20. Compressible Fluid Suspension Performance Testing

    National Research Council Canada - National Science Library

    Hoogterp, Francis

    2003-01-01

    ... compressible fluid suspension system that was designed and installed on the vehicle by DTI. The purpose of the tests was to evaluate the possible performance benefits of the compressible fluid suspension system...

  1. External radiation surveillance

    International Nuclear Information System (INIS)

    Antonio, E.J.

    1995-01-01

    This section of the 1994 Hanford Site Environmental Report describes how external radiation was measured, how surveys were performed, and the results of these measurements and surveys. External radiation exposure rates were measured at locations on and off the Hanford Site using thermoluminescent dosimeters (TLD). External radiation and contamination surveys were also performed with portable radiation survey instruments at locations on and around the Hanford Site

  2. External radiation surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, E.J.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report describes how external radiation was measured, how surveys were performed, and the results of these measurements and surveys. External radiation exposure rates were measured at locations on and off the Hanford Site using thermoluminescent dosimeters (TLD). External radiation and contamination surveys were also performed with portable radiation survey instruments at locations on and around the Hanford Site.

  3. Density ratios in compressions driven by radiation pressure

    International Nuclear Information System (INIS)

    Lee, S.

    1988-01-01

    It has been suggested that in the cannonball scheme of laser compression the pellet may be considered to be compressed by the 'brute force' of the radiation pressure. For such a radiation-driven compression, an energy balance method is applied to give an equation fixing the radius compression ratio K which is a key parameter for such intense compressions. A shock model is used to yield specific results. For a square-pulse driving power compressing a spherical pellet with a specific heat ratio of 5/3, a density compression ratio Γ of 27 is computed. Double (stepped) pulsing with linearly rising power enhances Γ to 1750. The value of Γ is not dependent on the absolute magnitude of the piston power, as long as this is large enough. Further enhancement of compression by multiple (stepped) pulsing becomes obvious. The enhanced compression increases the energy gain factor G for a 100 μm DT pellet driven by radiation power of 10 16 W from 6 for a square pulse power with 0.5 MJ absorbed energy to 90 for a double (stepped) linearly rising pulse with absorbed energy of 0.4 MJ assuming perfect coupling efficiency. (author)

  4. Huffman-based code compression techniques for embedded processors

    KAUST Repository

    Bonny, Mohamed Talal

    2010-09-01

    The size of embedded software is increasing at a rapid pace. It is often challenging and time consuming to fit an amount of required software functionality within a given hardware resource budget. Code compression is a means to alleviate the problem by providing substantial savings in terms of code size. In this article we introduce a novel and efficient hardware-supported compression technique that is based on Huffman Coding. Our technique reduces the size of the generated decoding table, which takes a large portion of the memory. It combines our previous techniques, Instruction Splitting Technique and Instruction Re-encoding Technique into new one called Combined Compression Technique to improve the final compression ratio by taking advantage of both previous techniques. The instruction Splitting Technique is instruction set architecture (ISA)-independent. It splits the instructions into portions of varying size (called patterns) before Huffman coding is applied. This technique improves the final compression ratio by more than 20% compared to other known schemes based on Huffman Coding. The average compression ratios achieved using this technique are 48% and 50% for ARM and MIPS, respectively. The Instruction Re-encoding Technique is ISA-dependent. It investigates the benefits of reencoding unused bits (we call them reencodable bits) in the instruction format for a specific application to improve the compression ratio. Reencoding those bits can reduce the size of decoding tables by up to 40%. Using this technique, we improve the final compression ratios in comparison to the first technique to 46% and 45% for ARM and MIPS, respectively (including all overhead that incurs). The Combined Compression Technique improves the compression ratio to 45% and 42% for ARM and MIPS, respectively. In our compression technique, we have conducted evaluations using a representative set of applications and we have applied each technique to two major embedded processor architectures

  5. Wavelet-based compression of pathological images for telemedicine applications

    Science.gov (United States)

    Chen, Chang W.; Jiang, Jianfei; Zheng, Zhiyong; Wu, Xue G.; Yu, Lun

    2000-05-01

    In this paper, we present the performance evaluation of wavelet-based coding techniques as applied to the compression of pathological images for application in an Internet-based telemedicine system. We first study how well suited the wavelet-based coding is as it applies to the compression of pathological images, since these images often contain fine textures that are often critical to the diagnosis of potential diseases. We compare the wavelet-based compression with the DCT-based JPEG compression in the DICOM standard for medical imaging applications. Both objective and subjective measures have been studied in the evaluation of compression performance. These studies are performed in close collaboration with expert pathologists who have conducted the evaluation of the compressed pathological images and communication engineers and information scientists who designed the proposed telemedicine system. These performance evaluations have shown that the wavelet-based coding is suitable for the compression of various pathological images and can be integrated well with the Internet-based telemedicine systems. A prototype of the proposed telemedicine system has been developed in which the wavelet-based coding is adopted for the compression to achieve bandwidth efficient transmission and therefore speed up the communications between the remote terminal and the central server of the telemedicine system.

  6. LZ-Compressed String Dictionaries

    OpenAIRE

    Arz, Julian; Fischer, Johannes

    2013-01-01

    We show how to compress string dictionaries using the Lempel-Ziv (LZ78) data compression algorithm. Our approach is validated experimentally on dictionaries of up to 1.5 GB of uncompressed text. We achieve compression ratios often outperforming the existing alternatives, especially on dictionaries containing many repeated substrings. Our query times remain competitive.

  7. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.

    2013-01-01

    We introduce a new compression scheme for labeled trees based on top trees [3]. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  8. Tree compression with top trees

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Landau, Gad M.

    2015-01-01

    We introduce a new compression scheme for labeled trees based on top trees. Our compression scheme is the first to simultaneously take advantage of internal repeats in the tree (as opposed to the classical DAG compression that only exploits rooted subtree repeats) while also supporting fast...

  9. Effect of Compression Garments on Physiological Responses After Uphill Running

    Directory of Open Access Journals (Sweden)

    Struhár Ivan

    2018-03-01

    Full Text Available Limited practical recommendations related to wearing compression garments for athletes can be drawn from the literature at the present time. We aimed to identify the effects of compression garments on physiological and perceptual measures of performance and recovery after uphill running with different pressure and distributions of applied compression. In a random, double blinded study, 10 trained male runners undertook three 8 km treadmill runs at a 6% elevation rate, with the intensity of 75% VO2max while wearing low, medium grade compression garments and high reverse grade compression. In all the trials, compression garments were worn during 4 hours post run. Creatine kinase, measurements of muscle soreness, ankle strength of plantar/dorsal flexors and mean performance time were then measured. The best mean performance time was observed in the medium grade compression garments with the time difference being: medium grade compression garments vs. high reverse grade compression garments. A positive trend in increasing peak torque of plantar flexion (60o·s-1, 120o·s-1 was found in the medium grade compression garments: a difference between 24 and 48 hours post run. The highest pain tolerance shift in the gastrocnemius muscle was the medium grade compression garments, 24 hour post run, with the shift being +11.37% for the lateral head and 6.63% for the medial head. In conclusion, a beneficial trend in the promotion of running performance and decreasing muscle soreness within 24 hour post exercise was apparent in medium grade compression garments.

  10. CoGI: Towards Compressing Genomes as an Image.

    Science.gov (United States)

    Xie, Xiaojing; Zhou, Shuigeng; Guan, Jihong

    2015-01-01

    Genomic science is now facing an explosive increase of data thanks to the fast development of sequencing technology. This situation poses serious challenges to genomic data storage and transferring. It is desirable to compress data to reduce storage and transferring cost, and thus to boost data distribution and utilization efficiency. Up to now, a number of algorithms / tools have been developed for compressing genomic sequences. Unlike the existing algorithms, most of which treat genomes as one-dimensional text strings and compress them based on dictionaries or probability models, this paper proposes a novel approach called CoGI (the abbreviation of Compressing Genomes as an Image) for genome compression, which transforms the genomic sequences to a two-dimensional binary image (or bitmap), then applies a rectangular partition coding algorithm to compress the binary image. CoGI can be used as either a reference-based compressor or a reference-free compressor. For the former, we develop two entropy-based algorithms to select a proper reference genome. Performance evaluation is conducted on various genomes. Experimental results show that the reference-based CoGI significantly outperforms two state-of-the-art reference-based genome compressors GReEn and RLZ-opt in both compression ratio and compression efficiency. It also achieves comparable compression ratio but two orders of magnitude higher compression efficiency in comparison with XM--one state-of-the-art reference-free genome compressor. Furthermore, our approach performs much better than Gzip--a general-purpose and widely-used compressor, in both compression speed and compression ratio. So, CoGI can serve as an effective and practical genome compressor. The source code and other related documents of CoGI are available at: http://admis.fudan.edu.cn/projects/cogi.htm.

  11. Effect of external energy on atomic, crystalline and powder ...

    Indian Academy of Sciences (India)

    Administrator

    rated by low-angle boundaries, leading to a decrease of atomic level strain ..... Fracture can only occur at defects or due to work ... slip planes and intersecting slip planes built in stress .... to an external compressive force the rather flexible elec-.

  12. Gain compression and its dependence on output power in quantum dot lasers

    Science.gov (United States)

    Zhukov, A. E.; Maximov, M. V.; Savelyev, A. V.; Shernyakov, Yu. M.; Zubov, F. I.; Korenev, V. V.; Martinez, A.; Ramdane, A.; Provost, J.-G.; Livshits, D. A.

    2013-06-01

    The gain compression coefficient was evaluated by applying the frequency modulation/amplitude modulation technique in a distributed feedback InAs/InGaAs quantum dot laser. A strong dependence of the gain compression coefficient on the output power was found. Our analysis of the gain compression within the frame of the modified well-barrier hole burning model reveals that the gain compression coefficient decreases beyond the lasing threshold, which is in a good agreement with the experimental observations.

  13. Digital cinema video compression

    Science.gov (United States)

    Husak, Walter

    2003-05-01

    The Motion Picture Industry began a transition from film based distribution and projection to digital distribution and projection several years ago. Digital delivery and presentation offers the prospect to increase the quality of the theatrical experience for the audience, reduce distribution costs to the distributors, and create new business opportunities for the theater owners and the studios. Digital Cinema also presents an opportunity to provide increased flexibility and security of the movies for the content owners and the theater operators. Distribution of content via electronic means to theaters is unlike any of the traditional applications for video compression. The transition from film-based media to electronic media represents a paradigm shift in video compression techniques and applications that will be discussed in this paper.

  14. Fingerprints in compressed strings

    DEFF Research Database (Denmark)

    Bille, Philip; Gørtz, Inge Li; Cording, Patrick Hagge

    2017-01-01

    In this paper we show how to construct a data structure for a string S of size N compressed into a context-free grammar of size n that supports efficient Karp–Rabin fingerprint queries to any substring of S. That is, given indices i and j, the answer to a query is the fingerprint of the substring S......[i,j]. We present the first O(n) space data structures that answer fingerprint queries without decompressing any characters. For Straight Line Programs (SLP) we get O(log⁡N) query time, and for Linear SLPs (an SLP derivative that captures LZ78 compression and its variations) we get O(log⁡log⁡N) query time...

  15. Method for compression molding of thermosetting plastics utilizing a temperature gradient across the plastic to cure the article

    Science.gov (United States)

    Heier, W. C. (Inventor)

    1974-01-01

    A method is described for compression molding of thermosetting plastics composition. Heat is applied to the compressed load in a mold cavity and adjusted to hold molding temperature at the interface of the cavity surface and the compressed compound to produce a thermal front. This thermal front advances into the evacuated compound at mean right angles to the compression load and toward a thermal fence formed at the opposite surface of the compressed compound.

  16. WSNs Microseismic Signal Subsection Compression Algorithm Based on Compressed Sensing

    Directory of Open Access Journals (Sweden)

    Zhouzhou Liu

    2015-01-01

    Full Text Available For wireless network microseismic monitoring and the problems of low compression ratio and high energy consumption of communication, this paper proposes a segmentation compression algorithm according to the characteristics of the microseismic signals and the compression perception theory (CS used in the transmission process. The algorithm will be collected as a number of nonzero elements of data segmented basis, by reducing the number of combinations of nonzero elements within the segment to improve the accuracy of signal reconstruction, while taking advantage of the characteristics of compressive sensing theory to achieve a high compression ratio of the signal. Experimental results show that, in the quantum chaos immune clone refactoring (Q-CSDR algorithm for reconstruction algorithm, under the condition of signal sparse degree higher than 40, to be more than 0.4 of the compression ratio to compress the signal, the mean square error is less than 0.01, prolonging the network life by 2 times.

  17. STUDYING DEFORMATIONS OF AN FLAT TRUSS STRUCTURE STATICALLY INDETERMINATED EXTERNALLY

    Directory of Open Access Journals (Sweden)

    Kirsanov Mikhail Nikolaevich

    2017-08-01

    Full Text Available A flat statically determinate parallel-chord truss structure has a cross-shaped grid and rests upon two rigid pin-bearing supports. Loads in bars are determined in a symbol form using the method of joint isolation by the computer mathematics Maple system. The peculiarity of the considered truss structure is its external static indeterminacy. In fact, all efforts and reactions of supports can be determined from the equilibrium conditions. But the inconvenience is necessary to consider the equilibrium of all the nodes of the truss. The Ritter cross-section method is not applicable to this truss structure. The sections that cut the truss into two parts and pass through the three rods, here exist only for several rods of the extreme panels. The purpose of this paper is to calculate a truss structure with a different number of panels in analytical and numerical form. Finite element calculation method with the use of software LISA 8.0 is applied. It’s noted that a truss structure is kinetically changeable when the number of spans is odd. The corresponding plan of probable velocities is given. In order to receive analytic dependence of deflection on the span number, the induction method and Maxwell-Moor formula has been applied. The operators of the compilation and solution of recurrence equations are involved in determining the general terms of the coefficient sequences. The formulas for calculation of loads in the most compressed bars of a truss structure were received.

  18. Compressed sensing electron tomography

    International Nuclear Information System (INIS)

    Leary, Rowan; Saghi, Zineb; Midgley, Paul A.; Holland, Daniel J.

    2013-01-01

    The recent mathematical concept of compressed sensing (CS) asserts that a small number of well-chosen measurements can suffice to reconstruct signals that are amenable to sparse or compressible representation. In addition to powerful theoretical results, the principles of CS are being exploited increasingly across a range of experiments to yield substantial performance gains relative to conventional approaches. In this work we describe the application of CS to electron tomography (ET) reconstruction and demonstrate the efficacy of CS–ET with several example studies. Artefacts present in conventional ET reconstructions such as streaking, blurring of object boundaries and elongation are markedly reduced, and robust reconstruction is shown to be possible from far fewer projections than are normally used. The CS–ET approach enables more reliable quantitative analysis of the reconstructions as well as novel 3D studies from extremely limited data. - Highlights: • Compressed sensing (CS) theory and its application to electron tomography (ET) is described. • The practical implementation of CS–ET is outlined and its efficacy demonstrated with examples. • High fidelity tomographic reconstruction is possible from a small number of images. • The CS–ET reconstructions can be more reliably segmented and analysed quantitatively. • CS–ET is applicable to different image content by choice of an appropriate sparsifying transform

  19. ExternE: Externalities of energy Vol. 5. Nuclear

    International Nuclear Information System (INIS)

    Dreicer, M.; Tort, V.; Manen, P.

    1995-01-01

    Since the early 1970s, there has been increased interest in the environmental impacts that are caused by the generation of electricity. The comparative risk assessment studies at that time used mainly deaths and injuries as impact indicators. By the end of the 1980s studies changed to the assessment of the costs imposed on society and the environment that were not included in the market price of the energy produced, the so-called external costs. The preliminary studies that were published set the conceptual basis, grounded in neo-classical economics, for the valuation of the health and environmental impacts that could be assessed. As a consequence of the many questions raised by the methodologies employed by these early studies, Directorate General XII (DG XII) of the Commission of the European Communities established a collaborative research programme with the United States Department of Energy to identify an appropriate methodology for this type of work. Following the completion of this collaboration, the DG XII programme has continued as the ExternE project. The main objective of the work carried out at CEPN was to develop an impact pathway methodology for the nuclear fuel cycle that would be consistent with the methodologies developed for other fuel cycles, without loosing the nuclear-specific techniques required for a proper evaluation. In this way, comparisons between the different fuel cycles would be possible. This report presents the methodology and demonstration of the results in the context of the French nuclear fuel cycle. The United States team at Oak Ridge National Laboratory has previously issued a draft report on the results of their assessment. The French fuel cycle was broken down into 8 separate stages. Reference sites and 1990s technology were chosen to represent the total nuclear fuel cycle, as it exists today. In addition, the transportation of material between the sites was considered. The facilities are assessed for routine operation, except

  20. Thermodynamic comparison of Peltier, Stirling, and vapor compression portable coolers

    International Nuclear Information System (INIS)

    Hermes, Christian J.L.; Barbosa, Jader R.

    2012-01-01

    Highlights: ► A Peltier, a Stirling, and two vapor compression refrigerators were compared. ► Tests were carried out to obtain key performance parameters of the systems. ► The overall 2nd-law efficiency was splited to take into account the internal and external irreversibilities. ► The Stirling and vapor compression refrigeration systems presented higher efficiencies. ► The thermoelectric device was not at the same efficiency level as the other coolers. -- Abstract: The present study compares the thermodynamic performance of four small-capacity portable coolers that employ different cooling technologies: thermoelectric, Stirling, and vapor compression using two different compressors (reciprocating and linear). The refrigeration systems were experimentally evaluated in a climatized chamber with controlled temperature and humidity. Tests were carried out at two different ambient temperatures (21 and 32 °C) in order to obtain key performance parameters of the systems (e.g., power consumption, cooling capacity, internal air temperature, and the hot end and cold end temperatures). These performance parameters were compared using a thermodynamic approach that splits the overall 2nd law efficiency into two terms, namely, the internal and external efficiencies. In doing so, the internal irreversibilities (e.g., friction in the working fluid in the Stirling and vapor compression machines, Joule heating and heat conduction in the thermoelectric devices of the Peltier cooler) were separated from the heat exchanger losses (external irreversibilities), allowing the comparison between different refrigeration technologies with respect to the same thermodynamic baseline.

  1. HVS-based medical image compression

    Energy Technology Data Exchange (ETDEWEB)

    Kai Xie [Institute of Image Processing and Pattern Recognition, Shanghai Jiaotong University, 200030 Shanghai (China)]. E-mail: xie_kai2001@sjtu.edu.cn; Jie Yang [Institute of Image Processing and Pattern Recognition, Shanghai Jiaotong University, 200030 Shanghai (China); Min Zhuyue [CREATIS-CNRS Research Unit 5515 and INSERM Unit 630, 69621 Villeurbanne (France); Liang Lixiao [Institute of Image Processing and Pattern Recognition, Shanghai Jiaotong University, 200030 Shanghai (China)

    2005-07-01

    Introduction: With the promotion and application of digital imaging technology in the medical domain, the amount of medical images has grown rapidly. However, the commonly used compression methods cannot acquire satisfying results. Methods: In this paper, according to the existed and stated experiments and conclusions, the lifting step approach is used for wavelet decomposition. The physical and anatomic structure of human vision is combined and the contrast sensitivity function (CSF) is introduced as the main research issue in human vision system (HVS), and then the main designing points of HVS model are presented. On the basis of multi-resolution analyses of wavelet transform, the paper applies HVS including the CSF characteristics to the inner correlation-removed transform and quantization in image and proposes a new HVS-based medical image compression model. Results: The experiments are done on the medical images including computed tomography (CT) and magnetic resonance imaging (MRI). At the same bit rate, the performance of SPIHT, with respect to the PSNR metric, is significantly higher than that of our algorithm. But the visual quality of the SPIHT-compressed image is roughly the same as that of the image compressed with our approach. Our algorithm obtains the same visual quality at lower bit rates and the coding/decoding time is less than that of SPIHT. Conclusions: The results show that under common objective conditions, our compression algorithm can achieve better subjective visual quality, and performs better than that of SPIHT in the aspects of compression ratios and coding/decoding time.

  2. HVS-based medical image compression

    International Nuclear Information System (INIS)

    Kai Xie; Jie Yang; Min Zhuyue; Liang Lixiao

    2005-01-01

    Introduction: With the promotion and application of digital imaging technology in the medical domain, the amount of medical images has grown rapidly. However, the commonly used compression methods cannot acquire satisfying results. Methods: In this paper, according to the existed and stated experiments and conclusions, the lifting step approach is used for wavelet decomposition. The physical and anatomic structure of human vision is combined and the contrast sensitivity function (CSF) is introduced as the main research issue in human vision system (HVS), and then the main designing points of HVS model are presented. On the basis of multi-resolution analyses of wavelet transform, the paper applies HVS including the CSF characteristics to the inner correlation-removed transform and quantization in image and proposes a new HVS-based medical image compression model. Results: The experiments are done on the medical images including computed tomography (CT) and magnetic resonance imaging (MRI). At the same bit rate, the performance of SPIHT, with respect to the PSNR metric, is significantly higher than that of our algorithm. But the visual quality of the SPIHT-compressed image is roughly the same as that of the image compressed with our approach. Our algorithm obtains the same visual quality at lower bit rates and the coding/decoding time is less than that of SPIHT. Conclusions: The results show that under common objective conditions, our compression algorithm can achieve better subjective visual quality, and performs better than that of SPIHT in the aspects of compression ratios and coding/decoding time

  3. Lossless quantum data compression and variable-length coding

    International Nuclear Information System (INIS)

    Bostroem, Kim; Felbinger, Timo

    2002-01-01

    In order to compress quantum messages without loss of information it is necessary to allow the length of the encoded messages to vary. We develop a general framework for variable-length quantum messages in close analogy to the classical case and show that lossless compression is only possible if the message to be compressed is known to the sender. The lossless compression of an ensemble of messages is bounded from below by its von-Neumann entropy. We show that it is possible to reduce the number of qbits passing through a quantum channel even below the von Neumann entropy by adding a classical side channel. We give an explicit communication protocol that realizes lossless and instantaneous quantum data compression and apply it to a simple example. This protocol can be used for both online quantum communication and storage of quantum data

  4. Drift Compression and Final Focus Options for Heavy Ion Fusion

    International Nuclear Information System (INIS)

    Hong Qin; Davidson, Ronald C.; Barnard, John J.; Lee, Edward P.

    2005-01-01

    A drift compression and final focus lattice for heavy ion beams should focus the entire beam pulse onto the same focal spot on the target. We show that this requirement implies that the drift compression design needs to satisfy a self-similar symmetry condition. For un-neutralized beams, the Lie symmetry group analysis is applied to the warm-fluid model to systematically derive the self-similar drift compression solutions. For neutralized beams, the 1-D Vlasov equation is solved explicitly, and families of self-similar drift compression solutions are constructed. To compensate for the deviation from the self-similar symmetry condition due to the transverse emittance, four time-dependent magnets are introduced in the upstream of the drift compression such that the entire beam pulse can be focused onto the same focal spot

  5. Biomedical sensor design using analog compressed sensing

    Science.gov (United States)

    Balouchestani, Mohammadreza; Krishnan, Sridhar

    2015-05-01

    The main drawback of current healthcare systems is the location-specific nature of the system due to the use of fixed/wired biomedical sensors. Since biomedical sensors are usually driven by a battery, power consumption is the most important factor determining the life of a biomedical sensor. They are also restricted by size, cost, and transmission capacity. Therefore, it is important to reduce the load of sampling by merging the sampling and compression steps to reduce the storage usage, transmission times, and power consumption in order to expand the current healthcare systems to Wireless Healthcare Systems (WHSs). In this work, we present an implementation of a low-power biomedical sensor using analog Compressed Sensing (CS) framework for sparse biomedical signals that addresses both the energy and telemetry bandwidth constraints of wearable and wireless Body-Area Networks (BANs). This architecture enables continuous data acquisition and compression of biomedical signals that are suitable for a variety of diagnostic and treatment purposes. At the transmitter side, an analog-CS framework is applied at the sensing step before Analog to Digital Converter (ADC) in order to generate the compressed version of the input analog bio-signal. At the receiver side, a reconstruction algorithm based on Restricted Isometry Property (RIP) condition is applied in order to reconstruct the original bio-signals form the compressed bio-signals with high probability and enough accuracy. We examine the proposed algorithm with healthy and neuropathy surface Electromyography (sEMG) signals. The proposed algorithm achieves a good level for Average Recognition Rate (ARR) at 93% and reconstruction accuracy at 98.9%. In addition, The proposed architecture reduces total computation time from 32 to 11.5 seconds at sampling-rate=29 % of Nyquist rate, Percentage Residual Difference (PRD)=26 %, Root Mean Squared Error (RMSE)=3 %.

  6. Incompressible limit of compressible Navier-Stokes equations

    International Nuclear Information System (INIS)

    Bessaih, H.

    1994-01-01

    In this paper we study the system which describes the motion of compressible viscous fluid in a bounded domain Ω of R 3 . When we introduce a parameter λ, that is the inverse of the Mach number, we prove, under small initial data and external force (for barotropic flows), that the solution of Navier-Stokes equations is the incompressible limit of the solution of compressible Navier-Stokes equations, as the Mach number becomes small. For this, we show the existence of a solution verifying estimates independent of λ. Compactness argument allow us to pass to the limit on λ in the nonlinear terms. (author). 17 refs

  7. Combined rankine and vapor compression cycles

    Science.gov (United States)

    Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

    2005-04-19

    An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

  8. [External cephalic version].

    Science.gov (United States)

    Navarro-Santana, B; Duarez-Coronado, M; Plaza-Arranz, J

    2016-08-01

    To analyze the rate of successful external cephalic versions in our center and caesarean sections that would be avoided with the use of external cephalic versions. From January 2012 to March 2016 external cephalic versions carried out at our center, which were a total of 52. We collected data about female age, gestational age at the time of the external cephalic version, maternal body mass index (BMI), fetal variety and situation, fetal weight, parity, location of the placenta, amniotic fluid index (ILA), tocolysis, analgesia, and newborn weight at birth, minor adverse effects (dizziness, hypotension and maternal pain) and major adverse effects (tachycardia, bradycardia, decelerations and emergency cesarean section). 45% of the versions were unsuccessful and 55% were successful. The percentage of successful vaginal delivery in versions was 84% (4% were instrumental) and 15% of caesarean sections. With respect to the variables studied, only significant differences in birth weight were found; suggesting that birth weight it is related to the outcome of external cephalic version. Probably we did not find significant differences due to the number of patients studied. For women with breech presentation, we recommend external cephalic version before the expectant management or performing a cesarean section. The external cephalic version increases the proportion of fetuses in cephalic presentation and also decreases the rate of caesarean sections.

  9. Piezosurgery in External Dacryocystorhinostomy.

    Science.gov (United States)

    Czyz, Craig N; Fowler, Amy M; Dutton, Jonathan J; Cahill, Kenneth V; Foster, Jill A; Hill, Robert H; Everman, Kelly R; Nabavi, Cameron B

    Dacryocystorhinostomy (DCR) can be performed via an external or endoscopic approach. The use of ultrasonic or piezosurgery has been well described for endoscopic DCRs but is lacking for external DCRs. This study presents a case series of external DCRs performed using piezosurgery evaluating results and complications. Prospective, consecutive case series of patients undergoing primary external DCR for lacrimal drainage insufficiency. A standard external DCR technique was used using 1 of 2 piezosurgery systems for all bone incision. All patients received silicone intubation to the lacrimal system. Surgical outcome was measured in terms of patient-reported epiphora as follows: 1) complete resolution, 2) improvement >50%, 3) improvement 50% improvement. There were 4 patients (7%) who had <50% improvement. There was 1 (2%) intraoperative complication and 2 (4%) postoperative complications recorded. Piezourgery is a viable modality for performing external DCRs. The lack of surgical complications shows a potential for decreased soft tissues damage. The surgical success rate based on patient-reported epiphora is similar to those published for mechanical external DCRs. This modality may benefit the novice surgeon in the reduction of soft and mucosal tissue damage.

  10. Impedance study of membrane dehydration and compression in proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Le Canut, Jean-Marc; Latham, Ruth; Merida, Walter; Harrington, David A. [Institute for Integrated Energy Systems, University of Victoria, Victoria, British Columbia (Canada)

    2009-07-15

    Electrochemical impedance spectroscopy (EIS) is used to measure drying and rehydration in proton exchange membrane fuel cells running under load. The hysteresis between forward and backward acquisition of polarization curves is shown to be largely due to changes in the membrane resistance. Drying tests are carried out with hydrogen and simulated reformate (hydrogen and carbon dioxide), and quasi-periodic drying and rehydration conditions are studied. The membrane hydration state is clearly linked to the high-frequency arc in the impedance spectrum, which increases in size for dry conditions indicating an increase in membrane resistance. Changes in impedance spectra as external compression is applied to the cell assembly show that EIS can separate membrane and interfacial effects, and that changes in membrane resistance dominate. Reasons for the presence of a capacitance in parallel with the membrane resistance are discussed. (author)

  11. Advanced exergy analysis of a R744 booster refrigeration system with parallel compression

    DEFF Research Database (Denmark)

    Gullo, Paride; Elmegaard, Brian; Cortella, Giovanni

    2016-01-01

    In this paper, the advanced exergy analysis was applied to a R744 booster refrigeration system with parallel compression taking into account the design external temperatures of 25 degrees C and 35 degrees C, as well as the operating conditions of a conventional European supermarket. The global...... efficiencies of all the chosen compressors were extrapolated from some manufactures' data and appropriated optimization procedures of the performance of the investigated solution were implemented.According to the results associated with the conventional exergy evaluation, the gas cooler/condenser, the HS (high...... stage) compressor and the MT (medium temperature) display cabinet exhibited the highest enhancement potential. The further splitting of their corresponding exergy destruction rates into their different parts and the following assessment of the interactions among the components allowed figuring out...

  12. Compressive Transient Imaging

    KAUST Repository

    Sun, Qilin

    2017-04-01

    High resolution transient/3D imaging technology is of high interest in both scientific research and commercial application. Nowadays, all of the transient imaging methods suffer from low resolution or time consuming mechanical scanning. We proposed a new method based on TCSPC and Compressive Sensing to achieve a high resolution transient imaging with a several seconds capturing process. Picosecond laser sends a serious of equal interval pulse while synchronized SPAD camera\\'s detecting gate window has a precise phase delay at each cycle. After capturing enough points, we are able to make up a whole signal. By inserting a DMD device into the system, we are able to modulate all the frames of data using binary random patterns to reconstruct a super resolution transient/3D image later. Because the low fill factor of SPAD sensor will make a compressive sensing scenario ill-conditioned, We designed and fabricated a diffractive microlens array. We proposed a new CS reconstruction algorithm which is able to denoise at the same time for the measurements suffering from Poisson noise. Instead of a single SPAD senor, we chose a SPAD array because it can drastically reduce the requirement for the number of measurements and its reconstruction time. Further more, it not easy to reconstruct a high resolution image with only one single sensor while for an array, it just needs to reconstruct small patches and a few measurements. In this thesis, we evaluated the reconstruction methods using both clean measurements and the version corrupted by Poisson noise. The results show how the integration over the layers influence the image quality and our algorithm works well while the measurements suffer from non-trival Poisson noise. It\\'s a breakthrough in the areas of both transient imaging and compressive sensing.

  13. Fast Compressive Tracking.

    Science.gov (United States)

    Zhang, Kaihua; Zhang, Lei; Yang, Ming-Hsuan

    2014-10-01

    It is a challenging task to develop effective and efficient appearance models for robust object tracking due to factors such as pose variation, illumination change, occlusion, and motion blur. Existing online tracking algorithms often update models with samples from observations in recent frames. Despite much success has been demonstrated, numerous issues remain to be addressed. First, while these adaptive appearance models are data-dependent, there does not exist sufficient amount of data for online algorithms to learn at the outset. Second, online tracking algorithms often encounter the drift problems. As a result of self-taught learning, misaligned samples are likely to be added and degrade the appearance models. In this paper, we propose a simple yet effective and efficient tracking algorithm with an appearance model based on features extracted from a multiscale image feature space with data-independent basis. The proposed appearance model employs non-adaptive random projections that preserve the structure of the image feature space of objects. A very sparse measurement matrix is constructed to efficiently extract the features for the appearance model. We compress sample images of the foreground target and the background using the same sparse measurement matrix. The tracking task is formulated as a binary classification via a naive Bayes classifier with online update in the compressed domain. A coarse-to-fine search strategy is adopted to further reduce the computational complexity in the detection procedure. The proposed compressive tracking algorithm runs in real-time and performs favorably against state-of-the-art methods on challenging sequences in terms of efficiency, accuracy and robustness.

  14. SeqCompress: an algorithm for biological sequence compression.

    Science.gov (United States)

    Sardaraz, Muhammad; Tahir, Muhammad; Ikram, Ataul Aziz; Bajwa, Hassan

    2014-10-01

    The growth of Next Generation Sequencing technologies presents significant research challenges, specifically to design bioinformatics tools that handle massive amount of data efficiently. Biological sequence data storage cost has become a noticeable proportion of total cost in the generation and analysis. Particularly increase in DNA sequencing rate is significantly outstripping the rate of increase in disk storage capacity, which may go beyond the limit of storage capacity. It is essential to develop algorithms that handle large data sets via better memory management. This article presents a DNA sequence compression algorithm SeqCompress that copes with the space complexity of biological sequences. The algorithm is based on lossless data compression and uses statistical model as well as arithmetic coding to compress DNA sequences. The proposed algorithm is compared with recent specialized compression tools for biological sequences. Experimental results show that proposed algorithm has better compression gain as compared to other existing algorithms. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Comparative data compression techniques and multi-compression results

    International Nuclear Information System (INIS)

    Hasan, M R; Ibrahimy, M I; Motakabber, S M A; Ferdaus, M M; Khan, M N H

    2013-01-01

    Data compression is very necessary in business data processing, because of the cost savings that it offers and the large volume of data manipulated in many business applications. It is a method or system for transmitting a digital image (i.e., an array of pixels) from a digital data source to a digital data receiver. More the size of the data be smaller, it provides better transmission speed and saves time. In this communication, we always want to transmit data efficiently and noise freely. This paper will provide some compression techniques for lossless text type data compression and comparative result of multiple and single compression, that will help to find out better compression output and to develop compression algorithms

  16. Analysis by compression

    DEFF Research Database (Denmark)

    Meredith, David

    MEL is a geometric music encoding language designed to allow for musical objects to be encoded parsimoniously as sets of points in pitch-time space, generated by performing geometric transformations on component patterns. MEL has been implemented in Java and coupled with the SIATEC pattern...... discovery algorithm to allow for compact encodings to be generated automatically from in extenso note lists. The MEL-SIATEC system is founded on the belief that music analysis and music perception can be modelled as the compression of in extenso descriptions of musical objects....

  17. Compressive Fatigue in Wood

    DEFF Research Database (Denmark)

    Clorius, Christian Odin; Pedersen, Martin Bo Uhre; Hoffmeyer, Preben

    1999-01-01

    An investigation of fatigue failure in wood subjected to load cycles in compression parallel to grain is presented. Small clear specimens of spruce are taken to failure in square wave formed fatigue loading at a stress excitation level corresponding to 80% of the short term strength. Four...... frequencies ranging from 0.01 Hz to 10 Hz are used. The number of cycles to failure is found to be a poor measure of the fatigue performance of wood. Creep, maximum strain, stiffness and work are monitored throughout the fatigue tests. Accumulated creep is suggested identified with damage and a correlation...

  18. Compressive full waveform lidar

    Science.gov (United States)

    Yang, Weiyi; Ke, Jun

    2017-05-01

    To avoid high bandwidth detector, fast speed A/D converter, and large size memory disk, a compressive full waveform LIDAR system, which uses a temporally modulated laser instead of a pulsed laser, is studied in this paper. Full waveform data from NEON (National Ecological Observatory Network) are used. Random binary patterns are used to modulate the source. To achieve 0.15 m ranging resolution, a 100 MSPS A/D converter is assumed to make measurements. SPIRAL algorithm with canonical basis is employed when Poisson noise is considered in the low illuminated condition.

  19. Metal Hydride Compression

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Terry A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Bowman, Robert [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smith, Barton [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Anovitz, Lawrence [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jensen, Craig [Hawaii Hydrogen Carriers LLC, Honolulu, HI (United States)

    2017-07-01

    Conventional hydrogen compressors often contribute over half of the cost of hydrogen stations, have poor reliability, and have insufficient flow rates for a mature FCEV market. Fatigue associated with their moving parts including cracking of diaphragms and failure of seal leads to failure in conventional compressors, which is exacerbated by the repeated starts and stops expected at fueling stations. Furthermore, the conventional lubrication of these compressors with oil is generally unacceptable at fueling stations due to potential fuel contamination. Metal hydride (MH) technology offers a very good alternative to both conventional (mechanical) and newly developed (electrochemical, ionic liquid pistons) methods of hydrogen compression. Advantages of MH compression include simplicity in design and operation, absence of moving parts, compactness, safety and reliability, and the possibility to utilize waste industrial heat to power the compressor. Beyond conventional H2 supplies of pipelines or tanker trucks, another attractive scenario is the on-site generating, pressuring and delivering pure H2 at pressure (≥ 875 bar) for refueling vehicles at electrolysis, wind, or solar generating production facilities in distributed locations that are too remote or widely distributed for cost effective bulk transport. MH hydrogen compression utilizes a reversible heat-driven interaction of a hydride-forming metal alloy with hydrogen gas to form the MH phase and is a promising process for hydrogen energy applications [1,2]. To deliver hydrogen continuously, each stage of the compressor must consist of multiple MH beds with synchronized hydrogenation & dehydrogenation cycles. Multistage pressurization allows achievement of greater compression ratios using reduced temperature swings compared to single stage compressors. The objectives of this project are to investigate and demonstrate on a laboratory scale a two-stage MH hydrogen (H2) gas compressor with a

  20. Performance evaluation of breast image compression techniques

    Energy Technology Data Exchange (ETDEWEB)

    Anastassopoulos, G; Lymberopoulos, D [Wire Communications Laboratory, Electrical Engineering Department, University of Patras, Greece (Greece); Panayiotakis, G; Bezerianos, A [Medical Physics Department, School of Medicine, University of Patras, Greece (Greece)

    1994-12-31

    Novel diagnosis orienting tele working systems manipulate, store, and process medical data through real time communication - conferencing schemes. One of the most important factors affecting the performance of these systems is image handling. Compression algorithms can be applied to the medical images, in order to minimize : a) the volume of data to be stored in the database, b) the demanded bandwidth from the network, c) the transmission costs, and to minimize the speed of the transmitted data. In this paper an estimation of all the factors of the process that affect the presentation of breast images is made, from the time the images are produced from a modality, till the compressed images are stored, or transmitted in a Broadband network (e.g. B-ISDN). The images used were scanned images of the TOR(MAX) Leeds breast phantom, as well as typical breast images. A comparison of seven compression techniques has been done, based on objective criteria such as Mean Square Error (MSE), resolution, contrast, etc. The user can choose the appropriate compression ratio in order to achieve the desired image quality. (authors). 12 refs, 4 figs.

  1. Artificial Neural Network Model for Predicting Compressive

    Directory of Open Access Journals (Sweden)

    Salim T. Yousif

    2013-05-01

    Full Text Available   Compressive strength of concrete is a commonly used criterion in evaluating concrete. Although testing of the compressive strength of concrete specimens is done routinely, it is performed on the 28th day after concrete placement. Therefore, strength estimation of concrete at early time is highly desirable. This study presents the effort in applying neural network-based system identification techniques to predict the compressive strength of concrete based on concrete mix proportions, maximum aggregate size (MAS, and slump of fresh concrete. Back-propagation neural networks model is successively developed, trained, and tested using actual data sets of concrete mix proportions gathered from literature.    The test of the model by un-used data within the range of input parameters shows that the maximum absolute error for model is about 20% and 88% of the output results has absolute errors less than 10%. The parametric study shows that water/cement ratio (w/c is the most significant factor  affecting the output of the model.     The results showed that neural networks has strong potential as a feasible tool for predicting compressive strength of concrete.

  2. Evaluation of Algorithms for Compressing Hyperspectral Data

    Science.gov (United States)

    Cook, Sid; Harsanyi, Joseph; Faber, Vance

    2003-01-01

    With EO-1 Hyperion in orbit NASA is showing their continued commitment to hyperspectral imaging (HSI). As HSI sensor technology continues to mature, the ever-increasing amounts of sensor data generated will result in a need for more cost effective communication and data handling systems. Lockheed Martin, with considerable experience in spacecraft design and developing special purpose onboard processors, has teamed with Applied Signal & Image Technology (ASIT), who has an extensive heritage in HSI spectral compression and Mapping Science (MSI) for JPEG 2000 spatial compression expertise, to develop a real-time and intelligent onboard processing (OBP) system to reduce HSI sensor downlink requirements. Our goal is to reduce the downlink requirement by a factor > 100, while retaining the necessary spectral and spatial fidelity of the sensor data needed to satisfy the many science, military, and intelligence goals of these systems. Our compression algorithms leverage commercial-off-the-shelf (COTS) spectral and spatial exploitation algorithms. We are currently in the process of evaluating these compression algorithms using statistical analysis and NASA scientists. We are also developing special purpose processors for executing these algorithms onboard a spacecraft.

  3. Performance evaluation of breast image compression techniques

    International Nuclear Information System (INIS)

    Anastassopoulos, G.; Lymberopoulos, D.; Panayiotakis, G.; Bezerianos, A.

    1994-01-01

    Novel diagnosis orienting tele working systems manipulate, store, and process medical data through real time communication - conferencing schemes. One of the most important factors affecting the performance of these systems is image handling. Compression algorithms can be applied to the medical images, in order to minimize : a) the volume of data to be stored in the database, b) the demanded bandwidth from the network, c) the transmission costs, and to minimize the speed of the transmitted data. In this paper an estimation of all the factors of the process that affect the presentation of breast images is made, from the time the images are produced from a modality, till the compressed images are stored, or transmitted in a Broadband network (e.g. B-ISDN). The images used were scanned images of the TOR(MAX) Leeds breast phantom, as well as typical breast images. A comparison of seven compression techniques has been done, based on objective criteria such as Mean Square Error (MSE), resolution, contrast, etc. The user can choose the appropriate compression ratio in order to achieve the desired image quality. (authors)

  4. The compression dome concept: the restorative implications.

    Science.gov (United States)

    Milicich, Graeme

    2017-01-01

    Evidence now supports the concept that the enamel on a tooth acts like a compression dome, much like the dome of a cathedral. With an overlying enamel compression dome, the underlying dentin is protected from damaging tensile forces. Disruption of a compression system leads to significant shifts in load pathways. The clinical restorative implications are significant and far-reaching. Cutting the wrong areas of a tooth exposes the underlying dentin to tensile forces that exceed natural design parameters. These forces lead to crack propagation, causing flexural pain and eventual fracture and loss of tooth structure. Improved understanding of the microanatomy of tooth structure and where it is safe to cut teeth has led to a revolution in dentistry that is known by several names, including microdentistry, minimally invasive dentistry, biomimetic dentistry, and bioemulation dentistry. These treatment concepts have developed due to a coalescence of principles of tooth microanatomy, material science, adhesive dentistry, and reinforcing techniques that, when applied together, will allow dentists to repair a compromised compression dome so that it more closely replicates the structure of the healthy tooth.

  5. Tensile and compressive failure modes of laminated composites loaded by fatigue with different mean stress

    Science.gov (United States)

    Rotem, Assa

    1990-01-01

    Laminated composite materials tend to fail differently under tensile or compressive load. Under tension, the material accumulates cracks and fiber fractures, while under compression, the material delaminates and buckles. Tensile-compressive fatigue may cause either of these failure modes depending on the specific damage occurring in the laminate. This damage depends on the stress ratio of the fatigue loading. Analysis of the fatigue behavior of the composite laminate under tension-tension, compression-compression, and tension-compression had led to the development of a fatigue envelope presentation of the failure behavior. This envelope indicates the specific failure mode for any stress ratio and number of loading cycles. The construction of the fatigue envelope is based on the applied stress-cycles to failure (S-N) curves of both tensile-tensile and compressive-compressive fatigue. Test results are presented to verify the theoretical analysis.

  6. Automated External Defibrillator

    Science.gov (United States)

    ... leads to a 10 percent reduction in survival. Training To Use an Automated External Defibrillator Learning how to use an AED and taking a CPR (cardiopulmonary resuscitation) course are helpful. However, if trained ...

  7. Energy policy and externalities

    International Nuclear Information System (INIS)

    Bertel, E.; Fraser, P.

    2002-01-01

    External costs of energy have been assessed in a number of authoritative and reliable studies based upon widely accepted methodologies such as life cycle analysis (LCA). However, although those costs are recognised by most stakeholders and decision makers, results from analytical work on externalities and LCA studies are seldom used in policy making. The International Energy Agency (IEA) and the Nuclear Energy Agency (NEA) convened a joint workshop in November 2001 to offer experts and policy makers an opportunity to present state-of-the-art results from analytical work on externalities and debate issues related to the relevance of external costs and LCA for policy-making purposes. The findings from the workshop highlight the need for further work in the field and the potential rote of international organisations like the IEA and the NEA in this context. (authors)

  8. Externally Verifiable Oblivious RAM

    Directory of Open Access Journals (Sweden)

    Gancher Joshua

    2017-04-01

    Full Text Available We present the idea of externally verifiable oblivious RAM (ORAM. Our goal is to allow a client and server carrying out an ORAM protocol to have disputes adjudicated by a third party, allowing for the enforcement of penalties against an unreliable or malicious server. We give a security definition that guarantees protection not only against a malicious server but also against a client making false accusations. We then give modifications of the Path ORAM [15] and Ring ORAM [9] protocols that meet this security definition. These protocols both have the same asymptotic runtimes as the semi-honest original versions and require the external verifier to be involved only when the client or server deviates from the protocol. Finally, we implement externally verified ORAM, along with an automated cryptocurrency contract to use as the external verifier.

  9. Free compression tube. Applications

    Science.gov (United States)

    Rusu, Ioan

    2012-11-01

    During the flight of vehicles, their propulsion energy must overcome gravity, to ensure the displacement of air masses on vehicle trajectory, to cover both energy losses from the friction between a solid surface and the air and also the kinetic energy of reflected air masses due to the impact with the flying vehicle. The flight optimization by increasing speed and reducing fuel consumption has directed research in the aerodynamics field. The flying vehicles shapes obtained through studies in the wind tunnel provide the optimization of the impact with the air masses and the airflow along the vehicle. By energy balance studies for vehicles in flight, the author Ioan Rusu directed his research in reducing the energy lost at vehicle impact with air masses. In this respect as compared to classical solutions for building flight vehicles aerodynamic surfaces which reduce the impact and friction with air masses, Ioan Rusu has invented a device which he named free compression tube for rockets, registered with the State Office for Inventions and Trademarks of Romania, OSIM, deposit f 2011 0352. Mounted in front of flight vehicles it eliminates significantly the impact and friction of air masses with the vehicle solid. The air masses come into contact with the air inside the free compression tube and the air-solid friction is eliminated and replaced by air to air friction.

  10. Photon compression in cylinders

    International Nuclear Information System (INIS)

    Ensley, D.L.

    1977-01-01

    It has been shown theoretically that intense microwave radiation is absorbed non-classically by a newly enunciated mechanism when interacting with hydrogen plasma. Fields > 1 Mg, lambda > 1 mm are within this regime. The predicted absorption, approximately P/sub rf/v/sub theta/sup e/, has not yet been experimentally confirmed. The applications of such a coupling are many. If microwave bursts approximately > 5 x 10 14 watts, 5 ns can be generated, the net generation of power from pellet fusion as well as various military applications becomes feasible. The purpose, then, for considering gas-gun photon compression is to obtain the above experimental capability by converting the gas kinetic energy directly into microwave form. Energies of >10 5 joules cm -2 and powers of >10 13 watts cm -2 are potentially available for photon interaction experiments using presently available technology. The following topics are discussed: microwave modes in a finite cylinder, injection, compression, switchout operation, and system performance parameter scaling

  11. Fingerprints in Compressed Strings

    DEFF Research Database (Denmark)

    Bille, Philip; Cording, Patrick Hagge; Gørtz, Inge Li

    2013-01-01

    The Karp-Rabin fingerprint of a string is a type of hash value that due to its strong properties has been used in many string algorithms. In this paper we show how to construct a data structure for a string S of size N compressed by a context-free grammar of size n that answers fingerprint queries...... derivative that captures LZ78 compression and its variations) we get O(loglogN) query time. Hence, our data structures has the same time and space complexity as for random access in SLPs. We utilize the fingerprint data structures to solve the longest common extension problem in query time O(logNlogℓ) and O....... That is, given indices i and j, the answer to a query is the fingerprint of the substring S[i,j]. We present the first O(n) space data structures that answer fingerprint queries without decompressing any characters. For Straight Line Programs (SLP) we get O(logN) query time, and for Linear SLPs (an SLP...

  12. Compressive sensing in medical imaging.

    Science.gov (United States)

    Graff, Christian G; Sidky, Emil Y

    2015-03-10

    The promise of compressive sensing, exploitation of compressibility to achieve high quality image reconstructions with less data, has attracted a great deal of attention in the medical imaging community. At the Compressed Sensing Incubator meeting held in April 2014 at OSA Headquarters in Washington, DC, presentations were given summarizing some of the research efforts ongoing in compressive sensing for x-ray computed tomography and magnetic resonance imaging systems. This article provides an expanded version of these presentations. Sparsity-exploiting reconstruction algorithms that have gained popularity in the medical imaging community are studied, and examples of clinical applications that could benefit from compressive sensing ideas are provided. The current and potential future impact of compressive sensing on the medical imaging field is discussed.

  13. Generalized massive optimal data compression

    Science.gov (United States)

    Alsing, Justin; Wandelt, Benjamin

    2018-05-01

    In this paper, we provide a general procedure for optimally compressing N data down to n summary statistics, where n is equal to the number of parameters of interest. We show that compression to the score function - the gradient of the log-likelihood with respect to the parameters - yields n compressed statistics that are optimal in the sense that they preserve the Fisher information content of the data. Our method generalizes earlier work on linear Karhunen-Loéve compression for Gaussian data whilst recovering both lossless linear compression and quadratic estimation as special cases when they are optimal. We give a unified treatment that also includes the general non-Gaussian case as long as mild regularity conditions are satisfied, producing optimal non-linear summary statistics when appropriate. As a worked example, we derive explicitly the n optimal compressed statistics for Gaussian data in the general case where both the mean and covariance depend on the parameters.

  14. On-Chip Neural Data Compression Based On Compressed Sensing With Sparse Sensing Matrices.

    Science.gov (United States)

    Zhao, Wenfeng; Sun, Biao; Wu, Tong; Yang, Zhi

    2018-02-01

    On-chip neural data compression is an enabling technique for wireless neural interfaces that suffer from insufficient bandwidth and power budgets to transmit the raw data. The data compression algorithm and its implementation should be power and area efficient and functionally reliable over different datasets. Compressed sensing is an emerging technique that has been applied to compress various neurophysiological data. However, the state-of-the-art compressed sensing (CS) encoders leverage random but dense binary measurement matrices, which incur substantial implementation costs on both power and area that could offset the benefits from the reduced wireless data rate. In this paper, we propose two CS encoder designs based on sparse measurement matrices that could lead to efficient hardware implementation. Specifically, two different approaches for the construction of sparse measurement matrices, i.e., the deterministic quasi-cyclic array code (QCAC) matrix and -sparse random binary matrix [-SRBM] are exploited. We demonstrate that the proposed CS encoders lead to comparable recovery performance. And efficient VLSI architecture designs are proposed for QCAC-CS and -SRBM encoders with reduced area and total power consumption.

  15. Rebound Attack on the Full LANE Compression Function

    DEFF Research Database (Denmark)

    Matusiewicz, Krystian; Naya-Plasencia, Maria; Nikolic, Ivica

    2009-01-01

    In this work, we apply the rebound attack to the AES based SHA-3 candidate Lane. The hash function Lane uses a permutation based compression function, consisting of a linear message expansion and 6 parallel lanes. In the rebound attack on Lane, we apply several new techniques to construct...... a collision for the full compression function of Lane-256 and Lane-512. Using a relatively sparse truncated differential path, we are able to solve for a valid message expansion and colliding lanes independently. Additionally, we are able to apply the inbound phase more than once by exploiting the degrees...

  16. Introduction to compressible fluid flow

    CERN Document Server

    Oosthuizen, Patrick H

    2013-01-01

    IntroductionThe Equations of Steady One-Dimensional Compressible FlowSome Fundamental Aspects of Compressible FlowOne-Dimensional Isentropic FlowNormal Shock WavesOblique Shock WavesExpansion Waves - Prandtl-Meyer FlowVariable Area FlowsAdiabatic Flow with FrictionFlow with Heat TransferLinearized Analysis of Two-Dimensional Compressible FlowsHypersonic and High-Temperature FlowsHigh-Temperature Gas EffectsLow-Density FlowsBibliographyAppendices

  17. Mammographic compression in Asian women.

    Science.gov (United States)

    Lau, Susie; Abdul Aziz, Yang Faridah; Ng, Kwan Hoong

    2017-01-01

    To investigate: (1) the variability of mammographic compression parameters amongst Asian women; and (2) the effects of reducing compression force on image quality and mean glandular dose (MGD) in Asian women based on phantom study. We retrospectively collected 15818 raw digital mammograms from 3772 Asian women aged 35-80 years who underwent screening or diagnostic mammography between Jan 2012 and Dec 2014 at our center. The mammograms were processed using a volumetric breast density (VBD) measurement software (Volpara) to assess compression force, compression pressure, compressed breast thickness (CBT), breast volume, VBD and MGD against breast contact area. The effects of reducing compression force on image quality and MGD were also evaluated based on measurement obtained from 105 Asian women, as well as using the RMI156 Mammographic Accreditation Phantom and polymethyl methacrylate (PMMA) slabs. Compression force, compression pressure, CBT, breast volume, VBD and MGD correlated significantly with breast contact area (pAsian women. The median compression force should be about 8.1 daN compared to the current 12.0 daN. Decreasing compression force from 12.0 daN to 9.0 daN increased CBT by 3.3±1.4 mm, MGD by 6.2-11.0%, and caused no significant effects on image quality (p>0.05). Force-standardized protocol led to widely variable compression parameters in Asian women. Based on phantom study, it is feasible to reduce compression force up to 32.5% with minimal effects on image quality and MGD.

  18. Effects of errors in velocity tilt on maximum longitudinal compression during neutralized drift compression of intense beam pulses: II. Analysis of experimental data of the Neutralized Drift Compression eXperiment-I (NDCX-I)

    International Nuclear Information System (INIS)

    Massidda, Scott; Kaganovich, Igor D.; Startsev, Edward A.; Davidson, Ronald C.; Lidia, Steven M.; Seidl, Peter; Friedman, Alex

    2012-01-01

    Neutralized drift compression offers an effective means for particle beam focusing and current amplification with applications to heavy ion fusion. In the Neutralized Drift Compression eXperiment-I (NDCX-I), a non-relativistic ion beam pulse is passed through an inductive bunching module that produces a longitudinal velocity modulation. Due to the applied velocity tilt, the beam pulse compresses during neutralized drift. The ion beam pulse can be compressed by a factor of more than 100; however, errors in the velocity modulation affect the compression ratio in complex ways. We have performed a study of how the longitudinal compression of a typical NDCX-I ion beam pulse is affected by the initial errors in the acquired velocity modulation. Without any voltage errors, an ideal compression is limited only by the initial energy spread of the ion beam, ΔΕ b . In the presence of large voltage errors, δU⪢ΔE b , the maximum compression ratio is found to be inversely proportional to the geometric mean of the relative error in velocity modulation and the relative intrinsic energy spread of the beam ions. Although small parts of a beam pulse can achieve high local values of compression ratio, the acquired velocity errors cause these parts to compress at different times, limiting the overall compression of the ion beam pulse.

  19. Combined effect of external and internal irradiation

    International Nuclear Information System (INIS)

    Kiradzhiev, G.

    1987-01-01

    Some of the general regularities of the combined effect of external irradiation and iodine 131 are discussed. Data are adduced showing that modification of the effects of these two radiation factors, when jointly applied, is also determined by the quantitative relations of the applied doses of external and internal irradiation, referred to a particular moment of the effects. It was shown that the effects of the radionuclides in these combined radiation injuries are basically realized by two mechanisms: 1. changes are found in the radionuclide kinetic parameters (nonspecific effects); 2. changes in their kinetic parameters are absent (specific effect). These two mechanisms underlie different approaches to therapy

  20. The effect of internal and external stress on two-way shape-memory behaviour in Co49Ni21.6Ga29.4 single crystals

    International Nuclear Information System (INIS)

    Liu, G D; Dai, X F; Luo, H Z; Liu, H Y; Meng, F B; Li, Y; Yu, X; Chen, J L; Wu, G H

    2011-01-01

    The effect of the internal stress on the two-way shape memory in Co 49 Ni 21.6 Ga 29.4 single crystals has been investigated. We found that the internal stress generated natively by the solidifying process works as a tensile force along the growth direction. Applying different compressive pre-stresses along the [0 0 1] direction, the shape-memory strain can be continuously changed from +1.0% to -2.3%. In the [1 1 0] direction, the strain monotonically increases from -2.0% to -4.0% due to a strong detwinning produced by the consistent effect of the external and internal stresses.

  1. Neutron scattering techniques for betaine calcium chloride dihydrate under applied external field (temperature, electric field and hydrostatic pressure); Etude par diffusion de neutrons du chlorure de calcium et de betaine dihydrate sous champ externe applique (temperature, champ electrique et pression hydrostatique)

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, O

    1997-11-17

    We have studied with neutron scattering techniques betaine calcium chloride dihydrate (BCCD), a dielectric aperiodic crystal which displays a Devil`s staircase type phase diagram made up of several incommensurate and commensurate phases, having a range of stability very sensitive to temperature, electric field and hydrostatic pressure. We have measured a global hysteresis of {delta}(T) of about 2-3 K in the two incommensurate phases. A structural study of the modulated commensurate phases 1/4 and 1/5 allows us to evidence that the atomic modulation functions are anharmonic. The relevance of the modelization of the modulated structure by polar Ising pseudo-spins is then directly established. On the basis of group theory calculation in the four dimensional super-space, we interpret this anharmonic modulation as a soliton regime with respect to the lowest-temperature non modulated ferroelectric phase. The continuous character of the transition to the lowest-temperature non modulated phase and the diffuse scattering observed in this phase are accounted for the presence of ferroelectric domains separated by discommensurations. Furthermore, we have shown that X-rays induce in BCCD a strong variation with time of irradiation of the intensity of satellite peaks, and more specifically for third order ones. This is why the `X-rays` structural model is found more harmonic than the `neutron` one. Under electric field applied along the vector b axis, we confirm that commensurate phases with {delta} = even/odd are favoured and hence are polar along this direction. We have evidenced at 10 kV / cm two new higher order commensurate phases in the phase INC2, corroborating the idea of a `complete` Devil`s air-case phase diagram. A phenomenon of generalized coexistence of phases occurs above 5 kV / cm. We have characterized at high field phase transitions between `coexisting` phases, which are distinguishable from classical lock-in transitions. Under hydrostatic pressure, our results

  2. Algorithm for Compressing Time-Series Data

    Science.gov (United States)

    Hawkins, S. Edward, III; Darlington, Edward Hugo

    2012-01-01

    An algorithm based on Chebyshev polynomials effects lossy compression of time-series data or other one-dimensional data streams (e.g., spectral data) that are arranged in blocks for sequential transmission. The algorithm was developed for use in transmitting data from spacecraft scientific instruments to Earth stations. In spite of its lossy nature, the algorithm preserves the information needed for scientific analysis. The algorithm is computationally simple, yet compresses data streams by factors much greater than two. The algorithm is not restricted to spacecraft or scientific uses: it is applicable to time-series data in general. The algorithm can also be applied to general multidimensional data that have been converted to time-series data, a typical example being image data acquired by raster scanning. However, unlike most prior image-data-compression algorithms, this algorithm neither depends on nor exploits the two-dimensional spatial correlations that are generally present in images. In order to understand the essence of this compression algorithm, it is necessary to understand that the net effect of this algorithm and the associated decompression algorithm is to approximate the original stream of data as a sequence of finite series of Chebyshev polynomials. For the purpose of this algorithm, a block of data or interval of time for which a Chebyshev polynomial series is fitted to the original data is denoted a fitting interval. Chebyshev approximation has two properties that make it particularly effective for compressing serial data streams with minimal loss of scientific information: The errors associated with a Chebyshev approximation are nearly uniformly distributed over the fitting interval (this is known in the art as the "equal error property"); and the maximum deviations of the fitted Chebyshev polynomial from the original data have the smallest possible values (this is known in the art as the "min-max property").

  3. Adiabatic compression and radiative compression of magnetic fields

    International Nuclear Information System (INIS)

    Woods, C.H.

    1980-01-01

    Flux is conserved during mechanical compression of magnetic fields for both nonrelativistic and relativistic compressors. However, the relativistic compressor generates radiation, which can carry up to twice the energy content of the magnetic field compressed adiabatically. The radiation may be either confined or allowed to escape

  4. Applied physics

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    The Physics Division research program that is dedicated primarily to applied research goals involves the interaction of energetic particles with solids. This applied research is carried out in conjunction with the basic research studies from which it evolved

  5. Medical image compression and its application to TDIS-FILE equipment

    International Nuclear Information System (INIS)

    Tsubura, Shin-ichi; Nishihara, Eitaro; Iwai, Shunsuke

    1990-01-01

    In order to compress medical images for filing and communication, we have developed a compression algorithm which compresses images with remarkable quality using a high-pass filtering method. Hardware for this compression algorithm was also developed and applied to TDIS (total digital imaging system)-FILE equipment. In the future, hardware based on this algorithm will be developed for various types of diagnostic equipment and PACS. This technique has the following characteristics: (1) significant reduction of artifacts; (2) acceptable quality for clinical evaluation at 15:1 to 20:1 compression ratio; and (3) high-speed processing and compact hardware. (author)

  6. On applying cognitive psychology.

    Science.gov (United States)

    Baddeley, Alan

    2013-11-01

    Recent attempts to assess the practical impact of scientific research prompted my own reflections on over 40 years worth of combining basic and applied cognitive psychology. Examples are drawn principally from the study of memory disorders, but also include applications to the assessment of attention, reading, and intelligence. The most striking conclusion concerns the many years it typically takes to go from an initial study, to the final practical outcome. Although the complexity and sheer timescale involved make external evaluation problematic, the combination of practical satisfaction and theoretical stimulation make the attempt to combine basic and applied research very rewarding. © 2013 The British Psychological Society.

  7. A Classroom Auction with Externalities: Applied to Mergers and Acquisitions

    Science.gov (United States)

    Meister, J. Patrick; Anderson, Kyle J.

    2007-01-01

    The authors describe an in-class exercise in which students participate in an auction to buy US Airways. The exercise is based on events of late 1995, in which neither United nor American Airlines decided to bid for US Airways. Two teams of students participate in an English auction. Students learn that the equilibrium of the sequential game is…

  8. Applying environmental externalities to US Clean Coal Technologies for Taiwan

    International Nuclear Information System (INIS)

    Szpunar, C.B.; Gillette, J.L.

    1992-01-01

    During the period 1971 to 1980, electricity consumption in Taiwan increased remarkably at an average rate of 12.2% per year. Despite experiencing a record low in 1982 and 1983, electricity demand returned to double digit growth, reaching 11.6% and 10.2% in 1987 and 1988, respectively, due to a strong economic recovery. In 1988, 71.6 TWh of electricity was produced, 21.1 TWh of which was from coal-fired units (29%). The electricity demand for Taiwan is expected to continue to grow at a very rapid rate during the 1990--2006 time frame. The average load is expected to grow at an annual rate of 5.6% while the peak load is projected to increase at an annual rate of 6.0%. All new coal-fired power plants are expected to comply with government regulations on S0 2 , NO x , and particulate emissions. Taper reports that all of its proposed coal-fired units will be equipped with modern flue gas emission reduction devices, such as electrostatic precipitators or baghouse filters, flue gas desulfurization and deco x devices, to reduce the pollutants to their minimum practical levels. New coal-based generation requirements in the sizes needed in Taiwan create an opportunity for several of the Cats currently under demonstration in the United States. Options to be considered are described

  9. On air-chemistry reduction for hypersonic external flow applications

    International Nuclear Information System (INIS)

    Ibrahim, Ashraf; Suman, Sawan; Girimaji, Sharath S.

    2015-01-01

    Highlights: • The existence of the slow manifold for the air-mixture system is shown. • The QSSA estimate of the slow manifold is fairly accurate. • For mid-temperature range the reduction mechanisms could be useful. - Abstract: In external hypersonic flows, viscous and compressibility effects generate very high temperatures leading to significant chemical reactions among air constituents. Therefore, hypersonic flow computations require coupled calculations of flow and chemistry. Accurate and efficient computations of air-chemistry kinetics are of much importance for many practical applications but calculations accounting for detailed chemical kinetics can be prohibitively expensive. In this paper, we investigate the possibility of applying chemical kinetics reduction schemes for hypersonic air-chemistry. We consider two chemical kinetics sets appropriate for three different temperature ranges: 2500 K to 4500 K; 4500 K to 9000 K; and above 9000 K. By demonstrating the existence of the so-called the slow manifold in each of the chemistry sets, we show that judicious chemical kinetics reduction leading to significant computational savings is possible without much loss in accuracy

  10. Externally perturbed unstable systems

    International Nuclear Information System (INIS)

    Posch, H.A.; Narnhofer, H.; Thirring, W.

    1991-01-01

    We discuss computer solutions of Newton's equation of motion for unstable systems in a container with time-dependent walls. An expansion leads to the formation of a cluster and a significant increase of the temperature. The question of entropy increase for expansion and compression of the system and the related problem of the feasibility of a perpetuum mobile of the second kind are investigated. (Authors)

  11. Asymptotic stability of steady compressible fluids

    CERN Document Server

    Padula, Mariarosaria

    2011-01-01

    This volume introduces a systematic approach to the solution of some mathematical problems that arise in the study of the hyperbolic-parabolic systems of equations that govern the motions of thermodynamic fluids. It is intended for a wide audience of theoretical and applied mathematicians with an interest in compressible flow, capillarity theory, and control theory. The focus is particularly on recent results concerning nonlinear asymptotic stability, which are independent of assumptions about the smallness of the initial data. Of particular interest is the loss of control that sometimes results when steady flows of compressible fluids are upset by large disturbances. The main ideas are illustrated in the context of three different physical problems: (i) A barotropic viscous gas in a fixed domain with compact boundary. The domain may be either an exterior domain or a bounded domain, and the boundary may be either impermeable or porous. (ii) An isothermal viscous gas in a domain with free boundaries. (iii) A h...

  12. Dictionary Approaches to Image Compression and Reconstruction

    Science.gov (United States)

    Ziyad, Nigel A.; Gilmore, Erwin T.; Chouikha, Mohamed F.

    1998-01-01

    This paper proposes using a collection of parameterized waveforms, known as a dictionary, for the purpose of medical image compression. These waveforms, denoted as phi(sub gamma), are discrete time signals, where gamma represents the dictionary index. A dictionary with a collection of these waveforms is typically complete or overcomplete. Given such a dictionary, the goal is to obtain a representation image based on the dictionary. We examine the effectiveness of applying Basis Pursuit (BP), Best Orthogonal Basis (BOB), Matching Pursuits (MP), and the Method of Frames (MOF) methods for the compression of digitized radiological images with a wavelet-packet dictionary. The performance of these algorithms is studied for medical images with and without additive noise.

  13. Hydrodynamics of compressible superfluids in confined geometries

    International Nuclear Information System (INIS)

    Malmi-Kakkada, Abdul N; Valls, Oriol T; Dasgupta, Chandan

    2014-01-01

    We present a study of the hydrodynamics of compressible superfluids in confined geometries. We use a perturbative procedure in terms of the dimensionless expansion parameter (v/v s ) 2 where v is the typical speed of the flow and v s is the speed of sound. A zero value of this parameter corresponds to the incompressible limit. We apply the procedure to two specific problems: the case of a trapped superfluid with a Gaussian profile of the local density, and that of a superfluid confined in a rotating obstructed cylinder. We find that the corrections due to finite compressibility which are, as expected, negligible for liquid He, are important but amenable to the perturbative treatment for typical ultracold atomic systems. (paper)

  14. Delamination of Compressed Thin Layers at Corners

    DEFF Research Database (Denmark)

    Sørensen, Kim D.; Jensen, Henrik Myhre; Clausen, Johan

    2008-01-01

    An analysis of delamination for a thin elastic layer under compression, attached to a substrate at a corner is carried out. The analysis is performed by combining results from interface fracture mechanics and the theory of thin shells. In contrast with earlier results for delamination on a flat s...... layers, Fracture mechanics, Crack closure, Steady state crack propagation.......An analysis of delamination for a thin elastic layer under compression, attached to a substrate at a corner is carried out. The analysis is performed by combining results from interface fracture mechanics and the theory of thin shells. In contrast with earlier results for delamination on a flat...... results for the fracture mechanical properties have been obtained, and these are applied in a study of the effect of contacting crack faces. Special attention has been given to analyse conditions under which steady state propagation of buckling driven delamination takes place. Keywords: Delamination, Thin...

  15. Application of PDF methods to compressible turbulent flows

    Science.gov (United States)

    Delarue, B. J.; Pope, S. B.

    1997-09-01

    A particle method applying the probability density function (PDF) approach to turbulent compressible flows is presented. The method is applied to several turbulent flows, including the compressible mixing layer, and good agreement is obtained with experimental data. The PDF equation is solved using a Lagrangian/Monte Carlo method. To accurately account for the effects of compressibility on the flow, the velocity PDF formulation is extended to include thermodynamic variables such as the pressure and the internal energy. The mean pressure, the determination of which has been the object of active research over the last few years, is obtained directly from the particle properties. It is therefore not necessary to link the PDF solver with a finite-volume type solver. The stochastic differential equations (SDE) which model the evolution of particle properties are based on existing second-order closures for compressible turbulence, limited in application to low turbulent Mach number flows. Tests are conducted in decaying isotropic turbulence to compare the performances of the PDF method with the Reynolds-stress closures from which it is derived, and in homogeneous shear flows, at which stage comparison with direct numerical simulation (DNS) data is conducted. The model is then applied to the plane compressible mixing layer, reproducing the well-known decrease in the spreading rate with increasing compressibility. It must be emphasized that the goal of this paper is not as much to assess the performance of models of compressibility effects, as it is to present an innovative and consistent PDF formulation designed for turbulent inhomogeneous compressible flows, with the aim of extending it further to deal with supersonic reacting flows.

  16. Magnetic Compression Experiment at General Fusion with Simulation Results

    Science.gov (United States)

    Dunlea, Carl; Khalzov, Ivan; Hirose, Akira; Xiao, Chijin; Fusion Team, General

    2017-10-01

    The magnetic compression experiment at GF was a repetitive non-destructive test to study plasma physics applicable to Magnetic Target Fusion compression. A spheromak compact torus (CT) is formed with a co-axial gun into a containment region with an hour-glass shaped inner flux conserver, and an insulating outer wall. External coil currents keep the CT off the outer wall (levitation) and then rapidly compress it inwards. The optimal external coil configuration greatly improved both the levitated CT lifetime and the rate of shots with good compressional flux conservation. As confirmed by spectrometer data, the improved levitation field profile reduced plasma impurity levels by suppressing the interaction between plasma and the insulating outer wall during the formation process. We developed an energy and toroidal flux conserving finite element axisymmetric MHD code to study CT formation and compression. The Braginskii MHD equations with anisotropic heat conduction were implemented. To simulate plasma / insulating wall interaction, we couple the vacuum field solution in the insulating region to the full MHD solution in the remainder of the domain. We see good agreement between simulation and experiment results. Partly funded by NSERC and MITACS Accelerate.

  17. External events analysis of the Ignalina Nuclear Power Plant

    International Nuclear Information System (INIS)

    Liaukonis, Mindaugas; Augutis, Juozas

    1999-01-01

    This paper presents analysis of external events impact on the safe operation of the Ignalina Nuclear Power Plant (INPP) safety systems. Analysis was based on the probabilistic estimation and modelling of the external hazards. The screening criteria were applied to the number of external hazards. The following external events such as aircraft failure on the INPP, external flooding, fire, extreme winds requiring further bounding study were analysed. Mathematical models were developed and event probabilities were calculated. External events analysis showed rather limited external events danger to Ignalina NPP. Results of the analysis were compared to analogous analysis in western NPPs and no great differences were specified. Calculations performed show that external events can not significantly influence the safety level of the Ignalina NPP operation. (author)

  18. Impact of multilayered compression bandages on sub-bandage interface pressure: a model.

    Science.gov (United States)

    Al Khaburi, J; Nelson, E A; Hutchinson, J; Dehghani-Sanij, A A

    2011-03-01

    Multi-component medical compression bandages are widely used to treat venous leg ulcers. The sub-bandage interface pressures induced by individual components of the multi-component compression bandage systems are not always simply additive. Current models to explain compression bandage performance do not take account of the increase in leg circumference when each bandage is applied, and this may account for the difference between predicted and actual pressures. To calculate the interface pressure when a multi-component compression bandage system is applied to a leg. Use thick wall cylinder theory to estimate the sub-bandage pressure over the leg when a multi-component compression bandage is applied to a leg. A mathematical model was developed based on thick cylinder theory to include bandage thickness in the calculation of the interface pressure in multi-component compression systems. In multi-component compression systems, the interface pressure corresponds to the sum of the pressures applied by individual bandage layers. However, the change in the limb diameter caused by additional bandage layers should be considered in the calculation. Adding the interface pressure produced by single components without considering the bandage thickness will result in an overestimate of the overall interface pressure produced by the multi-component compression systems. At the ankle (circumference 25 cm) this error can be 19.2% or even more in the case of four components bandaging systems. Bandage thickness should be considered when calculating the pressure applied using multi-component compression systems.

  19. Malignant external otitis

    International Nuclear Information System (INIS)

    Dupuch, K.M.; Iryboz, T.; Firat, M.; Levy, C.; Tubiana, J.M.

    1991-01-01

    This paper illustrates the value of CT and MR in early diagnosis and spread of malignant external otitis. The authors retrospectively analyzed 15 patients with proved malignant external otitis examined with postcontrast high-resolution CT (15/15) and MR (6/15) (T1- and T2-weighting). Gallium studies were done in 6/15 patients. Early diagnosis was made when CT demonstrated a soft-tissue mass of the external auditory canal associated with scattered zones of cortical bone erosions (13/15). Spread of the disease was better delineated by MR than CT, especially skull base extension (6/15). Temporomandibular joint involvement with extension into parotid or/and masticator spaces 6/15 was as well detected with CT as with MR. If CT remains the first and best procedure for diagnosis, MR - despite its cost - appears a good procedure to depict exact anatomic spread, allowing therapeutic management

  20. Productivity Change and Externalities

    DEFF Research Database (Denmark)

    Kravtsova, Victoria

    2014-01-01

    This paper contributes to the analysis of the impact of externalities on the host country's total factor productivity by taking into account different dimensions of spillover effects. Namely, engagement in exporting and foreign ownership is generally perceived as being beneficial to individual...... firms and the economy as a whole. The approach used in the current research accounts for different internal as well as external factors that individual firms face and evaluates the effect on changes in productivity, technology as well as the efficiency of domestic firms. The empirical analysis focuses...... on Hungary. While the country leads the group of post-socialist countries in the amount of attracted foreign direct investments (FDI) the effect of this policy on the economy remains unclear. The research finds that different externalities play a different role in productivity, technological and efficiency...

  1. Externality or sustainability economics?

    International Nuclear Information System (INIS)

    Bergh, Jeroen C.J.M. van den

    2010-01-01

    In an effort to develop 'sustainability economics' Baumgaertner and Quaas (2010) neglect the central concept of environmental economics-'environmental externality'. This note proposes a possible connection between the concepts of environmental externality and sustainability. In addition, attention is asked for other aspects of 'sustainability economics', namely the distinction weak/strong sustainability, spatial sustainability and sustainable trade, distinctive sustainability policy, and the ideas of early 'sustainability economists'. I argue that both sustainability and externalities reflect a systems perspective and propose that effective sustainability solutions require that more attention is given to system feedbacks, notably other-regarding preferences and social interactions, and energy and environmental rebound. The case of climate change and policy is used to illustrate particular statements. As a conclusion, a list of 20 insights and suggestions for research is offered. (author)

  2. Metasurface external cavity laser

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Luyao, E-mail: luyaoxu.ee@ucla.edu; Curwen, Christopher A.; Williams, Benjamin S. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, California 90095 (United States); Hon, Philip W. C.; Itoh, Tatsuo [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Chen, Qi-Sheng [Northrop Grumman Aerospace Systems, Redondo Beach, California 90278 (United States)

    2015-11-30

    A vertical-external-cavity surface-emitting-laser is demonstrated in the terahertz range, which is based upon an amplifying metasurface reflector composed of a sub-wavelength array of antenna-coupled quantum-cascade sub-cavities. Lasing is possible when the metasurface reflector is placed into a low-loss external cavity such that the external cavity—not the sub-cavities—determines the beam properties. A near-Gaussian beam of 4.3° × 5.1° divergence is observed and an output power level >5 mW is achieved. The polarized response of the metasurface allows the use of a wire-grid polarizer as an output coupler that is continuously tunable.

  3. Compressed Baryonic Matter of Astrophysics

    OpenAIRE

    Guo, Yanjun; Xu, Renxin

    2013-01-01

    Baryonic matter in the core of a massive and evolved star is compressed significantly to form a supra-nuclear object, and compressed baryonic matter (CBM) is then produced after supernova. The state of cold matter at a few nuclear density is pedagogically reviewed, with significant attention paid to a possible quark-cluster state conjectured from an astrophysical point of view.

  4. Streaming Compression of Hexahedral Meshes

    Energy Technology Data Exchange (ETDEWEB)

    Isenburg, M; Courbet, C

    2010-02-03

    We describe a method for streaming compression of hexahedral meshes. Given an interleaved stream of vertices and hexahedral our coder incrementally compresses the mesh in the presented order. Our coder is extremely memory efficient when the input stream documents when vertices are referenced for the last time (i.e. when it contains topological finalization tags). Our coder then continuously releases and reuses data structures that no longer contribute to compressing the remainder of the stream. This means in practice that our coder has only a small fraction of the whole mesh in memory at any time. We can therefore compress very large meshes - even meshes that do not file in memory. Compared to traditional, non-streaming approaches that load the entire mesh and globally reorder it during compression, our algorithm trades a less compact compressed representation for significant gains in speed, memory, and I/O efficiency. For example, on the 456k hexahedra 'blade' mesh, our coder is twice as fast and uses 88 times less memory (only 3.1 MB) with the compressed file increasing about 3% in size. We also present the first scheme for predictive compression of properties associated with hexahedral cells.

  5. Data Compression with Linear Algebra

    OpenAIRE

    Etler, David

    2015-01-01

    A presentation on the applications of linear algebra to image compression. Covers entropy, the discrete cosine transform, thresholding, quantization, and examples of images compressed with DCT. Given in Spring 2015 at Ocean County College as part of the honors program.

  6. Images compression in nuclear medicine

    International Nuclear Information System (INIS)

    Rebelo, M.S.; Furuie, S.S.; Moura, L.

    1992-01-01

    The performance of two methods for images compression in nuclear medicine was evaluated. The LZW precise, and Cosine Transformed, approximate, methods were analyzed. The results were obtained, showing that the utilization of approximated method produced images with an agreeable quality for visual analysis and compression rates, considerably high than precise method. (C.G.C.)

  7. The External Mind

    DEFF Research Database (Denmark)

    , Extended Mind and Distributed Cognition by Claudio Paolucci pp. 69-96 The Social Horizon of Embodied Language and Material Symbols by Riccardo Fusaroli pp. 97-123 Semiotics and Theories of Situated/Distributed Action and Cognition: a Dialogue and Many Intersections by Tommaso Granelli pp. 125-167 Building......The External Mind: an Introduction by Riccardo Fusaroli, Claudio Paolucci pp. 3-31 The sign of the Hand: Symbolic Practices and the Extended Mind by Massimiliano Cappuccio, Michael Wheeler pp. 33-55 The Overextended Mind by Shaun Gallagher pp. 57-68 The "External Mind": Semiotics, Pragmatism...

  8. Compression force and radiation dose in the Norwegian Breast Cancer Screening Program

    Energy Technology Data Exchange (ETDEWEB)

    Waade, Gunvor G.; Sanderud, Audun [Department of Life Sciences and Health, Faculty of Health Sciences, Oslo and Akershus University College of Applied Sciences, P.O. 4 St. Olavs Plass, 0130 Oslo (Norway); Hofvind, Solveig, E-mail: solveig.hofvind@kreftregisteret.no [Department of Life Sciences and Health, Faculty of Health Sciences, Oslo and Akershus University College of Applied Sciences, P.O. 4 St. Olavs Plass, 0130 Oslo (Norway); The Cancer Registry of Norway, P.O. 5313 Majorstuen, 0304 Oslo (Norway)

    2017-03-15

    Highlights: • Compression force and radiation dose for 17 951 screening mammograms were analyzed. • Large variations in mean applied compression force between the breast centers. • Limited associations between compression force and radiation dose. - Abstract: Purpose: Compression force is used in mammography to reduce breast thickness and by that decrease radiation dose and improve image quality. There are no evidence-based recommendations regarding the optimal compression force. We analyzed compression force and radiation dose between screening centers in the Norwegian Breast Cancer Screening Program (NBCSP), as a first step towards establishing evidence-based recommendations for compression force. Materials and methods: The study included information from 17 951 randomly selected screening examinations among women screened with equipment from four different venors at fourteen breast centers in the NBCSP, January-March 2014. We analyzed the applied compression force and radiation dose used on craniocaudal (CC) and mediolateral-oblique (MLO) view on left breast, by breast centers and vendors. Results: Mean compression force used in the screening program was 116N (CC: 108N, MLO: 125N). The maximum difference in mean compression force between the centers was 63N for CC and 57N for MLO. Mean radiation dose for each image was 1.09 mGy (CC: 1.04mGy, MLO: 1.14mGy), varying from 0.55 mGy to 1.31 mGy between the centers. Compression force alone had a negligible impact on radiation dose (r{sup 2} = 0.8%, p = < 0.001). Conclusion: We observed substantial variations in mean compression forces between the breast centers. Breast characteristics and differences in automated exposure control between vendors might explain the low association between compression force and radiation dose. Further knowledge about different automated exposure controls and the impact of compression force on dose and image quality is needed to establish individualised and evidence

  9. Compressive Sensing in Communication Systems

    DEFF Research Database (Denmark)

    Fyhn, Karsten

    2013-01-01

    . The need for cheaper, smarter and more energy efficient wireless devices is greater now than ever. This thesis addresses this problem and concerns the application of the recently developed sampling theory of compressive sensing in communication systems. Compressive sensing is the merging of signal...... acquisition and compression. It allows for sampling a signal with a rate below the bound dictated by the celebrated Shannon-Nyquist sampling theorem. In some communication systems this necessary minimum sample rate, dictated by the Shannon-Nyquist sampling theorem, is so high it is at the limit of what...... with using compressive sensing in communication systems. The main contribution of this thesis is two-fold: 1) a new compressive sensing hardware structure for spread spectrum signals, which is simpler than the current state-of-the-art, and 2) a range of algorithms for parameter estimation for the class...

  10. Effects of prolonged compression on the variations of haemoglobin oxygenation-assessment by spectral analysis of reflectance spectrophotometry signals

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zengyong; Tam, Eric W C; Mak, Arthur F T; Lau, Roy Y C [Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong (China)

    2006-11-07

    The consequences of rhythmical flow motion for nutrition and the oxygen supply to tissue are largely unknown. In this study, the periodic variations of haemoglobin oxygenation in compressed and uncompressed skin were evaluated with a reflection spectrometer using an in vivo Sprague-Dawley rat model. Skin compression was induced over the trochanter area by a locally applied external pressure of 13.3 kPa (100 mmHg) via a specifically designed pneumatic indentor. A total of 19 rats were used in this study. The loading duration is 6 h per day for four consecutive days. Haemoglobin oxygenation variations were quantified using spectral analysis based on wavelets' transformation. The results found that in both compressed and uncompressed skin, periodic variations of the haemoglobin oxygenation were characterized by two frequencies in the range of 0.01-0.05 Hz and 0.15-0.4 Hz. These frequency ranges coincide with those of the frequency range of the endothelial-related metabolic and myogenic activities found in the flow motion respectively. Tissue compression following the above loading schedule induced a significant decrease in the spectral amplitudes of frequency interval 0.01-0.05 Hz during the pre-occlusion period on day 3 and day 4 as compared to that on day 1 (p < 0.05). In contrast, at a frequency range of 0.15-0.4 Hz, prolonged compression caused a significant increase in spectral amplitude during the pre-occlusion period in the compressed tissue on day 3 (p = 0.041) and day 4 (p = 0.024) compared to that in the uncompressed tissue on day 1. These suggested that the variations of the haemoglobin oxygenation were closely related to the endothelial-related metabolic and myogenic activities. Increased amplitude in the frequency interval 0.15-0.4 Hz indicated an increased workload of the vascular smooth muscle and could be attributed to the increase of O{sub 2} consumption rates of arteriolar walls. The modification of vessel wall oxygen consumption might

  11. Powder compression mechanics of spray-dried lactose nanocomposites.

    Science.gov (United States)

    Hellrup, Joel; Nordström, Josefina; Mahlin, Denny

    2017-02-25

    The aim of this study was to investigate the structural impact of the nanofiller incorporation on the powder compression mechanics of spray-dried lactose. The lactose was co-spray-dried with three different nanofillers, that is, cellulose nanocrystals, sodium montmorillonite and fumed silica, which led to lower micron-sized nanocomposite particles with varying structure and morphology. The powder compression mechanics of the nanocomposites and physical mixtures of the neat spray-dried components were evaluated by a rational evaluation method with compression analysis as a tool, using the Kawakita equation and the Shapiro-Konopicky-Heckel equation. Particle rearrangement dominated the initial compression profiles due to the small particle size of the materials. The strong contribution of particle rearrangement in the materials with fumed silica continued throughout the whole compression profile, which prohibited an in-depth material characterization. However, the lactose/cellulose nanocrystals and the lactose/sodium montmorillonite nanocomposites demonstrated high yield pressure compared with the physical mixtures indicating increased particle hardness upon composite formation. This increase has likely to do with a reinforcement of the nanocomposite particles by skeleton formation of the nanoparticles. In summary, the rational evaluation of mechanical properties done by applying powder compression analysis proved to be a valuable tool for mechanical evaluation for this type of spray-dried composite materials, unless they demonstrate particle rearrangement throughout the whole compression profile. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. POLYCOMP: Efficient and configurable compression of astronomical timelines

    Science.gov (United States)

    Tomasi, M.

    2016-07-01

    This paper describes the implementation of polycomp, a open-sourced, publicly available program for compressing one-dimensional data series in tabular format. The program is particularly suited for compressing smooth, noiseless streams of data like pointing information, as one of the algorithms it implements applies a combination of least squares polynomial fitting and discrete Chebyshev transforms that is able to achieve a compression ratio Cr up to ≈ 40 in the examples discussed in this work. This performance comes at the expense of a loss of information, whose upper bound is configured by the user. I show two areas in which the usage of polycomp is interesting. In the first example, I compress the ephemeris table of an astronomical object (Ganymede), obtaining Cr ≈ 20, with a compression error on the x , y , z coordinates smaller than 1 m. In the second example, I compress the publicly available timelines recorded by the Low Frequency Instrument (LFI), an array of microwave radiometers onboard the ESA Planck spacecraft. The compression reduces the needed storage from ∼ 6.5 TB to ≈ 0.75 TB (Cr ≈ 9), thus making them small enough to be kept in a portable hard drive.

  13. Efficient traveltime compression for 3D prestack Kirchhoff migration

    KAUST Repository

    Alkhalifah, Tariq

    2010-12-13

    Kirchhoff 3D prestack migration, as part of its execution, usually requires repeated access to a large traveltime table data base. Access to this data base implies either a memory intensive or I/O bounded solution to the storage problem. Proper compression of the traveltime table allows efficient 3D prestack migration without relying on the usually slow access to the computer hard drive. Such compression also allows for faster access to desirable parts of the traveltime table. Compression is applied to the traveltime field for each source location on the surface on a regular grid using 3D Chebyshev polynomial or cosine transforms of the traveltime field represented in the spherical coordinates or the Celerity domain. We obtain practical compression levels up to and exceeding 20 to 1. In fact, because of the smaller size traveltime table, we obtain exceptional traveltime extraction speed during migration that exceeds conventional methods. Additional features of the compression include better interpolation of traveltime tables and more stable estimates of amplitudes from traveltime curvatures. Further compression is achieved using bit encoding, by representing compression parameters values with fewer bits. © 2010 European Association of Geoscientists & Engineers.

  14. Role of compressibility on driven magnetic reconnection

    International Nuclear Information System (INIS)

    Sato, T.; Hayashi, T.; Watanabe, K.; Horiuchi, R.; Tanaka, M.; Sawairi, N.; Kusano, K.

    1991-08-01

    Whether it is induced by an ideal (current driven) instability or by an external force, plasma flow causes a change in the magnetic field configuration and often gives rise to a current intensification locally, thereby a fast driven reconnection being driven there. Many dramatic phenomena in magnetically confined plasmas such as magnetospheric substorms, solar flares, MHD self-organization and tokamak sawtooth crash, may be attributed to this fast driven reconnection. Using a fourth order MHD simulation code it is confirmed that compressibility of the plasma plays a crucial role in leading to a fast (MHD time scale) driven reconnection. This indicates that the incompressible representation is not always applicable to the study of a global dynamical behavior of a magnetically confined plasma. (author)

  15. Relationship between medical compression and intramuscular pressure as an explanation of a compression paradox.

    Science.gov (United States)

    Uhl, J-F; Benigni, J-P; Cornu-Thenard, A; Fournier, J; Blin, E

    2015-06-01

    Using standing magnetic resonance imaging (MRI), we recently showed that medical compression, providing an interface pressure (IP) of 22 mmHg, significantly compressed the deep veins of the leg but not, paradoxically, superficial varicose veins. To provide an explanation for this compression paradox by studying the correlation between the IP exerted by medical compression and intramuscular pressure (IMP). In 10 legs of five healthy subjects, we studied the effects of different IPs on the IMP of the medial gastrocnemius muscle. The IP produced by a cuff manometer was verified by a Picopress® device. The IMP was measured with a 21G needle connected to a manometer. Pressure data were recorded in the prone and standing positions with cuff manometer pressures from 0 to 50 mmHg. In the prone position, an IP of less than 20 did not significantly change the IMP. On the contrary, a perfect linear correlation with the IMP (r = 0.99) was observed with an IP from 20 to 50 mmHg. We found the same correlation in the standing position. We found that an IP of 22 mmHg produced a significant IMP increase from 32 to 54 mmHg, in the standing position. At the same time, the subcutaneous pressure is only provided by the compression device, on healthy subjects. In other words, the subcutaneous pressure plus the IP is only a little higher than 22 mmHg-a pressure which is too low to reduce the caliber of the superficial veins. This is in accordance with our standing MRI 3D anatomical study which showed that, paradoxically, when applying low pressures (IP), the deep veins are compressed while the superficial veins are not. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  16. Process and application of shock compression by nanosecond pulses of frequency-doubled Nd:YAG laser

    Science.gov (United States)

    Sano, Yuji; Kimura, Motohiko; Mukai, Naruhiko; Yoda, Masaki; Obata, Minoru; Ogisu, Tatsuki

    2000-02-01

    The authors have developed a new process of laser-induced shock compression to introduce a residual compressive stress on material surface, which is effective for prevention of stress corrosion cracking (SCC) and enhancement of fatigue strength of metal materials. The process developed is unique and beneficial. It requires no pre-conditioning for the surface, whereas the conventional process requires that the so-called sacrificial layer is made to protect the surface from damage. The new process can be freely applied to water- immersed components, since it uses water-penetrable green light of a frequency-doubled Nd:YAG laser. The process developed has the potential to open up new high-power laser applications in manufacturing and maintenance technologies. The laser-induced shock compression process (LSP) can be used to improve a residual stress field from tensile to compressive. In order to understand the physics and optimize the process, the propagation of a shock wave generated by the impulse of laser irradiation and the dynamic response of the material were analyzed by time-dependent elasto-plastic calculations with a finite element program using laser-induced plasma pressure as an external load. The analysis shows that a permanent strain and a residual compressive stress remain after the passage of the shock wave with amplitude exceeding the yield strength of the material. A practical system materializing the LSP was designed, manufactured, and tested to confirm the applicability to core components of light water reactors (LWRs). The system accesses the target component and remotely irradiates laser pulses to the heat affected zone (HAZ) along weld lines. Various functional tests were conducted using a full-scale mockup facility, in which remote maintenance work in a reactor vessel could be simulated. The results showed that the system remotely accessed the target weld lines and successfully introduced a residual compressive stress. After sufficient training

  17. Externalities - an analysis using the EU ExternE-results

    International Nuclear Information System (INIS)

    2003-10-01

    The EU project ExternE quantified the externalities for the different energy technologies. In this work, the ExternE results are used in a MARKAL-analysis for the Nordic countries. The analysis does not go into detail, but gives some interesting indications: The external costs are not fully covered in the Nordic energy systems, the present taxes and charges are not high enough. The emissions from the energy systems would be strongly reduced, if taxes/environmental charges were set at the level ExternE calculate. The emissions from power production would be reduced most. Renewable energy sources and natural gas dominate the energy systems in the ExternE case

  18. Evaluation of mammogram compression efficiency

    International Nuclear Information System (INIS)

    Przelaskowski, A.; Surowski, P.; Kukula, A.

    2005-01-01

    Lossy image coding significantly improves performance over lossless methods, but a reliable control of diagnostic accuracy regarding compressed images is necessary. The acceptable range of compression ratios must be safe with respect to as many objective criteria as possible. This study evaluates the compression efficiency of digital mammograms in both numerically lossless (reversible) and lossy (irreversible) manner. Effective compression methods and concepts were examined to increase archiving and telediagnosis performance. Lossless compression as a primary applicable tool for medical applications was verified on a set 131 mammograms. Moreover, nine radiologists participated in the evaluation of lossy compression of mammograms. Subjective rating of diagnostically important features brought a set of mean rates given for each test image. The lesion detection test resulted in binary decision data analyzed statistically. The radiologists rated and interpreted malignant and benign lesions, representative pathology symptoms, and other structures susceptible to compression distortions contained in 22 original and 62 reconstructed mammograms. Test mammograms were collected in two radiology centers for three years and then selected according to diagnostic content suitable for an evaluation of compression effects. Lossless compression efficiency of the tested coders varied, but CALIC, JPEG-LS, and SPIHT performed the best. The evaluation of lossy compression effects affecting detection ability was based on ROC-like analysis. Assuming a two-sided significance level of p=0.05, the null hypothesis that lower bit rate reconstructions are as useful for diagnosis as the originals was false in sensitivity tests with 0.04 bpp mammograms. However, verification of the same hypothesis with 0.1 bpp reconstructions suggested their acceptance. Moreover, the 1 bpp reconstructions were rated very similarly to the original mammograms in the diagnostic quality evaluation test, but the

  19. External costs of electricity

    International Nuclear Information System (INIS)

    Rabl, A.; Spadaro, J.V.

    2005-01-01

    This article presents a synthesis of the ExternE project (External costs of Energy) of the European community about the external costs of power generation. Pollution impacts are calculated using an 'impact pathways' analysis, i.e. an analysis of the emission - dispersion - dose-response function - cost evaluation chain. Results are presented for different fuel cycles (with several technological variants) with their confidence intervals. The environmental impact costs are particularly high for coal: for instance, in France, for coal-fired power plants it is of the same order as the electricity retail price. For natural gas, this cost is about a third of the one for coal. On the contrary, the environmental impact costs for nuclear and renewable energies are low, typically of few per cent of the electricity price. The main part of these costs corresponds to the sanitary impacts, in particular the untimely mortality. In order to avoid any controversy about the cost evaluation of mortality, the reduction of the expectation of life due to the different fuel cycles is also indicated and the risks linked with nuclear energy are presented using several comparisons. (J.S.)

  20. On parabolic external maps

    DEFF Research Database (Denmark)

    Lomonaco, Luna; Petersen, Carsten Lunde; Shen, Weixiao

    2017-01-01

    We prove that any C1+BV degree d ≥ 2 circle covering h having all periodic orbits weakly expanding, is conjugate by a C1+BV diffeomorphism to a metrically expanding map. We use this to connect the space of parabolic external maps (coming from the theory of parabolic-like maps) to metrically expan...

  1. Stochastic Control - External Models

    DEFF Research Database (Denmark)

    Poulsen, Niels Kjølstad

    2005-01-01

    This note is devoted to control of stochastic systems described in discrete time. We are concerned with external descriptions or transfer function model, where we have a dynamic model for the input output relation only (i.e.. no direct internal information). The methods are based on LTI systems...

  2. Use of Bedside Compression Ultrasonography for Diagnosis of Deep Venous Thrombosis

    Directory of Open Access Journals (Sweden)

    Mohamad Moussa

    2017-07-01

    Full Text Available History of present illness: A 70-year-old female with a history of breast cancer and smoking for 50 years presented to the emergency department with left-lower extremity pain and swelling for two days. The patient denied recent long-distance travel, history of hypercoagulable disorder, or recent surgery. Physical examination revealed a warm, erythematous, 3+ edematous left-lower extremity with mild tenderness extending into the proximal thigh. Her D-dimer level was 2307ng/mL and vital signs were significant for a heart rate of 110bpm, oxygen saturation of 90% on 2 liters of oxygen, and blood pressure of 153/102. Significant findings: As shown in the still image of the performed ultrasound, a transverse view of the proximal-thigh revealed a visible thrombus (green shading occluding the lumen of the left common femoral vein (blue ring, which was non-compressible when direct pressure was applied to the probe. Also visible is a patent and compressible branch of the common femoral vein (purple ring and the femoral artery (red ring, highlighted by its thick vessel wall and pulsatile motion. Discussion: Deep venous thrombosis (DVT affects 1 per 1,000 individuals each year and may lead to complications such as recurrent DVT, pulmonary embolism, and death.1 The utilization of bedside compression ultrasonography allows for rapid diagnosis of DVT and has virtually replaced other diagnostic methods due to its non-invasive and inexpensive nature. When performing compression ultrasonography, the patient should be positioned to maximize distention of the leg veins. The extremity in question should be flexed at the knee and externally rotated at the hip (this fully exposes of the common, superficial, and deep femoral veins as well as the popliteal fossa and the head of the bed elevated at a 30-45 degree angle.2 In patients with an elevated D-dimer and low-to-moderate clinical probability, negative compression imaging of a single proximal location of the femoral

  3. Melting under shock compression

    International Nuclear Information System (INIS)

    Bennett, B.I.

    1980-10-01

    A simple model, using experimentally measured shock and particle velocities, is applied to the Lindemann melting formula to predict the density, temperature, and pressure at which a material will melt when shocked from room temperature and zero pressure initial conditions

  4. STOCHASTIC MODELING OF COMPRESSIVE STRENGTH OF PHOSPHORUS SLAG CONTENT CEMENT

    Directory of Open Access Journals (Sweden)

    Ali Allahverdi

    2016-07-01

    Full Text Available One of the common methods for quick determination of compressive strength as one of the most important properties for assessment of cement quality is to apply various modeling approaches. This study is aimed at finding a model for estimating the compressive strength of phosphorus slag content cements. For this purpose, the compressive strengths of chemically activated high phosphorus slag content cement prepared from phosphorus slag (80 wt.%, Portland cement (14 wt.% and a compound chemical activator containing sodium sulfate and anhydrite (6 wt.% were measured at various Blaine finenesses and curing times. Based on the obtained results, a primary stochastic model in terms of curing time and Blaine fineness has been developed. Then, another different dataset was used to incorporate composition variable including weight fractions of phosphorus slag, cement, and activator in the model. This model can be effectively used to predict the compressive strength of phosphorus slag content cements at various Blaine finenesses, curing times, and compositions.

  5. Investigating low-frequency compression using the Grid method

    DEFF Research Database (Denmark)

    Fereczkowski, Michal; Dau, Torsten; MacDonald, Ewen

    2016-01-01

    in literature. Moreover, slopes of the low-level portions of the BM I/O functions estimated at 500 Hz were examined, to determine whether the 500-Hz off-frequency forward masking curves were affected by compression. Overall, the collected data showed a trend confirming the compressive behaviour. However......There is an ongoing discussion about whether the amount of cochlear compression in humans at low frequencies (below 1 kHz) is as high as that at higher frequencies. It is controversial whether the compression affects the slope of the off-frequency forward masking curves at those frequencies. Here......, the Grid method with a 2-interval 1-up 3-down tracking rule was applied to estimate forward masking curves at two characteristic frequencies: 500 Hz and 4000 Hz. The resulting curves and the corresponding basilar membrane input-output (BM I/O) functions were found to be comparable to those reported...

  6. Object characterization simulator for estimating compressed breast during mammography

    International Nuclear Information System (INIS)

    Pinheiro, Luciana de J.S.; Rio, Margarita Chevalier del

    2011-01-01

    The measurement of the thickness of a compressed breast during the mammography test is necessary in order to calculate the glandular dose in mammography procedures, in an analysis of risk/benefit, given that the target organ in these procedures is highly sensitive to ionising radiation. However, mammography is a test of utmost importance in diagnosis. In theory, it may be possible to calculate the thickness of the compressed breast through the measurements of the focus object distance by using projections of radio opaque objects fixed to the compression tray. The facilities of the Laboratory of Applied Radioprotection to Mammography - LARAM were used for this study, as well as breast simulators with well defined thickness, in the assembly of the techniques for the measurement of the thickness of the compressed breast. The results showed that it is possible to determine this thickness through calculations and simulators through this method which is susceptible to be adequate to the dosimetry. (author)

  7. Quantum autoencoders for efficient compression of quantum data

    Science.gov (United States)

    Romero, Jonathan; Olson, Jonathan P.; Aspuru-Guzik, Alan

    2017-12-01

    Classical autoencoders are neural networks that can learn efficient low-dimensional representations of data in higher-dimensional space. The task of an autoencoder is, given an input x, to map x to a lower dimensional point y such that x can likely be recovered from y. The structure of the underlying autoencoder network can be chosen to represent the data on a smaller dimension, effectively compressing the input. Inspired by this idea, we introduce the model of a quantum autoencoder to perform similar tasks on quantum data. The quantum autoencoder is trained to compress a particular data set of quantum states, where a classical compression algorithm cannot be employed. The parameters of the quantum autoencoder are trained using classical optimization algorithms. We show an example of a simple programmable circuit that can be trained as an efficient autoencoder. We apply our model in the context of quantum simulation to compress ground states of the Hubbard model and molecular Hamiltonians.

  8. Compression of turbulent magnetized gas in giant molecular clouds

    Science.gov (United States)

    Birnboim, Yuval; Federrath, Christoph; Krumholz, Mark

    2018-01-01

    Interstellar gas clouds are often both highly magnetized and supersonically turbulent, with velocity dispersions set by a competition between driving and dissipation. This balance has been studied extensively in the context of gases with constant mean density. However, many astrophysical systems are contracting under the influence of external pressure or gravity, and the balance between driving and dissipation in a contracting, magnetized medium has yet to be studied. In this paper, we present three-dimensional magnetohydrodynamic simulations of compression in a turbulent, magnetized medium that resembles the physical conditions inside molecular clouds. We find that in some circumstances the combination of compression and magnetic fields leads to a rate of turbulent dissipation far less than that observed in non-magnetized gas, or in non-compressing magnetized gas. As a result, a compressing, magnetized gas reaches an equilibrium velocity dispersion much greater than would be expected for either the hydrodynamic or the non-compressing case. We use the simulation results to construct an analytic model that gives an effective equation of state for a coarse-grained parcel of the gas, in the form of an ideal equation of state with a polytropic index that depends on the dissipation and energy transfer rates between the magnetic and turbulent components. We argue that the reduced dissipation rate and larger equilibrium velocity dispersion has important implications for the driving and maintenance of turbulence in molecular clouds and for the rates of chemical and radiative processes that are sensitive to shocks and dissipation.

  9. The Effect of Foot Progression Angle on Knee Joint Compression Force during Walking

    DEFF Research Database (Denmark)

    Baldvinsson, Henrik Koblauch; Heilskov-Hansen, Thomas; Alkjær, Tine

    2013-01-01

    males walked at a fixed speed of 4.5 km/h under three conditions: Normal walking, internally rotated and externally rotated. All gait-trials were recorded by six infrared cameras. Net joint moments were calculated by 3D inverse dynamics. The results revealed that the medial knee joint compartment......It is unclear how rotations of the lower limb affect the knee joint compression forces during walking. Increases in the frontal plane knee moment have been reported when walking with internally rotated feet and a decrease when walking with externally rotated feet. The aim of this study...... was to investigate the knee joint compressive forces during walking with internal, external and normal foot rotation and to determine if the frontal plane knee joint moment is an adequate surrogate for the compression forces in the medial and lateral knee joint compartments under such gait modifications. Ten healthy...

  10. Compression etiology in tendinopathy.

    Science.gov (United States)

    Almekinders, Louis C; Weinhold, Paul S; Maffulli, Nicola

    2003-10-01

    Recent studies have emphasized that the etiology of tendinopathy is not as simple as was once thought. The etiology is likely to be multifactorial. Etiologic factors may include some of the traditional factors such as overuse, inflexibility, and equipment problems; however, other factors need to be considered as well, such as age-related tendon degeneration and biomechanical considerations as outlined in this article. More research is needed to determine the significance of stress-shielding and compression in tendinopathy. If they are confirmed to play a role, this finding may significantly alter our approach in both prevention and in treatment through exercise therapy. The current biomechanical studies indicate that certain joint positions are more likely to place tensile stress on the area of the tendon commonly affected by tendinopathy. These joint positions seem to be different than the traditional positions for stretching exercises used for prevention and rehabilitation of tendinopathic conditions. Incorporation of different joint positions during stretching exercises may exert more uniform, controlled tensile stress on these affected areas of the tendon and avoid stresshielding. These exercises may be able to better maintain the mechanical strength of that region of the tendon and thereby avoid injury. Alternatively, they could more uniformly stress a healing area of the tendon in a controlled manner, and thereby stimulate healing once an injury has occurred. Additional work will have to prove if a change in rehabilitation exercises is more efficacious that current techniques.

  11. Compressible Vortex Ring

    Science.gov (United States)

    Elavarasan, Ramasamy; Arakeri, Jayawant; Krothapalli, Anjaneyulu

    1999-11-01

    The interaction of a high-speed vortex ring with a shock wave is one of the fundamental issues as it is a source of sound in supersonic jets. The complex flow field induced by the vortex alters the propagation of the shock wave greatly. In order to understand the process, a compressible vortex ring is studied in detail using Particle Image Velocimetry (PIV) and shadowgraphic techniques. The high-speed vortex ring is generated from a shock tube and the shock wave, which precedes the vortex, is reflected back by a plate and made to interact with the vortex. The shadowgraph images indicate that the reflected shock front is influenced by the non-uniform flow induced by the vortex and is decelerated while passing through the vortex. It appears that after the interaction the shock is "split" into two. The PIV measurements provided clear picture about the evolution of the vortex at different time interval. The centerline velocity traces show the maximum velocity to be around 350 m/s. The velocity field, unlike in incompressible rings, contains contributions from both the shock and the vortex ring. The velocity distribution across the vortex core, core diameter and circulation are also calculated from the PIV data.

  12. Efficient temporal compression of coherent nanosecond pulses in compact SBS generator-amplifier setup

    OpenAIRE

    Schiemann, S.; Ubachs, W.M.G.; Hogervorst, W.

    1997-01-01

    A pulse compressor based on stimulated Brillouin scattering (SBS) in liquids is experimentally and theoretically investigated. It allows for the compression of Fourier-transform limited nanosecond pulses of several hundreds of millijoules of energy with both high conversion efficiency and a high temporal compression factor. The two-cell generator-amplifier arrangement is of a compact design not requiring external attenuation of the generator cell input energy. Pulses from an injection-seeded,...

  13. Applied Electromagnetics

    Energy Technology Data Exchange (ETDEWEB)

    Yamashita, H; Marinova, I; Cingoski, V [eds.

    2002-07-01

    These proceedings contain papers relating to the 3rd Japanese-Bulgarian-Macedonian Joint Seminar on Applied Electromagnetics. Included are the following groups: Numerical Methods I; Electrical and Mechanical System Analysis and Simulations; Inverse Problems and Optimizations; Software Methodology; Numerical Methods II; Applied Electromagnetics.

  14. Applied Electromagnetics

    International Nuclear Information System (INIS)

    Yamashita, H.; Marinova, I.; Cingoski, V.

    2002-01-01

    These proceedings contain papers relating to the 3rd Japanese-Bulgarian-Macedonian Joint Seminar on Applied Electromagnetics. Included are the following groups: Numerical Methods I; Electrical and Mechanical System Analysis and Simulations; Inverse Problems and Optimizations; Software Methodology; Numerical Methods II; Applied Electromagnetics

  15. Advances in compressible turbulent mixing

    International Nuclear Information System (INIS)

    Dannevik, W.P.; Buckingham, A.C.; Leith, C.E.

    1992-01-01

    This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately

  16. Mammography image compression using Wavelet

    International Nuclear Information System (INIS)

    Azuhar Ripin; Md Saion Salikin; Wan Hazlinda Ismail; Asmaliza Hashim; Norriza Md Isa

    2004-01-01

    Image compression plays an important role in many applications like medical imaging, televideo conferencing, remote sensing, document and facsimile transmission, which depend on the efficient manipulation, storage, and transmission of binary, gray scale, or color images. In Medical imaging application such Picture Archiving and Communication System (PACs), the image size or image stream size is too large and requires a large amount of storage space or high bandwidth for communication. Image compression techniques are divided into two categories namely lossy and lossless data compression. Wavelet method used in this project is a lossless compression method. In this method, the exact original mammography image data can be recovered. In this project, mammography images are digitized by using Vider Sierra Plus digitizer. The digitized images are compressed by using this wavelet image compression technique. Interactive Data Language (IDLs) numerical and visualization software is used to perform all of the calculations, to generate and display all of the compressed images. Results of this project are presented in this paper. (Author)

  17. Advances in compressible turbulent mixing

    Energy Technology Data Exchange (ETDEWEB)

    Dannevik, W.P.; Buckingham, A.C.; Leith, C.E. [eds.

    1992-01-01

    This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately.

  18. A measurement method for piezoelectric material properties under longitudinal compressive stress–-a compression test method for thin piezoelectric materials

    International Nuclear Information System (INIS)

    Kang, Lae-Hyong; Lee, Dae-Oen; Han, Jae-Hung

    2011-01-01

    We introduce a new compression test method for piezoelectric materials to investigate changes in piezoelectric properties under the compressive stress condition. Until now, compression tests of piezoelectric materials have been generally conducted using bulky piezoelectric ceramics and pressure block. The conventional method using the pressure block for thin piezoelectric patches, which are used in unimorph or bimorph actuators, is prone to unwanted bending and buckling. In addition, due to the constrained boundaries at both ends, the observed piezoelectric behavior contains boundary effects. In order to avoid these problems, the proposed method employs two guide plates with initial longitudinal tensile stress. By removing the tensile stress after bonding a piezoelectric material between the guide layers, longitudinal compressive stress is induced in the piezoelectric layer. Using the compression test specimens, two important properties, which govern the actuation performance of the piezoelectric material, the piezoelectric strain coefficients and the elastic modulus, are measured to evaluate the effects of applied electric fields and re-poling. The results show that the piezoelectric strain coefficient d 31 increases and the elastic modulus decreases when high voltage is applied to PZT5A, and the compression in the longitudinal direction decreases the piezoelectric strain coefficient d 31 but does not affect the elastic modulus. We also found that the re-poling of the piezoelectric material increases the elastic modulus, but the piezoelectric strain coefficient d 31 is not changed much (slightly increased) by re-poling

  19. Cladding creepdown under compression

    International Nuclear Information System (INIS)

    Hobson, D.O.

    1977-01-01

    Light-water power reactors use Zircaloy tubing as cladding to contain the UO 2 fuel pellets. In-service operating conditions impose an external hydrostatic force on the cladding, causing it to creep down into eventual contact with the fuel. Knowledge of the rate of such creepdown is of great importance to modelers of fuel element performance. An experimental system was devised for studying creepdown that meets several severe requirements by providing (1) correct stress state, (2) multiple positions for measuring radial displacement of the cladding surface, (3) high-precision data, and (4) an experimental configuration compact enough to fit in-reactor. A microcomputer-controlled, eddy-current monitoring system was developed for this study and has proven highly successful in measuring cladding deformation with time at temperatures of 371 0 C (700 0 F) and higher, and at pressures as high as 21 MPa

  20. Nonpainful wide-area compression inhibits experimental pain.

    Science.gov (United States)

    Honigman, Liat; Bar-Bachar, Ofrit; Yarnitsky, David; Sprecher, Elliot; Granovsky, Yelena

    2016-09-01

    Compression therapy, a well-recognized treatment for lymphoedema and venous disorders, pressurizes limbs and generates massive non-noxious afferent sensory barrages. The aim of this study was to study whether such afferent activity has an analgesic effect when applied on the lower limbs, hypothesizing that larger compression areas will induce stronger analgesic effects, and whether this effect correlates with conditioned pain modulation (CPM). Thirty young healthy subjects received painful heat and pressure stimuli (47°C for 30 seconds, forearm; 300 kPa for 15 seconds, wrist) before and during 3 compression protocols of either SMALL (up to ankles), MEDIUM (up to knees), or LARGE (up to hips) compression areas. Conditioned pain modulation (heat pain conditioned by noxious cold water) was tested before and after each compression protocol. The LARGE protocol induced more analgesia for heat than the SMALL protocol (P < 0.001). The analgesic effect interacted with gender (P = 0.015). The LARGE protocol was more efficient for females, whereas the MEDIUM protocol was more efficient for males. Pressure pain was reduced by all protocols (P < 0.001) with no differences between protocols and no gender effect. Conditioned pain modulation was more efficient than the compression-induced analgesia. For the LARGE protocol, precompression CPM efficiency positively correlated with compression-induced analgesia. Large body area compression exerts an area-dependent analgesic effect on experimental pain stimuli. The observed correlation with pain inhibition in response to robust non-noxious sensory stimulation may suggest that compression therapy shares similar mechanisms with inhibitory pain modulation assessed through CPM.

  1. Unilateral vestibular loss impairs external space representation.

    Directory of Open Access Journals (Sweden)

    Liliane Borel

    Full Text Available The vestibular system is responsible for a wide range of postural and oculomotor functions and maintains an internal, updated representation of the position and movement of the head in space. In this study, we assessed whether unilateral vestibular loss affects external space representation. Patients with Menière's disease and healthy participants were instructed to point to memorized targets in near (peripersonal and far (extrapersonal spaces in the absence or presence of a visual background. These individuals were also required to estimate their body pointing direction. Menière's disease patients were tested before unilateral vestibular neurotomy and during the recovery period (one week and one month after the operation, and healthy participants were tested at similar times. Unilateral vestibular loss impaired the representation of both the external space and the body pointing direction: in the dark, the configuration of perceived targets was shifted toward the lesioned side and compressed toward the contralesioned hemifield, with higher pointing error in the near space. Performance varied according to the time elapsed after neurotomy: deficits were stronger during the early stages, while gradual compensation occurred subsequently. These findings provide the first demonstration of the critical role of vestibular signals in the representation of external space and of body pointing direction in the early stages after unilateral vestibular loss.

  2. Cartesian anisotropic mesh adaptation for compressible flow

    International Nuclear Information System (INIS)

    Keats, W.A.; Lien, F.-S.

    2004-01-01

    Simulating transient compressible flows involving shock waves presents challenges to the CFD practitioner in terms of the mesh quality required to resolve discontinuities and prevent smearing. This paper discusses a novel two-dimensional Cartesian anisotropic mesh adaptation technique implemented for compressible flow. This technique, developed for laminar flow by Ham, Lien and Strong, is efficient because it refines and coarsens cells using criteria that consider the solution in each of the cardinal directions separately. In this paper the method will be applied to compressible flow. The procedure shows promise in its ability to deliver good quality solutions while achieving computational savings. The convection scheme used is the Advective Upstream Splitting Method (Plus), and the refinement/ coarsening criteria are based on work done by Ham et al. Transient shock wave diffraction over a backward step and shock reflection over a forward step are considered as test cases because they demonstrate that the quality of the solution can be maintained as the mesh is refined and coarsened in time. The data structure is explained in relation to the computational mesh, and the object-oriented design and implementation of the code is presented. Refinement and coarsening algorithms are outlined. Computational savings over uniform and isotropic mesh approaches are shown to be significant. (author)

  3. Context-Aware Image Compression.

    Directory of Open Access Journals (Sweden)

    Jacky C K Chan

    Full Text Available We describe a physics-based data compression method inspired by the photonic time stretch wherein information-rich portions of the data are dilated in a process that emulates the effect of group velocity dispersion on temporal signals. With this coding operation, the data can be downsampled at a lower rate than without it. In contrast to previous implementation of the warped stretch compression, here the decoding can be performed without the need of phase recovery. We present rate-distortion analysis and show improvement in PSNR compared to compression via uniform downsampling.

  4. Compressive sensing for urban radar

    CERN Document Server

    Amin, Moeness

    2014-01-01

    With the emergence of compressive sensing and sparse signal reconstruction, approaches to urban radar have shifted toward relaxed constraints on signal sampling schemes in time and space, and to effectively address logistic difficulties in data acquisition. Traditionally, these challenges have hindered high resolution imaging by restricting both bandwidth and aperture, and by imposing uniformity and bounds on sampling rates.Compressive Sensing for Urban Radar is the first book to focus on a hybrid of two key areas: compressive sensing and urban sensing. It explains how reliable imaging, tracki

  5. Rayleigh theory of ultrasound scattering applied to liquid-filled contrast nanoparticles.

    Science.gov (United States)

    Flegg, M B; Poole, C M; Whittaker, A K; Keen, I; Langton, C M

    2010-06-07

    We present a novel modified theory based upon Rayleigh scattering of ultrasound from composite nanoparticles with a liquid core and solid shell. We derive closed form solutions to the scattering cross-section and have applied this model to an ultrasound contrast agent consisting of a liquid-filled core (perfluorooctyl bromide, PFOB) encapsulated by a polymer shell (poly-caprolactone, PCL). Sensitivity analysis was performed to predict the dependence of the scattering cross-section upon material and dimensional parameters. A rapid increase in the scattering cross-section was achieved by increasing the compressibility of the core, validating the incorporation of high compressibility PFOB; the compressibility of the shell had little impact on the overall scattering cross-section although a more compressible shell is desirable. Changes in the density of the shell and the core result in predicted local minima in the scattering cross-section, approximately corresponding to the PFOB-PCL contrast agent considered; hence, incorporation of a lower shell density could potentially significantly improve the scattering cross-section. A 50% reduction in shell thickness relative to external radius increased the predicted scattering cross-section by 50%. Although it has often been considered that the shell has a negative effect on the echogeneity due to its low compressibility, we have shown that it can potentially play an important role in the echogeneity of the contrast agent. The challenge for the future is to identify suitable shell and core materials that meet the predicted characteristics in order to achieve optimal echogenity.

  6. CMOS Compressed Imaging by Random Convolution

    OpenAIRE

    Jacques, Laurent; Vandergheynst, Pierre; Bibet, Alexandre; Majidzadeh, Vahid; Schmid, Alexandre; Leblebici, Yusuf

    2009-01-01

    We present a CMOS imager with built-in capability to perform Compressed Sensing. The adopted sensing strategy is the random Convolution due to J. Romberg. It is achieved by a shift register set in a pseudo-random configuration. It acts as a convolutive filter on the imager focal plane, the current issued from each CMOS pixel undergoing a pseudo-random redirection controlled by each component of the filter sequence. A pseudo-random triggering of the ADC reading is finally applied to comp...

  7. Diffusion tensor imaging in spinal cord compression

    International Nuclear Information System (INIS)

    Wang, Wei; Qin, Wen; Hao, Nanxin; Wang, Yibin; Zong, Genlin

    2012-01-01

    Background Although diffusion tensor imaging has been successfully applied in brain research for decades, several main difficulties have hindered its extended utilization in spinal cord imaging. Purpose To assess the feasibility and clinical value of diffusion tensor imaging and tractography for evaluating chronic spinal cord compression. Material and Methods Single-shot spin-echo echo-planar DT sequences were scanned in 42 spinal cord compression patients and 49 healthy volunteers. The mean values of the apparent diffusion coefficient and fractional anisotropy were measured in region of interest at the cervical and lower thoracic spinal cord. The patients were divided into two groups according to the high signal on T2WI (the SCC-HI group and the SCC-nHI group for with or without high signal). A one-way ANOVA was used. Diffusion tensor tractography was used to visualize the morphological features of normal and impaired white matter. Results There were no statistically significant differences in the apparent diffusion coefficient and fractional anisotropy values between the different spinal cord segments of the normal subjects. All of the patients in the SCC-HI group had increased apparent diffusion coefficient values and decreased fractional anisotropy values at the lesion level compared to the normal controls. However, there were no statistically significant diffusion index differences between the SCC-nHI group and the normal controls. In the diffusion tensor imaging maps, the normal spinal cord sections were depicted as fiber tracts that were color-encoded to a cephalocaudal orientation. The diffusion tensor images were compressed to different degrees in all of the patients. Conclusion Diffusion tensor imaging and tractography are promising methods for visualizing spinal cord tracts and can provide additional information in clinical studies in spinal cord compression

  8. Effect of Kollidon VA®64 particle size and morphology as directly compressible excipient on tablet compression properties.

    Science.gov (United States)

    Chaudhary, R S; Patel, C; Sevak, V; Chan, M

    2018-01-01

    The study evaluates use of Kollidon VA ® 64 and a combination of Kollidon VA ® 64 with Kollidon VA ® 64 Fine as excipient in direct compression process of tablets. The combination of the two grades of material is evaluated for capping, lamination and excessive friability. Inter particulate void space is higher for such excipient due to the hollow structure of the Kollidon VA ® 64 particles. During tablet compression air remains trapped in the blend exhibiting poor compression with compromised physical properties of the tablets. Composition of Kollidon VA ® 64 and Kollidon VA ® 64 Fine is evaluated by design of experiment (DoE). A scanning electron microscopy (SEM) of two grades of Kollidon VA ® 64 exhibits morphological differences between coarse and fine grade. The tablet compression process is evaluated with a mix consisting of entirely Kollidon VA ® 64 and two mixes containing Kollidon VA ® 64 and Kollidon VA ® 64 Fine in ratio of 77:23 and 65:35. A statistical modeling on the results from the DoE trials resulted in the optimum composition for direct tablet compression as combination of Kollidon VA ® 64 and Kollidon VA ® 64 Fine in ratio of 77:23. This combination compressed with the predicted parameters based on the statistical modeling and applying main compression force between 5 and 15 kN, pre-compression force between 2 and 3 kN, feeder speed fixed at 25 rpm and compression range of 45-49 rpm produced tablets with hardness ranging between 19 and 21 kp, with no friability, capping, or lamination issue.

  9. Poor chest compression quality with mechanical compressions in simulated cardiopulmonary resuscitation: a randomized, cross-over manikin study.

    Science.gov (United States)

    Blomberg, Hans; Gedeborg, Rolf; Berglund, Lars; Karlsten, Rolf; Johansson, Jakob

    2011-10-01

    Mechanical chest compression devices are being implemented as an aid in cardiopulmonary resuscitation (CPR), despite lack of evidence of improved outcome. This manikin study evaluates the CPR-performance of ambulance crews, who had a mechanical chest compression device implemented in their routine clinical practice 8 months previously. The objectives were to evaluate time to first defibrillation, no-flow time, and estimate the quality of compressions. The performance of 21 ambulance crews (ambulance nurse and emergency medical technician) with the authorization to perform advanced life support was studied in an experimental, randomized cross-over study in a manikin setup. Each crew performed two identical CPR scenarios, with and without the aid of the mechanical compression device LUCAS. A computerized manikin was used for data sampling. There were no substantial differences in time to first defibrillation or no-flow time until first defibrillation. However, the fraction of adequate compressions in relation to total compressions was remarkably low in LUCAS-CPR (58%) compared to manual CPR (88%) (95% confidence interval for the difference: 13-50%). Only 12 out of the 21 ambulance crews (57%) applied the mandatory stabilization strap on the LUCAS device. The use of a mechanical compression aid was not associated with substantial differences in time to first defibrillation or no-flow time in the early phase of CPR. However, constant but poor chest compressions due to failure in recognizing and correcting a malposition of the device may counteract a potential benefit of mechanical chest compressions. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  10. ExternE transport methodology for external cost evaluation of air pollution

    DEFF Research Database (Denmark)

    Jensen, S. S.; Berkowicz, R.; Brandt, J.

    The report describes how the human exposure estimates based on NERI's human exposure modelling system (AirGIS) can improve the Danish data used for exposure factors in the ExternE Transport methodology. Initially, a brief description of the ExternE Tranport methodology is given and it is summarised...

  11. Mammographic compression – A need for mechanical standardization

    Energy Technology Data Exchange (ETDEWEB)

    Branderhorst, Woutjan, E-mail: w.branderhorst@amc.nl [Academic Medical Center, Department of Biomedical Engineering & Physics, P.O. Box 22660, 1100 DD Amsterdam (Netherlands); Sigmascreening B.V., Meibergdreef 45, 1105 BA Amsterdam (Netherlands); Groot, Jerry E. de, E-mail: jerry.degroot@sigmascreening.com [Academic Medical Center, Department of Biomedical Engineering & Physics, P.O. Box 22660, 1100 DD Amsterdam (Netherlands); Highnam, Ralph, E-mail: ralph.highnam@volparasolutions.com [Volpara Solutions Limited, P.O. Box 24404, Manners St Central, Wellington 6142 (New Zealand); Chan, Ariane, E-mail: ariane.chan@volparasolutions.com [Volpara Solutions Limited, P.O. Box 24404, Manners St Central, Wellington 6142 (New Zealand); Böhm-Vélez, Marcela, E-mail: marcelabvelez@gmail.com [Weinstein Imaging Associates, 5850 Centre Avenue, Pittsburgh, PA 15206 (United States); Broeders, Mireille J.M., E-mail: mireille.broeders@radboudumc.nl [Radboud University Medical Center, Department for Health Evidence, P.O. Box 9101, 6500 HB Nijmegen (Netherlands); LRCB Dutch Reference Center for Screening, P.O. Box 6873, 6503 GJ Nijmegen (Netherlands); Heeten, Gerard J. den, E-mail: g.denheeten@lrcb.nl [Academic Medical Center, Department of Radiology, P.O. Box 22660, 1100 DD Amsterdam (Netherlands); LRCB Dutch Reference Center for Screening, P.O. Box 6873, 6503 GJ Nijmegen (Netherlands); Grimbergen, Cornelis A., E-mail: c.a.grimbergen@amc.uva.nl [Academic Medical Center, Department of Biomedical Engineering & Physics, P.O. Box 22660, 1100 DD Amsterdam (Netherlands); Sigmascreening B.V., Meibergdreef 45, 1105 BA Amsterdam (Netherlands)

    2015-04-15

    Highlights: •We studied mechanical breast compression practice in two different clinical sites. •We visualized the distributions of not only the applied force but also the pressure. •The applied pressure was highly variable, both within and between the data sets. •The average applied pressure and the variation were higher for smaller breasts. •A proposal for improved individualization, by standardizing pressure, is discussed. -- Abstract: Background: A lack of consistent guidelines regarding mammographic compression has led to wide variation in its technical execution. Breast compression is accomplished by means of a compression paddle, resulting in a certain contact area between the paddle and the breast. This procedure is associated with varying levels of discomfort or pain. On current mammography systems, the only mechanical parameter available in estimating the degree of compression is the physical entity of force (daN). Recently, researchers have suggested that pressure (kPa), resulting from a specific force divided by contact area on a breast, might be a more appropriate parameter for standardization. Software has now become available which enables device-independent cross-comparisons of key mammographic metrics, such as applied compression pressure (force divided by contact area), breast density and radiation dose, between patient populations. Purpose: To compare the current compression practice in mammography between different imaging sites in the Netherlands and the United States from a mechanical point of view, and to investigate whether the compression protocols in these countries can be improved by standardization of pressure (kPa) as an objective mechanical parameter. Materials and methods: We retrospectively studied the available parameters of a set of 37,518 mammographic compressions (9188 women) from the Dutch national breast cancer screening programme (NL data set) and of another set of 7171 compressions (1851 women) from a breast imaging

  12. Checklists for external validity

    DEFF Research Database (Denmark)

    Dyrvig, Anne-Kirstine; Kidholm, Kristian; Gerke, Oke

    2014-01-01

    to an implementation setting. In this paper, currently available checklists on external validity are identified, assessed and used as a basis for proposing a new improved instrument. METHOD: A systematic literature review was carried out in Pubmed, Embase and Cinahl on English-language papers without time restrictions....... The retrieved checklist items were assessed for (i) the methodology used in primary literature, justifying inclusion of each item; and (ii) the number of times each item appeared in checklists. RESULTS: Fifteen papers were identified, presenting a total of 21 checklists for external validity, yielding a total...... of 38 checklist items. Empirical support was considered the most valid methodology for item inclusion. Assessment of methodological justification showed that none of the items were supported empirically. Other kinds of literature justified the inclusion of 22 of the items, and 17 items were included...

  13. Applied superconductivity

    CERN Document Server

    Newhouse, Vernon L

    1975-01-01

    Applied Superconductivity, Volume II, is part of a two-volume series on applied superconductivity. The first volume dealt with electronic applications and radiation detection, and contains a chapter on liquid helium refrigeration. The present volume discusses magnets, electromechanical applications, accelerators, and microwave and rf devices. The book opens with a chapter on high-field superconducting magnets, covering applications and magnet design. Subsequent chapters discuss superconductive machinery such as superconductive bearings and motors; rf superconducting devices; and future prospec

  14. Methods of compression of digital holograms, based on 1-level wavelet transform

    International Nuclear Information System (INIS)

    Kurbatova, E A; Cheremkhin, P A; Evtikhiev, N N

    2016-01-01

    To reduce the size of memory required for storing information about 3D-scenes and to decrease the rate of hologram transmission, digital hologram compression can be used. Compression of digital holograms by wavelet transforms is among most powerful methods. In the paper the most popular wavelet transforms are considered and applied to the digital hologram compression. Obtained values of reconstruction quality and hologram's diffraction efficiencies are compared. (paper)

  15. Medical Image Compression Based on Vector Quantization with Variable Block Sizes in Wavelet Domain

    OpenAIRE

    Jiang, Huiyan; Ma, Zhiyuan; Hu, Yang; Yang, Benqiang; Zhang, Libo

    2012-01-01

    An optimized medical image compression algorithm based on wavelet transform and improved vector quantization is introduced. The goal of the proposed method is to maintain the diagnostic-related information of the medical image at a high compression ratio. Wavelet transformation was first applied to the image. For the lowest-frequency subband of wavelet coefficients, a lossless compression method was exploited; for each of the high-frequency subbands, an optimized vector quantization with vari...

  16. Compressed gas fuel storage system

    Science.gov (United States)

    Wozniak, John J.; Tiller, Dale B.; Wienhold, Paul D.; Hildebrand, Richard J.

    2001-01-01

    A compressed gas vehicle fuel storage system comprised of a plurality of compressed gas pressure cells supported by shock-absorbing foam positioned within a shape-conforming container. The container is dimensioned relative to the compressed gas pressure cells whereby a radial air gap surrounds each compressed gas pressure cell. The radial air gap allows pressure-induced expansion of the pressure cells without resulting in the application of pressure to adjacent pressure cells or physical pressure to the container. The pressure cells are interconnected by a gas control assembly including a thermally activated pressure relief device, a manual safety shut-off valve, and means for connecting the fuel storage system to a vehicle power source and a refueling adapter. The gas control assembly is enclosed by a protective cover attached to the container. The system is attached to the vehicle with straps to enable the chassis to deform as intended in a high-speed collision.

  17. Compressed sensing for distributed systems

    CERN Document Server

    Coluccia, Giulio; Magli, Enrico

    2015-01-01

    This book presents a survey of the state-of-the art in the exciting and timely topic of compressed sensing for distributed systems. It has to be noted that, while compressed sensing has been studied for some time now, its distributed applications are relatively new. Remarkably, such applications are ideally suited to exploit all the benefits that compressed sensing can provide. The objective of this book is to provide the reader with a comprehensive survey of this topic, from the basic concepts to different classes of centralized and distributed reconstruction algorithms, as well as a comparison of these techniques. This book collects different contributions on these aspects. It presents the underlying theory in a complete and unified way for the first time, presenting various signal models and their use cases. It contains a theoretical part collecting latest results in rate-distortion analysis of distributed compressed sensing, as well as practical implementations of algorithms obtaining performance close to...

  18. Nonlinear compression of optical solitons

    Indian Academy of Sciences (India)

    linear pulse propagation is the nonlinear Schrödinger (NLS) equation [1]. There are ... Optical pulse compression finds important applications in optical fibres. The pulse com ..... to thank CSIR, New Delhi for financial support in the form of SRF.

  19. Transversely Compressed Bonded Joints

    DEFF Research Database (Denmark)

    Hansen, Christian Skodborg; Schmidt, Jacob Wittrup; Stang, Henrik

    2012-01-01

    The load capacity of bonded joints can be increased if transverse pressure is applied at the interface. The transverse pressure is assumed to introduce a Coulomb-friction contribution to the cohesive law for the interface. Response and load capacity for a bonded single-lap joint was derived using...

  20. Compression force-depth relationship during out-of-hospital cardiopulmonary resuscitation.

    Science.gov (United States)

    Tomlinson, A E; Nysaether, J; Kramer-Johansen, J; Steen, P A; Dorph, E

    2007-03-01

    Recent clinical studies reporting the high frequency of inadequate chest compression depth (compression depth in certain patients. Using a specially designed monitor/defibrillator equipped with a sternal pad fitted with an accelerometer and a pressure sensor, compression force and depth was measured during CPR in 91 adult out-of-hospital cardiac arrest patients. There was a strong non-linear relationship between the force of compression and depth achieved. Mean applied force for all patients was 30.3+/-8.2 kg and mean absolute compression depth 42+/-8 mm. For 87 of 91 patients 38 mm compression depth was obtained with less than 50 kg. Stiffer chests were compressed more forcefully than softer chests (pcompressed more deeply than stiffer chests (p=0.001). The force needed to reach 38 mm compression depth (F38) and mean compression force were higher for males than for females: 29.8+/-14.5 kg versus 22.5+/-10.2 kg (pcompression depth with age, but a significant 1.5 kg mean decrease in applied force for each 10 years increase in age (pcompressions performed. Average residual force during decompression was 1.7+/-1.0 kg, corresponding to an average residual depth of 3+/-2 mm. In most out-of-hospital cardiac arrest victims adequate chest compression depth can be achieved by a force<50 kg, indicating that an average sized and fit rescuer should be able to perform effective CPR in most adult patients.

  1. Crystal growth under external electric fields

    International Nuclear Information System (INIS)

    Uda, Satoshi; Koizumi, Haruhiko; Nozawa, Jun; Fujiwara, Kozo

    2014-01-01

    This is a review article concerning the crystal growth under external electric fields that has been studied in our lab for the past 10 years. An external field is applied electrostatically either through an electrically insulating phase or a direct injection of an electric current to the solid-interface-liquid. The former changes the chemical potential of both solid and liquid and controls the phase relationship while the latter modifies the transport and partitioning of ionic solutes in the oxide melt during crystallization and changes the solute distribution in the crystal

  2. Crystal growth under external electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Uda, Satoshi; Koizumi, Haruhiko; Nozawa, Jun; Fujiwara, Kozo [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)

    2014-10-06

    This is a review article concerning the crystal growth under external electric fields that has been studied in our lab for the past 10 years. An external field is applied electrostatically either through an electrically insulating phase or a direct injection of an electric current to the solid-interface-liquid. The former changes the chemical potential of both solid and liquid and controls the phase relationship while the latter modifies the transport and partitioning of ionic solutes in the oxide melt during crystallization and changes the solute distribution in the crystal.

  3. Indentation size effect and the plastic compressibility of glass

    Energy Technology Data Exchange (ETDEWEB)

    Smedskjaer, Morten M., E-mail: mos@bio.aau.dk [Section of Chemistry, Aalborg University, 9000 Aalborg (Denmark)

    2014-06-23

    Oxide glasses exhibit significant densification under an applied isostatic pressure at the glass transition temperature. The glass compressibility is correlated with the chemical composition and atomic packing density, e.g., borate glasses with planar triangular BO{sub 3} units are more disposed for densification than silicate glasses with tetrahedral units. We here show that there is a direct relation between the plastic compressibility following hot isostatic compression and the extent of the indentation size effect (ISE), which is the decrease of hardness with indentation load exhibited by most materials. This could suggest that the ISE is correlated with indentation-induced shear bands, which should form in greater density when the glass network is more adaptable to volume changes through structural and topological rearrangements under an applied pressure.

  4. Femoral Component External Rotation Affects Knee Biomechanics: A Computational Model of Posterior-stabilized TKA.

    Science.gov (United States)

    Kia, Mohammad; Wright, Timothy M; Cross, Michael B; Mayman, David J; Pearle, Andrew D; Sculco, Peter K; Westrich, Geoffrey H; Imhauser, Carl W

    2018-01-01

    The correct amount of external rotation of the femoral component during TKA is controversial because the resulting changes in biomechanical knee function associated with varying degrees of femoral component rotation are not well understood. We addressed this question using a computational model, which allowed us to isolate the biomechanical impact of geometric factors including bony shapes, location of ligament insertions, and implant size across three different knees after posterior-stabilized (PS) TKA. Using a computational model of the tibiofemoral joint, we asked: (1) Does external rotation unload the medial collateral ligament (MCL) and what is the effect on lateral collateral ligament tension? (2) How does external rotation alter tibiofemoral contact loads and kinematics? (3) Does 3° external rotation relative to the posterior condylar axis align the component to the surgical transepicondylar axis (sTEA) and what anatomic factors of the femoral condyle explain variations in maximum MCL tension among knees? We incorporated a PS TKA into a previously developed computational knee model applied to three neutrally aligned, nonarthritic, male cadaveric knees. The computational knee model was previously shown to corroborate coupled motions and ligament loading patterns of the native knee through a range of flexion. Implant geometries were virtually installed using hip-to-ankle CT scans through measured resection and anterior referencing surgical techniques. Collateral ligament properties were standardized across each knee model by defining stiffness and slack lengths based on the healthy population. The femoral component was externally rotated from 0° to 9° relative to the posterior condylar axis in 3° increments. At each increment, the knee was flexed under 500 N compression from 0° to 90° simulating an intraoperative examination. The computational model predicted collateral ligament forces, compartmental contact forces, and tibiofemoral internal/external and

  5. Image Segmentation, Registration, Compression, and Matching

    Science.gov (United States)

    Yadegar, Jacob; Wei, Hai; Yadegar, Joseph; Ray, Nilanjan; Zabuawala, Sakina

    2011-01-01

    A novel computational framework was developed of a 2D affine invariant matching exploiting a parameter space. Named as affine invariant parameter space (AIPS), the technique can be applied to many image-processing and computer-vision problems, including image registration, template matching, and object tracking from image sequence. The AIPS is formed by the parameters in an affine combination of a set of feature points in the image plane. In cases where the entire image can be assumed to have undergone a single affine transformation, the new AIPS match metric and matching framework becomes very effective (compared with the state-of-the-art methods at the time of this reporting). No knowledge about scaling or any other transformation parameters need to be known a priori to apply the AIPS framework. An automated suite of software tools has been created to provide accurate image segmentation (for data cleaning) and high-quality 2D image and 3D surface registration (for fusing multi-resolution terrain, image, and map data). These tools are capable of supporting existing GIS toolkits already in the marketplace, and will also be usable in a stand-alone fashion. The toolkit applies novel algorithmic approaches for image segmentation, feature extraction, and registration of 2D imagery and 3D surface data, which supports first-pass, batched, fully automatic feature extraction (for segmentation), and registration. A hierarchical and adaptive approach is taken for achieving automatic feature extraction, segmentation, and registration. Surface registration is the process of aligning two (or more) data sets to a common coordinate system, during which the transformation between their different coordinate systems is determined. Also developed here are a novel, volumetric surface modeling and compression technique that provide both quality-guaranteed mesh surface approximations and compaction of the model sizes by efficiently coding the geometry and connectivity

  6. Strength properties of interlocking compressed earth brick units

    Science.gov (United States)

    Saari, S.; Bakar, B. H. Abu; Surip, N. A.

    2017-10-01

    This study presents a laboratory investigation on the properties of interlocking compressed earth brick (ICEB) units. Compressive strength, which is one of the most important properties in masonry structures, is used to determine masonry performance. The compressive strength of the ICEB units was determined by applying a compressive strength test for 340 units from four types of ICEB. To analyze the strength of the ICEB units, each unit was capped by a steel plate at the top and bottom to create a flat surface, and then ICEB was loaded until failure. The average compressive strength of the corresponding ICEB units are as follows: wall brick, 19.15 N/mm2; beam brick, 16.99 N/mm2; column brick, 13.18 N/mm2; and half brick, 11.79 N/mm2. All the ICEB units had compressive strength of over 5 N/mm2, which is the minimum strength for a load-bearing brick. This study proves that ICEB units may be used as load-bearing bricks. The strength of ICEBs is equal to that of other common bricks and blocks that are currently available in the market.

  7. Potential Flow Model for Compressible Stratified Rayleigh-Taylor Instability

    Science.gov (United States)

    Rydquist, Grant; Reckinger, Scott; Owkes, Mark; Wieland, Scott

    2017-11-01

    The Rayleigh-Taylor Instability (RTI) is an instability that occurs when a heavy fluid lies on top of a lighter fluid in a gravitational field, or a gravity-like acceleration. It occurs in many fluid flows of a highly compressive nature. In this study potential flow analysis (PFA) is used to model the early stages of RTI growth for compressible fluids. In the localized region near the bubble tip, the effects of vorticity are negligible, so PFA is applicable, as opposed to later stages where the induced velocity due to vortices generated from the growth of the instability dominate the flow. The incompressible PFA is extended for compressibility effects by applying the growth rate and the associated perturbation spatial decay from compressible linear stability theory. The PFA model predicts theoretical values for a bubble terminal velocity for single-mode compressible RTI, dependent upon the Atwood (A) and Mach (M) numbers, which is a parameter that measures both the strength of the stratification and intrinsic compressibility. The theoretical bubble terminal velocities are compared against numerical simulations. The PFA model correctly predicts the M dependence at high A, but the model must be further extended to include additional physics to capture the behavior at low A. Undergraduate Scholars Program - Montana State University.

  8. International magnetic pulse compression workshop: (Proceedings)

    Energy Technology Data Exchange (ETDEWEB)

    Kirbie, H.C.; Newton, M.A.; Siemens, P.D.

    1991-04-01

    A few individuals have tried to broaden the understanding of specific and salient pulsed-power topics. One such attempt is this documentation of a workshop on magnetic switching as it applies primarily to pulse compression (power transformation), affording a truly international perspective by its participants under the initiative and leadership of Hugh Kirbie and Mark Newton of the Lawrence Livermore National Laboratory (LLNL) and supported by other interested organizations. During the course of the Workshop at Granlibakken, a great deal of information was amassed and a keen insight into both the problems and opportunities as to the use of this switching approach was developed. The segmented workshop format proved ideal for identifying key aspects affecting optimum performance in a variety of applications. Individual groups of experts addressed network and system modeling, magnetic materials, power conditioning, core cooling and dielectrics, and finally circuits and application. At the end, they came together to consolidate their input and formulate the workshop's conclusions, identifying roadblocks or suggesting research projects, particularly as they apply to magnetic switching's trump card--its high-average-power-handling capability (at least on a burst-mode basis). The workshop was especially productive both in the quality and quantity of information transfer in an environment conducive to a free and open exchange of ideas. We will not delve into the organization proper of this meeting, rather we wish to commend to the interested reader this volume, which provides the definitive and most up-to-date compilation on the subject of magnetic pulse compression from underlying principles to current state of the art as well as the prognosis for the future of magnetic pulse compression as a consensus of the workshop's organizers and participants.

  9. International magnetic pulse compression workshop: [Proceedings

    International Nuclear Information System (INIS)

    Kirbie, H.C.; Newton, M.A.; Siemens, P.D.

    1991-04-01

    A few individuals have tried to broaden the understanding of specific and salient pulsed-power topics. One such attempt is this documentation of a workshop on magnetic switching as it applies primarily to pulse compression (power transformation), affording a truly international perspective by its participants under the initiative and leadership of Hugh Kirbie and Mark Newton of the Lawrence Livermore National Laboratory (LLNL) and supported by other interested organizations. During the course of the Workshop at Granlibakken, a great deal of information was amassed and a keen insight into both the problems and opportunities as to the use of this switching approach was developed. The segmented workshop format proved ideal for identifying key aspects affecting optimum performance in a variety of applications. Individual groups of experts addressed network and system modeling, magnetic materials, power conditioning, core cooling and dielectrics, and finally circuits and application. At the end, they came together to consolidate their input and formulate the workshop's conclusions, identifying roadblocks or suggesting research projects, particularly as they apply to magnetic switching's trump card--its high-average-power-handling capability (at least on a burst-mode basis). The workshop was especially productive both in the quality and quantity of information transfer in an environment conducive to a free and open exchange of ideas. We will not delve into the organization proper of this meeting, rather we wish to commend to the interested reader this volume, which provides the definitive and most up-to-date compilation on the subject of magnetic pulse compression from underlying principles to current state of the art as well as the prognosis for the future of magnetic pulse compression as a consensus of the workshop's organizers and participants

  10. Applied mathematics

    CERN Document Server

    Logan, J David

    2013-01-01

    Praise for the Third Edition"Future mathematicians, scientists, and engineers should find the book to be an excellent introductory text for coursework or self-study as well as worth its shelf space for reference." -MAA Reviews Applied Mathematics, Fourth Edition is a thoroughly updated and revised edition on the applications of modeling and analyzing natural, social, and technological processes. The book covers a wide range of key topics in mathematical methods and modeling and highlights the connections between mathematics and the applied and nat

  11. Landscape externalities from onshore wind power

    International Nuclear Information System (INIS)

    Meyerhoff, Juergen; Ohl, Cornelia; Hartje, Volkmar

    2010-01-01

    The expansion of renewable energy is a central element of the German Federal Government's climate and energy policy. The target for 2020 is to produce 30% of the electricity from renewable energies. Wind power has been selected to be a major contributor to this change. Replacing old wind turbines by modern ones and building new turbines on land will be crucial in meeting this target. However, the expansion of onshore wind power is not universally accepted. In several regions of Germany residents are protesting against setting up new wind turbines. To determine the negative effects two choice experiments were applied in Westsachsen and Nordhessen, Germany. In both regions the externalities of wind power generation until 2020 based on today's state of technology were measured. The results show that negative landscape externalities would result from expanding wind power generation. Using latent class models three different groups of respondents experiencing different degrees of externalities were identified.

  12. 29 CFR 1917.154 - Compressed air.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Compressed air. 1917.154 Section 1917.154 Labor Regulations...) MARINE TERMINALS Related Terminal Operations and Equipment § 1917.154 Compressed air. Employees shall be... this part during cleaning with compressed air. Compressed air used for cleaning shall not exceed a...

  13. Double-compression method for biomedical images

    Science.gov (United States)

    Antonenko, Yevhenii A.; Mustetsov, Timofey N.; Hamdi, Rami R.; Małecka-Massalska, Teresa; Orshubekov, Nurbek; DzierŻak, RóŻa; Uvaysova, Svetlana

    2017-08-01

    This paper describes a double compression method (DCM) of biomedical images. A comparison of image compression factors in size JPEG, PNG and developed DCM was carried out. The main purpose of the DCM - compression of medical images while maintaining the key points that carry diagnostic information. To estimate the minimum compression factor an analysis of the coding of random noise image is presented.

  14. A compressibility based model for predicting the tensile strength of directly compressed pharmaceutical powder mixtures.

    Science.gov (United States)

    Reynolds, Gavin K; Campbell, Jacqueline I; Roberts, Ron J

    2017-10-05

    A new model to predict the compressibility and compactability of mixtures of pharmaceutical powders has been developed. The key aspect of the model is consideration of the volumetric occupancy of each powder under an applied compaction pressure and the respective contribution it then makes to the mixture properties. The compressibility and compactability of three pharmaceutical powders: microcrystalline cellulose, mannitol and anhydrous dicalcium phosphate have been characterised. Binary and ternary mixtures of these excipients have been tested and used to demonstrate the predictive capability of the model. Furthermore, the model is shown to be uniquely able to capture a broad range of mixture behaviours, including neutral, negative and positive deviations, illustrating its utility for formulation design. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Compression and rupture cycles as tools for compressibility characterization application to apatitic calcium phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Pontier, C. [S.P.C.T.S., Faculte des Sciences, Limoges (France); G.E.F., Faculte de Pharmacie, Limoges (France); Viana, M.; Chulia, D. [G.E.F., Faculte de Pharmacie, Limoges (France); Champion, E.; Bernache-Assollant, D. [S.P.C.T.S., Faculte des Sciences, Limoges (France)

    2002-07-01

    Measurement of the cycles of compression and rupture helps to understand the phenomena occurring during compaction. Different parameters are deduced from the cycles, such as the packing of the material and energies used during compression. The ratio between the energy of rupture and the energy of compaction defines the efficacy of compaction of the materials. This technique is applied to ceramic materials using apatitic calcium phosphates with a Ca/P molar ratio of 1.5 (apatitic tricalcium phosphate and {beta}-tricalcium phosphate) and 1.667 (stoichiometric hydroxyapatite). The methodology uses a uniaxial instrumented press to plot the cycles of compaction and rupture. The results point out the good compaction and cohesion properties of apatitic tricalcium phosphate, compared to the other apatitic materials. (orig.)

  16. Perceptual Image Compression in Telemedicine

    Science.gov (United States)

    Watson, Andrew B.; Ahumada, Albert J., Jr.; Eckstein, Miguel; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    The next era of space exploration, especially the "Mission to Planet Earth" will generate immense quantities of image data. For example, the Earth Observing System (EOS) is expected to generate in excess of one terabyte/day. NASA confronts a major technical challenge in managing this great flow of imagery: in collection, pre-processing, transmission to earth, archiving, and distribution to scientists at remote locations. Expected requirements in most of these areas clearly exceed current technology. Part of the solution to this problem lies in efficient image compression techniques. For much of this imagery, the ultimate consumer is the human eye. In this case image compression should be designed to match the visual capacities of the human observer. We have developed three techniques for optimizing image compression for the human viewer. The first consists of a formula, developed jointly with IBM and based on psychophysical measurements, that computes a DCT quantization matrix for any specified combination of viewing distance, display resolution, and display brightness. This DCT quantization matrix is used in most recent standards for digital image compression (JPEG, MPEG, CCITT H.261). The second technique optimizes the DCT quantization matrix for each individual image, based on the contents of the image. This is accomplished by means of a model of visual sensitivity to compression artifacts. The third technique extends the first two techniques to the realm of wavelet compression. Together these two techniques will allow systematic perceptual optimization of image compression in NASA imaging systems. Many of the image management challenges faced by NASA are mirrored in the field of telemedicine. Here too there are severe demands for transmission and archiving of large image databases, and the imagery is ultimately used primarily by human observers, such as radiologists. In this presentation I will describe some of our preliminary explorations of the applications

  17. Applied Enzymology.

    Science.gov (United States)

    Manoharan, Asha; Dreisbach, Joseph H.

    1988-01-01

    Describes some examples of chemical and industrial applications of enzymes. Includes a background, a discussion of structure and reactivity, enzymes as therapeutic agents, enzyme replacement, enzymes used in diagnosis, industrial applications of enzymes, and immobilizing enzymes. Concludes that applied enzymology is an important factor in…

  18. Estimation of exit temperatures in the isentropic compression of real ...

    African Journals Online (AJOL)

    This paper presents the estimation of exit temperatures in the isentropic compression of real gases based on the Peng-Robinson equation of state and entropy balance method. The methods were applied to Ar, N2, CH4, CO2, C2H4 and C2H6. Data obtained revealed that isentropic exponent method provides useful results ...

  19. Scalable RDF data compression with MapReduce

    NARCIS (Netherlands)

    Urbani, J.; Maassen, J.; Drost, N.; Seinstra, F.J.; Bal, H.E.

    2013-01-01

    The Semantic Web contains many billions of statements, which are released using the resource description framework (RDF) data model. To better handle these large amounts of data, high performance RDF applications must apply a compression technique. Unfortunately, because of the large input size,

  20. Neurovascular Compression in Essential Hypertension: Cause, Consequence or Unrelated Finding?

    Czech Academy of Sciences Publication Activity Database

    Ceral, J.; Žižka, J.; Eliáš, P.; Solař, M.; Klzo, L.; Reissigová, Jindra

    2007-01-01

    Roč. 21, č. 2 (2007), s. 179-181 ISSN 0950-9240 R&D Projects: GA MZd NA6169 Institutional research plan: CEZ:AV0Z10300504 Keywords : neurovascular compression * rostral ventrolateral medulla oblongata * hypertension Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.244, year: 2007

  1. Choice of compressed air fed system of a uranium mine

    International Nuclear Information System (INIS)

    Li Congkui; Lei Zeyong

    2006-01-01

    The selection of compressed air fed system in a uranium mine is discussed. The research indicates that the movable air compressor is better than the fixed one in energy saving, once capital cost and operational cost when it is applied in an underground uranium mine. (authors)

  2. Dynamic model including piping acoustics of a centrifugal compression system

    NARCIS (Netherlands)

    Helvoirt, van J.; Jager, de A.G.

    2007-01-01

    This paper deals with low frequency pulsation phenomena in full-scale centrifugal compression systems associated with compressor surge. The Greitzer lumped parameter model is applied to describe the dynamic behavior of an industrial compressor test rig and experimental evidence is provided for the

  3. METHOD AND APPARATUS FOR INSPECTION OF COMPRESSED DATA PACKAGES

    DEFF Research Database (Denmark)

    2008-01-01

    to be transferred over the data network. The method comprises the steps of: a) extracting payload data from the payload part of the package, b) appending the extracted payload data to a stream of data, c) probing the data package header so as to determine the compression scheme that is applied to the payload data...

  4. Prediction of potential compressive strength of Portland clinker from its mineralogy

    DEFF Research Database (Denmark)

    Svinning, K.; Høskuldsson, Agnar; Justnes, H.

    2010-01-01

    Based on a statistical model first applied for prediction of compressive strength up to 28 d from the microstructure of Portland cement, potential compressive strength of clinker has been predicted from its mineralogy. The prediction model was evaluated by partial least squares regression...

  5. Allergic Contact Dermatitis with Diffuse Erythematous Reaction from Diisopropanolamine in a Compress

    Directory of Open Access Journals (Sweden)

    Tomoko Rind

    2010-04-01

    Full Text Available Compresses containing a nonsteroidal antiinflammatory drug (NSAID are commonly used in Japan. However, this treatment may induce both allergic and photoallergic contact dermatitis from the NSAIDs and their ingredients. Here, we describe a case of allergic contact dermatitis with diffuse erythematous reaction due to diisopropanolamine in the applied compress. The absorption of diisopropanolamine might have been enhanced by the occlusive condition.

  6. Acoustical and Perceptual Comparison of Noise Reduction and Compression in Hearing Aids

    NARCIS (Netherlands)

    Brons, Inge; Houben, Rolph; Dreschler, Wouter A.

    2015-01-01

    Noise reduction and dynamic-range compression are generally applied together in hearing aids but may have opposite effects on amplification. This study evaluated the acoustical and perceptual effects of separate and combined processing of noise reduction and compression. Recordings of the output of

  7. Evaluation of a new image compression technique

    International Nuclear Information System (INIS)

    Algra, P.R.; Kroon, H.M.; Noordveld, R.B.; DeValk, J.P.J.; Seeley, G.W.; Westerink, P.H.

    1988-01-01

    The authors present the evaluation of a new image compression technique, subband coding using vector quantization, on 44 CT examinations of the upper abdomen. Three independent radiologists reviewed the original images and compressed versions. The compression ratios used were 16:1 and 20:1. Receiver operating characteristic analysis showed no difference in the diagnostic contents between originals and their compressed versions. Subjective visibility of anatomic structures was equal. Except for a few 20:1 compressed images, the observers could not distinguish compressed versions from original images. They conclude that subband coding using vector quantization is a valuable method for data compression in CT scans of the abdomen

  8. The auriculotemporal nerve in etiology of migraine headaches: compression points and anatomical variations.

    Science.gov (United States)

    Chim, Harvey; Okada, Haruko C; Brown, Matthew S; Alleyne, Brendan; Liu, Mengyuan T; Zwiebel, Samantha; Guyuron, Bahman

    2012-08-01

    The auriculotemporal nerve has been identified as one of the peripheral trigger sites for migraine headaches. However, its distal course is poorly mapped following emergence from the parotid gland. In addition, a reliable anatomical landmark for locating the potential compression points along the course of the nerve during surgery has not been sufficiently described. Twenty hemifaces on 10 fresh cadavers were dissected to trace the course of the auriculotemporal nerve from the inferior border of the zygomatic arch to its termination in the temporal scalp. The compression points were mapped and the distances were measured from the most anterosuperior point of the external auditory meatus, which was used as a fixed anatomical landmark. Three potential compression points along the course of the auriculotemporal nerve were identified. Compression points 1 and 2 corresponded to preauricular fascial bands. Compression point 1 was centered 13.1±5.9 mm anterior and 5.0±7.0 mm superior to the most anterosuperior point of the external auditory meatus, whereas compression point 2 was centered at 11.9±6.0 mm anterior and 17.2±10.4 mm superior to the most anterosuperior point of the external auditory meatus. A significant relationship was found between the auriculotemporal nerve and superficial temporal artery (compression point 3) in 80 percent of hemifaces, with three patterns of interaction: a single site of artery crossing over the nerve (62.5 percent), a helical intertwining relationship (18.8 percent), and nerve crossing over the artery (18.8 percent). Findings from this cadaver study provide information relevant to the operative localization of potential compression points along the auriculotemporal nerve.

  9. Compressive Phase Contrast Tomography

    International Nuclear Information System (INIS)

    Maia, Filipe; MacDowell, Alastair; Marchesini, Stefano; Padmore, Howard A.; Parkinson, Dula Y.; Pien, Jack; Schirotzek, Andre; Yang, Chao

    2010-01-01

    When x-rays penetrate soft matter, their phase changes more rapidly than their amplitude. Interference effects visible with high brightness sources creates higher contrast, edge enhanced images. When the object is piecewise smooth (made of big blocks of a few components), such higher contrast datasets have a sparse solution. We apply basis pursuit solvers to improve SNR, remove ring artifacts, reduce the number of views and radiation dose from phase contrast datasets collected at the Hard X-Ray Micro Tomography Beamline at the Advanced Light Source. We report a GPU code for the most computationally intensive task, the gridding and inverse gridding algorithm (non uniform sampled Fourier transform).

  10. Environmental external effects from wind power based on the EU ExternE methodology

    DEFF Research Database (Denmark)

    Ibsen, Liselotte Schleisner; Nielsen, Per Sieverts

    1998-01-01

    of the Danish part of the project is to implement the framework for externality evaluation, for three different power plants located in Denmark. The paper will focus on the assessment of the impacts of the whole fuel cycles for wind, natural gas and biogas. Priority areas for environmental impact assessment......The European Commission has launched a major study project, ExternE, to develop a methodology to quantify externalities. A “National Implementation Phase”, was started under the Joule II programme with the purpose of implementing the ExternE methodology in all member states. The main objective...

  11. Main problems of external monitoring in the accidental zone

    International Nuclear Information System (INIS)

    Gavrikov, O.K.; Gul'din, A.N.; Komarov, V.I.; Malkov, V.L.; Smirnov, N.V.; Sukhoruchkin, A.K.; Proskuryakov, A.G.

    1989-01-01

    Operational experience of the external monitoring service during emergency response is analysed as applied to the problems of optimization of environmental monitoring under accidental conditions. Problems of rapid and strategical environmental radiation monitoring are considered

  12. External corners as heat bridges

    Energy Technology Data Exchange (ETDEWEB)

    Berber, J.

    1984-08-01

    The maximum additional heat loss in vertical external corners depending on wall thickness is determined. In order to amire at a low k-value, a much smaller wall thickness is required in externally insulated walls than in monolithic constructions; the greater loss of heat bridge with external insulation stands in contrast to a higher loss in thick, monolithic walls. In relation to total losses, the additional losses through external corners are practically negligible.

  13. [External pancreatic fistulas management].

    Science.gov (United States)

    Stepan, E V; Ermolov, A S; Rogal', M L; Teterin, Yu S

    The main principles of treatment of external postoperative pancreatic fistulas are viewed in the article. Pancreatic trauma was the reason of pancreatic fistula in 38.7% of the cases, operations because of acute pancreatitis - in 25.8%, and pancreatic pseudocyst drainage - in 35.5%. 93 patients recovered after the treatment. Complex conservative treatment of EPF allowed to close fistulas in 74.2% of the patients with normal patency of the main pancreatic duct (MPD). The usage of octreotide 600-900 mcg daily for at least 5 days to decrease pancreatic secretion was an important part of the conservative treatment. Endoscopic papillotomy was performed in patients with major duodenal papilla obstruction and interruption of transporting of pancreatic secretion to duodenum. Stent of the main pancreatic duct was indicated in patients with extended pancreatic duct stenosis to normalize transport of pancreatic secretion to duodenum. Surgical formation of anastomosis between distal part of the main pancreatic duct and gastro-intestinal tract was carried out when it was impossible to fulfill endoscopic stenting of pancreatic duct either because of its interruption and diastasis between its ends, or in the cases of unsuccessful conservative treatment of external pancreatic fistula caused by drainage of pseudocyst.

  14. Breast compression – An exploration of problem solving and decision-making in mammography

    International Nuclear Information System (INIS)

    Nightingale, J.M.; Murphy, F.J.; Robinson, L.; Newton-Hughes, A.; Hogg, P.

    2015-01-01

    Objective: Breast compression decreases radiation dose and reduces potential for motion and geometric unsharpness, yet there is variability in applied compression force within and between some centres. This article explores the problem solving process applied to the application of breast compression force from the mammography practitioners' perspective. Methods: A qualitative analysis was undertaken using an existing full data set of transcribed qualitative data collected in a phenomenological study of mammography practitioner values, behaviours and beliefs. The data emerged from focus groups conducted at six NHS breast screening centres in England (participant n = 41), and semi-structured interviews with mammography educators (n = 6). A researcher followed a thematic content analysis process to extract data related to mammography compression problem solving, developing a series of categories, themes and sub-themes. Emerging themes were then peer-validated by two other researchers, and developed into a model of practice. Results: Seven consecutive stages contributed towards compression force problem solving: assessing the request; first impressions; explanations and consent; handling the breast and positioning; applying compression force; final adjustments; feedback. The model captures information gathering, problem framing, problem solving and decision making which inform an ‘ideal’ compression scenario. Behavioural problem solving, heuristics and intuitive decision making are reflected within this model. Conclusion: The application of compression should no longer be considered as one single task within mammography, but is now recognised as a seven stage problem solving continuum. This continuum model is the first to be applied to mammography, and is adaptable and transferable to other radiography practice settings. - Highlights: • Mammography compression should no longer be considered as one single examination task. • A seven stage breast

  15. Building indifferentiable compression functions from the PGV compression functions

    DEFF Research Database (Denmark)

    Gauravaram, P.; Bagheri, Nasour; Knudsen, Lars Ramkilde

    2016-01-01

    Preneel, Govaerts and Vandewalle (PGV) analysed the security of single-block-length block cipher based compression functions assuming that the underlying block cipher has no weaknesses. They showed that 12 out of 64 possible compression functions are collision and (second) preimage resistant. Black......, Rogaway and Shrimpton formally proved this result in the ideal cipher model. However, in the indifferentiability security framework introduced by Maurer, Renner and Holenstein, all these 12 schemes are easily differentiable from a fixed input-length random oracle (FIL-RO) even when their underlying block...

  16. Plasma heating by adiabatic compression

    International Nuclear Information System (INIS)

    Ellis, R.A. Jr.

    1972-01-01

    These two lectures will cover the following three topics: (i) The application of adiabatic compression to toroidal devices is reviewed. The special case of adiabatic compression in tokamaks is considered in more detail, including a discussion of the equilibrium, scaling laws, and heating effects. (ii) The ATC (Adiabatic Toroidal Compressor) device which was completed in May 1972, is described in detail. Compression of a tokamak plasma across a static toroidal field is studied in this device. The device is designed to produce a pre-compression plasma with a major radius of 17 cm, toroidal field of 20 kG, and current of 90 kA. The compression leads to a plasma with major radius of 38 cm and minor radius of 10 cm. Scaling laws imply a density increase of a factor 6, temperature increase of a factor 3, and current increase of a factor 2.4. An additional feature of ATC is that it is a large tokamak which operates without a copper shell. (iii) Data which show that the expected MHD behavior is largely observed is presented and discussed. (U.S.)

  17. Concurrent data compression and protection

    International Nuclear Information System (INIS)

    Saeed, M.

    2009-01-01

    Data compression techniques involve transforming data of a given format, called source message, to data of a smaller sized format, called codeword. The primary objective of data encryption is to ensure security of data if it is intercepted by an eavesdropper. It transforms data of a given format, called plaintext, to another format, called ciphertext, using an encryption key or keys. Thus, combining the processes of compression and encryption together must be done in this order, that is, compression followed by encryption because all compression techniques heavily rely on the redundancies which are inherently a part of a regular text or speech. The aim of this research is to combine two processes of compression (using an existing scheme) with a new encryption scheme which should be compatible with encoding scheme embedded in encoder. The novel technique proposed by the authors is new, unique and is highly secured. The deployment of sentinel marker' enhances the security of the proposed TR-One algorithm from 2/sup 44/ ciphertexts to 2/sup 44/ +2/sub 20/ ciphertexts thus imposing extra challenges to the intruders. (author)

  18. Radiologic image compression -- A review

    International Nuclear Information System (INIS)

    Wong, S.; Huang, H.K.; Zaremba, L.; Gooden, D.

    1995-01-01

    The objective of radiologic image compression is to reduce the data volume of and to achieve a lot bit rate in the digital representation of radiologic images without perceived loss of image quality. However, the demand for transmission bandwidth and storage space in the digital radiology environment, especially picture archiving and communication systems (PACS) and teleradiology, and the proliferating use of various imaging modalities, such as magnetic resonance imaging, computed tomography, ultrasonography, nuclear medicine, computed radiography, and digital subtraction angiography, continue to outstrip the capabilities of existing technologies. The availability of lossy coding techniques for clinical diagnoses further implicates many complex legal and regulatory issues. This paper reviews the recent progress of lossless and lossy radiologic image compression and presents the legal challenges of using lossy compression of medical records. To do so, the authors first describe the fundamental concepts of radiologic imaging and digitization. Then, the authors examine current compression technology in the field of medical imaging and discuss important regulatory policies and legal questions facing the use of compression in this field. The authors conclude with a summary of future challenges and research directions. 170 refs

  19. 30 CFR 75.1730 - Compressed air; general; compressed air systems.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressed air; general; compressed air systems... Compressed air; general; compressed air systems. (a) All pressure vessels shall be constructed, installed... Safety and Health district office. (b) Compressors and compressed-air receivers shall be equipped with...

  20. Applied dynamics

    CERN Document Server

    Schiehlen, Werner

    2014-01-01

    Applied Dynamics is an important branch of engineering mechanics widely applied to mechanical and automotive engineering, aerospace and biomechanics as well as control engineering and mechatronics. The computational methods presented are based on common fundamentals. For this purpose analytical mechanics turns out to be very useful where D’Alembert’s principle in the Lagrangian formulation proves to be most efficient. The method of multibody systems, finite element systems and continuous systems are treated consistently. Thus, students get a much better understanding of dynamical phenomena, and engineers in design and development departments using computer codes may check the results more easily by choosing models of different complexity for vibration and stress analysis.

  1. Applied optics

    International Nuclear Information System (INIS)

    Orszag, A.; Antonetti, A.

    1988-01-01

    The 1988 progress report, of the Applied Optics laboratory, of the (Polytechnic School, France), is presented. The optical fiber activities are focused on the development of an optical gyrometer, containing a resonance cavity. The following domains are included, in the research program: the infrared laser physics, the laser sources, the semiconductor physics, the multiple-photon ionization and the nonlinear optics. Investigations on the biomedical, the biological and biophysical domains are carried out. The published papers and the congress communications are listed [fr

  2. Effects of errors in velocity tilt on maximum longitudinal compression during neutralized drift compression of intense beam pulses: I. general description

    Energy Technology Data Exchange (ETDEWEB)

    Kaganovich, Igor D.; Massidda, Scottt; Startsev, Edward A.; Davidson, Ronald C.; Vay, Jean-Luc; Friedman, Alex

    2012-06-21

    Neutralized drift compression offers an effective means for particle beam pulse compression and current amplification. In neutralized drift compression, a linear longitudinal velocity tilt (head-to-tail gradient) is applied to the non-relativistic beam pulse, so that the beam pulse compresses as it drifts in the focusing section. The beam current can increase by more than a factor of 100 in the longitudinal direction. We have performed an analytical study of how errors in the velocity tilt acquired by the beam in the induction bunching module limit the maximum longitudinal compression. It is found that the compression ratio is determined by the relative errors in the velocity tilt. That is, one-percent errors may limit the compression to a factor of one hundred. However, a part of the beam pulse where the errors are small may compress to much higher values, which are determined by the initial thermal spread of the beam pulse. It is also shown that sharp jumps in the compressed current density profile can be produced due to overlaying of different parts of the pulse near the focal plane. Examples of slowly varying and rapidly varying errors compared to the beam pulse duration are studied. For beam velocity errors given by a cubic function, the compression ratio can be described analytically. In this limit, a significant portion of the beam pulse is located in the broad wings of the pulse and is poorly compressed. The central part of the compressed pulse is determined by the thermal spread. The scaling law for maximum compression ratio is derived. In addition to a smooth variation in the velocity tilt, fast-changing errors during the pulse may appear in the induction bunching module if the voltage pulse is formed by several pulsed elements. Different parts of the pulse compress nearly simultaneously at the target and the compressed profile may have many peaks. The maximum compression is a function of both thermal spread and the velocity errors. The effects of the

  3. Rectal perforation by compressed air.

    Science.gov (United States)

    Park, Young Jin

    2017-07-01

    As the use of compressed air in industrial work has increased, so has the risk of associated pneumatic injury from its improper use. However, damage of large intestine caused by compressed air is uncommon. Herein a case of pneumatic rupture of the rectum is described. The patient was admitted to the Emergency Room complaining of abdominal pain and distension. His colleague triggered a compressed air nozzle over his buttock. On arrival, vital signs were stable but physical examination revealed peritoneal irritation and marked distension of the abdomen. Computed tomography showed a large volume of air in the peritoneal cavity and subcutaneous emphysema at the perineum. A rectal perforation was found at laparotomy and the Hartmann procedure was performed.

  4. Compact torus compression of microwaves

    International Nuclear Information System (INIS)

    Hewett, D.W.; Langdon, A.B.

    1985-01-01

    The possibility that a compact torus (CT) might be accelerated to large velocities has been suggested by Hartman and Hammer. If this is feasible one application of these moving CTs might be to compress microwaves. The proposed mechanism is that a coaxial vacuum region in front of a CT is prefilled with a number of normal electromagnetic modes on which the CT impinges. A crucial assumption of this proposal is that the CT excludes the microwaves and therefore compresses them. Should the microwaves penetrate the CT, compression efficiency is diminished and significant CT heating results. MFE applications in the same parameters regime have found electromagnetic radiation capable of penetrating, heating, and driving currents. We report here a cursory investigation of rf penetration using a 1-D version of a direct implicit PIC code

  5. Premixed autoignition in compressible turbulence

    Science.gov (United States)

    Konduri, Aditya; Kolla, Hemanth; Krisman, Alexander; Chen, Jacqueline

    2016-11-01

    Prediction of chemical ignition delay in an autoignition process is critical in combustion systems like compression ignition engines and gas turbines. Often, ignition delay times measured in simple homogeneous experiments or homogeneous calculations are not representative of actual autoignition processes in complex turbulent flows. This is due the presence of turbulent mixing which results in fluctuations in thermodynamic properties as well as chemical composition. In the present study the effect of fluctuations of thermodynamic variables on the ignition delay is quantified with direct numerical simulations of compressible isotropic turbulence. A premixed syngas-air mixture is used to remove the effects of inhomogeneity in the chemical composition. Preliminary results show a significant spatial variation in the ignition delay time. We analyze the topology of autoignition kernels and identify the influence of extreme events resulting from compressibility and intermittency. The dependence of ignition delay time on Reynolds and turbulent Mach numbers is also quantified. Supported by Basic Energy Sciences, Dept of Energy, United States.

  6. Lossless Compression of Broadcast Video

    DEFF Research Database (Denmark)

    Martins, Bo; Eriksen, N.; Faber, E.

    1998-01-01

    We investigate several techniques for lossless and near-lossless compression of broadcast video.The emphasis is placed on the emerging international standard for compression of continous-tone still images, JPEG-LS, due to its excellent compression performance and moderatecomplexity. Except for one...... cannot be expected to code losslessly at a rate of 125 Mbit/s. We investigate the rate and quality effects of quantization using standard JPEG-LS quantization and two new techniques: visual quantization and trellis quantization. Visual quantization is not part of baseline JPEG-LS, but is applicable...... in the framework of JPEG-LS. Visual tests show that this quantization technique gives much better quality than standard JPEG-LS quantization. Trellis quantization is a process by which the original image is altered in such a way as to make lossless JPEG-LS encoding more effective. For JPEG-LS and visual...

  7. Compressibility of rotating black holes

    International Nuclear Information System (INIS)

    Dolan, Brian P.

    2011-01-01

    Interpreting the cosmological constant as a pressure, whose thermodynamically conjugate variable is a volume, modifies the first law of black hole thermodynamics. Properties of the resulting thermodynamic volume are investigated: the compressibility and the speed of sound of the black hole are derived in the case of nonpositive cosmological constant. The adiabatic compressibility vanishes for a nonrotating black hole and is maximal in the extremal case--comparable with, but still less than, that of a cold neutron star. A speed of sound v s is associated with the adiabatic compressibility, which is equal to c for a nonrotating black hole and decreases as the angular momentum is increased. An extremal black hole has v s 2 =0.9 c 2 when the cosmological constant vanishes, and more generally v s is bounded below by c/√(2).

  8. Compressive behavior of fine sand.

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Bradley E. (Air Force Research Laboratory, Eglin, FL); Kabir, Md. E. (Purdue University, West Lafayette, IN); Song, Bo; Chen, Wayne (Purdue University, West Lafayette, IN)

    2010-04-01

    The compressive mechanical response of fine sand is experimentally investigated. The strain rate, initial density, stress state, and moisture level are systematically varied. A Kolsky bar was modified to obtain uniaxial and triaxial compressive response at high strain rates. A controlled loading pulse allows the specimen to acquire stress equilibrium and constant strain-rates. The results show that the compressive response of the fine sand is not sensitive to strain rate under the loading conditions in this study, but significantly dependent on the moisture content, initial density and lateral confinement. Partially saturated sand is more compliant than dry sand. Similar trends were reported in the quasi-static regime for experiments conducted at comparable specimen conditions. The sand becomes stiffer as initial density and/or confinement pressure increases. The sand particle size become smaller after hydrostatic pressure and further smaller after dynamic axial loading.

  9. Apparent stress-strain relationships in experimental equipment where magnetorheological fluids operate under compression mode

    International Nuclear Information System (INIS)

    Mazlan, S A; Ekreem, N B; Olabi, A G

    2008-01-01

    This paper presents an experimental investigation of two different magnetorheological (MR) fluids, namely, water-based and hydrocarbon-based MR fluids in compression mode under various applied currents. Finite element method magnetics was used to predict the magnetic field distribution inside the MR fluids generated by a coil. A test rig was constructed where the MR fluid was sandwiched between two flat surfaces. During the compression, the upper surface was moved towards the lower surface in a vertical direction. Stress-strain relationships were obtained for arrangements of equipment where each type of fluid was involved, using compression test equipment. The apparent compressive stress was found to be increased with the increase in magnetic field strength. In addition, the apparent compressive stress of the water-based MR fluid showed a response to the compressive strain of greater magnitude. However, during the compression process, the hydrocarbon-based MR fluid appeared to show a unique behaviour where an abrupt pressure drop was discovered in a region where the apparent compressive stress would be expected to increase steadily. The conclusion is drawn that the apparent compressive stress of MR fluids is influenced strongly by the nature of the carrier fluid and by the magnitude of the applied current

  10. Image Quality Assessment for Different Wavelet Compression Techniques in a Visual Communication Framework

    Directory of Open Access Journals (Sweden)

    Nuha A. S. Alwan

    2013-01-01

    Full Text Available Images with subband coding and threshold wavelet compression are transmitted over a Rayleigh communication channel with additive white Gaussian noise (AWGN, after quantization and 16-QAM modulation. A comparison is made between these two types of compression using both mean square error (MSE and structural similarity (SSIM image quality assessment (IQA criteria applied to the reconstructed image at the receiver. The two methods yielded comparable SSIM but different MSE measures. In this work, we justify our results which support previous findings in the literature that the MSE between two images is not indicative of structural similarity or the visibility of errors. It is found that it is difficult to reduce the pointwise errors in subband-compressed images (higher MSE. However, the compressed images provide comparable SSIM or perceived quality for both types of compression provided that the retained energy after compression is the same.

  11. Giant negative linear compression positively coupled to massive thermal expansion in a metal-organic framework.

    Science.gov (United States)

    Cai, Weizhao; Katrusiak, Andrzej

    2014-07-04

    Materials with negative linear compressibility are sought for various technological applications. Such effects were reported mainly in framework materials. When heated, they typically contract in the same direction of negative linear compression. Here we show that this common inverse relationship rule does not apply to a three-dimensional metal-organic framework crystal, [Ag(ethylenediamine)]NO3. In this material, the direction of the largest intrinsic negative linear compression yet observed in metal-organic frameworks coincides with the strongest positive thermal expansion. In the perpendicular direction, the large linear negative thermal expansion and the strongest crystal compressibility are collinear. This seemingly irrational positive relationship of temperature and pressure effects is explained and the mechanism of coupling of compressibility with expansivity is presented. The positive coupling between compression and thermal expansion in this material enhances its piezo-mechanical response in adiabatic process, which may be used for designing new artificial composites and ultrasensitive measuring devices.

  12. A Novel Range Compression Algorithm for Resolution Enhancement in GNSS-SARs

    Directory of Open Access Journals (Sweden)

    Yu Zheng

    2017-06-01

    Full Text Available In this paper, a novel range compression algorithm for enhancing range resolutions of a passive Global Navigation Satellite System-based Synthetic Aperture Radar (GNSS-SAR is proposed. In the proposed algorithm, within each azimuth bin, firstly range compression is carried out by correlating a reflected GNSS intermediate frequency (IF signal with a synchronized direct GNSS base-band signal in the range domain. Thereafter, spectrum equalization is applied to the compressed results for suppressing side lobes to obtain a final range-compressed signal. Both theoretical analysis and simulation results have demonstrated that significant range resolution improvement in GNSS-SAR images can be achieved by the proposed range compression algorithm, compared to the conventional range compression algorithm.

  13. Wavelet compression of multichannel ECG data by enhanced set partitioning in hierarchical trees algorithm.

    Science.gov (United States)

    Sharifahmadian, Ershad

    2006-01-01

    The set partitioning in hierarchical trees (SPIHT) algorithm is very effective and computationally simple technique for image and signal compression. Here the author modified the algorithm which provides even better performance than the SPIHT algorithm. The enhanced set partitioning in hierarchical trees (ESPIHT) algorithm has performance faster than the SPIHT algorithm. In addition, the proposed algorithm reduces the number of bits in a bit stream which is stored or transmitted. I applied it to compression of multichannel ECG data. Also, I presented a specific procedure based on the modified algorithm for more efficient compression of multichannel ECG data. This method employed on selected records from the MIT-BIH arrhythmia database. According to experiments, the proposed method attained the significant results regarding compression of multichannel ECG data. Furthermore, in order to compress one signal which is stored for a long time, the proposed multichannel compression method can be utilized efficiently.

  14. The application of sparse linear prediction dictionary to compressive sensing in speech signals

    Directory of Open Access Journals (Sweden)

    YOU Hanxu

    2016-04-01

    Full Text Available Appling compressive sensing (CS,which theoretically guarantees that signal sampling and signal compression can be achieved simultaneously,into audio and speech signal processing is one of the most popular research topics in recent years.In this paper,K-SVD algorithm was employed to learn a sparse linear prediction dictionary regarding as the sparse basis of underlying speech signals.Compressed signals was obtained by applying random Gaussian matrix to sample original speech frames.Orthogonal matching pursuit (OMP and compressive sampling matching pursuit (CoSaMP were adopted to recovery original signals from compressed one.Numbers of experiments were carried out to investigate the impact of speech frames length,compression ratios,sparse basis and reconstruction algorithms on CS performance.Results show that sparse linear prediction dictionary can advance the performance of speech signals reconstruction compared with discrete cosine transform (DCT matrix.

  15. Correlations between quality indexes of chest compression.

    Science.gov (United States)

    Zhang, Feng-Ling; Yan, Li; Huang, Su-Fang; Bai, Xiang-Jun

    2013-01-01

    Cardiopulmonary resuscitation (CPR) is a kind of emergency treatment for cardiopulmonary arrest, and chest compression is the most important and necessary part of CPR. The American Heart Association published the new Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care in 2010 and demanded for better performance of chest compression practice, especially in compression depth and rate. The current study was to explore the relationship of quality indexes of chest compression and to identify the key points in chest compression training and practice. Totally 219 healthcare workers accepted chest compression training by using Laerdal ACLS advanced life support resuscitation model. The quality indexes of chest compression, including compression hands placement, compression rate, compression depth, and chest wall recoil as well as self-reported fatigue time were monitored by the Laerdal Computer Skills and Reporting System. The quality of chest compression was related to the gender of the compressor. The indexes in males, including self-reported fatigue time, the accuracy of compression depth and the compression rate, the accuracy of compression rate, were higher than those in females. However, the accuracy of chest recoil was higher in females than in males. The quality indexes of chest compression were correlated with each other. The self-reported fatigue time was related to all the indexes except the compression rate. It is necessary to offer CPR training courses regularly. In clinical practice, it might be better to change the practitioner before fatigue, especially for females or weak practitioners. In training projects, more attention should be paid to the control of compression rate, in order to delay the fatigue, guarantee enough compression depth and improve the quality of chest compression.

  16. Compression for the management of venous leg ulcers: which material do we have?

    Science.gov (United States)

    Partsch, Hugo

    2014-05-01

    Compression therapy is the most important basic treatment modality in venous leg ulcers. The review focusses on the materials which are used: 1. Compression bandages, 2. Compression stockings, 3. Self-adjustable Velcro-devices, 4. Compression pumps, 5. Hybrid devices. Compression bandages, usually applied by trained staff, provide a wide spectrum of materials with different elastic properties. To make bandaging easier, safer and more effective, most modern bandages combine different material components. Self-management of venous ulcers has become feasible by introducing double compression stockings ("ulcer kits") and self-adjustable Velcro devices. Compression pumps can be used as adjunctive measures, especially for patients with restricted mobility. The combination of sustained and intermittent compression ("hybrid device") is a promising new tool. The interface pressure corresponding to the dosage of compression therapy determines the hemodynamic efficacy of each device. In order to reduce ambulatory venous hypertension compression pressures of more than 50 mm Hg in the upright position are desirable. At the same time pressure should be lower in the resting position in order to be tolerated. This prerequisite may be fulfilled by using inelastic, short stretch material including multicomponent bandages and cohesive surfaces, all characterized by high stiffness. Such materials do not give way when calf muscles contract during walking which leads to high peaks of interface pressure ("massaging effect"). © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  17. Compression of positron clouds using rotating wall electric fields

    International Nuclear Information System (INIS)

    Werf, Dirk Peter van der; Isaac, Christopher Aled; Baker, Christopher John; Mortensen, Timothy; Charlton, Michael

    2012-01-01

    An asymmetric dipolar rotating electric field can be used to compress a trapped cloud of positrons when applied with a frequency close that of their axial bounce, and in the presence of a low pressure molecular gas to provide cooling. Measurements of the compression rate and associated parameters are presented and compared with results of a theory we have developed. The latter treats positron behaviour in a perfect Penning trap potential, in the presence of the rotating field, with the cooling modelled in the Stokes viscous drag approximation. Good agreement between the theory and experiment has been found, which has allowed us to identify the phenomenon as a new form of sideband cooling.

  18. Compressing Control System Data for Efficient Storage and Retrieval

    International Nuclear Information System (INIS)

    Christopher Larrieu

    2003-01-01

    The controls group at the Thomas Jefferson National Accelerator Facility (Jefferson Lab), acquires multiple terabytes of EPICS control system data per year via CZAR, its new archiving system. By heuristically applying a combination of rudimentary compression techniques, in conjunction with several specialized data transformations and algorithms, the CZAR storage engine reduces the size of this data by approximately 88 percent, without any loss of information. While the compression process requires significant memory and processor time, the decompression routine suffers only slightly in this regard

  19. Negative compressibility observed in graphene containing resonant impurities

    International Nuclear Information System (INIS)

    Chen, X. L.; Wang, L.; Li, W.; Wang, Y.; He, Y. H.; Wu, Z. F.; Han, Y.; Zhang, M. W.; Xiong, W.; Wang, N.

    2013-01-01

    We observed negative compressibility in monolayer graphene containing resonant impurities under different magnetic fields. Hydrogenous impurities were introduced into graphene by electron beam (e-beam) irradiation. Resonant states located in the energy region of ±0.04 eV around the charge neutrality point were probed in e-beam-irradiated graphene capacitors. Theoretical results based on tight-binding and Lifshitz models agreed well with experimental observations of graphene containing a low concentration of resonant impurities. The interaction between resonant states and Landau levels was detected by varying the applied magnetic field. The interaction mechanisms and enhancement of the negative compressibility in disordered graphene are discussed.

  20. Fecal impaction causing pelvic venous compression and edema

    Directory of Open Access Journals (Sweden)

    Sara Naramore

    2015-09-01

    Full Text Available Chronic constipation is a common condition which may result in fecal impaction. A 13-year-old male with chronic constipation and encopresis presented with fecal impaction for three weeks. The impaction caused abdominal pain, distension, encopresis, and decreased oral intake. He was found in severe distress with non-pitting edema of his feet and ankles along with perineal edema. The pedal edema worsened after receiving a fluid bolus, so concern arose for venous compression or a thrombus. A Duplex Ultrasound demonstrated changes in the venous waveforms of the bilateral external iliac and common femoral veins without thrombosis. Manual disimpaction and polyethylene glycol 3350 with electrolytes resolved the pedal and perineal edema. Four months later, he had soft bowel movements without recurrence of the edema. A repeat Duplex Ultrasound was normal. We present a child in whom severe fecal impaction caused pelvic venous compression resulting in bilateral pedal and perineal edema.

  1. Basic life support and automated external defibrillator skills among ambulance personnel: a manikin study performed in a rural low-volume ambulance setting

    Directory of Open Access Journals (Sweden)

    Nielsen Anne

    2012-05-01

    Full Text Available Abstract Background Ambulance personnel play an essential role in the ‘Chain of Survival’. The prognosis after out-of-hospital cardiac arrest was dismal on a rural Danish island and in this study we assessed the cardiopulmonary resuscitation performance of ambulance personnel on that island. Methods The Basic Life Support (BLS and Automated External Defibrillator (AED skills of the ambulance personnel were tested in a simulated cardiac arrest. Points were given according to a scoring sheet. One sample t test was used to analyze the deviation from optimal care according to the 2005 guidelines. After each assessment, individual feedback was given. Results On 3 consecutive days, we assessed the individual EMS teams responding to OHCA on the island. Overall, 70% of the maximal points were achieved. The hands-off ratio was 40%. Correct compression/ventilation ratio (30:2 was used by 80%. A mean compression depth of 40–50 mm was achieved by 55% and the mean compression depth was 42 mm (SD 7 mm. The mean compression rate was 123 per min (SD 15/min. The mean tidal volume was 746 ml (SD 221 ml. Only the mean tidal volume deviated significantly from the recommended (p = 0.01. During the rhythm analysis, 65% did not perform any visual or verbal safety check. Conclusion The EMS providers achieved 70% of the maximal points. Tidal volumes were larger than recommended when mask ventilation was applied. Chest compression depth was optimally performed by 55% of the staff. Defibrillation safety checks were not performed in 65% of EMS providers.

  2. External Measures of Cognition

    Directory of Open Access Journals (Sweden)

    Osvaldo eCairo

    2011-10-01

    Full Text Available The human brain is undoubtedly the most impressive, complex and intricate organ that has evolved over time. It is also probably the least understood, and for that reason, the one that is currently attracting the most attention. In fact, the number of comparative analyses that focus on the evolution of brain size in Homo sapiens and other species has increased dramatically in recent years. In neuroscience, no other issue has generated so much interest and been the topic of so many heated debates as the difference in brain size between socially defined population groups, both its connotations and implications. For over a century, external measures of cognition have been related to intelligence. However, it is still unclear whether these measures actually correspond to cognitive abilities. In summary, this paper must be reviewed with this premise in mind.

  3. Bevalac external beamline optics

    Energy Technology Data Exchange (ETDEWEB)

    Kalnins, J.G.; Krebs, G.F.; Tekawa, M.M.; Alonso, J.R.

    1987-04-01

    This handbook is intended as an aid for tuning the external particle beam (EPB) lines at the Lawrence Berkeley Laboratory's Bevalac. The information contained within will be useful to the Bevalac's Main Control Room and experimenters alike. First, some general information is given concerning the EPB lines and beam optics. Next, each beam line is described in detail: schematics of the beam line components are shown, all the variables required to run a beam transport program are presented, beam envelopes are given with wire chamber pictures and magnet currents, focal points and magnifications. Some preliminary scaling factors are then presented which should aid in choosing a given EPB magnet's current for a given central Bevalac field. Finally, some tuning hints are suggested.

  4. Bevalac external beamline optics

    International Nuclear Information System (INIS)

    Kalnins, J.G.; Krebs, G.F.; Tekawa, M.M.; Alonso, J.R.

    1987-04-01

    This handbook is intended as an aid for tuning the external particle beam (EPB) lines at the Lawrence Berkeley Laboratory's Bevalac. The information contained within will be useful to the Bevalac's Main Control Room and experimenters alike. First, some general information is given concerning the EPB lines and beam optics. Next, each beam line is described in detail: schematics of the beam line components are shown, all the variables required to run a beam transport program are presented, beam envelopes are given with wire chamber pictures and magnet currents, focal points and magnifications. Some preliminary scaling factors are then presented which should aid in choosing a given EPB magnet's current for a given central Bevalac field. Finally, some tuning hints are suggested

  5. Assessment of the externalities of biomass energy for electricity production

    Energy Technology Data Exchange (ETDEWEB)

    Linares, P; Leal, J; Saez, R M

    1996-10-01

    This study presents a methodology for the quantification of the socioeconomic and environmental externalities of the biomass fuel cycle. It is based on the one developed by the ExternE Project of the European Commission, based in turn in the damage function approach, and which has been extended and modified for a better adaptation to biomass energy systems. The methodology has been applied to a 20 MW biomass power plant, fueled by Cynara cardunculus, in southern Spain. The externalities addressed have been macroeconomic effects, employment, CO{sub 2}, fixation, erosion, and non-point source pollution. The results obtained should be considered only as subtotals, since there are still other externalities to be quantified. anyway, and in spite of the uncertainty existing, these results suggest that total cost (those including internal and external costs) of biomass energy are lower than those of conventional energy sources, what, if taken into account, would make biomass more competitive than it is now. (Author)

  6. Compressive system identification of LTI and LTV ARX models: The limited data set case

    NARCIS (Netherlands)

    Sanandaij, B. M.; Vincent, T. L.; Wakin, M. B.; Toth, R.; Poolla, K.

    2011-01-01

    In this paper, we consider identifying Auto Regressive with eXternal input (ARX) models for both Linear Time-Invariant (LTI) and Linear Time-Variant (LTV) systems. We aim at doing the identification from the smallest possible number of observations. This is inspired by the field of Compressive

  7. Excessive chest compression rate is associated with insufficient compression depth in prehospital cardiac arrest

    NARCIS (Netherlands)

    Monsieurs, Koenraad G.; De Regge, Melissa; Vansteelandt, Kristof; De Smet, Jeroen; Annaert, Emmanuel; Lemoyne, Sabine; Kalmar, Alain F.; Calle, Paul A.

    2012-01-01

    Background and goal of study: The relationship between chest compression rate and compression depth is unknown. In order to characterise this relationship, we performed an observational study in prehospital cardiac arrest patients. We hypothesised that faster compressions are associated with

  8. A biomechanical model of mammographic compressions.

    Science.gov (United States)

    Chung, J H; Rajagopal, V; Nielsen, P M F; Nash, M P

    2008-02-01

    A number of biomechanical models have been proposed to improve nonrigid registration techniques for multimodal breast image alignment. A deformable breast model may also be useful for overcoming difficulties in interpreting 2D X-ray projections (mammograms) of 3D volumes (breast tissues). If a deformable model could accurately predict the shape changes that breasts undergo during mammography, then the model could serve to localize suspicious masses (visible in mammograms) in the unloaded state, or in any other deformed state required for further investigations (such as biopsy or other medical imaging modalities). In this paper, we present a validation study that was conducted in order to develop a biomechanical model based on the well-established theory of continuum mechanics (finite elasticity theory with contact mechanics) and demonstrate its use for this application. Experimental studies using gel phantoms were conducted to test the accuracy in predicting mammographic-like deformations. The material properties of the gel phantom were estimated using a nonlinear optimization process, which minimized the errors between the experimental and the model-predicted surface data by adjusting the parameter associated with the neo-Hookean constitutive relation. Two compressions (the equivalent of cranio-caudal and medio-lateral mammograms) were performed on the phantom, and the corresponding deformations were recorded using a MRI scanner. Finite element simulations were performed to mimic the experiments using the estimated material properties with appropriate boundary conditions. The simulation results matched the experimental recordings of the deformed phantom, with a sub-millimeter root-mean-square error for each compression state. Having now validated our finite element model of breast compression, the next stage is to apply the model to clinical images.

  9. Computational simulation of breast compression based on segmented breast and fibroglandular tissues on magnetic resonance images

    Energy Technology Data Exchange (ETDEWEB)

    Shih, Tzu-Ching [Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, 40402, Taiwan (China); Chen, Jeon-Hor; Nie Ke; Lin Muqing; Chang, Daniel; Nalcioglu, Orhan; Su, Min-Ying [Tu and Yuen Center for Functional Onco-Imaging and Radiological Sciences, University of California, Irvine, CA 92697 (United States); Liu Dongxu; Sun Lizhi, E-mail: shih@mail.cmu.edu.t [Department of Civil and Environmental Engineering, University of California, Irvine, CA 92697 (United States)

    2010-07-21

    This study presents a finite element-based computational model to simulate the three-dimensional deformation of a breast and fibroglandular tissues under compression. The simulation was based on 3D MR images of the breast, and craniocaudal and mediolateral oblique compression, as used in mammography, was applied. The geometry of the whole breast and the segmented fibroglandular tissues within the breast were reconstructed using triangular meshes by using the Avizo (registered) 6.0 software package. Due to the large deformation in breast compression, a finite element model was used to simulate the nonlinear elastic tissue deformation under compression, using the MSC.Marc (registered) software package. The model was tested in four cases. The results showed a higher displacement along the compression direction compared to the other two directions. The compressed breast thickness in these four cases at a compression ratio of 60% was in the range of 5-7 cm, which is a typical range of thickness in mammography. The projection of the fibroglandular tissue mesh at a compression ratio of 60% was compared to the corresponding mammograms of two women, and they demonstrated spatially matched distributions. However, since the compression was based on magnetic resonance imaging (MRI), which has much coarser spatial resolution than the in-plane resolution of mammography, this method is unlikely to generate a synthetic mammogram close to the clinical quality. Whether this model may be used to understand the technical factors that may impact the variations in breast density needs further investigation. Since this method can be applied to simulate compression of the breast at different views and different compression levels, another possible application is to provide a tool for comparing breast images acquired using different imaging modalities--such as MRI, mammography, whole breast ultrasound and molecular imaging--that are performed using different body positions and under

  10. Intradiscal pressure depends on recent loading and correlates with disc height and compressive stiffness.

    NARCIS (Netherlands)

    Vergroesen, P.P.A.; van der Veen, A.J.; van Royen, B.J.; Kingma, I.; Smit, T.H.

    2014-01-01

    Purpose Intervertebral discs exhibit time-dependent deformation (creep), which could influence the relation between applied stress and intradiscal pressure. This study investigates the effect of prolonged dynamic loading on intradiscal pressure, disc height and compressive stiffness, and examines

  11. The impact of chest compression rates on quality of chest compressions : a manikin study

    OpenAIRE

    Field, Richard A.; Soar, Jasmeet; Davies, Robin P.; Akhtar, Naheed; Perkins, Gavin D.

    2012-01-01

    Purpose\\ud Chest compressions are often performed at a variable rate during cardiopulmonary resuscitation (CPR). The effect of compression rate on other chest compression quality variables (compression depth, duty-cycle, leaning, performance decay over time) is unknown. This randomised controlled cross-over manikin study examined the effect of different compression rates on the other chest compression quality variables.\\ud Methods\\ud Twenty healthcare professionals performed two minutes of co...

  12. Modeling DPOAE input/output function compression: comparisons with hearing thresholds.

    Science.gov (United States)

    Bhagat, Shaum P

    2014-09-01

    Basilar membrane input/output (I/O) functions in mammalian animal models are characterized by linear and compressed segments when measured near the location corresponding to the characteristic frequency. A method of studying basilar membrane compression indirectly in humans involves measuring distortion-product otoacoustic emission (DPOAE) I/O functions. Previous research has linked compression estimates from behavioral growth-of-masking functions to hearing thresholds. The aim of this study was to compare compression estimates from DPOAE I/O functions and hearing thresholds at 1 and 2 kHz. A prospective correlational research design was performed. The relationship between DPOAE I/O function compression estimates and hearing thresholds was evaluated with Pearson product-moment correlations. Normal-hearing adults (n = 16) aged 22-42 yr were recruited. DPOAE I/O functions (L₂ = 45-70 dB SPL) and two-interval forced-choice hearing thresholds were measured in normal-hearing adults. A three-segment linear regression model applied to DPOAE I/O functions supplied estimates of compression thresholds, defined as breakpoints between linear and compressed segments and the slopes of the compressed segments. Pearson product-moment correlations between DPOAE compression estimates and hearing thresholds were evaluated. A high correlation between DPOAE compression thresholds and hearing thresholds was observed at 2 kHz, but not at 1 kHz. Compression slopes also correlated highly with hearing thresholds only at 2 kHz. The derivation of cochlear compression estimates from DPOAE I/O functions provides a means to characterize basilar membrane mechanics in humans and elucidates the role of compression in tone detection in the 1-2 kHz frequency range. American Academy of Audiology.

  13. Sustainability of compressive residual stress by stress improvement processes

    International Nuclear Information System (INIS)

    Nishikawa, Satoru; Okita, Shigeru; Yamaguchi, Atsunori

    2013-01-01

    Stress improvement processes are countermeasures against stress corrosion cracking in nuclear power plant components. It is necessary to confirm whether compressive residual stress induced by stress improvement processes can be sustained under operation environment. In order to evaluate stability of the compressive residual stress in 60-year operating conditions, the 0.07% cyclic strains of 200 times at 593 K were applied to the welded specimens, then a thermal aging treatment for 1.66x10 6 s at 673 K was carried out. As the result, it was confirmed that the compressive residual stresses were sustained on both surfaces of the dissimilar welds of austenitic stainless steel (SUS316L) and nickel base alloy (NCF600 and alloy 182) processed by laser peening (LP), water jet peening (WJP), ultrasonic shot peening (USP), shot peening (SP) and polishing under 60-year operating conditions. (author)

  14. A Review On Segmentation Based Image Compression Techniques

    Directory of Open Access Journals (Sweden)

    S.Thayammal

    2013-11-01

    Full Text Available Abstract -The storage and transmission of imagery become more challenging task in the current scenario of multimedia applications. Hence, an efficient compression scheme is highly essential for imagery, which reduces the requirement of storage medium and transmission bandwidth. Not only improvement in performance and also the compression techniques must converge quickly in order to apply them for real time applications. There are various algorithms have been done in image compression, but everyone has its own pros and cons. Here, an extensive analysis between existing methods is performed. Also, the use of existing works is highlighted, for developing the novel techniques which face the challenging task of image storage and transmission in multimedia applications.

  15. Compression of magnetohydrodynamic simulation data using singular value decomposition

    International Nuclear Information System (INIS)

    Castillo Negrete, D. del; Hirshman, S.P.; Spong, D.A.; D'Azevedo, E.F.

    2007-01-01

    Numerical calculations of magnetic and flow fields in magnetohydrodynamic (MHD) simulations can result in extensive data sets. Particle-based calculations in these MHD fields, needed to provide closure relations for the MHD equations, will require communication of this data to multiple processors and rapid interpolation at numerous particle orbit positions. To facilitate this analysis it is advantageous to compress the data using singular value decomposition (SVD, or principal orthogonal decomposition, POD) methods. As an example of the compression technique, SVD is applied to magnetic field data arising from a dynamic nonlinear MHD code. The performance of the SVD compression algorithm is analyzed by calculating Poincare plots for electron orbits in a three-dimensional magnetic field and comparing the results with uncompressed data

  16. Analysis on soil compressibility changes of samples stabilized with lime

    Directory of Open Access Journals (Sweden)

    Elena-Andreea CALARASU

    2016-12-01

    Full Text Available In order to manage and control the stability of buildings located on difficult foundation soils, several techniques of soil stabilization were developed and applied worldwide. Taking into account the major significance of soil compressibility on construction durability and safety, the soil stabilization with a binder like lime is considered one of the most used and traditional methods. The present paper aims to assess the effect of lime content on soil geotechnical parameters, especially on compressibility ones, based on laboratory experimental tests, for several soil categories in admixture with different lime dosages. The results of this study indicate a significant improvement of stabilized soil parameters, such as compressibility and plasticity, in comparison with natural samples. The effect of lime stabilization is related to an increase of soil structure stability by increasing the bearing capacity.

  17. A novel high-frequency encoding algorithm for image compression

    Science.gov (United States)

    Siddeq, Mohammed M.; Rodrigues, Marcos A.

    2017-12-01

    In this paper, a new method for image compression is proposed whose quality is demonstrated through accurate 3D reconstruction from 2D images. The method is based on the discrete cosine transform (DCT) together with a high-frequency minimization encoding algorithm at compression stage and a new concurrent binary search algorithm at decompression stage. The proposed compression method consists of five main steps: (1) divide the image into blocks and apply DCT to each block; (2) apply a high-frequency minimization method to the AC-coefficients reducing each block by 2/3 resulting in a minimized array; (3) build a look up table of probability data to enable the recovery of the original high frequencies at decompression stage; (4) apply a delta or differential operator to the list of DC-components; and (5) apply arithmetic encoding to the outputs of steps (2) and (4). At decompression stage, the look up table and the concurrent binary search algorithm are used to reconstruct all high-frequency AC-coefficients while the DC-components are decoded by reversing the arithmetic coding. Finally, the inverse DCT recovers the original image. We tested the technique by compressing and decompressing 2D images including images with structured light patterns for 3D reconstruction. The technique is compared with JPEG and JPEG2000 through 2D and 3D RMSE. Results demonstrate that the proposed compression method is perceptually superior to JPEG with equivalent quality to JPEG2000. Concerning 3D surface reconstruction from images, it is demonstrated that the proposed method is superior to both JPEG and JPEG2000.

  18. Compressing Data Cube in Parallel OLAP Systems

    Directory of Open Access Journals (Sweden)

    Frank Dehne

    2007-03-01

    Full Text Available This paper proposes an efficient algorithm to compress the cubes in the progress of the parallel data cube generation. This low overhead compression mechanism provides block-by-block and record-by-record compression by using tuple difference coding techniques, thereby maximizing the compression ratio and minimizing the decompression penalty at run-time. The experimental results demonstrate that the typical compression ratio is about 30:1 without sacrificing running time. This paper also demonstrates that the compression method is suitable for Hilbert Space Filling Curve, a mechanism widely used in multi-dimensional indexing.

  19. CEPRAM: Compression for Endurance in PCM RAM

    OpenAIRE

    González Alberquilla, Rodrigo; Castro Rodríguez, Fernando; Piñuel Moreno, Luis; Tirado Fernández, Francisco

    2017-01-01

    We deal with the endurance problem of Phase Change Memories (PCM) by proposing Compression for Endurance in PCM RAM (CEPRAM), a technique to elongate the lifespan of PCM-based main memory through compression. We introduce a total of three compression schemes based on already existent schemes, but targeting compression for PCM-based systems. We do a two-level evaluation. First, we quantify the performance of the compression, in terms of compressed size, bit-flips and how they are affected by e...

  20. Applied geodesy

    International Nuclear Information System (INIS)

    Turner, S.

    1987-01-01

    This volume is based on the proceedings of the CERN Accelerator School's course on Applied Geodesy for Particle Accelerators held in April 1986. The purpose was to record and disseminate the knowledge gained in recent years on the geodesy of accelerators and other large systems. The latest methods for positioning equipment to sub-millimetric accuracy in deep underground tunnels several tens of kilometers long are described, as well as such sophisticated techniques as the Navstar Global Positioning System and the Terrameter. Automation of better known instruments such as the gyroscope and Distinvar is also treated along with the highly evolved treatment of components in a modern accelerator. Use of the methods described can be of great benefit in many areas of research and industrial geodesy such as surveying, nautical and aeronautical engineering, astronomical radio-interferometry, metrology of large components, deformation studies, etc

  1. Applied mathematics

    International Nuclear Information System (INIS)

    Nedelec, J.C.

    1988-01-01

    The 1988 progress report of the Applied Mathematics center (Polytechnic School, France), is presented. The research fields of the Center are the scientific calculus, the probabilities and statistics and the video image synthesis. The research topics developed are: the analysis of numerical methods, the mathematical analysis of the physics and mechanics fundamental models, the numerical solution of complex models related to the industrial problems, the stochastic calculus and the brownian movement, the stochastic partial differential equations, the identification of the adaptive filtering parameters, the discrete element systems, statistics, the stochastic control and the development, the image synthesis techniques for education and research programs. The published papers, the congress communications and the thesis are listed [fr

  2. Entropy, Coding and Data Compression

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 9. Entropy, Coding and Data Compression. S Natarajan. General Article Volume 6 Issue 9 September 2001 pp 35-45. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/006/09/0035-0045 ...

  3. Shock compression of synthetic opal

    International Nuclear Information System (INIS)

    Inoue, A; Okuno, M; Okudera, H; Mashimo, T; Omurzak, E; Katayama, S; Koyano, M

    2010-01-01

    Structural change of synthetic opal by shock-wave compression up to 38.1 GPa has been investigated by using SEM, X-ray diffraction method (XRD), Infrared (IR) and Raman spectroscopies. Obtained information may indicate that the dehydration and polymerization of surface silanole due to high shock and residual temperature are very important factors in the structural evolution of synthetic opal by shock compression. Synthetic opal loses opalescence by 10.9 and 18.4 GPa of shock pressures. At 18.4 GPa, dehydration and polymerization of surface silanole and transformation of network structure may occur simultaneously. The 4-membered ring of TO 4 tetrahedrons in as synthetic opal may be relaxed to larger ring such as 6-membered ring by high residual temperature. Therefore, the residual temperature may be significantly high at even 18.4 GPa of shock compression. At 23.9 GPa, opal sample recovered the opalescence. Origin of this opalescence may be its layer structure by shock compression. Finally, sample fuse by very high residual temperature at 38.1 GPa and the structure closes to that of fused SiO 2 glass. However, internal silanole groups still remain even at 38.1 GPa.

  4. Range Compressed Holographic Aperture Ladar

    Science.gov (United States)

    2017-06-01

    entropy saturation behavior of the estimator is analytically described. Simultaneous range-compression and aperture synthesis is experimentally...4 2.1 Circular and Inverse -Circular HAL...2.3 Single Aperture, Multi-λ Imaging ...................................................................................... 14 2.4 Simultaneous Range

  5. Compression of Probabilistic XML documents

    NARCIS (Netherlands)

    Veldman, Irma

    2009-01-01

    Probabilistic XML (PXML) files resulting from data integration can become extremely large, which is undesired. For XML there are several techniques available to compress the document and since probabilistic XML is in fact (a special form of) XML, it might benefit from these methods even more. In

  6. Shock compression of synthetic opal

    Science.gov (United States)

    Inoue, A.; Okuno, M.; Okudera, H.; Mashimo, T.; Omurzak, E.; Katayama, S.; Koyano, M.

    2010-03-01

    Structural change of synthetic opal by shock-wave compression up to 38.1 GPa has been investigated by using SEM, X-ray diffraction method (XRD), Infrared (IR) and Raman spectroscopies. Obtained information may indicate that the dehydration and polymerization of surface silanole due to high shock and residual temperature are very important factors in the structural evolution of synthetic opal by shock compression. Synthetic opal loses opalescence by 10.9 and 18.4 GPa of shock pressures. At 18.4 GPa, dehydration and polymerization of surface silanole and transformation of network structure may occur simultaneously. The 4-membered ring of TO4 tetrahedrons in as synthetic opal may be relaxed to larger ring such as 6-membered ring by high residual temperature. Therefore, the residual temperature may be significantly high at even 18.4 GPa of shock compression. At 23.9 GPa, opal sample recovered the opalescence. Origin of this opalescence may be its layer structure by shock compression. Finally, sample fuse by very high residual temperature at 38.1 GPa and the structure closes to that of fused SiO2 glass. However, internal silanole groups still remain even at 38.1 GPa.

  7. Shock compression of synthetic opal

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, A; Okuno, M; Okudera, H [Department of Earth Sciences, Kanazawa University Kanazawa, Ishikawa, 920-1192 (Japan); Mashimo, T; Omurzak, E [Shock Wave and Condensed Matter Research Center, Kumamoto University, Kumamoto, 860-8555 (Japan); Katayama, S; Koyano, M, E-mail: okuno@kenroku.kanazawa-u.ac.j [JAIST, Nomi, Ishikawa, 923-1297 (Japan)

    2010-03-01

    Structural change of synthetic opal by shock-wave compression up to 38.1 GPa has been investigated by using SEM, X-ray diffraction method (XRD), Infrared (IR) and Raman spectroscopies. Obtained information may indicate that the dehydration and polymerization of surface silanole due to high shock and residual temperature are very important factors in the structural evolution of synthetic opal by shock compression. Synthetic opal loses opalescence by 10.9 and 18.4 GPa of shock pressures. At 18.4 GPa, dehydration and polymerization of surface silanole and transformation of network structure may occur simultaneously. The 4-membered ring of TO{sub 4} tetrahedrons in as synthetic opal may be relaxed to larger ring such as 6-membered ring by high residual temperature. Therefore, the residual temperature may be significantly high at even 18.4 GPa of shock compression. At 23.9 GPa, opal sample recovered the opalescence. Origin of this opalescence may be its layer structure by shock compression. Finally, sample fuse by very high residual temperature at 38.1 GPa and the structure closes to that of fused SiO{sub 2} glass. However, internal silanole groups still remain even at 38.1 GPa.

  8. Shock compression and quasielastic release in tantalum

    International Nuclear Information System (INIS)

    Johnson, J.N.; Hixson, R.S.; Tonks, D.L.; Gray, G.T. III

    1994-01-01

    Previous studies of quasielastic release in shock-loaded FCC metals have shown a strong influence of the defect state on the leading edge, or first observable arrival, of the release wave. This is due to the large density of pinned dislocation segments behind the shock front, their relatively large pinning separation, and a very short response time as determined by the drag coefficient in the shock-compressed state. This effect is entirely equivalent to problems associated with elastic moduli determination using ultrasonic methods. This is particularly true for FCC metals, which have an especially low Peierls stress, or inherent lattice resistance, that has little influence in pinning dislocation segments and inhibiting anelastic deformation. BCC metals, on the other hand, have a large Peierls stress that essentially holds dislocation segments in place at low net applied shear stresses and thus allows fully elastic deformation to occur in the complete absence of anelastic behavior. Shock-compression and release experiments have been performed on tantalum (BCC), with the observation that the leading release disturbance is indeed elastic. This conclusion is established by examination of experimental VISAR records taken at the tantalum/sapphire (window) interface in a symmetric-impact experiment which subjects the sample to a peak longitudinal stress of approximately 7.3 GPa, in comparison with characteristic code calculations. copyright 1994 American Institute of Physics

  9. Dynamical instability of hot and compressed nuclei

    International Nuclear Information System (INIS)

    Ngo, C.; Leray, S.; Spina, M.E.; Ngo, H.

    1989-01-01

    The dynamical evolution of a hot and compressed nucleus is described by means of an extended liquid-drop model. Using only the continuity equation and the energy conservation we show that the system expands after a while. The possible global instabilities of the drop are studied by applying the general conditions of stability of dynamical systems. We find that the nucleus is unstable if it can reach a low density configuration (≅0.07 nucleon/fm 3 ). Such a configuration is obtained if the initial compression of the nucleus is large enough. It is shown that the thermal excitation energy has much less influence than the compressional energy. These instability conditions are in good agreement with those obtained previously within the framework of lattice percolation and the same model for the dynamical expansion. Since local instabilities may also very likely be present, we propose to study them using a restructured aggregation model. They lead to a multifragmentation of the system, a mechanism which is known experimentally to exist. We find that local instabilities occur at smaller (but very close) density values than global ones. A moment analysis of the calculated multifragmentation events allows to extract a critical exponent in excellent agreement with the one deduced experimentally from Au-induced reactions. (orig.)

  10. Theory of compression and expansion of hydrogels

    Energy Technology Data Exchange (ETDEWEB)

    Iwata, M. [Suzuka National College of Tech., Mie (Japan). Dept. of Industrial Chemistry; Koda, S.; Nomura, H. [Nagoya University, Nagoya (Japan). Dept. of Molecular Design and Engineering

    1999-10-01

    Compression and expansion processes of cross-linked sodium polyacrylate hydrogels under mechanical pressure were investigated. A packed spherical gel bed shows irreversible deformation when the applied pressure is decreased; the expansion behavior depends on the maximum pressure applied to the gel bed. The time required to attain a certain degree of deformation is directly proportional to the square of the total solid volume of the gel bed; this relation is very similar to that observed in expression or expansion processes of ordinary solid-liquid mixtures. The driving force of the deformation is an effective osmotic pressure gradient in the gel bed, where the effective osmotic pressure of the gel is the difference between the swelling pressure of the gel and the pressure applied to the gel. The flow rate of liquid through any gel layer can be expressed by Darcy's equation. The deformation ceases when the swelling pressure of each gel particle is equal to the applied pressure. Thus, the deformation of a packed gel bed can be recognized as a process of equalizing the swelling pressure distribution in the bed. (author)

  11. Hyperspectral image compressing using wavelet-based method

    Science.gov (United States)

    Yu, Hui; Zhang, Zhi-jie; Lei, Bo; Wang, Chen-sheng

    2017-10-01

    Hyperspectral imaging sensors can acquire images in hundreds of continuous narrow spectral bands. Therefore each object presented in the image can be identified from their spectral response. However, such kind of imaging brings a huge amount of data, which requires transmission, processing, and storage resources for both airborne and space borne imaging. Due to the high volume of hyperspectral image data, the exploration of compression strategies has received a lot of attention in recent years. Compression of hyperspectral data cubes is an effective solution for these problems. Lossless compression of the hyperspectral data usually results in low compression ratio, which may not meet the available resources; on the other hand, lossy compression may give the desired ratio, but with a significant degradation effect on object identification performance of the hyperspectral data. Moreover, most hyperspectral data compression techniques exploits the similarities in spectral dimensions; which requires bands reordering or regrouping, to make use of the spectral redundancy. In this paper, we explored the spectral cross correlation between different bands, and proposed an adaptive band selection method to obtain the spectral bands which contain most of the information of the acquired hyperspectral data cube. The proposed method mainly consist three steps: First, the algorithm decomposes the original hyperspectral imagery into a series of subspaces based on the hyper correlation matrix of the hyperspectral images between different bands. And then the Wavelet-based algorithm is applied to the each subspaces. At last the PCA method is applied to the wavelet coefficients to produce the chosen number of components. The performance of the proposed method was tested by using ISODATA classification method.

  12. A study of diesel-hydrogen fuel exhaust emissions in a compression ignition engine/generator assembly

    International Nuclear Information System (INIS)

    Karri, V.; Hafez, H.A.; Kirkegaard, J.F.

    2006-01-01

    A compression engine and duel-fuel supply system was studied in order to determine the influence of hydrogen gas on a diesel engine's exhaust system. Commercially available solenoid valves and pulse actuators were used in a customized mechatronic control unit (MICU) to inject the hydrogen gas into the cylinders during the experiments. The MICU was designed as a generic external attachment. Diesel fuel was used to ignite the hydrogen gas-air mixture after compression. Various different electrical loads were then applied using an alternator in order to stimulate the engine governor and control diesel flow. Results of the study showed that measured carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxide (NO x ) loads of exhaust emissions increased, while emissions of carbon dioxide (CO 2 ) decreased. Results also showed that higher temperatures and levels of NO x occurred when hydrogen was mixed with the induced air. It was concluded that higher levels of hydrogen may be needed to reduce emissions. 17 refs., 5 tabs., 2 figs

  13. Atomistic simulation of rapid compression of fractured silicon carbide

    International Nuclear Information System (INIS)

    Romano, A.; Li, J.; Yip, S.

    2006-01-01

    Deformation mechanisms of a crack in silicon carbide under high-rate compression are investigated by molecular dynamics simulation. The penny-shaped crack is in tension throughout the simulation while a variable compression is applied in an in-plane direction. Two different mechanisms of crack-tip response are observed: (1) At low tension, a disordered band forms from the crack surface in the direction orthogonal to the compression, which grows as the compressional force is increased in a manner suggesting a stress-induced transition from an ordered to a disordered phase. Moreover the crack is observed to close. (2) At a tension sufficient to allow the crack to remain open, the compressional stress induces formation of disordered regions along the boundaries of the opened crack, which grow and merge into a band as the compression proceeds. This process is driven by bending of the initial crack, which transforms into a curved slit. This mechanism induces incorporation of fragments of perfect crystal into the disordered band. Similar mechanisms have been experimentally observed to occur in porous SiC under high-strain rate compression

  14. Distributed Source Coding Techniques for Lossless Compression of Hyperspectral Images

    Directory of Open Access Journals (Sweden)

    Barni Mauro

    2007-01-01

    Full Text Available This paper deals with the application of distributed source coding (DSC theory to remote sensing image compression. Although DSC exhibits a significant potential in many application fields, up till now the results obtained on real signals fall short of the theoretical bounds, and often impose additional system-level constraints. The objective of this paper is to assess the potential of DSC for lossless image compression carried out onboard a remote platform. We first provide a brief overview of DSC of correlated information sources. We then focus on onboard lossless image compression, and apply DSC techniques in order to reduce the complexity of the onboard encoder, at the expense of the decoder's, by exploiting the correlation of different bands of a hyperspectral dataset. Specifically, we propose two different compression schemes, one based on powerful binary error-correcting codes employed as source codes, and one based on simpler multilevel coset codes. The performance of both schemes is evaluated on a few AVIRIS scenes, and is compared with other state-of-the-art 2D and 3D coders. Both schemes turn out to achieve competitive compression performance, and one of them also has reduced complexity. Based on these results, we highlight the main issues that are still to be solved to further improve the performance of DSC-based remote sensing systems.

  15. Compressive sensing scalp EEG signals: implementations and practical performance.

    Science.gov (United States)

    Abdulghani, Amir M; Casson, Alexander J; Rodriguez-Villegas, Esther

    2012-11-01

    Highly miniaturised, wearable computing and communication systems allow unobtrusive, convenient and long term monitoring of a range of physiological parameters. For long term operation from the physically smallest batteries, the average power consumption of a wearable device must be very low. It is well known that the overall power consumption of these devices can be reduced by the inclusion of low power consumption, real-time compression of the raw physiological data in the wearable device itself. Compressive sensing is a new paradigm for providing data compression: it has shown significant promise in fields such as MRI; and is potentially suitable for use in wearable computing systems as the compression process required in the wearable device has a low computational complexity. However, the practical performance very much depends on the characteristics of the signal being sensed. As such the utility of the technique cannot be extrapolated from one application to another. Long term electroencephalography (EEG) is a fundamental tool for the investigation of neurological disorders and is increasingly used in many non-medical applications, such as brain-computer interfaces. This article investigates in detail the practical performance of different implementations of the compressive sensing theory when applied to scalp EEG signals.

  16. Moving image compression and generalization capability of constructive neural networks

    Science.gov (United States)

    Ma, Liying; Khorasani, Khashayar

    2001-03-01

    To date numerous techniques have been proposed to compress digital images to ease their storage and transmission over communication channels. Recently, a number of image compression algorithms using Neural Networks NNs have been developed. Particularly, several constructive feed-forward neural networks FNNs have been proposed by researchers for image compression, and promising results have been reported. At the previous SPIE AeroSense conference 2000, we proposed to use a constructive One-Hidden-Layer Feedforward Neural Network OHL-FNN for compressing digital images. In this paper, we first investigate the generalization capability of the proposed OHL-FNN in the presence of additive noise for network training and/ or generalization. Extensive experimental results for different scenarios are presented. It is revealed that the constructive OHL-FNN is not as robust to additive noise in input image as expected. Next, the constructive OHL-FNN is applied to moving images, video sequences. The first, or other specified frame in a moving image sequence is used to train the network. The remaining moving images that follow are then generalized/compressed by this trained network. Three types of correlation-like criteria measuring the similarity of any two images are introduced. The relationship between the generalization capability of the constructed net and the similarity of images is investigated in some detail. It is shown that the constructive OHL-FNN is promising even for changing images such as those extracted from a football game.

  17. Semi-confined compression of microfabricated polymerized biomaterial constructs

    International Nuclear Information System (INIS)

    Moraes, Christopher; Likhitpanichkul, Morakot; Simmons, Craig A; Sun, Yu; Zhao, Ruogang

    2011-01-01

    Mechanical forces are critical parameters in engineering functional tissue because of their established influence on cellular behaviour. However, identifying ideal combinations of mechanical, biomaterial and chemical stimuli to obtain a desired cellular response requires high-throughput screening technologies, which may be realized through microfabricated systems. This paper reports on the development and characterization of a MEMS device for semi-confined biomaterial compression. An array of these devices would enable studies involving mechanical deformation of three-dimensional biomaterials, an important parameter in creating physiologically relevant microenvironments in vitro. The described device has the ability to simultaneously apply a range of compressive mechanical stimuli to multiple polymerized hydrogel microconstructs. Local micromechanical strains generated within the semi-confined hydrogel cylinders are characterized and compared with those produced in current micro- and macroscale technologies. In contrast to previous work generating unconfined compression in microfabricated devices, the semi-confined compression model used in this work generates uniform regions of strain within the central portion of each hydrogel, demonstrated here to range from 20% to 45% across the array. The uniform strains achieved simplify experimental analysis and improve the utility of the compression platform. Furthermore, the system is compatible with a wide variety of polymerizable biomaterials, enhancing device versatility and usability in tissue engineering and fundamental cell biology studies

  18. External Events PSA for the Paks NPP

    International Nuclear Information System (INIS)

    Bareith, Attila; Karsa, Zoltan; Siklossy, Tamas; Vida, Zoltan

    2014-01-01

    quantification and interpretation of results. The risk of core damage induced by natural external hazards was quantified to the extent seen feasible. In addition to risk quantification, unresolved issues and necessary follow-on analyses were identified and proposed. At present an action plan is being developed for these analyses. Core damage risk has been assessed quantitatively for wind, snow and frost hazards. Detailed importance, sensitivity and uncertainty analyses were conducted. Moreover the main risk contributors induced by these external events were also identified. Additional follow-on analyses were proposed to enable an improved risk quantification by means of reducing uncertainties, establishing a better technical basis for the applied analytical assumptions, or decreasing unnecessarily high conservatism. Based on the findings of hazard assessment and plant response analysis, the core damage risk induced by extreme rainfall and lightning was found to be insignificant. However, some follow-on analyses were proposed and safety enhancement measures were conceptualised to fully underpin this conclusion. Due to lack of appropriate data and supporting analysis on the capacity of plant systems and components no PSA model has been developed yet for extreme temperatures. Follow-on analyses necessary for quantifying the risk of core damage induced by extreme temperatures have been identified. (authors)

  19. Effect of compressibility on the hypervelocity penetration

    Science.gov (United States)

    Song, W. J.; Chen, X. W.; Chen, P.

    2018-02-01

    We further consider the effect of rod strength by employing the compressible penetration model to study the effect of compressibility on hypervelocity penetration. Meanwhile, we define different instances of penetration efficiency in various modified models and compare these penetration efficiencies to identify the effects of different factors in the compressible model. To systematically discuss the effect of compressibility in different metallic rod-target combinations, we construct three cases, i.e., the penetrations by the more compressible rod into the less compressible target, rod into the analogously compressible target, and the less compressible rod into the more compressible target. The effects of volumetric strain, internal energy, and strength on the penetration efficiency are analyzed simultaneously. It indicates that the compressibility of the rod and target increases the pressure at the rod/target interface. The more compressible rod/target has larger volumetric strain and higher internal energy. Both the larger volumetric strain and higher strength enhance the penetration or anti-penetration ability. On the other hand, the higher internal energy weakens the penetration or anti-penetration ability. The two trends conflict, but the volumetric strain dominates in the variation of the penetration efficiency, which would not approach the hydrodynamic limit if the rod and target are not analogously compressible. However, if the compressibility of the rod and target is analogous, it has little effect on the penetration efficiency.

  20. The effect of compressive stress on the Young's modulus of unirradiated and irradiated nuclear graphites

    International Nuclear Information System (INIS)

    Oku, T.; Usui, T.; Ero, M.; Fukuda, Y.

    1977-01-01

    The Young's moduli of unirradiated and high temperature (800 to 1000 0 C) irradiated graphites for HTGR were measured by the ultrasonic method in the direction of applied compressive stress during and after stressing. The Young's moduli of all the tested graphites decreased with increasing compressive stress both during and after stressing. In order to investigate the reason for the decrease in Young's modulus by applying compressive stress, the mercury pore diameter distributions of a part of the unirradiated and irradiated specimens were measured. The change in pore distribution is believed to be associated with structural changes produced by irradiation and compressive stressing. The residual strain, after removing the compressive stress, showed a good correlation with the decrease in Young's modulus caused by the compressive stress. The decrease in Young's modulus by applying compressive stress was considered to be due to the increase in the mobile dislocation density and the growth or formation of cracks. The results suggest, however, that the mechanism giving the larger contribution depends on the brand of graphite, and in anisotropic graphite it depends on the direction of applied stress and the irradiation conditions. (author)