Sample records for rapid thoracoabdominal compression

  1. Comparison of respiratory inductance plethysmography with thoracoabdominal compression in bronchial challenges in infants and young children.

    Springer, C; Godfrey, S; Vilozni, D; Bar-Yishay, E; Noviski, N; Avital, A


    Respiratory inductance plethysmography measuring thoracoabdominal asynchrony (TAA) has been claimed to be a useful tool for measuring changes in airway resistance in infants. In this study we evaluated the response to methacholine by thoracoabdominal compression and respiratory inductance plethysmography. Seventeen infants (mean age, 13.1 +/- 4.7 mo) with recurrent episodes of cough or wheeze underwent bronchial challenge with inhaled methacholine. Lung function was evaluated by measuring maximal expiratory flow at resting lung volume (VmaxFRC), and the degree of TAA was measured by phase angle (theta). Methacholine was inhaled for 1 min during tidal breathing using increasing doubling concentrations until a fall of at least 40% in VmaxFRC was achieved (final concentration). All infants responded to the final concentration of methacholine by a significant fall in VmaxFRC (from 31 +/- 10 to 12 +/- 5 ml/s/kg, p inductance plethysmography is a sensitive method to measure bronchial reactivity to methacholine in most of the infants studied (14 of 17, 82%). A concentration of methacholine causing an increase in theta of at least 2.0 standard deviations above baseline is equivalent to the concentration causing a 40% fall in VmaxFRC.

  2. Feasibility of repetitive lung function measurements by raised volume rapid thoracoabdominal compression during methacholine challenge in young infants

    Loland, Lotte; Bisgaard, Hans


    was successfully measured in 87% by transcutaneous oxygen pressure. No serious adverse events were observed during testing or after discharge from the clinic. The methacholine dose range was appropriate as PD could be determined in the majority of infants. FEV(0.5) values in 21% of infants dropped > 40% during...... function by RVRTC during methacholine challenge in young infants in a single center leads us to conclude that the test is feasible and safe to perform in asymptomatic young infants....

  3. Feasibility of repetitive lung function measurements by raised volume rapid thoracoabdominal compression during methacholine challenge in young infants

    Loland, L.; Bisgaard, H.


    was successfully measured in 87% by transcutaneous oxygen pressure. No serious adverse events were observed during testing or after discharge from the clinic. The methacholine dose range was appropriate as PD could be determined in the majority of infants. FEV(0.5) values in 21% of infants dropped > 40% during...... the test. Short-lasting, self-limiting episodes of hypoxemia of parents were changes in the patterns of sleeping (95%), eating (57%), and behavior (58%) of the infant after hospital discharge....... The mean acceptability rating among parents was 8 on a scale from 1 to 10, with 13% rating

  4. Visual combustion research using the rapid compression expansion machine

    Imhof, Dino; Takasaki, Koji [Kyushu Univ. (Japan). Lab. of Engine and Combustion (ECO)


    A large Rapid Compression Expansion Machine (RCEM) has been built at Kyushu University, Japan, for research on large marine engines. Three focal points of research are testing light cycle oil using a multiple injection to establish its potential as a low sulphur fuel; abnormal combustion caused by lubricating oil in lean burn gas engines; visualising high pressure natural gas injection (GI). (orig.)

  5. Primary closure of thoraco-abdominal ectopia cordis

    Singal A


    Full Text Available Thoraco-abdominal ectopia cordis is an unusual congenital anomaly. The case of a 45-days-old female child, who presented with a defect in the chest and upper abdomen and visible cardiac pulsations and bulge during crying, is being reported. There was an inferior sternal cleft with divarication of the recti up to the umbilicus. The cleft was covered with a thin translucent membrane. Primary repair was accomplished successfully without causing mediastinal compression.

  6. Hepatic hydrothorax occurring rapidly after manual abdominal compression


    Hepatic hydrothorax is a relatively infrequent but potentially serious complication of liver cirrhosis that often causes respiratory dysfunction. Several hypotheses for the development of hepatic hydrothorax have been suggested to explain a transdiaphragmatic shift of ascitic fluid through small defects between the peritoneal cavity and the pleural space. However, the rapid development of hydrothorax within several hours is seldom encountered. In addition, the causal factors for rapid passage of ascitic fluid into the pleural cavity are unknown. This report describes a patient with liver cirrhosis who suffered rapid development of a hydrothorax after manual compression of the abdomen.

  7. Performance Characterization and Auto-Ignition Performance of a Rapid Compression Machine

    Hao Liu; Hongguang Zhang; Zhicheng Shi; Haitao Lu; Guangyao Zhao; Baofeng Yao


      A rapid compression machine (RCM) test bench is developed in this study. The performance characterization and auto-ignition performance tests are conducted at an initial temperature of 293 K, a compression ratio of 9.5...

  8. Rapid MR spectroscopic imaging of lactate using compressed sensing

    Vidya Shankar, Rohini; Agarwal, Shubhangi; Geethanath, Sairam; Kodibagkar, Vikram D.


    Imaging lactate metabolism in vivo may improve cancer targeting and therapeutics due to its key role in the development, maintenance, and metastasis of cancer. The long acquisition times associated with magnetic resonance spectroscopic imaging (MRSI), which is a useful technique for assessing metabolic concentrations, are a deterrent to its routine clinical use. The objective of this study was to combine spectral editing and prospective compressed sensing (CS) acquisitions to enable precise and high-speed imaging of the lactate resonance. A MRSI pulse sequence with two key modifications was developed: (1) spectral editing components for selective detection of lactate, and (2) a variable density sampling mask for pseudo-random under-sampling of the k-space `on the fly'. The developed sequence was tested on phantoms and in vivo in rodent models of cancer. Datasets corresponding to the 1X (fully-sampled), 2X, 3X, 4X, 5X, and 10X accelerations were acquired. The under-sampled datasets were reconstructed using a custom-built algorithm in MatlabTM, and the fidelity of the CS reconstructions was assessed in terms of the peak amplitudes, SNR, and total acquisition time. The accelerated reconstructions demonstrate a reduction in the scan time by up to 90% in vitro and up to 80% in vivo, with negligible loss of information when compared with the fully-sampled dataset. The proposed unique combination of spectral editing and CS facilitated rapid mapping of the spatial distribution of lactate at high temporal resolution. This technique could potentially be translated to the clinic for the routine assessment of lactate changes in solid tumors.

  9. Rapid compression induced solidification of two amorphous phases of poly(ethylene terephthalate)

    Hong, S M [Laboratory of High Pressure Physics, Southwest Jiaotong University, Chengdu, 610031 (China); Liu, X R [Laboratory of High Pressure Physics, Southwest Jiaotong University, Chengdu, 610031 (China); Su, L [Laboratory of High Pressure Physics, Southwest Jiaotong University, Chengdu, 610031 (China); Huang, D H [Laboratory of High Pressure Physics, Southwest Jiaotong University, Chengdu, 610031 (China); Li, L B [Foods Research Centre Unilever R and D, Vlaardingen Olivier van Noortlaan, 120, 3133 AT Vlaardingen (Netherlands)


    Melts of poly(ethylene terephthalate) were solidified by rapid compression to 2 GPa within 20 ms and by a series of comparative processes including natural cooling, slow compressing and rapid cooling, respectively. By combining XRD and differential scanning calorimetry data of the recovered samples, it is made clear that rapid compression induces two kinds of amorphous phases. One is relatively stable and can also be formed in the slow compression and the cooling processes. Another is metastable and transforms to crystalline phase at 371 K. This metastable amorphous phase cannot be obtained by slow compression or natural cooling, and its crystallization temperature is remarkably different from that of the metastable amorphous phase formed in the rapid cooling sample.

  10. Using NIR and ATR-FTIR spectroscopy to rapidly detect compression wood in Pinus radiata

    McLean, J. Paul; Jin, Guangwu; Brennan, Maree; Nieuwoudt, Michel K; Harris, Philip J


    .... Traditional methods of detecting it are often time consuming and subjective. This study aimed to rapidly and impartially detect compression wood through the use of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR...

  11. Thoraco-abdominal aortic aneurysm branched repair

    Verhoeven, E. L. G.; Tielliu, I. F. J.; Ferreira, M.; Zipfel, B.; Adam, D. J.


    Open thoraco-abdominal aortic aneurysm repair is a demanding procedure with high impact on the patient and the operating team. Results from expert centres show mortality rates between 3-21%, with extensive morbidity including renal failure and paraplegia. Endovascular repair of abdominal aortic aneu

  12. A Rapid Compression Expansion Machine (RCEM) for studying chemical kinetics: Experimental principle and first applications

    Werler, Marc; Maas, Ulrich


    A novel extension of a rapid compression machine (RCM), namely a Rapid Compression Expansion Machine (RCEM), is described and its use for studying chemical kinetics is demonstrated. Like conventional RCMs, the RCEM quickly compresses a fuel/air mixture by pushing a piston into a cylinder; the resulting high temperatures and pressures initiate chemical reactions. In addition, the machine can rapidly expand the compressed gas in a controlled way by pulling the piston outwards again. This freezes chemical activity after a pre-defined reaction duration, and therefore allows a convenient probe sampling and ex-situ gas analysis of stable species. The RCEM therefore is a promising instrument for studying chemical kinetics, including also partially reacted fuel/air mixtures. The setup of the RCEM, its experimental characteristics and its use for studying chemical reactions are outlined in detail. To allow comparisons of RCEM results with predictions of chemical reaction mechanisms, a simple numerical model of the RCE...

  13. Rapid adaptation to time-compressed speech in young and older adults.

    Simhony, Ma'ayan; Grinberg, Michal; Lavie, Limor; Banai, Karen


    The ability of human listeners to comprehend rapid speech improves quickly with experience, a process known as adaptation. Whether inefficient adaptation to rapid speech partially accounts for the marked difficulties of older listeners with rapid speech is not clear. Two conditions of adaptation to time-compressed speech were used. A baseline condition intended to test the hypothesis that adaptation is different in older and younger listeners, and an interference condition in which sentences compressed to two different rates were interleaved. Identification accuracy was compared between two time points (before and after adaptation) and between older and younger listeners. The effects of adaptation did not differ between younger and older listeners in either adaptation condition. It seems that once initial performance differences are taken into account, rapid adaptation to time-compressed speech is as effective and as immune to interference by competing speech rates in younger and older adults.

  14. Developments in time-resolved high pressure x-ray diffraction using rapid compression and decompression

    Smith, Jesse S.; Sinogeikin, Stanislav V.; Lin, Chuanlong; Rod, Eric; Bai, Ligang; Shen, Guoyin [High Pressure Collaborative Access Team, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439 (United States)


    Complementary advances in high pressure research apparatus and techniques make it possible to carry out time-resolved high pressure research using what would customarily be considered static high pressure apparatus. This work specifically explores time-resolved high pressure x-ray diffraction with rapid compression and/or decompression of a sample in a diamond anvil cell. Key aspects of the synchrotron beamline and ancillary equipment are presented, including source considerations, rapid (de)compression apparatus, high frequency imaging detectors, and software suitable for processing large volumes of data. A number of examples are presented, including fast equation of state measurements, compression rate dependent synthesis of metastable states in silicon and germanium, and ultrahigh compression rates using a piezoelectric driven diamond anvil cell.

  15. Rapid Fatal Outcome from Pulmonary Arteries Compression in Transitional Cell Carcinoma

    Ioannis A. Voutsadakis


    Full Text Available Transitional cell carcinoma of the urinary bladder is a malignancy that metastasizes frequently to lymph nodes including the mediastinal lymph nodes. This occurrence may produce symptoms due to compression of adjacent structures such as the superior vena cava syndrome or dysphagia from esophageal compression. We report the case of a 59-year-old man with metastatic transitional cell carcinoma for whom mediastinal lymphadenopathy led to pulmonary artery compression and a rapidly fatal outcome. This rare occurrence has to be distinguished from pulmonary embolism, a much more frequent event in cancer patients, in order that proper and prompt treatment be initiated.

  16. Compressible instability of rapidly expanding spherical material interfaces

    Mankbadi, Mina Reda

    The focus herein is on the instability of a material interface formed during an abrupt release of concentrated energy as in detonative combustion, explosive dispersals, and inertial-confinement fusion. These applications are modeled as a spherical shock-tube in which high-pressure gas initially contained in a small spherical shell is suddenly released. A forward-moving shock and an inward-moving secondary shock are formed, and between them a material interface develops that separates high-density fluid from the low-density one. The wrinkling of this interface controls mixing and energy release. The interface's stability is studied with and without the inclusion of metalized particulates. A numerical scheme is developed to discretize the full nonlinear equations of the base flow, and the 3D linearized perturbed flow equations. Linearization is followed by spherical harmonic decomposition of the disturbances, thereby reducing the 3D computational domain to one-dimensional radial domain. The 3D physical nature of the disturbances is maintained throughout the procedure. An extended Roe-Pike scheme coupled with a WENO scheme is developed to capture the discontinuities and accurately predict the disturbances. In Chapter 2, the contact interface's stability is analyzed in the inviscid single-phase. The disturbances grow exponentially and the growth rate is insensitive to the radial initial-disturbance profile. For wave numbers less than 100, the results are in accordance with previous theories but clarify that compressibility reduces the growth rate. Unlike the classical RTI, the growth rate reaches saturation at high wavenumbers. The parametric studies show that for specific ratios of initial pressure and temperature, the instability can be eliminated altogether. Chapter 3 discusses the full effects of viscosity and thermal diffusivity. Although Prandtl number effects are minimal, viscous effects dampen the high-wave numbers. For a given Reynolds number there is a peak

  17. Performance Characterization and Auto-Ignition Performance of a Rapid Compression Machine

    Hao Liu


    Full Text Available A rapid compression machine (RCM test bench is developed in this study. The performance characterization and auto-ignition performance tests are conducted at an initial temperature of 293 K, a compression ratio of 9.5 to 16.5, a compressed temperature of 650 K to 850 K, a driving gas pressure range of 0.25 MPa to 0.7 MPa, an initial pressure of 0.04 MPa to 0.09 MPa, and a nitrogen dilution ratio of 35% to 65%. A new type of hydraulic piston is used to address the problem in which the hydraulic buffer adversely affects the rapid compression process. Auto-ignition performance tests of the RCM are then performed using a DME–O2–N2 mixture. The two-stage ignition delay and negative temperature coefficient (NTC behavior of the mixture are observed. The effects of driving gas pressure, compression ratio, initial pressure, and nitrogen dilution ratio on the two-stage ignition delay are investigated. Results show that both the first-stage and overall ignition delays tend to increase with increasing driving gas pressure. The driving gas pressure within a certain range does not significantly influence the compressed pressure. With increasing compression ratio, the first-stage ignition delay is shortened, whereas the second-stage ignition delay is extended. With increasing initial pressure, both the first-stage and second-stage ignition delays are shortened. The second-stage ignition delay is shortened to a greater extent than that of the first-stage. With increasing nitrogen dilution ratio, the first-stage ignition delay is shortened, whereas the second-stage is extended. Thus, overall ignition delay presents different trends under various compression ratios and compressed pressure conditions.

  18. Kinetics of the B1-B2 phase transition in KCl under rapid compression

    Lin, Chuanlong; Smith, Jesse S.; Sinogeikin, Stanislav V.; Park, Changyong; Kono, Yoshio; Kenney-Benson, Curtis; Rod, Eric; Shen, Guoyin, E-mail: [HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439 (United States)


    Kinetics of the B1-B2 phase transition in KCl has been investigated under various compression rates (0.03–13.5 GPa/s) in a dynamic diamond anvil cell using time-resolved x-ray diffraction and fast imaging. Our experimental data show that the volume fraction across the transition generally gives sigmoidal curves as a function of pressure during rapid compression. Based upon classical nucleation and growth theories (Johnson-Mehl-Avrami-Kolmogorov theories), we propose a model that is applicable for studying kinetics for the compression rates studied. The fit of the experimental volume fraction as a function of pressure provides information on effective activation energy and average activation volume at a given compression rate. The resulting parameters are successfully used for interpreting several experimental observables that are compression-rate dependent, such as the transition time, grain size, and over-pressurization. The effective activation energy (Q{sub eff}) is found to decrease linearly with the logarithm of compression rate. When Q{sub eff} is applied to the Arrhenius equation, this relationship can be used to interpret the experimentally observed linear relationship between the logarithm of the transition time and logarithm of the compression rates. The decrease of Q{sub eff} with increasing compression rate results in the decrease of the nucleation rate, which is qualitatively in agreement with the observed change of the grain size with compression rate. The observed over-pressurization is also well explained by the model when an exponential relationship between the average activation volume and the compression rate is assumed.

  19. Rapid intermittent compression increases skin circulation in chronically ischemic legs with infra-popliteal arterial obstruction.

    van Bemmelen, P S; Weiss-Olmanni, J; Ricotta, J J


    Intermittent pneumatic compression (IPC) has been shown, by duplex, to increase popliteal artery flow in normal legs and in legs with superficial femoral artery occlusion. The objective of this study was to see if IPC improves distal circulation in legs with severe infra-popliteal disease. Sixteen chronically ischemic legs with arteriographically demonstrated crural or pedal disease were studied during compression with an ArtAssist compression-device. This device delivers rapid compression of the foot and calf. Cutaneous laser-Doppler flux was measured continuously at the dorsal aspect of the distal forefoot. The findings were compared to those in thirteen normal controls of similar age. In ischemic legs, the spontaneous changes in skin-flux are minimal: mean resting flux in sitting position was 0.87 +/- 0.46 AU (Arbitrary Units). Upon activation of the compression device the maximum flux increased to 4.55 +/- 1.35 AU. The difference was statistically significant (p < 0.001). This response was similar to that in normal controls. Arterial flow augmentation upon compression is associated with increased skin-flux. This response remains present in severe disease of the crural outflow-arteries. Further investigation to define the role of intermittent compression for management of chronic arterial disease is warranted.

  20. Ignition properties of methane/hydrogen mixtures in a rapid compression machine

    Gersen, S.; Anikin, N. B.; Mokhov, A. V.; Levinsky, H. B.


    We investigate changes in the combustion behavior of methane, the primary component of natural gas, upon hydrogen addition by characterizing the autoignition behavior of methane/hydrogen mixtures in a rapid compression machine (RCM). Ignition delay times were measured under stoichiometric conditions

  1. [Postoperative spinal cord ischemia in thoracoabdominal aneurysms].

    Latorre, J; Rosendo, A; Vidal, J; Sarrias, M


    At the present article, 12 cases of paraplegia secondary to the surgical treatment of thoracoabdominal aneurysms are presented. Study includes patients admitted between 1973-1987 for treatment and rehabilitation of its medular injury. Factors of risk, surgical technics practiced, peroperative complications and type of medular injury are analyzed. The most common medular injury was an anterior medular syndrome (rather than 60%). In the same way, preventive methods are analyzed and somatosensory evoked potentials (SEP) and motor evoked potentials (MEP), both in developing phase at the present moment, are recommended as the most viable method for detecting changes during the surgical procedure.

  2. Angiographic improvement after rapid intermittent compression treatment [ArtAssist] for small vessel obstruction.

    van Bemmelen, Paul; Char, Daniel; Giron, Fabio; Ricotta, John J


    A case is presented of a female ex-smoker who underwent bypass or exploration of all three below-knee arteries with failed results. Three separate arteriograms, performed at other academic institutions, demonstrated progressive, severe involvement of the pedal arteries. Therefore, the patient was prepared to undergo below-knee amputation surgery for uncontrollable rest pain and progressive necrosis of the forefoot; instead, the patient underwent 4 months of intermittent compression treatment. A fourth arteriogram, performed after 4 months of intermittent compression treatment (using rapid inflation/deflation and high-pressure cycle; ArtAssist demonstrated marked improvement of the posterior tibial artery runoff and development of more extensive collateral arteries in the calf. The patient's rest pain subsided and successful limb salvage was accomplished with a modified transmetatarsal amputation. This case could encourage other practitioners to repeat arteriography after compression treatments, which may redirect the treatment plan for selected patients with critical limb ischemia and nonreconstructable peripheral vascular disease.

  3. Elective visceral hybrid repair of type III thoracoabdominal aortic aneurysm

    Marjanović Ivan


    Full Text Available Introduction. According to the classification given by Crawford et al. type III thoracoabdominal aortic aneurysm (TAAA is dilatation of the aorta from the level of the rib 6 to the separation of the aorta below the renal arteries, capturing all the visceral branch of aorta. Visceral hybrid reconstruction of TAAA is a procedure developed in recent years in the world, which involves a combination of conventional, open and endovascular aortic reconstruction surgery at the level of separation of the left subclavian artery to the level of visceral branches of aorta. Case report. We presented a 75-years-old man, with elective visceral hybrid reconstruction of type III TAAA. Computerized scanning (CT angiography of the patient showed type III TAAA with the maximum transverse diameter of aneurysm of 92 mm. Aneurysm started at the level of the sixth rib, and the end of the aneurysm was 1 cm distal to the level of renal arteries. Aneurysm compressed the esophagus, causing the patient difficulty in swallowing act, especially solid food, and frequent back pain. From the other comorbidity, the patient had been treated for a long time, due to chronic obstructive pulmonary disease and hypertension. In general endotracheal anesthesia with epidural analgesia, the patient underwent visceral hybrid reconstruction of TAAA, which combines classic, open vascular surgery and endovascular procedures. Classic vascular surgery is visceral reconstruction using by-pass procedure from the distal, normal aorta to all visceral branches: celiac trunk, superior mesenteric artery and both renal arteries, with ligature of all arteries very close to the aorta. After that, by synchronous endovascular technique a complete aneurysmal exclusion of thoracoabdominal aneurysm with thoracic stent-graft was performed. The postoperative course was conducted properly and the patient left the Clinic for Vascular Surgery on postoperative day 21. Control CT, performed 3 months after the surgery

  4. Management of Recurrent Delayed Neurologic Deficit After Thoracoabdominal Aortic Operation.

    Boutrous, Mina L; Afifi, Rana O; Safi, Hazim J; Estrera, Anthony L


    Delayed neurologic deficit (DND) is a devastating adverse event after thoracoabdominal aortic aneurysm repair. Multiple adjuncts have been devised to counteract the development of DND, most notably cerebrospinal fluid (CSF) drainage. We report a case of a 63-year-old woman in whom DND developed four times during the first 10 days after her thoracoabdominal aortic operation. This necessitated lumbar drain "weaning" to allow for a slowly rising CSF pressure and preservation of lower extremity motor function.

  5. Gasoline surrogate modeling of gasoline ignition in a rapid compression machine and comparison to experiments

    Mehl, M; Kukkadapu, G; Kumar, K; Sarathy, S M; Pitz, W J; Sung, S J


    The use of gasoline in homogeneous charge compression ignition engines (HCCI) and in duel fuel diesel - gasoline engines, has increased the need to understand its compression ignition processes under engine-like conditions. These processes need to be studied under well-controlled conditions in order to quantify low temperature heat release and to provide fundamental validation data for chemical kinetic models. With this in mind, an experimental campaign has been undertaken in a rapid compression machine (RCM) to measure the ignition of gasoline mixtures over a wide range of compression temperatures and for different compression pressures. By measuring the pressure history during ignition, information on the first stage ignition (when observed) and second stage ignition are captured along with information on the phasing of the heat release. Heat release processes during ignition are important because gasoline is known to exhibit low temperature heat release, intermediate temperature heat release and high temperature heat release. In an HCCI engine, the occurrence of low-temperature and intermediate-temperature heat release can be exploited to obtain higher load operation and has become a topic of much interest for engine researchers. Consequently, it is important to understand these processes under well-controlled conditions. A four-component gasoline surrogate model (including n-heptane, iso-octane, toluene, and 2-pentene) has been developed to simulate real gasolines. An appropriate surrogate mixture of the four components has been developed to simulate the specific gasoline used in the RCM experiments. This chemical kinetic surrogate model was then used to simulate the RCM experimental results for real gasoline. The experimental and modeling results covered ultra-lean to stoichiometric mixtures, compressed temperatures of 640-950 K, and compression pressures of 20 and 40 bar. The agreement between the experiments and model is encouraging in terms of first

  6. The Taylor-Proudman column in a rapidly-rotating compressible fluid I. energy transports

    Park, Jun Sang [Halla University, Wonju (Korea, Republic of)


    A theoretical study is made of the steady flow of a compressible fluid in a rapidly rotating finite cylinder. Flow is generated by imposing mechanical and/or thermal disturbances at the rotating endwall disks. Both the Ekman and Rossby numbers are small. An examination is made of the energy budget for a control volume in the Ekman boundary layer. A combination of physical variables, which is termed the energy flux content, consisting of temperature and modified angular momentum, emerges to be relevant. The distinguishing features of a compressible fluid, in contrast to those of an incompressible fluid, are noted. A plausible argument is given to explain the difficulty in achieving the Taylor-Proudman column in a compressible rotating fluid. For the Taylor-Proudman column to be sustained, in the interior, it is shown that the net energy transport between the solid disk wall and the interior fluid should vanish. Physical rationalizations are facilitated by resorting to the concept of the afore-stated energy flux content.

  7. Thoraco-abdominal ectopia cordis in southwest Cameroon.

    Chishugi, John B; Franke, Trixy J


    Ectopia cordis is a rare congenital defect where the heart is completely displaced outside the chest wall. Cantrell's pentalogy is an embryologic anomaly with five classic midline deficiencies often associated with ectopia cordis. Here we present a case of thoraco-abdominal ectopia cordis, brief literature review, and possible implications for changes in antenatal care.

  8. Ectopia cordis, a successful single stage thoracoabdominal repair.

    Samir, Khaled; Ghez, Olivier; Metras, Dominique; Kreitmann, Bernard


    This is a report of a case of the rare ectopia cordis malformation of the thoracoabdominal type without intracardiac anomalies. The patient had a successful single stage repair with reduction of the herniating heart and reconstruction of a cartilaginous cover to protect the heart. The result was very good and the follow up for 13 months was very satisfactory.

  9. Thoraco-abdominal Ectopia Cordis in Southwest Cameroon

    Chishugi, John B; Franke, Trixy J


    Ectopia cordis is a rare congenital defect where the heart is completely displaced outside the chest wall. Cantrell's pentalogy is an embryologic anomaly with five classic midline deficiencies often associated with ectopia cordis. Here we present a case of thoraco-abdominal ectopia cordis, brief literature review, and possible implications for changes in antenatal care.

  10. Low arginine plasma levels in patients after thoracoabdominal aortic surgery.

    Nijveldt, R J; Prins, H A; Siroen, M P; Rauwerda, J A; Teerlink, T; van Leeuwen, P A


    Thoracoabdominal aortic surgery is a high-risk procedure and associated with a significant morbidity and mortality. Ischemia reperfusion of visceral organs and lower extremities is one of the most important determinants of this morbidity. Arginine is the precursor of nitric oxide and arginine plasma levels are important in maintaining organ blood flow. Furthermore, arginine is important in wound healing and the immune system. Because of increased utilization of arginine, low arginine plasma levels could be expected after thoracoabdominal aortic surgery. We therefore measured arginine plasma levels in these patients. Six patients with thoracoabdominal aortic aneurysm were included in this study. University Hospital Vrije Universiteit, Department of Surgery, Amsterdam, The Netherlands. Six patients undergoing thoracoabdominal aortic surgery. Plasma levels of arginine were measured by high-performance liquid chromatography. Very low arginine plasma levels were seen on the first postoperative day. From day 1 arginine slowly increased, but did not reach normal plasma levels on day 6. A significant decrease of arginine plasma levels was found and because of the fact that arginine has multiple functions, it may be important to keep these arginine plasma levels at normal or even higher levels in patients undergoing major vascular surgery. European Journal of Clinical Nutrition (2000) 54, 615-617.

  11. Human respiration at rest in rapid compression and at high pressures and gas densities

    Gelfand, R.; Lambertsen, C. J.; Strauss, R.; Clark, J. M.; Puglia, C. D.


    The ventilation (V), end-tidal PCO2 (PACO2), and CO2 elimination rate were determined in men at rest breathing CO2-free gas over the pressure range 1-50 ATA and the gas density range 0.4-25 g/l, during slow and rapid compressions, at stable elevated ambient pressures and during slow decompressions. Progressive increase in pulmonary gas flow resistance due to elevation of ambient pressure and inspired gas density to the He-O2 equivalent of 5000 feet of seawater was found to produce a complex pattern of change in PACO2. It was found that as both ambient pressure and pulmonary gas flow resistance were progressively raised, PACO2 at first increased, went through a maximum, and then declined towards values near the 1 ATA level. It is concluded that this pattern of PACO2 change results from the interaction on ventilation of the increase in pulmonary resistance due to the elevation of gas density with the increase in respiratory drive postulated as due to generalized central nervous system excitation associated with exposure to high hydrostatic pressure. It is suggested that a similar interaction exists between increased gas flow resistance and the increase in respiratory drive related to nitrogen partial pressure and the resulting narcosis.

  12. The Effect of Diluent Gases In The Shock Tube and Rapid Compression Machine

    Silke, E; W?rmel, J; O?Conaire, M; Simmie, J; Curran, H


    Studying the details of hydrocarbon chemistry in an internal combustion engine is not straightforward. A number of factors, including varying conditions of temperature and pressure, complex fluid motions, as well as variation in the composition of gasoline, render a meaningful characterization of the combusting system difficult. Some simplified experimental laboratory devices offer an alternative to complex engine environments: they remove some of the complexities that exist in real engines but retain the ability to work under engine-relevant conditions. The choice of simplified experimental devices is limited by the range of temperature and pressure at which they can operate; only the shock tube and rapid compression machine (RCM) can reach engine-relevant temperatures and pressures quickly enough and yet withstand the high pressures that occur after the ignition event. Both devices, however, suffer a common drawback: the use of inert diluent gases has been shown to affect the measured ignition delay time under some experimental conditions. Interestingly, this effect appears to be opposite in the shock tube and RCM: in the comparative study of the carrier gases argon and nitrogen, argon decreases the ignition delay time in the shock tube, but increases it in the RCM. This observation is investigated in more detail in this study.

  13. Multiple multilayer stents for thoracoabdominal aortic aneurysm: a possible new tool for aortic endovascular surgery.

    Tolva, Valerio Stefano; Bianchi, Paolo Guy; Cireni, Lea Valeria; Lombardo, Alma; Keller, Guido Carlo; Parati, Gianfranco; Casana, Renato Maria


    Endovascular surgery data are confirming the paramount role of modern endovascular tools for a safe and sure exclusion of thoracoabdominal lesions. A 57-year-old female presented with severe comorbidity affected by a 58 mm thoracoabdominal aortic aneurysm (TAAA). After patient-informed consent and local Ethical Committee and Italian Public Health Ministry authorization, three multilayer stents were implanted in the thoracoabdominal aortic tract, obtaining at a 20-month computed tomography scan follow up, a complete exclusion of the TAAA, with normal patency of visceral vessels. Multilayer stents can be used in thoracoabdominal aortic aneurysm, with positive results.

  14. Final Report 02-ERD-033: Rapid Resolidification of Metals using Dynamic Compression

    Streitz, F H; Nguyen, J H; Orlikowski, D; Minich, R; Moriarty, J A; Holmes, N C


    The purpose of this project is to develop a greater understanding of the kinetics involved during a liquid-solid phase transition occurring at high pressure and temperature. Kinetic limitations are known to play a large role in the dynamics of solidification at low temperatures, determining, e.g., whether a material crystallizes upon freezing or becomes an amorphous solid. The role of kinetics is not at all understood in transitions at high temperature when extreme pressures are involved. In order to investigate time scales during a dynamic compression experiment we needed to create an ability to alter the length of time spent by the sample in the transition region. Traditionally, the extreme high-pressure phase diagram is studied through a few static and dynamic techniques: static compression involving diamond anvil cells (DAC) [1], shock compression [2, 3], and quasi-isentropic compression [4, 5, 6, 7, 8, 9, 10]. Static DAC experiments explore equilibrium material properties along an isotherm or an isobar [1]. Dynamic material properties can be explored with shock compression [2, 3], probing single states on the Hugoniot, or with quasi-isentropic compression [4, 5, 6, 7, 8, 9, 10]. In the case of shocks, pressures variation typically occurs on a sub-nanosecond time scale or faster [11]. Previous quasi-isentropic techniques have yielded pressure ramps on the 10-100 nanosecond time-scale for samples that are several hundred microns thick [4, 5, 6, 7]. In order to understand kinetic effects at high temperatures and high pressures, we need to span a large dynamic range (strain rates, relaxation times, etc.) as well as control the thermodynamic path that the material experiences. Compression rates, for instance, need to bridge those of static experiments (seconds to hours) and those of the Z-accelerator (10{sup 6} s{sup -1}) [4] or even laser ablation techniques (10{sup 6} s{sup -1} to 10{sup 8} s{sup -1}) [7]. Here, we present a new technique that both extends the

  15. Time-resolved temperature measurements in a rapid compression machine using quantum cascade laser absorption in the intrapulse mode

    Nasir, Ehson Fawad


    A temperature sensor based on the intrapulse absorption spectroscopy technique has been developed to measure in situ temperature time-histories in a rapid compression machine (RCM). Two quantum-cascade lasers (QCLs) emitting near 4.55μm and 4.89μm were operated in pulsed mode, causing a frequency "down-chirp" across two ro-vibrational transitions of carbon monoxide. The down-chirp phenomenon resulted in large spectral tuning (δν ∼2.8cm-1) within a single pulse of each laser at a high pulse repetition frequency (100kHz). The wide tuning range allowed the application of the two-line thermometry technique, thus making the sensor quantitative and calibration-free. The sensor was first tested in non-reactive CO-N2 gas mixtures in the RCM and then applied to cases of n-pentane oxidation. Experiments were carried out for end of compression (EOC) pressures and temperatures ranging 9.21-15.32bar and 745-827K, respectively. Measured EOC temperatures agreed with isentropic calculations within 5%. Temperature rise measured during the first-stage ignition of n-pentane is over-predicted by zero-dimensional kinetic simulations. This work presents, for the first time, highly time-resolved temperature measurements in reactive and non-reactive rapid compression machine experiments. © 2016 Elsevier Ltd.

  16. Analysis of high risk factors related to acute respiratory distress syndrome following severe thoracoabdominal injuries

    ZHENG Guo-shou; BAI Xiang-jun; ZHAN Cheng-ye


    Objective: To investigate the high risk factors related to acute respiratory distress syndrome ( ARDS ) following serious thoracoabdominal injuries.Methods: The clinical data of 282 patients with serious thoracoabdominal injuries were retrospectively studied. Univariate and Cox multivariate regression analysis were used to determine the risk factors related to ARDS following serious thoracoabdominal injuries.Results: The incidence of ARDS was 31.9% (90/282) in patients with serious thoracoabdominal injuries.The mortality caused by ARDS was 37.8% (34/90). The univariate analysis and multivariate analysis demonstrated that the clinical conditions such as elder age, shock,dyspnea, abnormal arterial blood gas, hemopneumothorax,pulmonary contusion, flail chest, coexisting pulmonary diseases, multiple abdominal injury and high ISS score were the independent high risk factors related to ARDS.Conclusion: There are many high risk factors related to ARDS following severe thoracoabdominal injuries, which should be detected early and treated timely to decrease the incidence and mortality of ARDS.

  17. Contemporary spinal cord protection during thoracic and thoracoabdominal aortic surgery and endovascular aortic repair

    Etz, Christian D; Weigang, Ernst; Hartert, Marc


    Ischaemic spinal cord injury (SCI) remains the Achilles heel of open and endovascular descending thoracic and thoracoabdominal repair. Neurological outcomes have improved coincidentially with the introduction of neuroprotective measures. However, SCI (paraplegia and paraparesis) remains the most...

  18. A 'one in a million' case of pulsating thoracoabdominal mass.

    Tan, Lay Ong


    Ectopia cordis is a rare congenital malformation in which the heart is located partially or totally outside the thoracic cavity. It comprises 0.1% of congenital heart diseases. The authors present a case of a male baby born at term by emergency caesarean section due to prolonged fetal bradycardia, who was noted to have a large pulsating mass in the thoracoabdominal area. In view of lower thoracolumbar abdominal defect, ectopic placement of the umbilicus, deficiency of the diaphragmatic pericardium, deficiency of anterior diaphragm and intracardiac abnormalities, a diagnosis of ectopia cordis-Pentalogy of Cantrell was made. He was transferred to a tertiary centre and required oxygen supplement initially. He was sent home after 1 week, on propanolol, with weekly oxygen saturation checks. He is awaiting further surgical intervention pending the required weight gain.

  19. Thoracic spinal trauma associated with closed thoraco-abdominal injury

    路磊; 吴立文; 范广宇


    Objective: To explore the management of thoracic spinal trauma (TST) associated with closed thoraco-abdominal injuries (CTAI). Methods: A retrospective study was made on 259 patients with TST admitted to our department as an emergency treatment from January 1996 to June 2001. We summarized the clinical features of TST associated with CTAI. Results: Among 259 patients with thoracic spinal trauma, 112 were associated with CTAI. Traffic accident was the most common cause. The force causing upper TST was more violent than that causing the lower. Pulmonary complications were the leading cause of death in this group. Surgery could not improve neurological function for completely paraplegic patients.Conclusions: The reason that upper TST has the tendency to be associated with CTAI is its special anatomical feature. Routine ultrasonic examination can avoid misdiagnosis of latent closed abdominal injuries associated with spinal injury. The presence of potential injuries, especially CTAI, should be considered when deciding whether or not to perform surgery early.

  20. Characteristics of natural gas lean combustion through the compression of quiescent charge in a rapid compression combustor; Kyusoku asshuku nensho sochinai seishi yokongoki asshuku ni okeru tennen gas no kihaku nensho tokusei

    Kataoka, K. [Okayama University of Science, Okayama (Japan); Segawa, D.; Kadota, T.; Hirooka, S. [University of Osaka Prefecture, Osaka (Japan). Faculty of Engineering; Higashino, K. [Osaka Gas Co. Ltd., Osaka (Japan)


    In order to develop a natural gas fueled spark ignition engine with high thermal efficiency and clean exhaust gases, combustion characteristics of natural gas and air mixtures were examined using a rapid compression combustor. We concentrated on lean mixtures because of their potential for high efficiency and low pollutant emissions. To elucidate the effect of compression-induced physical aspects on the combustion process, the charge was kept quiescent before the start of the compression process. The results showed that an increased charge pressure increased the time required for combustion. A high compression ratio or piston speed tended to shorten the combustion time, but their effects were rather weak. An increased humidity in mixtures measurably increased the combustion time. The stratified charge, which was examined using the soap bubble method, markedly improved the combustion process of lean mixtures. 7 refs., 15 figs., 1 tab.

  1. Effects of gadolinium chloride on basal flow and compression-induced rapid hyperemia in the rabbit masseter muscle.

    Turturici, M; Roatta, S


    Aim of the present study is to investigate the role of mechano-sensitive channels on basal muscle blood flow and on the compression-induced rapid hyperaemia. To this aim, the mechano-sensitive channel blocker Gadolinium (Gd(3+)) is employed, which already proved to reduce the myogenic response in isolated vessels. Muscle blood flow (MaBF) was recorded from the masseteric artery in 8 urethane-anesthetized rabbits. Rapid hyperemic responses were evoked by 1-s lasting compressions of the masseter muscle (MC) delivered before and after close arterial infusion of Gd(3+) in the masseteric artery. Three infusions were performed at 1-h interval, producing estimated plasma concentration (EPC) of 0.045, 0.45 and 4.5 mM, in the masseteric artery. The amplitude of the hyperaemic response to MC, equal to 195±77% of basal flow in control condition, was reduced by 9.5±19.4% (p=0.18) and 45±28% (p<0.01) while basal MaBf increased by 10±3% (p=0.90) and by 68±30% (p<0.01) at EPC of 0.045 and 0.45 mM, respectively. At EPC of 4.5 mM a strong reduction in both MaBF (by 54±13%, p<0.01) and MC response (75±12%, p<0.01) was instead observed. These effects did not depend on time from infusion. At all doses employed Gd(3+) never affected arterial blood pressure, heart rate and contralateral MaBF. While the effects observed at the highest EPC likely result from blood vessel occlusion due to Gd(3+) precipitation, the effects observed at lower concentrations demonstrate that Gd(3+) affects musculo-vascular function by decreasing both resting vascular tone and responsiveness to mechanical stimuli. The results are compatible with a Gd(3+)-induced blockade of vascular mechano-sensitive channels.

  2. Multiple multilayer stents for thoracoabdominal aortic aneurysm: a possible new tool for aortic endovascular surgery

    Tolva VS


    Full Text Available Valerio Stefano Tolva,1,3 Paolo Guy Bianchi,1 Lea Valeria Cireni,1 Alma Lombardo,1 Guido Carlo Keller,1 Gianfranco Parati,2,3 Renato Maria Casana11Surgical Department Istituto Auxologico Italiano IRCCS, Milan, Italy; 2Department of Cardiology, Istituto Auxologico Italiano, Università degli Studi di Milano-Bicocca, Bicocca, Milan, Italy; 3Department of Internal Medicine, San Gerardo Hospital, Università degli Studi di Milano-Bicocca, Bicocca, Milan, ItalyPurpose: Endovascular surgery data are confirming the paramount role of modern endovascular tools for a safe and sure exclusion of thoracoabdominal lesions.Case report: A 57-year-old female presented with severe comorbidity affected by a 58 mm thoracoabdominal aortic aneurysm (TAAA. After patient-informed consent and local Ethical Committee and Italian Public Health Ministry authorization, three multilayer stents were implanted in the thoracoabdominal aortic tract, obtaining at a 20-month computed tomography scan follow up, a complete exclusion of the TAAA, with normal patency of visceral vessels.Conclusion: Multilayer stents can be used in thoracoabdominal aortic aneurysm, with positive results.Keywords: chimney technique, renal artery stenosis, thoracoabdominal aneurysm, vascular complication

  3. Tratamento cirúrgico dos aneurismas toracoabdominais da aorta Surgical treatment of thoracoabdominal aortic aneurysms

    Januário M Souza


    Full Text Available Foram operados, em nosso Serviço, 161 aneurismas da aorta, sendo 99 por dissecção e 62 por outras causas. Em cinco pacientes, os aneurismas eram de localização toracoabdominal, sendo três por degeneração aterosclerótica e dois por dissecção; três pacientes eram do sexo feminino e a idade variou de 31 a 71 anos. Dois pacientes submeteram-se a aneurismectomia previamente (um da aorta ascendente e outro da porção proximal da aorta torácica. Revascularização miocárdica foi feita em um paciente, 40 dias antes da aneurismectomia. A indicação em todos os pacientes foi dor, causada por compressão do aneurisma, sendo que, em dois, havia insuficiência respiratória associada. Todos os pacientes foram operados através de incisão toracoabdominal e abertura do diafragma. A aorta foi substituída por tubo de Dacron, desde sua porção proximal até sua bifurcação, e as artérias viscerais foram implantadas no tubo. Quatro pacientes foram operados com pinçamento da aorta; um paciente necessitou emprego de circulação extracorpórea e parada circulatória, por impossibilidade de pinçamento da aorta junto à artéria subclávia. Todos os pacientes sobreviveram ao ato cirúrgico, ocorrendo dois óbitos no pós-operatório, um subitamente no 12º dia e outro por coma neurológico secundário a parada cardíaca causada por hipoxia.Five patients have been operated on of thoracoabdominal aortic aneurysms. The mean age was 53 years (range 31-71 and three were women. All the patients were symptomatic, three of them had arteriosclerotic aneurysms, and the other two had dissecting aneurysms. Three patients had been operated on previously. The exposure of aneurysm was made through a thoracoabdominal incision, in four patients clamps were placed above and below the aneurysm and it was incised longitudinally. Bypass between left atrium and left femoral artery with hypothermia and circulatory arrest was used in the other patients, since the

  4. Hybrid Thoracic Endovascular Aortic Repair for Intercostal Patch Aneurysm after Thoracoabdominal Aortic Replacement.

    Kitahara, Hiroto; Yoshitake, Akihiro; Hachiya, Takashi; Okamoto, Kazuma; Hirano, Akinori; Kasai, Mio; Akamatsu, Yuta; Oka, Hidetoshi; Shimizu, Hideyuki


    We report a case of hybrid thoracic endovascular aortic repair for intercostal patch aneurysm after thoracoabdominal aortic replacement. Eighteen years ago, a 63-year-old woman with Marfan syndrome had undergone thoracoabdominal aortic replacement with reimplantation of the intercostal artery in an island fashion. Follow-up computed tomography (CT) revealed a remaining intercostal patch aneurysm of diameter 60 mm 17 years after the last operation. Hybrid thoracic endovascular aortic repair for exclusion of this intercostal patch aneurysm was successfully performed, with visceral artery bypasses. Postoperative CT showed no anastomotic stenosis or endoleak.

  5. Long-term durability of open thoracic and thoracoabdominal aneurysm repair.

    Fischbein, Michael P; Miller, D Craig


    Results of open surgical repair of descending and thoracoabdominal aortic aneurysms have improved dramatically over the years. Nevertheless, while adjunctive protective strategies, such as spinal cord drainage and distal aortic perfusion, have improved outcomes, clinical challenges remain. In the current era, thoracic aortic surgeons must possess both open and endovascular stent-graft capabilities to offer these complex patients the most optimal and individualized treatment approach. Herein we summarize the contemporary outcomes of open surgical repair of patients with either descending thoracic or thoracoabdominal aortic aneurysms, focusing on the risk of complications and means for preventing their occurrence.

  6. Large neonatal thoracoabdominal aneurysm : case report and review of the literature

    Buddingh, K. Tim; Zeebregts, Clark J.; Tilanus, Martijn E. C.; Roofthooft, Marc T. R.; Broens, Paul M. A.

    We present a neonate with a large saccular aneurysm of the thoracoabdominal aorta, extending from the intrathoracic aorta to the left common iliac artery. No underlying cause could be identified. Despite an early diagnosis, the aneurysm was deemed inoperable because of the lengthy involvement and

  7. Paediatric penetrating thoraco-abdominal injury: Role of minimallly invasive surgery

    Jack Donati-Bourne


    Full Text Available We report two cases of penetrating thoraco-abdominal injuries who presented to our trauma centre. One with stab to lower left chest and the other one had pallet injury to right upper abdomen. The clinical presentation, radiological investigations and operative intervention are reviewed.

  8. Simultaneous resection of left atrial myxoma and esophageal carcinoma via right thoraco-abdominal approach.

    Ni, Buqing; Lu, Xiaohu; Gong, Qixing; Shao, Yongfeng


    Concomitant occurrence of atrial myxoma and esophageal carcinoma is an extremely rare entity. Here we present two cases of synchronously suffered left atrial myxoma and esophageal carcinoma. Both patients underwent simultaneous resection of two tumors via the right thoraco-abdominal approach and recovered well.

  9. [Medico-social and administrative aspects of optimization of thoracoabdominal aortic aneurism surgical treatment].

    Belov, Iu V; Komarov, R N


    Improvement of diagnostics, availability and quality of surgical help for patients with thoracoabdominal aneurisms is necessary. Cardiosurgical hospitals should be supplied with modern equipment, new technologies should be wider introduced to practice. Establishing departments of aortic surgery with the concentration of patients in the single center together with the risin the level of surgical skills are crucial.

  10. Hybrid procedures for thoracoabdominal aortic aneurysms and dissections

    ZHANG Hong-peng; GUO Wei; LIU Xiao-ping; JIA Xin; XIONG Jiang; MA Xiao-hui


    Background Hybrid procedures including debranching of visceral and renal arteries followed by endovascular exclusion of the thoracoabdominal aortic aneurysm (TAAA) have recently been proposed as a less invasive alternative to conventional TAAA surgery.This study aimed to evaluate the immediate and long-term outcomes of hybrid procedures for TAAA in high-risk patients.Methods Between September 1998 and May 2012,32 high-risk TAAA patients (five females,median age 61.5 years)underwent hybrid procedures at a single institution.Simultaneous approach and staged approach were performed on the basis of patients' conditions.Follow-up computed tomography angiography (CTA) was routinely performed before discharge and at 6,12 months and annually thereafter.Results Procedural success was achieved in all cases.The median hospital stay was (21.5±2.3) days,and the median procedure time was (420±31) minutes.Blood loss averaged (2100±261) ml.A total of 124 visceral artery bypasses was performed.Two patients (6.3%) died within 30 days.One patient exhibited complete paraplegia (3.1%).The visceral graft patency was 96.1% at 3 years.All-cause survival rates were 93.8%,87.5%,81.3% and 53.1% at 1,2,3 and 5 years,respectively.No patient died due to aortic events.The freedom rates from aortic events were 96.9%,93.6%,87.5%,68.8% at 1,2,3 and 5 years,respectively.Conclusions The results of visceral hybrid repair for high-risk patients with complex TAAAs are encouraging.However,the procedure is still a significant physiological insult to patients.Until branched and fenestrated endovascular repair become more common,hybrid procedure will continue to have a role in high-risk patients.

  11. Thoraco-abdominal coordination and performance during uphill running at altitude

    Bernardi, Eva; Pratali, Lorenza; Mandolesi, Gaia; Spiridonova, Maria; Roi, Giulio Sergio; Cogo, Annalisa


    Introduction Running races on mountain trails at moderate-high altitude with large elevation changes throughout has become increasingly popular. During exercise at altitude, ventilatory demands increase due to the combined effects of exercise and hypoxia. Aim To investigate the relationships between thoraco-abdominal coordination, ventilatory pattern, oxygen saturation (SpO2), and endurance performance in runners during high-intensity uphill exercise. Methods Fifteen participants (13 males, mean age 42±9 yrs) ran a “Vertical Kilometer,” i.e., an uphill run involving a climb of approximately 1000 m with a slope greater than 30%. The athletes were equipped with a portable respiratory inductive plethysmography system, a finger pulse oximeter and a global positioning unit (GPS). The ventilatory pattern (ventilation (VE), tidal volume (VT), respiratory rate (RR), and VE/VT ratio), thoraco-abdominal coordination, which is represented by the phase angle (PhA), and SpO2 were evaluated at rest and during the run. Before and after the run, we assessed respiratory function, respiratory muscle strength and the occurrence of interstitial pulmonary edema by thoracic ultrasound. Results Two subjects were excluded from the respiratory inductive plethysmography analysis due to motion artifacts. A quadratic relationship between the slope and the PhA was observed (r = 0.995, p = 0.036). When the slope increased above 30%, the PhA increased, indicating a reduction in thoraco-abdominal coordination. The reduced thoraco-abdominal coordination was significantly related to reduced breathing efficiency (i.e., an increased VE/VT ratio; r = 0.961, p = 0.038) and SpO2 (r = -0.697, pabdominal coordination and consequent reduction in SpO2 were associated with interstitial pulmonary edema. Conclusion Reductions in thoraco-abdominal coordination are associated with a less efficient ventilatory pattern and lower SpO2 during uphill running. This fact could have a negative effect on performance

  12. Hybrid procedure in the treatment of thoracoabdominal aortic aneurysms: Case report

    Davidović Lazar B.


    Full Text Available Introduction. Treatment of thoracoabdominal aortic aneurysms is a major problem in vascular surgery. Conventional open repair is associated with significant rates of mortality and morbidity and therefore, there is a need for better solutions. One of them is a hybrid procedure that includes visceral debranching. This paper presents the first such case performed in Serbia, with a brief overview on all published procedures worldwide. Case Outline. A 57-year-old woman was admitted to the hospital because of thoracoabdominal aneurysms type V by Crawford-Safi classifications. Because of the significant comorbidities it was concluded that conventional treatment would bear unacceptably high perioperative risk, and that the possible alternative could be the hybrid procedure in two stages. In the first stage aortobiliacal reconstruction with bifurcated Dacron graft (16×8 mm and visceral debranching with hand made tailored branched graft was done. In the second act, the thoracoabdominal aneurysm was excluded with implantation of the endovascular Valiant stent graft, 34×150 mm (Medtronic, Santa Rosa, CA. Control MSCT angiography showed a proper visceral branch patency and positioning of the stent graft without endoleaks. Nine months after the procedure the patient was symptom-free, with no aneurysm, diameter change and no graft-related complication. All visceral branches were patent. Conclusion. So far about 500 cases of visceral debranching have been published with the aim of treating thoracoabdominal aneurysms, and still we have no valid guidelines concerning this method. However, in carefully selected high-risk patients this is an excellent alternative to open surgery of thoracoabdominal aneurysms.

  13. Implementation of 3D spatial indexing and compression in a large-scale molecular dynamics simulation database for rapid atomic contact detection

    Toofanny Rudesh D


    problems. The speed up enables on-the-fly calculation and visualization of contacts and rapid cross simulation analysis for knowledge discovery. Using page compression for the atomic coordinate tables and indexes saves ~36% of disk space without any significant decrease in calculation time and should be considered for other non-transactional databases in MS SQL SERVER 2008.

  14. 面向GPU快速处理的地面材质数据压缩方法%Ground Material Data Compression Method for GPU Rapid Processing

    陆巍巍; 徐涛; 徐珂文


    To solve the problems of saving and loading of mass ground materiel data in radar imaging simulation, an adap?tive max run length coding and modified pairing based algorithm is proposed for data compression. It reduces the amount of data in storage, and eliminates bottleneck of data flow. The compression algorithm is designed for GPU rapid processing, so the compressed data can be decompressed in GPU effectively.%为解决雷达图像仿真中海量地面材质数据的存储和加载问题,采用基于自适应最大行程长度编码和修正偶对的压缩算法进行材质数据的压缩,从而有效地减少了数据的存储量,消除数据传输的瓶颈,提高了数据传输的吞吐能力.压缩算法面向GPU快速处理,得到压缩数据适用于GPU进行快速解压.

  15. Characterization of a two-dimensional temperature field within a rapid compression machine using a toluene planar laser-induced fluorescence imaging technique

    Strozzi, Camille; Sotton, Julien; Mura, Arnaud; Bellenoue, Marc


    The homogeneous charge compression ignition (HCCI) combustion process is an advanced operating mode for automotive engines. The self-ignition mechanisms that occur within the combustion chamber exhibit extreme temperature dependence. Therefore, the thorough understanding of corresponding phenomena requires the use of diagnostic methods featuring a sufficient thermal sensitivity, applicable in severe conditions similar to those encountered within engines. In this respect, toluene planar laser-induced fluorescence (PLIF) is applied to the inert compression flow generated within an optical rapid compression machine (RCM). A relatively simple diagnostic system is retained: a single wavelength excitation device (266 nm) and a single (filtered) collection system. This diagnostic system is associated with an image processing strategy specifically adapted to RCM devices. Despite the severe conditions under consideration (40 bar, 700-950 K), the method allows us to obtain relatively large two-dimensional temperature fields that display a level of description seldom achieved in such devices. In particular the temperature gradients, which play a crucial role in HCCI combustion processes, can be estimated. The present experimental results confirm the good reliability and accuracy of the method. The information gathered with this toluene PLIF method puts in evidence its high potentialities for the study of aero-thermal-reactive processes as they take place in real engine conditions. The retained strategy also brings new possibilities of non-intrusive analysis for flows practically encountered within industrial devices.

  16. Hybrid treatment of recurring thoracoabdominal aortic aneurysm concomitant with retrograde type A aortic dissection

    ZHANG Min-hong; GUO Wei; DU Xin; XIONG Jiang


    So far, standard therapy of complex thoracoabdominal aortic disease is open surgical repair requiring aortic clamping and replacement of the involved segment.Despite significant improvements, morbidity and mortality of open surgery remain high.I As a result, open surgery is often withheld owing to severe comorbidities of the patients. Endovascular technique has emerged as an alternative for treatment of these diseases in high risk patients,2 and has enlarged the options of treatment of complex aortic diseases. However, an endovascular approach alone is often deemed unsuitable for some complex aortic disorders because of the close proximity of the supraaortic or visceral branches. A hybrid open-endovascular approach has therefore been proposed as a viable alternative. We present here a unique patient with recurring thoracoabdominal aortic aneurysm (TAAA) concomitant with an aortic dissection (AD) treated by a hybrid open-endovascular approach.

  17. A rare case of blunt thoracoabdominal trauma with small bowel perforation from air bags.

    Liverani, A; Pezzatini, M; Conte, S; Mari, F; Milillo, A; Gasparrini, M; Marino, G; Catracchia, V; -Favi, F


    Vehicle collisions represent more than 75% of mechanism of blunt abdominal trauma. In spite of the incomparable improvement of car safety devices, recent studies pointed out that the air bags might cause injuries, specially when it is not associated with seatbelt. In fact, some studies pointed out that crash victims using air bags alone have increased injury severity, hospitalisations, thoracoabdominal procedure, and rehabilitation. Some of the most frequently injured organs reported from air bag deployment are the liver (38%), the spleen (23%) and digestive system (17%). Injury of the hollow viscera are far less common. In particular, blunt abdominal trauma resulting in small bowel perforation is an infrequent lesion. These injuries are difficult to diagnose because specific signs are poor and a delay in treatment increases mortality and morbidity of the patients. We describe a case of thoracoabdominal trauma that occurred during a head-on collision after an air bag deployment without seatbelt use.

  18. Right trisegmentectomy with thoracoabdominal approach after transarterial embolization for giant hepatic hemangioma

    Hyung-Il Seo; Hong Jae Jo; Mun Sup Sim; Suk Kim


    Hepatic hemangiomas need to be treated surgically in cases where they are accompanied with symptoms, have a risk of rupture, or are hardly distinguishable from malignancy. The present authors conducted embolization of the right hepatic artery one day before an operation for a huge hemangioma accompanied with symptoms and confirmed a decrease in its size. The authors performed a right trisegmentectomy through a J-shape incision, using a thoracoabdominal approach, and safely removed a giant hemangioma of 32.0 cm ±26.5 cm ± 8.0 cm in size and 2300 g in weight. Even for inexperienced surgeons, a J-shape incision with a thoracoabdominal approach is considered a safe and useful method when right-side hepatectomy is required for a large mass in the right liver.

  19. Cholesterol crystal embolism and delayed-onset paraplegia after thoracoabdominal aneurysm repair.

    Nasr, Bahaa; Schneider, Fabrice; Marques da Fonseca, Pedro; Gouny, Pierre


    Postoperative paraplegia caused by ischemic injury of the spinal cord is the most disabling complication of thoracoabdominal surgery. We described the case of a 75-year-old patient who underwent a thoracoabdominal aneurysm repair (type IV aneurysm according to Crawford classification). The aorta clamping was done at the T11 level without specific medullary protection. The first postoperative week was uneventful. On the postoperative day 8, renal failure and livedo of the left lower limb occurred together with complete hypotonic paraplegia and severe sepsis. Exploratory laparotomy revealed a gangrenous cholecystitis, and skin biopsies showed cholesterol crystals embolisms in the hypodermis small arteries. The patient died on the postoperative day 28 from a multiorgan failure. In this case, paraplegia was due to cholesterol crystal embolism, which migrated secondarily after aortic clamping.

  20. Coagulopathy associated with sac reperfusion for reversing paraplegia after endovascular repair of type II thoracoabdominal aneurysm.

    Lioupis, Christos; Katsanos, Konstantinos; Clough, Rachel; Matharu, Nick; Modarai, Bijan; Carrell, Tom; Taylor, Peter


    Sac perfusion may be helpful in preventing or reversing spinal cord injury after endovascular repair of thoracoabdominal aneurysms and it has been used as an adjunct to the standard physiologic measures of sustained hypertension and cerebrospinal fluid drainage. Coagulopathy as a result of endoleak after endovascular aneurysm repair has been reported, and very rare cases of treatment after repair of these endoleaks have been described. We report a 73-year-old man who had endovascular repair of a type II thoracoabdominal aneurysm with a branched stent graft. Sac reperfusion was initiated to manage postoperative paraplegia. The paraplegia partially resolved but severe hemorrhagic complications developed that were attributed to sac perfusion-related hyperfibrinolysis. Discontinuation of sac perfusion resolved the coagulopathy but resulted in paraplegia.

  1. Unusual management of thoracoabdominal impalement injury to the right hemiliver and diaphragm

    Raimundas Lunevicius; Adrian O'Sullivan


    Laparotomy or thoracolaparotomy is a traditional management approach for thoracoabdominal impalement injury associated with major liver and diaphragmatic injuries.We successfully treated the impalement injury with minimally invasive management.A male was brought to our trauma centre with the 15 cm long handle of the knife protruded from right lateral thoracoabdominal region.CT scan revealed that the knife blade traversed through the right costophrenic recess into segment 8 of the liver.There was an intraparenchymal haematoma and a collection of fluid in the abdominal cavity.The conservative management plan consisting of removing the impaled knife,observing,monitoring and managing complications was undertaken.A multidisciplinary approach to manage a parent with less invasive techniques yielded a good outcome.This management option may be considered as an alternative for open surgery for hemodynamically stable patients in experienced centres.

  2. Clinical analysis of craniocerebral trauma complicated with thoracoabdominal injuries in 2 165 cases

    陈卫群; 王刚; 赵万; 何亮珍


    Objective: To explore the optimal treatment for craniocerebral trauma complicated with thoraco-abdominal injuries.Methods: A total of 2 165 cases of craniocerebral trauma complicated with thoraco-abdominal injuries admitted to our hospital between July 1993 and June 2003 were retrospectively studied. Among them, 382 cases sustained severe craniocerebral trauma (in which 167 were complicated with shock ), 733 thoracic injuries, 645 abdominal injuries and 787 thoraco-abdominal injuries. On admittance, 294 cases had developed shock. With the prime goal of saving life, respiratory and circulatory systems and encephalothilipsis were especially treated and monitored.Priority in management was directed to severe or open injures rather than to moderate or closed injures. For cases with cerebral hernia due to intracranial hematoma and severe shock due to blood loss, cerebral hernia and shock were treated concurrently.Results: After treatment, 2024 ( 93.49 % ) cases survived and the other 141 (6.51%) died. Among patients who had severe craniocerebral injury with shock and those without, 78 (46.71%) and 53 (24.56%) died,respectively. For patients who had underwent craniocerebral and thoraco-abdominal operations concurrently and those who had not, the death rates were 58.49%-65.96% and 28.57 % respectively, indicating a significant difference ( P < 0.05 ).Conclusions: Treatment for hematoma hernia, shock and disturbed respiration is the key in the management of multiple trauma of craniocerebral, thoracic or abdominal injuries, especially when two or three conditions occurred simultaneously. Unless it is necessary, operations at two different parts at the same time is not recommended. It is preferred to start two concurrent operations at different time.


    Karine J. Sarro; Barros, Ricardo M.L.; Silvatti, Amanda P.


    This work aimed to verify if swimmers present better chest wall coordination during breathing than healthy non-athletes analyzing the correlation between ribs motion and the variation of thoracoabdominal volumes. The results of two up-to-date methods based on videogrammetry were correlated in this study. The first one measured the volumes of 4 separate compartments of the chest wall (superior thorax, inferior thorax, superior abdomen and inferior abdomen) as a function of time. The second cal...

  4. Massive thoracoabdominal aortic thrombosis in a patient with iatrogenic Cushing syndrome.

    Kim, Dong Hun; Choi, Dong-Hyun; Lee, Young-Min; Kang, Joon Tae; Chae, Seung Seok; Kim, Bo-Bae; Ki, Young-Jae; Kim, Jin Hwa; Chung, Joong-Wha; Koh, Young-Youp


    Massive thoracoabdominal aortic thrombosis is a rare finding in patients with iatrogenic Cushing syndrome in the absence of any coagulation abnormality. It frequently represents an urgent surgical situation. We report the case of an 82-year-old woman with massive aortic thrombosis secondary to iatrogenic Cushing syndrome. A follow-up computed tomography scan showed a decreased amount of thrombus in the aorta after anticoagulation therapy alone.

  5. Massive Thoracoabdominal Aortic Thrombosis in a Patient with Iatrogenic Cushing Syndrome

    Kim, Dong Hun; Choi, Dong Hyun; Lee, Young Min; Kim, Bo Bae; Ki, Young Jae; Kim, Jin Hwa; Chung, Joong Wha; Koh, Young Youp [Chosun University School of Medicine, Gwangju (Korea, Republic of); Kang, Joon Tae; Chae, Seung Seok [Dept. of nternal Medicine, Mokpo Jung-Ang General Hospital, Mokpo (Korea, Republic of)


    Massive thoracoabdominal aortic thrombosis is a rare finding in patients with iatrogenic Cushing syndrome in the absence of any coagulation abnormality. It frequently represents an urgent surgical situation. We report the case of an 82-year-old woman with massive aortic thrombosis secondary to iatrogenic Cushing syndrome. A follow-up computed tomography scan showed a decreased amount of thrombus in the aorta after anticoagulation therapy alone.

  6. Risk control and prevention of spinal cord damage due to surgery of thoracoabdominal aneurysms: medicolegal aspects.

    de Mol, B; Hamerlijnck, R; Vermeulen, F E; de Geest, R


    Surgery of thoracoabdominal aneurysms is accompanied by many complications of which spinal cord damage is the most serious. Such a complication tends to be the subject of litigation and medicolegal assessment. This report presents a risk control concept focussed on the reduction of spinal cord damage after surgery for a thoracoabdominal aneurysm. This concept may provide a basis for a risk management program in major surgery. Apart from sparing the patient a serious complication, improvement of the quality of care and anticipation of a medicolegal assessment were considered valuable benefits of such an effort. It is described how the threat of litigation--also in Europe--may affect clinical practice. A definition of surgical failure is described related to the five elements of risk homeostasis: complexity, linkage, cascade, human factor and safety margins. Limitations of risk control in the surgery of thoracoabdominal aneurysms are described. Finally the role of perception of risks by patient and doctor as well as the importance of informed consent and adequate disclosure are described in respect of medical quality improvement and litigation.

  7. Optimal control applied to a thoraco-abdominal CPR model.

    Jung, Eunok; Lenhart, Suzanne; Protopopescu, Vladimir; Babbs, Charles


    The techniques of optimal control are applied to a validated blood circulation model of cardiopulmonary resuscitation (CPR), consisting of a system of seven difference equations. In this system, the non-homogeneous forcing terms are chest and abdominal pressures acting as the 'controls'. We seek to maximize the blood flow, as measured by the pressure difference between the thoracic aorta and the right atrium. By applying optimal control methods, we characterize the optimal waveforms for external chest and abdominal compression during cardiac arrest and CPR in terms of the solutions of the circulation model and of the corresponding adjoint system. Numerical results are given for various scenarios. The optimal waveforms confirm the previously discovered positive effects of active decompression and interposed abdominal compression. These waveforms can be implemented with manual (Lifestick-like) and mechanical (vest-like) devices to achieve levels of blood flow substantially higher than those provided by standard CPR, a technique which, despite its long history, is far from optimal.

  8. Multi-slice computed tomography for diagnosis of combined thoracoabdominal injury

    Liu Jun


    Full Text Available Purpose: To investigate the diagnostic value of multi-slice computed tomography (MSCT for combined thoracoabdominal injury. Methods: A retrospective study was conducted to analyze the clinical data and MSCT images of 68 patients who sustained a combined thoracoabdominal injury associated with diaphragm rupture, and 18 patients without diaphragm rupture. All the patients were admitted and treated in the Chongqing Emergency Medical Center (a level I trauma center between July 2005 and February 2014. There were 71 males and 15 females with a mean age of 39.1 years (range 13e88 years. Among the 86 patients, 40 patients suffered a penetrating injury, 46 suffered a blunt injury as a result of road traffic accident in 21 cases, fall from a height in 16, and crushing injury in 9. The MSCT images were retrospectively reviewed by two radiologists. The results of CT diagnosis were compared with surgical findings and/or follow-up results. Results: Among the 86 cases, diaphragm discontinuity was found in 29 cases, segmental nonrecognition of the diaphragm in 14, diaphragmatic hernia in 21, collar sign in 14, dependent viscera sign in 18, elevated abdominal organs in 21, bowel wall thickening and/or hematoma in 6, and pneumoperitoneum in 8. CT diagnostic accuracy for diaphragm rupture was 88.4% in the right side and 90.7% in the left side. CT diagnostic accuracy for hemopneumothorax, pulmonary contusion, mediastinal hemorrhage, kidney and adrenal gland injuries was 100%, while for liver, spleen and pancreas injuries was 96.5%, 96.5%, 94.2% respectively. Conclusion: To reach an early diagnosis of combined thoracoabdominal injury, surgeons and radiologists should be familiar with all kinds of images which might show signs of diaphragm rupture, such as diaphragm discontinuity, segmental nonrecognition of the diaphragm, dangling diaphragm sign, diaphragm herniation, collar sign, dependent viscera sign, and elevated abdominal organs.

  9. Endovascular Treatment of a Symptomatic Thoracoabdominal Aortic Aneurysm by Chimney and Periscope Techniques for Total Visceral and Renal Artery Revascularization

    Cariati, Maurizio, E-mail: [San Carlo Borromeo Hospital, Department of Diagnostic Sciences (Italy); Mingazzini, Pietro; Dallatana, Raffaello [San Carlo Borromeo Hospital, Department of Vascular Surgery (Italy); Rossi, Umberto G. [San Carlo Borromeo Hospital, Department of Diagnostic Sciences (Italy); Settembrini, Alberto [San Carlo Borromeo Hospital, Università degli Studi di Milano (Italy); Santuari, Davide [San Carlo Borromeo Hospital, Department of Vascular Surgery (Italy)


    Conventional endovascular therapy of thoracoabdominal aortic aneurysm with involving visceral and renal arteries is limited by the absence of a landing zone for the aortic endograft. Solutions have been proposed to overcome the problem of no landing zone; however, most of them are not feasible in urgent and high-risk patients. We describe a case that was successfully treated by total endovascular technique with a two-by-two chimney-and-periscope approach in a patient with acute symptomatic type IV thoracoabdominal aortic aneurysm with supra-anastomotic aneurysm formation involving the renal and visceral arteries and a pseduaneurismatic sac localized in the left ileopsoas muscle.

  10. Thoracoabdominal pseudocyst of pancreas: An rarelocation, managed by retrocolic retrogastric Roux-en-Ycystojejunostomy


    Pseudocyst formation is a common complication ofacute and chronic pancreatitis. Most common siteof pseudocyst is lesser sac; mediastinal extension ofpseudocyst is rare. Other possibilities of posterior mediastinalcyst must be considered. This patient presentedwith computed tomography abdomen with thorax showinga large thoraco-abdominal pseudocyst with rightsided pleural effusion. It was confirmed to be pancreaticpseudocyst by analyzing fluid for amylase and lipaseduring surgery. In our patient, the pseudocyst wasaccessible transabdominaly. Cystogastrostomy was notpossible as it was causing twisting of cardio-esophagealjunction; we did retrocolic and retrogastric Roux-en-Ycystojejunostomy. Only two such cases were reported inliterature.

  11. Modified technique for reconstructing the visceral arteries in thoracoabdominal aortic repair.

    Kondoh, Haruhiko; Funatsu, Toshihiro; Taniguchi, Kazuhiro


    We present a modified technique for reconstructing the visceral arteries in thoracoabdominal aortic repair. After the proximal and distal anastomosis of a main tubular graft with four pre-sewn side branches, each visceral artery is cannulated and perfused with 25 °C blood (sum total, 800 mL/min). Then, each side branch is placed around the main graft, forming a gently curved loop around it. Finally, the orifice of each visceral artery is sutured to a side branch. This technique prevents kinking of the side branches and enables hemostasis to be secured with a clear view of all the suture lines.

  12. Radiographic anatomy of the thoraco-abdominal cavity of the ostrich (Struthio camelus

    W.M. Wagner


    Full Text Available This study provides a reference for the radiographic anatomy of the thoraco-abdominal cavity of female ostriches as a representative of ratites. One ostrich cadaver, 2 adult and 2 growing ostriches were used. Right lateral radiographs produced by a 6-frame technique and 2 dorsoventral radiographs produced by an adapted 3-frame technique were selected and schematic illustrations of these were labelled to illustrate normal radiographic anatomy. Differences from other avian species and unique features of the ostrich are briefly discussed.

  13. Intercostal Artery Reconstruction: The Simple and Effective Technique on Spinal Cord Protection during Thoracoabdominal Aortic Replacement.

    Zhang, Liang; Sun, Xiao-Gang; Yu, Cun-Tao; Chang, Qian; Qian, Xiang-Yang


    To retrospectively analyze the role of intercostal artery reconstruction in the spinal cord protection for patients undergoing extensive thoracoabdominal aortic aneurysm repair. From August 2007 to 2014, thoracoabdominal aortas (Crawford II) of 81 consecutive patients with mean age 39.4 ± 10.32 years were repaired. Seventy-three of these patients (90.12%) were diagnosed with aortic dissection in our group, 25 (30.86%) with Stanford type A dissection and 48 (59.26%) with Stanford B aortic dissection. All 25 patients with type A dissection have previously undergone surgical procedures which include Bentall's procedures in 11 cases, ascending aortic replacement in 6 cases, and total aortic arch replacement in 8 cases. All procedures were performed under profound hypothermia with interval cardiac arrest after making a thoracoabdominal incision. Extracorporeal circulation was instituted with 2 arterial cannulae and a single venous cannula in the right atrium. T6-T12 intercostal arteries and L1 and L2 lumbar arteries were formed to a neo-intercostal artery in place and were connected to an 8 mm branch for maintaining spinal cord blood perfusion. Visceral arteries were joined into a patch and anastomosed to the end of the main graft. The left renal artery was anastomosed to an 8 mm branch or joined to the patch. The other 10 mm branches were anastomosed to iliac arteries. With 100% follow-up, early mortality was 7.4%. Six deaths were recorded; 1 patient died of cerebral hemorrhage, 3 of renal failure, 1 of heart failure because of myocardial infarction, and the last one died from the rupture of celiac artery dissection. The rate of postoperative spinal cord deficits was 3.7%, 2 patients with paraplegia and 1 patient with paraparesis. None had bladder or rectum dysfunction. Neo-intercostal arteries were clogged in 12 patients within follow-up period and formed pseudoaneurysm in 2 patients with Marfan syndrome. The mean survival time in this group was 54.22 ± 3.03

  14. Endovascular stent graft repair of multiple tuberculous thoracoabdominal aneurysms

    Kim, Sung Jung; Won, Je Hwan [Dept. of Radiology, Ajou University School of Medicine, Suwon (Korea, Republic of)


    We describe a case of multiple tuberculous aneurysms of the descending thoracic aorta and abdominal aorta repaired with endovascular stent graft. The case was a 47-year-old man who presented with three saccular pseudoaneurysms of aortoiliac bifurcation at computed tomography (CT) scan. Despite of antimycobacterial treatment, these aneurysms grew rapidly and saccular pseudoaneurysm of the descending thoracic aorta was newly seen. A bifurcated stent graft was successfully implanted in the aortoiliac bifurcation. Subsequently, endovascular stent graft was placed well in the descending thoracic aorta. Fourteen months after the procedure, the patient was stable and serial CT images showed regression of aneurysms with ongoing antimycobacterial treatment. Therefore, endovascular stent graft repair with antimycobacterial therapy may be a treatment option in patients with multiple tuberculous aneurysms.

  15. Early patency rate and fate of reattached intercostal arteries after repair of thoracoabdominal aortic aneurysms.

    Omura, Atsushi; Yamanaka, Katsuhiro; Miyahara, Shunsuke; Sakamoto, Toshihito; Inoue, Takeshi; Okada, Kenji; Okita, Yutaka


    The present study analyzes the early patency of intercostal artery reconstruction, using graft interposition and aortic patch anastomosis, and determines the fate of reattached intercostal arteries after repair of thoracoabdominal aortic aneurysms. We selected 115 patients (mean age, 63 ± 15 years; range, 19-83 years; male, n = 83) treated by thoracoabdominal aortic aneurysm repair with 1 or more reconstructed intercostal arteries at the Kobe University Graduate School of Medicine between October 1999 and December 2012. The intercostal arteries were reconstructed using graft interposition (n = 66), aortic patch anastomosis (n = 42), or both (n = 7). The hospital mortality rate was 7.8% (n = 9). Eleven patients (9.6%) developed spinal cord ischemic injury (permanent, n = 6, transient, n = 5). The average number of reconstructed intercostal arteries per patient was 3.0 ± 1.5 (1-7), and 345 intercostal arteries were reattached. The overall patency rate was 74.2% (256/345) and that of aortic patch anastomosis was significantly better than that of graft interposition (90.8% [109/120] vs 65.3% [147/225], P intercostal arteries became dilated in 2 patients. Aortic patch anastomosis might offer better patency rates and prevent spinal cord ischemic injury compared with graft interposition. Although aneurysmal changes in intercostal artery reconstructions are rare, large blocks of aortic wall reconstruction should be closely monitored. Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  16. The "open branch" technique: A new way to prevent paraplegia after total endovascular repair of thoracoabdominal aneurysm.

    Krajcer, Zvonimir; Echeverria, Angela


    Spinal cord ischemia (SCI) has been one of the most concerning complications after surgical and endovascular thoracoabdominal aortic aneurysm repair "Open Branch" is an innovative technique to reduce the incidence of SCI Further studies in a larger number of patients with varying pathologies are needed to confirm the advantages of this technique.

  17. Thoraco-Abdominal Duplication Cyst- Role Tc-99m Pertechnetate SPECT-CT Scintigraphy in Localising Ectopic Gastric Mucosa

    Ravina, Mudalsha; Datta, Deepanksha; Rangan, Kasturi; Suraj, Ajay Singh; Gambhir, Sanjay


    Thoraco-abdominal duplication cyst, a congenital malformation of the posterior primitive foregut rarely presents with anaemia. Ectopic gastric mucosa is seen in around 20%-30% of the enteric duplication cysts. We report the scintigraphic findings of one such case which helped in final diagnosis and management of the patient.

  18. Properties of chicken manure pyrolysis bio-oil blended with diesel and its combustion characteristics in RCEM, Rapid Compression and Expansion Machine

    Sunbong Lee


    Full Text Available Bio-oil (bio-oil was produced from chicken manure in a pilot-scale pyrolysis facility. The raw bio-oil had a very high viscosity and sediments which made direct application to diesel engines difficult. The bio-oil was blended with diesel fuel with 25% and 75% volumetric ratio at the normal temperature, named as blend 25. A rapid compression and expansion machine was used for a combustion test under the experimental condition corresponding to the medium operation point of a light duty diesel engine using diesel fuel, and blend 25 for comparison. The injection related pressure signal and cylinder pressure signal were instantaneously picked up to analyze the combustion characteristics in addition to the measurement of NOx and smoke emissions. Blend 25 resulted in reduction of the smoke emission by 80% and improvements of the apparent combustion efficiency while the NOx emission increased by 40%. A discussion was done based on the analysis results of combustion.

  19. A ‘One in a million’ case of pulsating thoracoabdominal mass

    Tan, Lay Ong; Lim, Soo Yen; Sharif, Farhana


    Ectopia cordis is a rare congenital malformation in which the heart is located partially or totally outside the thoracic cavity. It comprises 0.1% of congenital heart diseases. The authors present a case of a male baby born at term by emergency caesarean section due to prolonged fetal bradycardia, who was noted to have a large pulsating mass in the thoracoabdominal area. In view of lower thoracolumbar abdominal defect, ectopic placement of the umbilicus, deficiency of the diaphragmatic pericardium, deficiency of anterior diaphragm and intracardiac abnormalities, a diagnosis of ectopia cordis—Pentalogy of Cantrell was made. He was transferred to a tertiary centre and required oxygen supplement initially. He was sent home after 1 week, on propanolol, with weekly oxygen saturation checks. He is awaiting further surgical intervention pending the required weight gain. PMID:23148397

  20. Chest wall reconstruction in thoracoabdominal ectopia cordis: using the pedicled osteomuscular latissimus dorsi composite flap.

    Lampert, Joshua A; Harmaty, Marco; Thompson, Elizabeth Chabner; Sett, Suvro; Koch, R Michael


    Ectopia cordis is a rare congenital defect characterized by complete or partial displacement of the heart outside the thoracic cavity. Repair of ectopia cordis can present a reconstructive challenge often requiring a staged approach. Ideally, structural integrity and protection of the heart are restored using autologous tissues capable of growth. In addition, reconstruction of the thorax must proceed without compromise to pulmonary or cardiovascular stability. The following article describes repair of thoracoabdominal ectopia cordis in a patient with pentalogy of Cantrell. Reconstruction of the chest wall was accomplished using a musculoosseus composite flap involving segments of the 9th and 10th ribs and overlying pedicled latissimus dorsi muscle. This is the first report known to the authors of such a repair.

  1. Elective reconstruction of thoracoabdominal aortic aneurysm type IV by transabdominal approach

    Marjanović Ivan


    Full Text Available Introduction. Thoracoabdominal aortic aneurysm (TAAA type IV represents an aortic dilatation from the level of the diaphragmatic hiatus to the iliac arteries branches, including visceral branches of the aorta. In the traditional procedure of TAAA type IV repair, the body is opened using thoractomy and laparotomy in order to provide adequate exposure of the descending thoracic and abdominal aorta for safe aortic reconstruction. Case report. We reported a 71-yearold man with elective reconstruction of the TAAA type IV performed by transabdominal approach. Computed tomography scans angiography revealed a TAAA type IV with diameter of 62 mm in the region of celiac trunk and superior mesenteric artery branching, and the largest diameter of 75 mm in the infrarenal aortic level. The patient comorbidity included a chronic obstructive pulmonary disease and hypertension, therefore he was treated for a prolonged period. In preparation for the planned aortic reconstruction asymptomatic carotid disease (occlusion of the left internal carotid artery and subtotal stenosis of the right internal carotid artery was diagnosed. Within the same intervention percutaneous transluminal angioplasty with stent placement in right internal carotid artery was made. In general, under endotracheal anesthesia and epidural analgesia, with transabdominal approach performed aortic reconstruction with tubular dakron graft 24 mm were, and reimplantation of visceral aortic branches into the graft performed. Postoperative course was uneventful, and the patient was discharged on the postoperative day 17. Control computed tomography scan angiography performed three months after the operation showed vascular state of the patient to be in order. Conclusion. Complete transabdominal approach to TAAA type IV represents an appropriate substitute for thoracoabdominal approach, without compromising safety of the patient. This approach is less traumatic, especially in patients with impaired

  2. Breathing pattern, thoracoabdominal motion and muscular activity during three breathing exercises

    G.M. Tomich


    Full Text Available The objective of the present study was to evaluate breathing pattern, thoracoabdominal motion and muscular activity during three breathing exercises: diaphragmatic breathing (DB, flow-oriented (Triflo II incentive spirometry and volume-oriented (Voldyne incentive spirometry. Seventeen healthy subjects (12 females, 5 males aged 23 ± 5 years (mean ± SD were studied. Calibrated respiratory inductive plethysmography was used to measure the following variables during rest (baseline and breathing exercises: tidal volume (Vt, respiratory frequency (f, rib cage contribution to Vt (RC/Vt, inspiratory duty cycle (Ti/Ttot, and phase angle (PhAng. Sternocleidomastoid muscle activity was assessed by surface electromyography. Statistical analysis was performed by ANOVA and Tukey or Friedman and Wilcoxon tests, with the level of significance set at P < 0.05. Comparisons between baseline and breathing exercise periods showed a significant increase of Vt and PhAng during all exercises, a significant decrease of f during DB and Voldyne, a significant increase of Ti/Ttot during Voldyne, and no significant difference in RC/Vt. Comparisons among exercises revealed higher f and sternocleidomastoid activity during Triflo II (P < 0.05 with respect to DB and Voldyne, without a significant difference in Vt, Ti/Ttot, PhAng, or RC/Vt. Exercises changed the breathing pattern and increased PhAng, a variable of thoracoabdominal asynchrony, compared to baseline. The only difference between DB and Voldyne was a significant increase of Ti/Ttot compared to baseline. Triflo II was associated with higher f values and electromyographic activity of the sternocleidomastoid. In conclusion, DB and Voldyne showed similar results while Triflo II showed disadvantages compared to the other breathing exercises.


    Karine J. Sarro


    Full Text Available This work aimed to verify if swimmers present better chest wall coordination during breathing than healthy non-athletes analyzing the correlation between ribs motion and the variation of thoracoabdominal volumes. The results of two up-to-date methods based on videogrammetry were correlated in this study. The first one measured the volumes of 4 separate compartments of the chest wall (superior thorax, inferior thorax, superior abdomen and inferior abdomen as a function of time. The second calculated the rotation angle of the 2nd to the 10th ribs around the quasi-transversal axis also in function of time. The chest wall was represented by 53 markers, attached to the ribs, vertebrae, thorax and abdomen of 15 male swimmers and of 15 non- athletes. A kinematical analysis system equipped with 6 digital video cameras (60Hz was used to obtain the 3D coordinates of the markers. Correlating the curves of ribs rotation angles with the curves of the separate volumes, swimmers presented higher values than non-athletes when the superior and inferior abdomen were considered and the highest correlation values were found in swimmers for the inferior thorax. These results suggest a better coordination between ribs motion and thoracoabdominal volumes in swimmers, indicating the prevalent and coordinated action of the diaphragm and abdominal muscles to inflate and deflate the chest wall. The results further suggest that swimming practice leads to the formation of an optimized breathing pattern and can partially explain the higher lung volumes found in these athletes reported in literature.

  4. [Thoraco-abdominal aortic replacement in chronic phase in a patient with temporary paraplegia after Stanford B acute dissection].

    Takahashi, Goro; Hata, Masaki; Tabayashi, Koichi


    A 42-year-old man underwent was performed with thoraco-abdominal aneurysm replacement accompaniedy with reconstruction of abdominal branches and intercostal arteries. Eighteen months before, he had suffered from Stanford already been cured with paraplegia on being type B acute aortic dissection combined with paraplegia. When paraplegia had been occurred, cerebrospinal fluid drainage was had been performed promptly, and 4 days later, neurologic deficit was disappeared in 1 day. During the thoraco-abdominal aortic operation, cerebrospinal fluid drainage was performed done again. After the operation, paraplegia did was not occurred and he did not feel somewhat wrong with his legs. He was discharged from hospital on foot by himself. This case showed the efficacy of cerebral spinal fluid drainage for not only both with the prevention but also and treatment of paraplegia.

  5. Novel Visceral-Anastomosis-First Approach in Open Repair of a Ruptured Type 2 Thoracoabdominal Aortic Aneurysm: Causes behind a Mortal Outcome

    Einar Dregelid


    Full Text Available Case reports to analyze causes and possible prevention of complications in a new setting are important. We present an open repair of a ruptured type 2 thoracoabdominal aortic aneurysm in a 78-year-old man. Lower-body perfusion through a temporary extracorporeal axillobifemoral arterial prosthesis shunt was combined with the use of a branch to the permanent aortic prosthesis to enable rapid visceral revascularization using a visceral-anastomosis-first approach. The patient died due to transfusion-induced capillary leak syndrome and left colon necrosis; the latter was probably caused by a combination of back-bleeding from lumbar arteries causing a steal effect, an accidental shunt obstruction, and hemodynamic instability towards the end of the operation. The visceral-anastomosis-first approach did not contribute to the complications. This approach reduces the time when visceral organs are perfused only via collateral arteries to the time needed for suturing the visceral anastomoses. This may be important when collateral perfusion is marginal.

  6. Alterations of thoraco-abdominal volumes and asynchronies in patients with spinal muscle atrophy type III.

    LoMauro, Antonella; Romei, Marianna; Priori, Rita; Laviola, Marianna; D'Angelo, Maria Grazia; Aliverti, Andrea


    Spinal muscular atrophy (SMA) is characterized by degeneration of motor neurons resulting in muscle weakness. For the mild type III form, a sub-classification into type IIIA and IIIB, based on age of motor impairment, was recently proposed. To investigate if SMA IIIA (more severe) and IIIB differ also in terms of respiratory function, thoracoabdominal kinematics was measured during quiet breathing, inspiration preceding cough and inspiratory capacity on 5 type IIIA and 9 type IIIB patients. Four patients with SMA II (more severe than types III) and 19 healthy controls were also studied. Rib cage motion was similar in SMA IIIB and controls. Conversely, in SMA IIIA and SMA II it was significantly reduced and sometime paradoxical during quiet breathing in supine position. Our results suggest that in SMA IIIA intercostal muscles are weakened and the diaphragm is preserved similarly to SMA II, while in SMA IIIB the action of all inspiratory muscles is maintained. Sub-classification of type III seems feasible also for respiratory function.

  7. Quantitative vertebral compression fracture evaluation using a height compass

    Yao, Jianhua; Burns, Joseph E.; Wiese, Tatjana; Summers, Ronald M.


    Vertebral compression fractures can be caused by even minor trauma in patients with pathological conditions such as osteoporosis, varying greatly in vertebral body location and compression geometry. The location and morphology of the compression injury can guide decision making for treatment modality (vertebroplasty versus surgical fixation), and can be important for pre-surgical planning. We propose a height compass to evaluate the axial plane spatial distribution of compression injury (anterior, posterior, lateral, and central), and distinguish it from physiologic height variations of normal vertebrae. The method includes four steps: spine segmentation and partition, endplate detection, height compass computation and compression fracture evaluation. A height compass is computed for each vertebra, where the vertebral body is partitioned in the axial plane into 17 cells oriented about concentric rings. In the compass structure, a crown-like geometry is produced by three concentric rings which are divided into 8 equal length arcs by rays which are subtended by 8 common central angles. The radius of each ring increases multiplicatively, with resultant structure of a central node and two concentric surrounding bands of cells, each divided into octants. The height value for each octant is calculated and plotted against octants in neighboring vertebrae. The height compass shows intuitive display of the height distribution and can be used to easily identify the fracture regions. Our technique was evaluated on 8 thoraco-abdominal CT scans of patients with reported compression fractures and showed statistically significant differences in height value at the sites of the fractures.

  8. "Compressed" Compressed Sensing

    Reeves, Galen


    The field of compressed sensing has shown that a sparse but otherwise arbitrary vector can be recovered exactly from a small number of randomly constructed linear projections (or samples). The question addressed in this paper is whether an even smaller number of samples is sufficient when there exists prior knowledge about the distribution of the unknown vector, or when only partial recovery is needed. An information-theoretic lower bound with connections to free probability theory and an upper bound corresponding to a computationally simple thresholding estimator are derived. It is shown that in certain cases (e.g. discrete valued vectors or large distortions) the number of samples can be decreased. Interestingly though, it is also shown that in many cases no reduction is possible.

  9. Thoracoabdominal wall defect with complete ectopia cordis and gastroschisis: a case report and review of the literature.

    Pepper, Michael A; Fishbein, Gregory A; Teitell, Michael A


    Ventral wall defects are extremely rare anomalies that are likely caused by the failure of the ventral wall to close during week 4 of development. We report a case of severe thoracoabdominal wall defect including complete thoracic ectopia cordis and gastroschisis. This combination represents a novel constellation of findings in a single patient. This unique case further demonstrates an anatomically normal heart with age-appropriate development and an intact diaphragm. We review the literature of other reports and discussions of entities that share overlapping features with this case.

  10. [Late results of the "simplified technique" in the surgical management of a thoracoabdominal aortic aneurysm, ten years later - clinical report].

    Dinis da Gama, A


    The authors report the clinical case of a dissecting thoracoabdominal aortic aneurysm, in a 49-years old female, with the diagnosis of Marfan's syndrome, who underwent surgical treatment utilizing the "simplified technique", introduced by ourselves in 1983, for the management of this most demanding situation. Reviewed ten years later, having reassumed her social and professional life, a control angio-CT disclosed the procedure of aortic reconstruction and the revascularization of the digestive and renal arteries working in excellent condition. The unique and singular reconstructive procedure here utilized and its excellent long term result, justify its presentation and divulgation.

  11. 股动脉穿刺置管术后快速手法压迫止血的体会%Rapid manual compression for puncturing site hemostasis after femoral catheterization: preliminary experience



    目的 探讨股动脉穿刺置管术后快速手法压迫止血的止血效果及并发症.方法 总结了一套快速手法压迫止血的方法(平均止血时间约2 min),并对324例行介入股动脉穿刺置管患者术后立即进行快速手法压迫止血,术后1 d对患者穿刺点周围的皮肤观察并行相应的触诊检查.结果 324例经股动脉穿刺置管介入术后患者均用了快速手法压迫止血,其中4例患者穿刺点周围皮下片状淤青,余患者穿刺点周围未见明显淤青,其有效止血率高达98.8%(320/324).320例患者中6例患者穿刺点周围出现局部皮肤轻度压伤,未予处理1周后均自行修复.结论 股动脉穿刺置管介入诊疗术后快速手法压迫止血是一种省时、省力、安全、经济、可重复、环保、实用的止血方法.%Objective To discuss the hemostasis effect of rapid manual compression performed immediately after the catheterization through femoral artery, and to analyze its complications. Methods Based on the author's experience obtained from dozens of years' practice in interventional field, the author summarized an effective hemostasis technique, which was performed through rapid manual compression on the pun cturing point. The mean compression time with hand was only about two minutes. This manipulation procedure for hemostasis had been carried out in 324 patients immediately after the catheterization through femoral artery was finished. One day after the catheterization, observation of the skin around the puncture point and palpation of the puncturing site were conducted. Results Rapid manual compression hemostasis was successfully carried out in all 324 patients, of whom subcutaneous ecchymosis around the puncture site was seen in only four. The effective hemostasis rate was 98.8% (320/324). In another six patients mild skin injury due to compression around the puncture site was observed, which, without any medication, recovered spontaneously in one week

  12. Ultrasound beamforming using compressed data.

    Li, Yen-Feng; Li, Pai-Chi


    The rapid advancements in electronics technologies have made software-based beamformers for ultrasound array imaging feasible, thus facilitating the rapid development of high-performance and potentially low-cost systems. However, one challenge to realizing a fully software-based system is transferring data from the analog front end to the software back end at rates of up to a few gigabits per second. This study investigated the use of data compression to reduce the data transfer requirements and optimize the associated trade-off with beamforming quality. JPEG and JPEG2000 compression techniques were adopted. The acoustic data of a line phantom were acquired with a 128-channel array transducer at a center frequency of 3.5 MHz, and the acoustic data of a cyst phantom were acquired with a 64-channel array transducer at a center frequency of 3.33 MHz. The receive-channel data associated with each transmit event are separated into 8 × 8 blocks and several tiles before JPEG and JPEG2000 data compression is applied, respectively. In one scheme, the compression was applied to raw RF data, while in another only the amplitude of baseband data was compressed. The maximum compression ratio of RF data compression to produce an average error of lower than 5 dB was 15 with JPEG compression and 20 with JPEG2000 compression. The image quality is higher with baseband amplitude data compression than with RF data compression; although the maximum overall compression ratio (compared with the original RF data size), which was limited by the data size of uncompressed phase data, was lower than 12, the average error in this case was lower than 1 dB when the compression ratio was lower than 8.

  13. Effects of a multidisciplinary body weight reduction program on static and dynamic thoraco-abdominal volumes in obese adolescents.

    LoMauro, Antonella; Cesareo, Ambra; Agosti, Fiorenza; Tringali, Gabriella; Salvadego, Desy; Grassi, Bruno; Sartorio, Alessandro; Aliverti, Andrea


    The objective of this study was to characterize static and dynamic thoraco-abdominal volumes in obese adolescents and to test the effects of a 3-week multidisciplinary body weight reduction program (MBWRP), entailing an energy-restricted diet, psychological and nutritional counseling, aerobic physical activity, and respiratory muscle endurance training (RMET), on these parameters. Total chest wall (VCW), pulmonary rib cage (VRC,p), abdominal rib cage (VRC,a), and abdominal (VAB) volumes were measured on 11 male adolescents (Tanner stage: 3-5; BMI standard deviation score: >2; age: 15.9 ± 1.3 years; percent body fat: 38.4%) during rest, inspiratory capacity (IC) maneuver, and incremental exercise on a cycle ergometer at baseline and after 3 weeks of MBWRP. At baseline, the progressive increase in tidal volume was achieved by an increase in end-inspiratory VCW (p obese adolescents adopt a thoraco-abdominal operational pattern characterized by abdominal rib cage hyperinflation as a form of lung recruitment during incremental cycle exercise. Additionally, a short period of MBWRP including RMET is associated with improved exercise performance, lung and chest wall volume recruitment, unloading of respiratory muscles, and reduced dyspnea.

  14. [Mistakes and complications in the diagnosis and medical services for persons with closed thoraco-abdominal injuries during pre-hospitalization stage].

    Baramiia, N M; Antoniuk, M H; Zaruts'kyĭ, Ia L; Dorosh, V M; Sabov, V I


    Results of medical care, given to injured persons with closed thoracoabdominal trauma on the prehospital stage were analyzed. Lacks and complications in tactic of treatment and diagnosis were determined. Mistakes of the medical ambulance care physicians were noted in 51.3% of observations.

  15. The use of fenestrated and branched endovascular aneurysm repair for juxtarenal and thoracoabdominal aneurysms: A systematic review and cost-effectiveness analysis

    N. Armstrong (Nigel); L.T. Burgers (Laura); S. Deshpande (Sohan); M.J. Al (Maiwenn); R. Riemsma; S.R. Vallabhaneni; P. Holt (Peter); J.L. Severens (Hans); J. Kleijnen (Jos)


    textabstractBackground: Patients with large abdominal aortic aneurysms (AAAs) are usually offered reparative treatment given the high mortality risk. There is uncertainty about how to treat juxtarenal AAAs (JRAAAs) or thoracoabdominal aortic aneurysms (TAAAs). Endovascular repair of an abdominal aor

  16. The use of fenestrated and branched endovascular aneurysm repair for juxtarenal and thoracoabdominal aneurysms: A systematic review and cost-effectiveness analysis

    N. Armstrong (Nigel); L.T. Burgers (Laura); S. Deshpande (Sohan); M.J. Al (Maiwenn); R. Riemsma; S.R. Vallabhaneni; P. Holt (Peter); J.L. Severens (Hans); J. Kleijnen (Jos)


    textabstractBackground: Patients with large abdominal aortic aneurysms (AAAs) are usually offered reparative treatment given the high mortality risk. There is uncertainty about how to treat juxtarenal AAAs (JRAAAs) or thoracoabdominal aortic aneurysms (TAAAs). Endovascular repair of an abdominal aor

  17. Proportional assist ventilation decreases thoracoabdominal asynchrony and chest wall distortion in preterm infants.

    Musante, G; Schulze, A; Gerhardt, T; Everett, R; Claure, N; Schaller, P; Bancalari, E


    Thoracoabdominal asynchrony (TAA) and chest wall distortion (CWD) are commonly seen in preterm infants secondary to a highly compliant rib cage and poor compensation of distorting forces by inspiratory rib cage muscles. Continuous positive airway pressure (CPAP) reduces TAA and CWD by stenting the chest wall. We hypothesized that application of positive airway pressure only during inspiration and in proportion to an infant's inspiratory effort should have a similar but more pronounced effect than CPAP alone. A ventilator providing airway pressure changes in proportion to flow and volume generated by an infant (proportional assist ventilation) was used to unload the respiratory pump during inspiration. Ten preterm infants were studied [birth weight, 745 (635-1175) g; gestational age, 26.5 (24-31) wk; postnatal age 3 (1-7) d; medium (range)]. TAA and CWD were determined by respiratory inductive plethysmography. TAA was expressed as the phase angle between the rib cage and abdominal motion and CWD as the total compartmental displacement ratio. In addition, we measured tidal volume with a pneumotachograph and esophageal and airway pressure deflections with pressure transducers. Measurements were obtained during alternating periods of CPAP and two different degrees of support (Gain 1 = 1.09 +/- 0.68, Gain 2 = 1.84 +/- 0.84 cm H(2)O/mL) that were provided by a proportional assist ventilator. Phase angle and the total compartmental displacement ratio decreased with increasing gain compared with CPAP alone. Peak airway pressure increased from 0.6 to 3.8 to 7.6 cm H(2)O above positive end-expiratory pressure (PEEP) with CPAP, Gain 1, and Gain 2, respectively, as tidal volume increased from 2.8 to 4.1 to 4.7 mL/kg. Esophageal pressure changes decreased only little with increasing gain. Chest wall excursion increased and abdominal movement decreased, indicating a redistribution of tidal volume between chest and abdomen. We conclude that proportional assist ventilation reduces

  18. Intimal aortic sarcoma mimicking ruptured thoracoabdominal type IV aneurysm. a rare case report and review of the literature

    Dedeilias Panagiotis


    Full Text Available Abstract Primary intimal aortic sarcoma represents a very rare and highly lethal medical entity. Diagnosis is made either by embolic events caused by the tumor or by surrounding tissue symptoms such as pain. Herein we report an extremely rare case of a 51-year-old man previously operated for ascending aortic aneurysm, who presented with clinical and radiological findings suggestive of a ruptured thoracoabdominal type IV aneurysm. The patient underwent radical resection of the aorta and surrounding tissue with placement of a composite 4-branched graft. The diagnosis was made by frozen section and regular histopathologic examination of the specimen and the patient received adjuvant chemotherapy. Nine months after surgery the patient is still alive and has no signs of recurrence. We review the literature and discuss the option of postoperative chemotherapy.

  19. Propofol for Anesthesia and Postoperative Sedation Resulted in Fewer Inflammatory Responses than Sevoflurane Anesthesia and Midazolam Sedation after Thoracoabdominal Esophagectomy.

    Nakanuno, Ryuichi; Yasuda, Toshimichi; Hamada, Hiroshi; Yoshikawa, Hiroshi; Nakamura, Ryuji; Saeki, Noboru; Kawamoto, Masashi


    Responses to surgical stress can be modulated by anesthetics. We prospectively compared the effects of two different anesthetic/sedative techniques on the peak postoperative bladder temperature (BT) and the postoperative C-reactive protein (CRP) level. Twenty patients who were scheduled to undergo elective thoracoabdominal esophagectomy were allocated to receive either propofol anesthesia followed by propofol sedation (PP group, n = 10) or sevoflurane anesthesia followed by midazolam sedation (SM group, n = 10). In each case, the patient's peak bladder temperature was measured on the morning after surgery, and their serum CRP levels were assessed on postoperative days (POD) 1, 2, and 3. The patients' postoperative clinical courses were also evaluated. The peak postoperative BT (degrees C) (37.6 ± 0.4 vs. 38.2 ± 0.6, respectively; p midazolam sedation.

  20. An underwater acoustic data compression method based on compressed sensing

    郭晓乐; 杨坤德; 史阳; 段睿


    The use of underwater acoustic data has rapidly expanded with the application of multichannel, large-aperture underwater detection arrays. This study presents an underwater acoustic data compression method that is based on compressed sensing. Underwater acoustic signals are transformed into the sparse domain for data storage at a receiving terminal, and the improved orthogonal matching pursuit (IOMP) algorithm is used to reconstruct the original underwater acoustic signals at a data processing terminal. When an increase in sidelobe level occasionally causes a direction of arrival estimation error, the proposed compression method can achieve a 10 times stronger compression for narrowband signals and a 5 times stronger compression for wideband signals than the orthogonal matching pursuit (OMP) algorithm. The IOMP algorithm also reduces the computing time by about 20% more than the original OMP algorithm. The simulation and experimental results are discussed.


    Veloso, Ana Paula Limongi Richardelli; Cusmanich, Karla Garcez

    Obesity can affect the thorax, diaphragm, and alterations in respiratory function even if the lungs are within normality. The respiratory compliance is very reduced by the increase in fat mass. To evaluate the effect of the physical therapeutic respiratory exercises on the thoracoabdominal mobility of obese individuals in pre-bariatric surgery. Cross-sectional and descriptive study, which used the cirtometry (axillary, xiphoid and abdominal) to evaluate the mobility of 74 individuals, 27 men and 47 women, in pre-bariatric surgery, assisted by the team EMAD, after eight weeks of physiotherapy, following a protocol of exercises, reevaluating and compared the measures pre and post intervention. Had positive correlation abdominal mobility in the total volume of all participants (p=0.010) and also for all the measures in the measurement of residual volume in three levels (p=0.000). Comparing genders, in total volume, cirtometry abdominal greater for women (p=0.015) when compared to men and residual volume, significance for either men or women in all measurements (p=0.000). Obese patients that underwent the physiotherapeutic treatment during the preoperative period, had pré respiratory dynamics improved by the increase in the mobility of the chest cavity and by the improvement of respiratory conscience. A obesidade pode afetar o tórax e o diafragma, determinando alterações na função respiratória, mesmo quando os pulmões se apresentam dentro da normalidade. A complacência respiratória é muito reduzida pelo aumento de massa gordurosa. Avaliar o efeito de exercícios fisioterapêuticos respiratórios sobre a mobilidade torácica de indivíduos obesos no pré-operatório de cirurgia bariátrica. Estudo transversal e descritivo, que utilizou a cirtometria (axilar, xifoide e abdominal) para avaliar a mobilidade de 74 indivíduos, 27 homens e 47 mulheres, em pré-operatório de cirurgia bariátrica, assistidos pela equipe EMAD, após oito semanas de fisioterapia

  2. In vivo performance of the polyesterurethane Vascugraft prosthesis implanted as a thoraco-abdominal bypass in dogs: an exploratory study.

    Zhang, Z; King, M W; Marois, Y; Marois, M; Guidoin, R


    Among the various prototype vascular prostheses that have been developed over recent years as small vessel substitutes, the Vascugraft polyurethane device produced by Braun-Melsungen AG has a number of attractive features. As well as having high mechanical compliance similar to that of the arterial tree, it has been manufactured from a specially synthesized poly(ester urethane) with improved biostability and its microfibrous structure provides a highly porous wall with open communicating pores. With a view to evaluating the in vivo biofunctionality and biostability of this prosthesis in the dog, 10 mm diameter grafts were implanted as thoraco-abdominal bypasses for prescheduled periods of 1 months and 12 months, and their performance monitored in terms of gross morphology, histology and the measurement of the chemical and physical properties of the explanted and cleaned specimens. Both grafts were patent at retrieval. Each had a smooth and glistening flow surface without organized mural thrombi and showed the development of a thin collagenous internal capsule with the presence of endothelial-like cells. Both grafts were well encapsulated externally and revealed a small distal bend or kink which is frequently observed by any thoraco-abdominal bypass in dogs. The fresh explanted prostheses were cleaned by a new enzyme treatment which provided specimens for microscopic, mechanical and thermal analyses, as well as studies of the surface and bulk chemistry. By comparing the results from the explanted and cleaned material with those of the virgin prosthesis, we have observed some deterioration in the integrity of the microfibrous structure, some loss in mechanical performance, marginal changes in molecular weight, and an apparent microphase separation of the hard and soft segment domains at a depth of a few microns. While the biofunctionality of a 10 mm calibre device has been demonstrated, additional in vivo studies are recommended to assess the biofunctionality at

  3. Real-time 3D visualization of the thoraco-abdominal surface during breathing with body movement and deformation extraction.

    Povšič, K; Jezeršek, M; Možina, J


    Real-time 3D visualization of the breathing displacements can be a useful diagnostic tool in order to immediately observe the most active regions on the thoraco-abdominal surface. The developed method is capable of separating non-relevant torso movement and deformations from the deformations that are solely related to breathing. This makes it possible to visualize only the breathing displacements. The system is based on the structured laser triangulation principle, with simultaneous spatial and color data acquisition of the thoraco-abdominal region. Based on the tracking of the attached passive markers, the torso movement and deformation is compensated using rigid and non-rigid transformation models on the three-dimensional (3D) data. The total time of 3D data processing together with visualization equals 20 ms per cycle.In vitro verification of the rigid movement extraction was performed using the iterative closest point algorithm as a reference. Furthermore, a volumetric evaluation on a live subject was performed to establish the accuracy of the rigid and non-rigid model. The root mean square deviation between the measured and the reference volumes shows an error of  ±0.08 dm(3) for rigid movement extraction. Similarly, the error was calculated to be  ±0.02 dm(3) for torsional deformation extraction and  ±0.11 dm(3) for lateral bending deformation extraction. The results confirm that during the torso movement and deformation, the proposed method is sufficiently accurate to visualize only the displacements related to breathing. The method can be used, for example, during the breathing exercise on an indoor bicycle or a treadmill.

  4. Wellhead compression

    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)


    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)

  5. Compressive beamforming

    Xenaki, Angeliki; Mosegaard, Klaus


    Sound source localization with sensor arrays involves the estimation of the direction-of-arrival (DOA) from a limited number of observations. Compressive sensing (CS) solves such underdetermined problems achieving sparsity, thus improved resolution, and can be solved efficiently with convex...

  6. Posição prona e diminuição da assincronia toracoabdominal em recém-nascidos prematuros Prone position and reduced thoracoabdominal asynchrony in preterm newborns

    Trícia G. Oliveira


    Full Text Available OBJETIVO: Avaliar a influência das posições prona e supina em recém-nascidos prematuros pós-síndrome do desconforto respiratório, respirando espontaneamente e em estado de sono ativo, sobre variáveis de padrão respiratório, movimento toracoabdominal e saturação periférica da hemoglobina pelo oxigênio. MÉTODOS: Estudo quase experimental. Doze prematuros com peso > 1.000 g no momento do estudo foram estudados nas duas posições, em ordem randomizada. A pletismografia respiratória por indutância foi utilizada para avaliação do padrão respiratório (volume corrente, frequência respiratória, ventilação minuto, fluxo inspiratório médio e do movimento toracoabdominal (índice de trabalho respiratório, relação de fase inspiratória, relação de fase expiratória, relação de fase respiratória total e ângulo de fase. A oximetria de pulso registrou a saturação periférica de oxigênio. Para a análise estatística foram realizados os testes t de Student para amostras pareadas ou Wilcoxon. Foi considerado significativo p OBJECTIVE: To assess the effect of prone and supine positions on breathing pattern variables, thoracoabdominal motion and peripheral oxygen saturation of hemoglobin of premature newborn infants recovering from respiratory distress syndrome, while breathing spontaneously and in rapid eye movement sleep. METHODS: This was a quasi-experimental study. Twelve preterms weighing > 1,000 g at enrollment were studied in both positions, in random order. Respiratory inductive plethysmography was used to analyze breathing pattern (tidal volume, respiratory rate, minute ventilation, mean inspiratory flow and thoracoabdominal motion (labored breathing index, phase relation in inspiration, phase relation in expiration, phase relation in total breath and phase angle. Pulse oximetry was used to evaluate peripheral oxygen saturation. Student's t test for paired samples or the Wilcoxon test were used for statistical

  7. The applicability of the wind compression model

    Cariková, Zuzana


    Compression of the stellar winds from rapidly rotating hot stars is described by the wind compression model. However, it was also shown that rapid rotation leads to rotational distortion of the stellar surface, resulting in the appearance of non-radial forces acting against the wind compression. In this note we justify the wind compression model for moderately rotating white dwarfs and slowly rotating giants. The former could be conducive to understanding density/ionization structure of the mass outflow from symbiotic stars and novae, while the latter can represent an effective mass-transfer mode in the wide interacting binaries.

  8. Compressed sensing for body MRI.

    Feng, Li; Benkert, Thomas; Block, Kai Tobias; Sodickson, Daniel K; Otazo, Ricardo; Chandarana, Hersh


    The introduction of compressed sensing for increasing imaging speed in magnetic resonance imaging (MRI) has raised significant interest among researchers and clinicians, and has initiated a large body of research across multiple clinical applications over the last decade. Compressed sensing aims to reconstruct unaliased images from fewer measurements than are traditionally required in MRI by exploiting image compressibility or sparsity. Moreover, appropriate combinations of compressed sensing with previously introduced fast imaging approaches, such as parallel imaging, have demonstrated further improved performance. The advent of compressed sensing marks the prelude to a new era of rapid MRI, where the focus of data acquisition has changed from sampling based on the nominal number of voxels and/or frames to sampling based on the desired information content. This article presents a brief overview of the application of compressed sensing techniques in body MRI, where imaging speed is crucial due to the presence of respiratory motion along with stringent constraints on spatial and temporal resolution. The first section provides an overview of the basic compressed sensing methodology, including the notion of sparsity, incoherence, and nonlinear reconstruction. The second section reviews state-of-the-art compressed sensing techniques that have been demonstrated for various clinical body MRI applications. In the final section, the article discusses current challenges and future opportunities. 5 J. Magn. Reson. Imaging 2017;45:966-987. © 2016 International Society for Magnetic Resonance in Medicine.

  9. Hybrid treatment of bullet embolism at the abdominal aortic bifurcation, complicated with thoracoabdominal aorta pseudoaneurysm and common iliac artery occlusion: case report

    Patrick Bastos Metzger


    Full Text Available Embolization due to a firearm projectile entering the bloodstream is a rare event that is unlikely to be suspected during initial treatment of trauma patients. We describe and discuss a case of bullet embolism of the abdominal aortic bifurcation, complicated by a pseudoaneurysm of the thoracoabdominal aorta and occlusion of the right common iliac artery, but successfully treated using a combination of endovascular methods and conventional surgery.

  10. Early outcomes and perioperative risk assessment in elective open thoracoabdominal aortic aneurysm repair: An analysis of national data over a five-year period.

    Dayama, Anand; Sugano, Dordaneh; Reeves, James G; Rivera, Aksim; Tsilimparis, Nikolaos


    Open surgical repair of thoracoabdominal aortic aneurysms remains associated with significant morbidity and mortality. We sought to analyse multicentre national data on early outcomes of open surgical thoracoabdominal aortic aneurysm repair. Patients who underwent open repair of thoracoabdominal aortic aneurysm from 2005 to 2010 were identified from the National Surgical Quality Improvement Program database. The primary endpoint was mortality at 30 days. Patient demographics, clinical variables, and intraoperative parameters were analysed by univariate and multivariate logistic regression methods to identify risk factors for mortality. Of the 682 elective repairs, 30-day outcomes of elective repairs were: 10.0% mortality, 21.6% surgical complications, 42.2% pulmonary complications, 17.2% renal complications, 12.9% cardiovascular complications, 19.2% septic complications, and 6.6% wound complications. Multivariate logistic regression analysis showed that age, ASA-class IV, dependent functional status prior to surgery, and operation time are independent risk factors for mortality. Our study found a higher rate of mortality nationwide, as compared to several previous single center studies.

  11. Technical Aspects of Implanting the t-Branch Off-the-Shelf Multibranched Stent-Graft for Thoracoabdominal Aneurysms.

    Tsilimparis, Nikolaos; Fiorucci, Beatrice; Debus, Eike Sebastian; Rohlffs, Fiona; Kölbel, Tilo


    To describe the planning and technique for implantation of the t-Branch off-the-shelf multibranched aortic endograft. Total endovascular repair of thoracoabdominal aneurysms (TAAAs) with branched endografts is one of the most important paradigm shifts in the past decade. The t-Branch endograft, an off-the-shelf multibranched graft introduced in the European market in late 2012, allows treatment of patients with suitable anatomy in both the elective and urgent settings to avoid delays related to manufacturing time of custom-made devices. The steps required for the planning and implantation of the device are described, including some tips and tricks. The use of an off-the-shelf multibranched device is an appealing option in the treatment of TAAAs, especially in the acute setting. Nevertheless, results of complex aortic repairs with this specific device are associated with a learning curve and can be improved by identifying a number of intraoperative risks and paying heed to several technical details.

  12. Incidência de empiema pleural nos ferimentos tóraco-abdominais Incidence of pleural empyema after thoracoabdominal injuries

    Mauro José Fontelles


    Full Text Available OBJETIVO: Os ferimentos penetrantes com comprometimento simultâneo das cavidades torácica e abdominal (FTA, além da dificuldade diagnóstica, merecem especial atenção em relação à conduta adotada para o tratamento do espaço pleural. O objetivo do presente estudo foi identificar os principais fatores relacionados à incidência de empiema pleural em pacientes com ferimentos penetrantes localizados na transição toracoabdominal. MÉTODO: Utilizando-se o modelo estatístico de regressão logística múltipla, os autores analisaram 110 pacientes com ferida toracoabdominal penetrante, submetidos à drenagem pleural fechada e laparotomia. A complicação empiema pleural foi estudada quanto à incidência e fatores envolvidos. Considerou-se o nível alfa igual a 0,05. RESULTADOS: Do total, 91 (82,7% pacientes eram do sexo masculino e 19 (17,3% do feminino. A faixa etária situou-se entre 13 e 63 anos. Os FTA foram causados por projétil de arma de fogo em 60 casos (54,5% e por arma branca em 50 casos (45,5%. O empiema pleural incidiu em quatro (3,6% dos pacientes estudados. Na análise estatística a incidência de empiema pleural esteve relacionada com: lesão de víscera oca (OR=3,1386, p=0.4005; lesão do lado esquerdo do diafragma (OR= 12,98, p=0,1178 e choque hemorrágico à admissão (OR=23,9639, p=0,0250. CONCLUSÕES: A chance da ocorrência de empiema pleural foi cerca de três vezes maior em pacientes com lesão de víscera oca e, de 13 vezes se a esta lesão estava associada à lesão do lado esquerdo do diafragma; aumentando para 24 vezes se estes pacientes apresentavam, concomitantemente, estado de choque hemorrágico à admissão.BACKGROUND: Penetrating Thoracoabdominal trauma, besides the diagnosis difficulty, deserve special attention with respect to the adopted strategy for the pleural space treatment. METHODS: Using the logistic regression model the authors analyzed 110 patients with penetrating Thoracoabdominal trauma

  13. 腹及胸腹主动脉瘤围手术期的护理探讨%Nursing of Abdominal and Thoracoabdominal Aortic Aneurysm in Peroperative

    台文霞; 苏兰若


    报告1986年~1998年间收治的腹及胸腹主动脉瘤72例,其中胸腹主动脉瘤(Thoracoabdominal Aotic Aneurysm,TAAA)8例,腹主动脉瘤(Abdominal Aortic Aneurysm,AAA)64例.65例行手术治疗,1例髂总动脉埋泵,6例未手术.详细讨论了腹及胸腹主动脉瘤围手术期的护理在成功治疗该血管疾病中的重要性.

  14. Compressive Sensing Over Networks

    Feizi, Soheil; Effros, Michelle


    In this paper, we demonstrate some applications of compressive sensing over networks. We make a connection between compressive sensing and traditional information theoretic techniques in source coding and channel coding. Our results provide an explicit trade-off between the rate and the decoding complexity. The key difference of compressive sensing and traditional information theoretic approaches is at their decoding side. Although optimal decoders to recover the original signal, compressed by source coding have high complexity, the compressive sensing decoder is a linear or convex optimization. First, we investigate applications of compressive sensing on distributed compression of correlated sources. Here, by using compressive sensing, we propose a compression scheme for a family of correlated sources with a modularized decoder, providing a trade-off between the compression rate and the decoding complexity. We call this scheme Sparse Distributed Compression. We use this compression scheme for a general multi...

  15. Compression limits in cascaded quadratic soliton compression

    Bache, Morten; Bang, Ole; Krolikowski, Wieslaw;


    Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency.......Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency....

  16. Satellite data compression

    Huang, Bormin


    Satellite Data Compression covers recent progress in compression techniques for multispectral, hyperspectral and ultra spectral data. A survey of recent advances in the fields of satellite communications, remote sensing and geographical information systems is included. Satellite Data Compression, contributed by leaders in this field, is the first book available on satellite data compression. It covers onboard compression methodology and hardware developments in several space agencies. Case studies are presented on recent advances in satellite data compression techniques via various prediction-

  17. Emission Characteristics of Direct Injection Natural Gas Engine Using Rapid Compression Machine%用快速压缩装置研究直喷式天然气发动机排放特性

    黄佐华; 曾科; 杨中乐


    使用快速压缩装置进行了直喷式天然气发动机排放特性的研究.测量了三种不同方式下的排放,并与均相混合气燃烧情况进行了对比.实验结果表明,在宽广的当量比范围内,天然气直喷方式的燃烧效率高于0.95.由于混合气的分层燃烧,天然气喷射方式在宽广的当量比范围内保持较低的HC排放量,同等功率下的低CO2排放量,低NOx排放量,其NOx排放在理论当量比处的降低更为明显.直喷天然气发动机既具备柴油机发动机效率高的特点,又具备预混燃烧发动机排放低的特点.%Investigation of emission characteristics of a direct injection natural gas engine is carried out using a rapid compression machine.The emissions of three injection modes are measured and compared with that of the homogeneous combustion mode.The experimental results show that the combustion efficiency of the direct injection natural gas combustion is above 0.95 for all fuel supplying modes in the wide range of overall equivalence ratio.Fuel injection can operate within a wide range of equivalence ratio and has low unburned hydrocarbon emission (HC),low CO2 emission for the same power output,low NOx emission due to the mixture stratification compared with homogeneous combustion engine,especially in the range near the stoichiometric equivalence ratio where engine power output is needed.Consequently,the direct injection natural gas engine has the advantages of high thermal efficiency like diesel engine and low emission of premixed mixture combustion.

  18. Pentalogy of Cantrell with thoracoabdominal ectopia cordis: Attempted surgical correction and review of recent literature to aid prognostication prior to surgery

    Vered Lack


    Full Text Available Complete ectopia cordis (EC is a rare congenital condition where the heart is extrathoracic, uncovered by pericardium and skin. This condition is often accompanied by intracardiac as well as other congenital anomalies. The thoracoabdominal type is frequently associated with varying degrees of Pentalogy of Cantrell (POC. Unless addressed early post-natally, EC is incompatible with life. Surgery is usually staged, with cover of exposed organs an immediate priority, followed by repair of structural cardiac lesions. Formal repair of the chest wall is performed at a later stage. We present a case of thoracoabdominal EC with complete POC. The patient underwent surgery to cover the exposed heart and the abdominal wall defect, but demised within 48 h due to systemic sepsis. Data gained from a literature survey shows that if the congenital heart defect is haemodynamically stable, and if cover is achieved immediately after birth, there is an associated improved survival. In addition, antenatal diagnosis was found to improve planning of delivery, resulting in improved hemodynamic stability, decreased incidence of sepsis, shorter time to intervention and better overall survival.

  19. Rapid Prototyping Reconsidered

    Desrosier, James


    Continuing educators need additional strategies for developing new programming that can both reduce the time to market and lower the cost of development. Rapid prototyping, a time-compression technique adapted from the high technology industry, represents one such strategy that merits renewed evaluation. Although in higher education rapid…

  20. Perceptually Lossless Wavelet Compression

    Watson, Andrew B.; Yang, Gloria Y.; Solomon, Joshua A.; Villasenor, John


    The Discrete Wavelet Transform (DWT) decomposes an image into bands that vary in spatial frequency and orientation. It is widely used for image compression. Measures of the visibility of DWT quantization errors are required to achieve optimal compression. Uniform quantization of a single band of coefficients results in an artifact that is the sum of a lattice of random amplitude basis functions of the corresponding DWT synthesis filter, which we call DWT uniform quantization noise. We measured visual detection thresholds for samples of DWT uniform quantization noise in Y, Cb, and Cr color channels. The spatial frequency of a wavelet is r 2(exp -1), where r is display visual resolution in pixels/degree, and L is the wavelet level. Amplitude thresholds increase rapidly with spatial frequency. Thresholds also increase from Y to Cr to Cb, and with orientation from low-pass to horizontal/vertical to diagonal. We propose a mathematical model for DWT noise detection thresholds that is a function of level, orientation, and display visual resolution. This allows calculation of a 'perceptually lossless' quantization matrix for which all errors are in theory below the visual threshold. The model may also be used as the basis for adaptive quantization schemes.

  1. [Positive experience in long-term follow-up and surgical management of a stenosing lesion of the thoracoabdominal portion of the aorta and its branches in non-specific aortoarteritis].

    Zotov, S P; Shcherbakov, A V; Kugeev, A F; Shakirov, R G; Kireev, K A; Borovikov, D A; Safronov, V G; Rostovtsev, M V; Konashov, A G; Zhabreev, A V


    The article is based on experience gained in 25-year follow-up of a female patient presenting with pathology of the thoracoabdominal aorta and its branches in non-specific aortoarteritis. Discussed herein are clinical peculiarities of the development and course of the disease, analysing the outcomes of the reconstructive operations performed, followed by due assessment of efficacy of long-term treatment.

  2. Incidência de fístulas digestivas nos ferimentos toracoabdominais Incidence of digestive fistula after thoracoabdominal wounds

    Mario Mantovani


    Full Text Available Os ferimentos penetrantes localizados na transição toracoabdominal (FTA, além da dificuldade diagnóstica, merecem especial atenção em relação à conduta adotada para o controle das complicações abdominais. Os autores analisaram 110 pacientes atendidos na Disciplina de Cirurgia do Trauma do Departamento de Cirurgia da UNICAMP, de 1988 a 1998, apresentando ferida penetrante toracoabdominal e submetidos à laparotomia exploradora com drenagem pleural fechada. As fístulas digestivas foram estudadas quanto à incidência, ao tratamento e à evolução pós-operatória. Do total de pacientes, 91 (82,7% eram do sexo masculino e 19 (17,3% do sexo feminino. A faixa etária situou-se entre 13 e 63 anos. Os FTA foram causados por projétil de arma de fogo (PAF em 60 (54,5% casos e por arma branca (FAB em 50 (45,5%. As fístulas digestivas ocorreram em seis (5,4% dos pacientes estudados, sendo quatro (3,6% casos de fístula pancreática, um (0,9% de fístula gástrica e um (0,9% de fístula biliar, todos tratados de maneira conservadora, apresentando evolução favorável com resolução espontânea.Penetrating trauma in the lower chest, is a diagnosis challenge and deserves special attention with respect to the treatment for abdominal complications. One hundred and ten patients admitted to the emergency unit of UNICAMP - University Hospital Trauma Center from 1988 to 1998 who presented thoracoabdominal penetrating wounds and were submitted to laparotomy and closed tube thoracostomy were analysed. Incidence, treatment and postoperative evolution. Digestive fistula was studied. Ninety-one patients (82,7% were male and 19 (17,3% female, with the age varying between 13 to 63 years old. Gunshot wounds ocurred in 60 (54,5% patients, while stab wounds in 50 (45,5%. Digestive fistula occurred in six (5,4% patients; four (3,6% were pancreatic fistula, one (0,9% biliar which and one (0,9% gastric were managed nonoperative with a satisfactory evolution.

  3. Evolution Of Nonlinear Waves in Compressing Plasma

    P.F. Schmit, I.Y. Dodin, and N.J. Fisch


    Through particle-in-cell simulations, the evolution of nonlinear plasma waves is examined in one-dimensional collisionless plasma undergoing mechanical compression. Unlike linear waves, whose wavelength decreases proportionally to the system length L(t), nonlinear waves, such as solitary electron holes, conserve their characteristic size {Delta} during slow compression. This leads to a substantially stronger adiabatic amplification as well as rapid collisionless damping when L approaches {Delta}. On the other hand, cessation of compression halts the wave evolution, yielding a stable mode.

  4. Focus on Compression Stockings

    ... the stocking every other day with a mild soap. Do not use Woolite™ detergent. Use warm water ... compression clothing will lose its elasticity and its effectiveness. Compression stockings last for about 4-6 months ...

  5. A Compressive Superresolution Display

    Heide, Felix


    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. Value of MR angiography of Adamkiewicz artery as a preoperative investigation for thoracic-descending and thoracoabdominal aortic aneurysms. Retrospective study of 106 cases

    Yamada, Naoaki; Ogino, Hitoshi; Hanabusa, Yuji; Sasaki, Hiroaki; Minatoya Kenji [National Cardiovascular Center, Suita, Osaka (Japan)


    We reviewed 106 cases who underwent MR angiography to visualize the Adamkiewicz artery (AKA) as a preoperative evaluation of the thoracic descending and thoracoabdominal aortic aneurysms. MR angiography depicted the AKA successfully in 68% of the patients. However, segmental artery that gives rise the AKA was occluded in 41% at its origin from the aorta. In one patient with postoperative paraplegia, broad infarction in the upper thoracic cord seems not to be related to the territory of the AKA that was visualized by MR angiography. Preoperative MR angiography serves planning of surgery, and can reduce time of aortic cross-clamping. However, our understanding of the value of MR angiography to prevent spinal cord ischemic injury requires further clinical investigation. (author)

  7. Aneurisma toracoabdominal roto: modificação do circuito de perfusão visceral Thoracoabdominal aneurysm rupture: a modification of the visceral perfusion circuit

    Eduardo Faccini Rocha


    Full Text Available Paciente portador de aneurisma toracoabdominal (ATA tipo lV, roto, submetido a tratamento cirúrgico utilizando perfusão visceral assistida por bomba centrífuga e oxigenador de membrana neonatal. Este circuito permite a perfusão visceral com sangue oxigenado, durante o período de isquemia, e infusão de volume rápido via venosa após a retirada da pinça.A patient with ruptured type IV thoracoabdominal aortic aneurysm (TAAA, underwent surgical treatment utilizing visceral perfusion assisted by a centrifugal pump and neonatal membrane oxygenator. This circuit allows visceral perfusion with oxygenated blood during the ischemic period and the fast infusion of intravenous volume after clamp removal.

  8. Microbunching and RF Compression

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


    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. Hyperspectral data compression

    Motta, Giovanni; Storer, James A


    Provides a survey of results in the field of compression of remote sensed 3D data, with a particular interest in hyperspectral imagery. This work covers topics such as compression architecture, lossless compression, lossy techniques, and more. It also describes a lossless algorithm based on vector quantization.

  10. Compressed gas manifold

    Hildebrand, Richard J.; Wozniak, John J.


    A compressed gas storage cell interconnecting manifold including a thermally activated pressure relief device, a manual safety shut-off valve, and a port for connecting the compressed gas storage cells to a motor vehicle power source and to a refueling adapter. The manifold is mechanically and pneumatically connected to a compressed gas storage cell by a bolt including a gas passage therein.

  11. Compressing Binary Decision Diagrams

    Hansen, Esben Rune; Satti, Srinivasa Rao; Tiedemann, Peter


    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  12. Compressing Binary Decision Diagrams

    Rune Hansen, Esben; Srinivasa Rao, S.; Tiedemann, Peter

    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  13. Compressing Binary Decision Diagrams

    Hansen, Esben Rune; Satti, Srinivasa Rao; Tiedemann, Peter


    The paper introduces a new technique for compressing Binary Decision Diagrams in those cases where random access is not required. Using this technique, compression and decompression can be done in linear time in the size of the BDD and compression will in many cases reduce the size of the BDD to 1...

  14. 胸腹主动脉置换术治疗支架“象鼻”手术后胸腹主动脉夹层动脉瘤%Surgery for thoracoabdominal aorta dissecting aneurysm following Sun's procedure with the thoracoabdominal aorta replacement

    刘巍; 郭世超; 邢晓燕; 孙立忠; 朱俊明; 刘永民; 陈雷; 里程楠; 乔志钰; 胡海瓯; 杨祎


    目的 探讨孙氏手术后远端胸腹主动脉夹层动脉瘤的手术方式和治疗经验.方法 2009年6月至2011年5月,13例孙氏手术后胸腹主动脉夹层动脉瘤患者接受胸腹主动脉置换手术治疗.男11例,女2例;年龄28 ~ 58岁,平均39.3岁.均为Stanford A型主动脉夹层、孙氏手术后患者.病因为马方综合征10例,高血压3例.全组均为CrawfordⅡ型胸腹主动脉夹层动脉瘤.“象鼻”支架以远胸腹主动脉最大直径4.0~8.0cm,平均(5.78±1.00) cm.经胸腹联合切口、腹膜外入路,采用四分支人工血管翻转、分段阻断技术行胸腹主动脉置换术.采用深低温停循环技术7例,常温非体外循环技术6例.结果 无手术早期死亡.12例患者治愈出院.采用深低温停循环技术的患者中1例术后截瘫,后出现败血症、伪膜性肠炎、呼吸衰竭,于术后102天死亡.1例出现缺血、缺氧脑病,脱水治疗6天后清醒、治愈出院.全组患者术后胸腹主动脉螺旋CT复查示人工血管通畅、无扭曲、无假性动脉瘤.3例患者肋间动脉分支闭塞,但无脊髓缺血症状.患者均随访1~ 24个月,平均(9.6±2.1)个月.随访期间患者人工血管通畅,无假性动脉瘤形成,无脑部、脊髓及腹腔脏器等缺血表现.结论 孙氏手术能降低手术难度;减少并发症.常温非体外循环下,采用四分支人工血管翻转、分段阻断技术可以简化胸腹主动脉置换术,减少并发症.%Objective To explore the surgical techniques and clinical experiences in treating thoracoabdominal aorta dissecting aneurysm following Sun's procedure.Methods From June 2009 to May 2011,thoracoabdominal aorta replacement was performed in thirteen patients with thoracoabdominal aorta dissecting aneurysm following Sun's procedure in Beijing Anzhen Hospital.Among which,eleven were male,and two were female with a mean age 39.3 years (28 -58 years).All cases were Stanford A aortic dissection,and were underwent

  15. Multi-resolution terrain height-field data compression for rapid GPU decoding%GPU 快速解压的多分辨率地形高程数据压缩算法

    张兵强; 姜本清; 方君


    为了缓解实时地形可视化中海量数据的存储和传输压力,在构建地形数据多分辨率金字塔模型的基础上,提出了一种适于 GPU 实时解压的分块高程数据无损压缩和有损压缩算法。该算法首先对地形块数据进行线性预测,对高分辨率地形块的预测误差采用递归变长的无损编码方法,保留了高分辨率地形数据的细节特征;对低分辨率地形块的预测误差,在考虑地形块本身简化误差的基础上采用了分组的有损量化编码方法。给出了GPU 上实现快速并行解压的处理流程。实验结果表明,该算法实现了有效的数据压缩,具有很高的实时解压效率。%To release the burden for massive-data storage and transmission in real-time large terrain visualization systems, based on the multi-resolution pyramid model for terrain data,this paper proposed a compression algorithm for terrain blocks that was suitable for fast decoding on the GPU.At first,the algorithm implemented linear prediction for terrain blocks,and then coded residual errors for lossless compression of the full-resolution data based on RBUC(recursive bottom up complete). The lossless residual coding method reserved the details of the full-resolution data.As for the residual errors on coarser levels in the terrain blocks,it adopted a grouped and quantized coding method for lossy compression.The quantization levels were based on the simplified errors of low-resolution blocks.At last,it designed the processing flow for fast and parallel decompres-sion on GPU.The experimental results show that the algorithm can be used to compress terrain height-field datasets effectively and supports real-time decompression with high efficiency.

  16. Squish: Near-Optimal Compression for Archival of Relational Datasets

    Gao, Yihan; Parameswaran, Aditya


    Relational datasets are being generated at an alarmingly rapid rate across organizations and industries. Compressing these datasets could significantly reduce storage and archival costs. Traditional compression algorithms, e.g., gzip, are suboptimal for compressing relational datasets since they ignore the table structure and relationships between attributes. We study compression algorithms that leverage the relational structure to compress datasets to a much greater extent. We develop Squish, a system that uses a combination of Bayesian Networks and Arithmetic Coding to capture multiple kinds of dependencies among attributes and achieve near-entropy compression rate. Squish also supports user-defined attributes: users can instantiate new data types by simply implementing five functions for a new class interface. We prove the asymptotic optimality of our compression algorithm and conduct experiments to show the effectiveness of our system: Squish achieves a reduction of over 50% in storage size relative to systems developed in prior work on a variety of real datasets.

  17. Lossless Medical Image Compression

    Nagashree G


    Full Text Available Image compression has become an important process in today‟s world of information exchange. Image compression helps in effective utilization of high speed network resources. Medical Image Compression is very important in the present world for efficient archiving and transmission of images. In this paper two different approaches for lossless image compression is proposed. One uses the combination of 2D-DWT & FELICS algorithm for lossy to lossless Image Compression and another uses combination of prediction algorithm and Integer wavelet Transform (IWT. To show the effectiveness of the methodology used, different image quality parameters are measured and shown the comparison of both the approaches. We observed the increased compression ratio and higher PSNR values.

  18. Celiac Artery Compression Syndrome

    Mohammed Muqeetadnan


    Full Text Available Celiac artery compression syndrome is a rare disorder characterized by episodic abdominal pain and weight loss. It is the result of external compression of celiac artery by the median arcuate ligament. We present a case of celiac artery compression syndrome in a 57-year-old male with severe postprandial abdominal pain and 30-pound weight loss. The patient eventually responded well to surgical division of the median arcuate ligament by laparoscopy.

  19. Compressed sensing & sparse filtering

    Carmi, Avishy Y; Godsill, Simon J


    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. Wavelet image compression

    Pearlman, William A


    This book explains the stages necessary to create a wavelet compression system for images and describes state-of-the-art systems used in image compression standards and current research. It starts with a high level discussion of the properties of the wavelet transform, especially the decomposition into multi-resolution subbands. It continues with an exposition of the null-zone, uniform quantization used in most subband coding systems and the optimal allocation of bitrate to the different subbands. Then the image compression systems of the FBI Fingerprint Compression Standard and the JPEG2000 S

  1. Stiffness of compression devices

    Giovanni Mosti


    Full Text Available This issue of Veins and Lymphatics collects papers coming from the International Compression Club (ICC Meeting on Stiffness of Compression Devices, which took place in Vienna on May 2012. Several studies have demonstrated that the stiffness of compression products plays a major role for their hemodynamic efficacy. According to the European Committee for Standardization (CEN, stiffness is defined as the pressure increase produced by medical compression hosiery (MCH per 1 cm of increase in leg circumference.1 In other words stiffness could be defined as the ability of the bandage/stockings to oppose the muscle expansion during contraction.

  2. Radiation exposure of children in pediatric radiology, Pt. 8. Radiation doses during thoracoabdominal babygram and abdominal X-ray examination of the newborn and young infants; Zur Strahlenexposition von Kindern in der paediatrischen Radiologie. T. 8. Strahlendosen beim thorakoabdominalen babygramm und bei der abdomenaufnahme neugeborener und saeuglinge

    Schneider, Karl; Seidenbusch, M.C. [Abt. Radiologie, Dr. von Haunersches Kinderspital, Klinikum der Univ. Muenchen (Germany)


    Purpose: Reconstruction of radiation doses for the thoracoabdominal babygram and the abdomen X-ray from radiographic settings and exposure data acquired at Dr. von Hauner's Kinderspital (children's hospital of the University of Munich, DvHK) between 1976 and 2007; comparison of these dose values with values reported in the literature; recommendation of a reference dose value for the thoracoabdominal babygram. Materials and Methods: The data from all X-ray examinations performed since 1976 at DvHK were stored electronically in a database. After 30 years of data collection, the database now includes 305 107 radiological examinations (radiographs and fluoroscopies), especially 1493 thoracoabdominal babygrams and 3632 abdomen X-rays of newborns and young infants. With the computer program PAeDOS, a specific dose reconstruction algorithm was developed. Results: the entrance dose values of thoracoabdominal babygrams and abdomen X-rays in DvHK could be reduced in the last 30 years by a factor of 5 to 8. They are far below the entrance dose values reported by other radiology departments in Europe. Nevertheless, a slight increase in the entrance doses that correlates with the introduction of a digital storage phosphor system could be observed in the last years. Conclusion: because nearly all radiosensitive body organs in early life are involved during a thoracoabdominal babygram and because of the high radiation sensitivity of newborns, thoracoabdominal babygrams should be performed in neonatology with caution. A dose value of 1.0 cGy cm{sup 2} could serve as the actual reference dose value for the thoracoabdominal babygram of the newborn. (orig.)

  3. Effects of aerobic training combined with respiratory muscle stretching on the functional exercise capacity and thoracoabdominal kinematics in patients with COPD: a randomized and controlled trial

    Wada JT


    Full Text Available Juliano T Wada,1 Erickson Borges-Santos,1 Desiderio Cano Porras,1 Denise M Paisani,1 Alberto Cukier,2 Adriana C Lunardi,1 Celso RF Carvalho1 1Department of Physical Therapy, 2Department of Cardiopneumology, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil Background: Patients with COPD present a major recruitment of the inspiratory muscles, predisposing to chest incoordination, increasing the degree of dyspnea and impairing their exercise capacity. Stretching techniques could decrease the respiratory muscle activity and improve their contractile capacity; however, the systemic effects of stretching remain unknown.Objective: The aim of this study was to evaluate the effects of aerobic training combined with respiratory muscle stretching on functional exercise capacity and thoracoabdominal kinematics in patients with COPD.Design: This study was a randomized and controlled trial.Participants: A total of 30 patients were allocated to a treatment group (TG or a control group (CG; n=15, each group.Intervention: The TG was engaged in respiratory muscle stretching and the CG in upper and lower limb muscle stretching. Both groups performed 24 sessions (twice a week, 12 weeks of aerobic training.Evaluations: Functional exercise capacity (6-minute walk test, thoracoabdominal kinematics (optoelectronic plethysmography, and respiratory muscle activity (surface electromyography were evaluated during exercise. Analysis of covariance was used to compare the groups at a significance level of 5%.Results: After the intervention, the TG showed improved abdominal (ABD contribution, compartmental volume, mobility, and functional exercise capacity with decreased dyspnea when compared with the CG (P<0.01. The TG also showed a decreased respiratory muscle effort required to obtain the same pulmonary volume compared to the CG (P<0.001.Conclusion: Our results suggest that aerobic training combined with respiratory muscle stretching increases the functional

  4. Respiratory muscle training with normocapnic hyperpnea improves ventilatory pattern and thoracoabdominal coordination, and reduces oxygen desaturation during endurance exercise testing in COPD patients

    Bernardi E


    Full Text Available Eva Bernardi,1 Luca Pomidori,1 Faisy Bassal,1 Marco Contoli,2 Annalisa Cogo11Biomedical Sport Studies Center, University of Ferrara, Ferrara, 2Respiratory Section, Department of Medical Sciences, University of Ferrara, Cona (FE, ItalyBackground: Few data are available about the effects of respiratory muscle training with normocapnic hyperpnea (NH in COPD. The aim is to evaluate the effects of 4 weeks of NH (Spirotiger® on ventilatory pattern, exercise capacity, and quality of life (QoL in COPD patients.Methods: Twenty-six COPD patients (three females, ages 49–82 years, were included in this study. Spirometry and maximal inspiratory pressure, St George Respiratory Questionnaire, 6-minute walk test, and symptom-limited endurance exercise test (endurance test to the limit of tolerance [tLim] at 75%–80% of peak work rate up to a Borg Score of 8–9/10 were performed before and after NH. Patients were equipped with ambulatory inductive plethysmography (LifeShirt® to evaluate ventilatory pattern and thoracoabdominal coordination (phase angle [PhA] during tLim. After four supervised sessions, subjects trained at home for 4 weeks – 10 minutes twice a day at 50% of maximal voluntary ventilation. The workload was adjusted during the training period to maintain a Borg Score of 5–6/10.Results: Twenty subjects completed the study. After NH, maximal inspiratory pressure significantly increased (81.5±31.6 vs 91.8±30.6 cmH2O, P<0.01; exercise endurance time (+150 seconds, P=0.04, 6-minute walk test (+30 meters, P=0.03, and QoL (-8, P<0.01 all increased. During tLim, the ventilatory pattern changed significantly (lower ventilation, lower respiratory rate, higher tidal volume; oxygen desaturation, PhA, and dyspnea Borg Score were lower for the same work intensity (P<0.01, P=0.02, and P<0.01, respectively; one-way ANOVA. The improvement in tidal volume and oxygen saturation after NH were significantly related (R2=0.65, P<0.01.Conclusion: As

  5. Compression Ratio Adjuster

    Akkerman, J. W.


    New mechanism alters compression ratio of internal-combustion engine according to load so that engine operates at top fuel efficiency. Ordinary gasoline, diesel and gas engines with their fixed compression ratios are inefficient at partial load and at low-speed full load. Mechanism ensures engines operate as efficiently under these conditions as they do at highload and high speed.

  6. Magnetized Plasma Compression for Fusion Energy

    Degnan, James; Grabowski, Christopher; Domonkos, Matthew; Amdahl, David


    Magnetized Plasma Compression (MPC) uses magnetic inhibition of thermal conduction and enhancement of charge particle product capture to greatly reduce the temporal and spatial compression required relative to un-magnetized inertial fusion (IFE)--to microseconds, centimeters vs nanoseconds, sub-millimeter. MPC greatly reduces the required confinement time relative to MFE--to microseconds vs minutes. Proof of principle can be demonstrated or refuted using high current pulsed power driven compression of magnetized plasmas using magnetic pressure driven implosions of metal shells, known as imploding liners. This can be done at a cost of a few tens of millions of dollars. If demonstrated, it becomes worthwhile to develop repetitive implosion drivers. One approach is to use arrays of heavy ion beams for energy production, though with much less temporal and spatial compression than that envisioned for un-magnetized IFE, with larger compression targets, and with much less ambitious compression ratios. A less expensive, repetitive pulsed power driver, if feasible, would require engineering development for transient, rapidly replaceable transmission lines such as envisioned by Sandia National Laboratories. Supported by DOE-OFES.

  7. Normal and Time-Compressed Speech

    Lemke, Ulrike; Kollmeier, Birger; Holube, Inga


    Short-term and long-term learning effects were investigated for the German Oldenburg sentence test (OLSA) using original and time-compressed fast speech in noise. Normal-hearing and hearing-impaired participants completed six lists of the OLSA in five sessions. Two groups of normal-hearing listeners (24 and 12 listeners) and two groups of hearing-impaired listeners (9 listeners each) performed the test with original or time-compressed speech. In general, original speech resulted in better speech recognition thresholds than time-compressed speech. Thresholds decreased with repetition for both speech materials. Confirming earlier results, the largest improvements were observed within the first measurements of the first session, indicating a rapid initial adaptation phase. The improvements were larger for time-compressed than for original speech. The novel results on long-term learning effects when using the OLSA indicate a longer phase of ongoing learning, especially for time-compressed speech, which seems to be limited by a floor effect. In addition, for normal-hearing participants, no complete transfer of learning benefits from time-compressed to original speech was observed. These effects should be borne in mind when inviting listeners repeatedly, for example, in research settings.

  8. Spectral Animation Compression

    Chao Wang; Yang Liu; Xiaohu Guo; Zichun Zhong; Binh Le; Zhigang Deng


    This paper presents a spectral approach to compress dynamic animation consisting of a sequence of homeomor-phic manifold meshes. Our new approach directly compresses the field of deformation gradient defined on the surface mesh, by decomposing it into rigid-body motion (rotation) and non-rigid-body deformation (stretching) through polar decompo-sition. It is known that the rotation group has the algebraic topology of 3D ring, which is different from other operations like stretching. Thus we compress these two groups separately, by using Manifold Harmonics Transform to drop out their high-frequency details. Our experimental result shows that the proposed method achieves a good balance between the reconstruction quality and the compression ratio. We compare our results quantitatively with other existing approaches on animation compression, using standard measurement criteria.

  9. Self-ignition and oxidation of various hydrocarbons between 600 and 1000 K at high pressure: experimental study with fast compression machine and modeling; Autoinflammation et oxydation de divers hydrocarbures entre 600 et 1000 K a haute pression: etude experimentale en machine a compression rapide et modelisation

    Ribaucour, M.


    Low- and intermediate-temperature oxidation and self-ignition of hydrocarbons play a major role in spark ignition, diesel and HCCI (homogenous charge compression ignition) engines. A deep understanding of the chemistry linked with both phenomena is necessary to improve the engines efficiency and to reduce the formation of pollutants. This document treats of works about the self-ignition and oxidation at high pressure of various hydrocarbons between 600 and 1000 deg. K. The experimental tool used is a fast compression machine fitted with a fast sampling system for the measurement of self-ignition delays and of the concentrations of intermediate oxidation products. The advantages and limitations of this tool are discussed. The self-ignition of various hydrocarbons is compared using pre-defined data which characterize the phenomenologies like cold flames, negative temperature coefficients and self-ignition limits. The hydrocarbons considered are pure or binary mixtures of alkanes, pent-1-ene and n-butyl-benzene. The development of high pressure oxidation reaction schemes of alkanes between 600 and 1000 deg. K is described. It is directly based on the analysis of intermediate oxidation products. This methodology is also applied to pent-1-ene and n-butyl-benzene. The construction of detailed thermo-kinetic models of oxidation and the modeling of phenomena are made for n-butane, n-heptane, for the 3 pentane isomers, for pent-1-ene and n-butyl-benzene. Finally, the perspectives of future works are evoked. They concern new modeling and new methodologies to be applied in more predictive thermo-kinetic models and the reduction of detailed models in order to include them inside fluid dynamics codes. (J.S.)

  10. Vascular compression syndromes.

    Czihal, Michael; Banafsche, Ramin; Hoffmann, Ulrich; Koeppel, Thomas


    Dealing with vascular compression syndromes is one of the most challenging tasks in Vascular Medicine practice. This heterogeneous group of disorders is characterised by external compression of primarily healthy arteries and/or veins as well as accompanying nerval structures, carrying the risk of subsequent structural vessel wall and nerve damage. Vascular compression syndromes may severely impair health-related quality of life in affected individuals who are typically young and otherwise healthy. The diagnostic approach has not been standardised for any of the vascular compression syndromes. Moreover, some degree of positional external compression of blood vessels such as the subclavian and popliteal vessels or the celiac trunk can be found in a significant proportion of healthy individuals. This implies important difficulties in differentiating physiological from pathological findings of clinical examination and diagnostic imaging with provocative manoeuvres. The level of evidence on which treatment decisions regarding surgical decompression with or without revascularisation can be relied on is generally poor, mostly coming from retrospective single centre studies. Proper patient selection is critical in order to avoid overtreatment in patients without a clear association between vascular compression and clinical symptoms. With a focus on the thoracic outlet-syndrome, the median arcuate ligament syndrome and the popliteal entrapment syndrome, the present article gives a selective literature review on compression syndromes from an interdisciplinary vascular point of view.

  11. Critical Data Compression

    Scoville, John


    A new approach to data compression is developed and applied to multimedia content. This method separates messages into components suitable for both lossless coding and 'lossy' or statistical coding techniques, compressing complex objects by separately encoding signals and noise. This is demonstrated by compressing the most significant bits of data exactly, since they are typically redundant and compressible, and either fitting a maximally likely noise function to the residual bits or compressing them using lossy methods. Upon decompression, the significant bits are decoded and added to a noise function, whether sampled from a noise model or decompressed from a lossy code. This results in compressed data similar to the original. For many test images, a two-part image code using JPEG2000 for lossy coding and PAQ8l for lossless coding produces less mean-squared error than an equal length of JPEG2000. Computer-generated images typically compress better using this method than through direct lossy coding, as do man...

  12. Experimental study of hot electrons propagation and energy deposition in solid or laser-shock compressed targets: applications to fast igniter; Etude experimentale de la propagation et du depot d'energie d'electrons rapides dans une cible solide ou comprimee par choc laser: application a l'allumeur rapide

    Pisani, F


    In the fast igniter scheme, a recent approach proposed for the inertial confinement fusion, the idea is to dissociate the fuel ignition phase from its compression. The ignition phase would be then achieved by means of an external energy source: a fast electron beam generated by the interaction with an ultra-intense laser. The main goal of this work is to study the mechanisms of the hot electron energy transfer to the compressed fuel. We intent in particular to study the role of the electric and collisional effects involved in the hot electron propagation in a medium with properties similar to the compressed fuel. We carried out two experiments, one at the Vulcan laser facility (England) and the second one at the new LULI 100 TW laser (France). During the first experiment, we obtained the first results on the hot electron propagation in a dense and hot plasma. The innovating aspect of this work was in particular the use of the laser-shock technique to generate high pressures, allowing the strongly correlated and degenerated plasma to be created. The role of the electric and magnetic effects due to the space charge associated with the fast electron beam has been investigated in the second experiment. Here we studied the propagation in materials with different electrical characteristics: an insulator and a conductor. The analysis of the results showed that only by taking into account simultaneously the two propagation mechanisms (collisions and electric effects) a correct treatment of the energy deposition is possible. We also showed the importance of taking into account the induced modifications due to the electrons beam crossing the target, especially the induced heating. (author)

  13. Prediction by Compression

    Ratsaby, Joel


    It is well known that text compression can be achieved by predicting the next symbol in the stream of text data based on the history seen up to the current symbol. The better the prediction the more skewed the conditional probability distribution of the next symbol and the shorter the codeword that needs to be assigned to represent this next symbol. What about the opposite direction ? suppose we have a black box that can compress text stream. Can it be used to predict the next symbol in the stream ? We introduce a criterion based on the length of the compressed data and use it to predict the next symbol. We examine empirically the prediction error rate and its dependency on some compression parameters.

  14. LZW Data Compression

    Dheemanth H N


    Full Text Available Lempel–Ziv–Welch (LZW is a universal lossless data compression algorithm created by Abraham Lempel, Jacob Ziv, and Terry Welch. LZW compression is one of the Adaptive Dictionary techniques. The dictionary is created while the data are being encoded. So encoding can be done on the fly. The dictionary need not be transmitted. Dictionary can be built up at receiving end on the fly. If the dictionary overflows then we have to reinitialize the dictionary and add a bit to each one of the code words. Choosing a large dictionary size avoids overflow, but spoils compressions. A codebook or dictionary containing the source symbols is constructed. For 8-bit monochrome images, the first 256 words of the dictionary are assigned to the gray levels 0-255. Remaining part of the dictionary is filled with sequences of the gray levels.LZW compression works best when applied on monochrome images and text files that contain repetitive text/patterns.

  15. Shocklets in compressible flows

    袁湘江; 男俊武; 沈清; 李筠


    The mechanism of shocklets is studied theoretically and numerically for the stationary fluid, uniform compressible flow, and boundary layer flow. The conditions that trigger shock waves for sound wave, weak discontinuity, and Tollmien-Schlichting (T-S) wave in compressible flows are investigated. The relations between the three types of waves and shocklets are further analyzed and discussed. Different stages of the shocklet formation process are simulated. The results show that the three waves in compressible flows will transfer to shocklets only when the initial disturbance amplitudes are greater than the certain threshold values. In compressible boundary layers, the shocklets evolved from T-S wave exist only in a finite region near the surface instead of the whole wavefront.

  16. Reference Based Genome Compression

    Chern, Bobbie; Manolakos, Alexandros; No, Albert; Venkat, Kartik; Weissman, Tsachy


    DNA sequencing technology has advanced to a point where storage is becoming the central bottleneck in the acquisition and mining of more data. Large amounts of data are vital for genomics research, and generic compression tools, while viable, cannot offer the same savings as approaches tuned to inherent biological properties. We propose an algorithm to compress a target genome given a known reference genome. The proposed algorithm first generates a mapping from the reference to the target genome, and then compresses this mapping with an entropy coder. As an illustration of the performance: applying our algorithm to James Watson's genome with hg18 as a reference, we are able to reduce the 2991 megabyte (MB) genome down to 6.99 MB, while Gzip compresses it to 834.8 MB.

  17. Deep Blind Compressed Sensing

    Singh, Shikha; Singhal, Vanika; Majumdar, Angshul


    This work addresses the problem of extracting deeply learned features directly from compressive measurements. There has been no work in this area. Existing deep learning tools only give good results when applied on the full signal, that too usually after preprocessing. These techniques require the signal to be reconstructed first. In this work we show that by learning directly from the compressed domain, considerably better results can be obtained. This work extends the recently proposed fram...

  18. Reference Based Genome Compression

    Chern, Bobbie; Ochoa, Idoia; Manolakos, Alexandros; No, Albert; Venkat, Kartik; Weissman, Tsachy


    DNA sequencing technology has advanced to a point where storage is becoming the central bottleneck in the acquisition and mining of more data. Large amounts of data are vital for genomics research, and generic compression tools, while viable, cannot offer the same savings as approaches tuned to inherent biological properties. We propose an algorithm to compress a target genome given a known reference genome. The proposed algorithm first generates a mapping from the reference to the target gen...

  19. Alternative Compression Garments

    Stenger, M. B.; Lee, S. M. C.; Ribeiro, L. C.; Brown, A. K.; Westby, C. M.; Platts, S. H.


    Orthostatic intolerance after spaceflight is still an issue for astronauts as no in-flight countermeasure has been 100% effective. Future anti-gravity suits (AGS) may be similar to the Shuttle era inflatable AGS or may be a mechanical compression device like the Russian Kentavr. We have evaluated the above garments as well as elastic, gradient compression garments of varying magnitude and determined that breast-high elastic compression garments may be a suitable replacement to the current AGS. This new garment should be more comfortable than the AGS, easy to don and doff, and as effective a countermeasure to orthostatic intolerance. Furthermore, these new compression garments could be worn for several days after space flight as necessary if symptoms persisted. We conducted two studies to evaluate elastic, gradient compression garments. The purpose of these studies was to evaluate the comfort and efficacy of an alternative compression garment (ACG) immediately after actual space flight and 6 degree head-down tilt bed rest as a model of space flight, and to determine if they would impact recovery if worn for up to three days after bed rest.

  20. Magnetic Compression Experiment at General Fusion

    Dunlea, Carl; Howard, Stephen; Epp, Kelly; Zawalski, Wade; Kim, Charlson; Fusion Team, General


    The magnetic compression experiment at General Fusion was designed as 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. The experiment has external coils to keep the CT off the outer wall (levitation) and then rapidly compress it inwards. Experiments used a variety of levitation/compression field profiles. The optimal configuration was seen to improve levitated CT lifetime by around 50% over that with the original design field. Suppression of impurity influx to the plasma is thought to be a significant factor in the improvement, as supported by spectrometer data. Improved levitation field may reduce the amount of edge plasma and current that intersects the insulating outer wall during the formation process. Higher formation current and stuffing field, and correspondingly higher CT flux, was possible with the improved configuration. Significant field and density compression factors were routinely observed. The level of MHD activity was reduced, and lifetime was increased further by matching the decay rate of the levitation field to that of the CT fields. Details of experimental results and comparisons to equilibrium models and MHD simulations will be presented.

  1. Early diagnosis and treatment of combined thoracoabdominal injury%胸腹联合伤的早期诊断与治疗

    李侠; 李增春; 刘养洲; 陈国庭; 韩庆辉; 李光; 靳晓丽; 王圣刚; 赵中辛


    Objective To summarize the experience in early diagnosis and emergency treatment for combined thoracoabdominal injury (CTI). Methods Clinical data of 58 cases of CTI admitted to our hospital from June 2001 to August 2009 were analyzed retrospectively.All the patients were treated by closed drainage of thoracic cavity,of which 12 cases were treated with thoracotomy,31 with laparotomy,seven with thoracic and abdominal incisions and three with combined thoracoabdominal incision.Internal fixation for long limb bones was performed in 27 cases,spinal laminectomy and pedicle screw fixation in five and amputation in one. Results After operation,six cases were found to have adult respiratory distress syndrome (ARDS) and 12 cases were complicated with multiple organ dysfunction syndrome (MODS).Fifty-three cases were cured and five died. Conclusions CTI based multiple injuries are severe and complicated.CT scan in the early stage plays a significant role in the diagnosis of CTI and closed drainage of thoracic cavity is an important assurance of the security of abdominal operation.Early diagnosis,correct choice of operation procedures and reasonable handling order of injured organs can improve the successful rescue rate for multiple injury patients.%目的 总结以胸腹部联合伤为主的多发伤的早期诊断与急诊手术的经验. 方法 对2001年7月-2009年8月收治的58例以胸腹联合伤为主的多发伤患者的临床资料进行回顾性分析. 结果 患者入院后均行胸腔闭式引流术.开胸手术12例,剖腹手术36例,同时行胸部和腹部切口7例,经胸腹联合切口3例.其中行四肢长干骨内固定术27例,脊柱椎板减压椎弓根内固定术5例,截肢术1例.术后发生成人呼吸窘迫综合征6例,并发多器官功能不全综合征12例.治愈53例,死亡5例. 结论 以胸腹联合伤为主的多发伤病情重,表现复杂.早期CT扫描对以胸腹联合伤为主的多发伤的早期诊断有重要作用.胸腔闭式

  2. Comparison of intra-aortic computed tomography angiography to conventional angiography in the presurgical visualization of the Adamkiewicz artery: first results in patients with thoracoabdominal aortic aneurysms

    Clarencon, Frederic [Paris VI University, Department of Interventional Neuroradiology, Pitie-Salpetriere Hospital, Paris (France); Pitie-Salpetriere Hospital, Department of Neuroradiology, Paris (France); Maria, Federico di; Cormier, Evelyne; Sourour, Nader; Gabrieli, Joseph; Iosif, Christina; Chiras, Jacques [Paris VI University, Department of Interventional Neuroradiology, Pitie-Salpetriere Hospital, Paris (France); Gaudric, Julien; Koskas, Fabien [Paris VI University, Department of Vascular Surgery, Pitie-Salpetriere Hospital, Paris (France); Jenny, Catherine [Paris VI University, Department of Radiophysics, Pitie-Salpetriere Hospital, Paris (France)


    The aim of this study was to compare the sensitivity of intra-aortic computed tomography angiography (IA-CTA) to that of regular spinal digital subtraction angiography for the presurgical location of the Adamkiewicz artery (AKA). Thirty patients (21 males, 9 females; mean age 64 years) had an IA-CTA for the location of the AKA before surgery of aneurysm (n = 24) or dissection (n = 6) of the thoracoabdominal aorta. After femoral artery puncture, a pigtail catheter was positioned at the origin of the descending aorta. CT acquisition was performed with an intra-aortic iodinated contrast media injection (15 mL/s, 120 mL). The visualization of the AKA and the location of the feeder(s) to the AKA were independently evaluated by two observers. Interrater agreement was calculated using a kappa test. Spinal angiogram by selective catheterization was systematically performed to confirm the results of the IA-CTA. The AKA was visualized by the IA-CTA in 27/30 cases (90 %); in 26/31 (84 %) cases, the continuity with the aorta was satisfactorily seen. Interrater agreement was good for the visualization of the AKA and its feeder(s): 0.625 and 0.87, respectively. In 75 % of the cases for which the AKA was visualized, the selective catheterization confirmed the results of the IA-CTA. In the remaining 25 % of the cases, the selective catheterization could not be performed due to marked vessels' tortuosity or ostium stenosis. IA-CTA is a feasible technique in a daily practice that presents a good sensitivity for the location of the AKA. (orig.)

  3. Transverse Compression of Tendons.

    Salisbury, S T Samuel; Buckley, C Paul; Zavatsky, Amy B


    A study was made of the deformation of tendons when compressed transverse to the fiber-aligned axis. Bovine digital extensor tendons were compression tested between flat rigid plates. The methods included: in situ image-based measurement of tendon cross-sectional shapes, after preconditioning but immediately prior to testing; multiple constant-load creep/recovery tests applied to each tendon at increasing loads; and measurements of the resulting tendon displacements in both transverse directions. In these tests, friction resisted axial stretch of the tendon during compression, giving approximately plane-strain conditions. This, together with the assumption of a form of anisotropic hyperelastic constitutive model proposed previously for tendon, justified modeling the isochronal response of tendon as that of an isotropic, slightly compressible, neo-Hookean solid. Inverse analysis, using finite-element (FE) simulations of the experiments and 10 s isochronal creep displacement data, gave values for Young's modulus and Poisson's ratio of this solid of 0.31 MPa and 0.49, respectively, for an idealized tendon shape and averaged data for all the tendons and E = 0.14 and 0.10 MPa for two specific tendons using their actual measured geometry. The compression load versus displacement curves, as measured and as simulated, showed varying degrees of stiffening with increasing load. This can be attributed mostly to geometrical changes in tendon cross section under load, varying according to the initial 3D shape of the tendon.


    Li Hongbo


    In an inner-product space, an invertible vector generates a reflection with re-spect to a hyperplane, and the Clifford product of several invertible vectors, called a versor in Clifford algebra, generates the composition of the corresponding reflections, which is an orthogonal transformation. Given a versor in a Clifford algebra, finding another sequence of invertible vectors of strictly shorter length but whose Clifford product still equals the input versor, is called versor compression. Geometrically, versor compression is equivalent to decomposing an orthogoual transformation into a shorter sequence of reflections. This paper proposes a simple algorithm of compressing versors of symbolic form in Clifford algebra. The algorithm is based on computing the intersections of lines with planes in the corresponding Grassmann-Cayley algebra, and is complete in the case of Euclidean or Minkowski inner-product space.

  5. Image compression for dermatology

    Cookson, John P.; Sneiderman, Charles; Colaianni, Joseph; Hood, Antoinette F.


    Color 35mm photographic slides are commonly used in dermatology for education, and patient records. An electronic storage and retrieval system for digitized slide images may offer some advantages such as preservation and random access. We have integrated a system based on a personal computer (PC) for digital imaging of 35mm slides that depict dermatologic conditions. Such systems require significant resources to accommodate the large image files involved. Methods to reduce storage requirements and access time through image compression are therefore of interest. This paper contains an evaluation of one such compression method that uses the Hadamard transform implemented on a PC-resident graphics processor. Image quality is assessed by determining the effect of compression on the performance of an image feature recognition task.

  6. Automatic relational database compression scheme design based on swarm evolution

    HU Tian-lei; CHEN Gang; LI Xiao-yan; DONG Jin-xiang


    Compression is an intuitive way to boost the performance of a database system. However, compared with other physical database design techniques, compression consumes large amount of CPU power. There is a trade-off between the reduction of disk access and the overhead of CPU processing. Automatic design and adaptive administration of database systems are widely demanded, and the automatic selection of compression schema to compromise the trade-off is very important. In this paper,we present a model with novel techniques to integrate a rapidly convergent agent-based evolution framework, i.e. the SWAF (SWarm Algorithm Framework), into adaptive attribute compression for relational database. The model evolutionally consults statistics of CPU load and IO bandwidth to select compression schemas considering both aspects of the trade-off. We have implemented a prototype model on Oscar RDBMS with experiments highlighting the correctness and efficiency of our techniques.

  7. Algorithms and data structures for grammar-compressed strings

    Cording, Patrick Hagge

    demanding task. In this thesis we design data structures for accessing and searching compressed data efficiently. Our results can be divided into two categories. In the first category we study problems related to pattern matching. In particular, we present new algorithms for counting and comparing...... substrings, and a new algorithm for finding all occurrences of a pattern in which we may insert gaps. In the other category we deal with accessing and decompressing parts of the compressed string. We show how to quickly access a single character of the compressed string, and present a data structure......Textual databases for e.g. biological or web-data are growing rapidly, and it is often only feasible to store the data in compressed form. However, compressing the data comes at a price. Traditional algorithms for e.g. pattern matching requires all data to be decompressed - a computationally...

  8. Compressive Shift Retrieval

    Ohlsson, Henrik; Eldar, Yonina C.; Yang, Allen Y.; Sastry, S. Shankar


    The classical shift retrieval problem considers two signals in vector form that are related by a shift. The problem is of great importance in many applications and is typically solved by maximizing the cross-correlation between the two signals. Inspired by compressive sensing, in this paper, we seek to estimate the shift directly from compressed signals. We show that under certain conditions, the shift can be recovered using fewer samples and less computation compared to the classical setup. Of particular interest is shift estimation from Fourier coefficients. We show that under rather mild conditions only one Fourier coefficient suffices to recover the true shift.

  9. Graph Compression by BFS

    Alberto Apostolico


    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.

  10. Image data compression investigation

    Myrie, Carlos


    NASA continuous communications systems growth has increased the demand for image transmission and storage. Research and analysis was conducted on various lossy and lossless advanced data compression techniques or approaches used to improve the efficiency of transmission and storage of high volume stellite image data such as pulse code modulation (PCM), differential PCM (DPCM), transform coding, hybrid coding, interframe coding, and adaptive technique. In this presentation, the fundamentals of image data compression utilizing two techniques which are pulse code modulation (PCM) and differential PCM (DPCM) are presented along with an application utilizing these two coding techniques.

  11. Image compression in local helioseismology

    Löptien, Björn; Gizon, Laurent; Schou, Jesper


    Context. Several upcoming helioseismology space missions are very limited in telemetry and will have to perform extensive data compression. This requires the development of new methods of data compression. Aims. We give an overview of the influence of lossy data compression on local helioseismology. We investigate the effects of several lossy compression methods (quantization, JPEG compression, and smoothing and subsampling) on power spectra and time-distance measurements of supergranulation flows at disk center. Methods. We applied different compression methods to tracked and remapped Dopplergrams obtained by the Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory. We determined the signal-to-noise ratio of the travel times computed from the compressed data as a function of the compression efficiency. Results. The basic helioseismic measurements that we consider are very robust to lossy data compression. Even if only the sign of the velocity is used, time-distance helioseismology is still...

  12. Fingerprints in Compressed Strings

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


    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...

  13. Multiple snapshot compressive beamforming

    Gerstoft, Peter; Xenaki, Angeliki; Mecklenbrauker, Christoph F.


    For sound fields observed on an array, compressive sensing (CS) reconstructs the multiple source signals at unknown directions-of-arrival (DOAs) using a sparsity constraint. The DOA estimation is posed as an underdetermined problem expressing the field at each sensor as a phase-lagged superposition...

  14. Compressive CFAR radar detection

    Anitori, L.; Otten, M.P.G.; Rossum, W.L. van; Maleki, A.; Baraniuk, R.


    In this paper we develop the first Compressive Sensing (CS) adaptive radar detector. We propose three novel architectures and demonstrate how a classical Constant False Alarm Rate (CFAR) detector can be combined with ℓ1-norm minimization. Using asymptotic arguments and the Complex Approximate Messag

  15. Compressive CFAR Radar Processing

    Anitori, L.; Rossum, W.L. van; Otten, M.P.G.; Maleki, A.; Baraniuk, R.


    In this paper we investigate the performance of a combined Compressive Sensing (CS) Constant False Alarm Rate (CFAR) radar processor under different interference scenarios using both the Cell Averaging (CA) and Order Statistic (OS) CFAR detectors. Using the properties of the Complex Approximate Mess

  16. Beamforming Using Compressive Sensing


    dB to align the peak at 7.3o. Comparing peaks to val- leys , compressive sensing provides a greater main to interference (and noise) ratio...elements. Acknowledgments This research was supported by the Office of Naval Research. The authors would like to especially thank of Roger Gauss and Joseph

  17. Topogram-based automated selection of the tube potential and current in thoraco-abdominal trauma CT - a comparison to fixed kV with mAs modulation alone

    Frellesen, Claudia; Stock, Wenzel; Kerl, J.M.; Lehnert, Thomas; Wichmann, Julian L.; Beeres, Martin; Schulz, Boris; Bodelle, Boris; Vogl, Thomas J. [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Nau, Christoph; Geiger, Emanuel; Wutzler, Sebastian [Clinic of the Goethe University, Department of Trauma, Hand and Reconstructive Surgery, Frankfurt (Germany); Ackermann, Hanns [Clinic of the Goethe University, Department of Biostatistics and Mathematical Modelling, Frankfurt (Germany); Bauer, Ralf W. [Clinic of the Goethe University, Department of Diagnostic and Interventional Radiology, Frankfurt (Germany); Klinikum der Goethe-Universitaet, Institut fuer Diagnostische und Interventionelle Radiologie, Frankfurt am Main (Germany)


    To investigate the impact of automated attenuation-based tube potential selection on image quality and exposure parameters in polytrauma patients undergoing contrast-enhanced thoraco-abdominal CT. One hundred patients were examined on a 16-slice device at 120 kV with 190 ref.mAs and automated mA modulation only. Another 100 patients underwent 128-slice CT with automated mA modulation and topogram-based automated tube potential selection (autokV) at 100, 120 or 140 kV. Volume CT dose index (CTDI{sub vol}), dose-length product (DLP), body diameters, noise, signal-to-noise ratio (SNR) and subjective image quality were compared. In the autokV group, 100 kV was automatically selected in 82 patients, 120 kV in 12 patients and 140 kV in 6 patients. Patient diameters increased with higher kV settings. The median CTDI{sub vol} (8.3 vs. 12.4 mGy; -33 %) and DLP (594 vs. 909 mGy cm; -35 %) in the entire autokV group were significantly lower than in the group with fixed 120 kV (p < 0.05 for both). Image quality remained at a constantly high level at any selected kV level. Topogram-based automated selection of the tube potential allows for significant dose savings in thoraco-abdominal trauma CT while image quality remains at a constantly high level. (orig.)

  18. Huffman-based code compression techniques for embedded processors

    Bonny, Mohamed Talal


    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

  19. A Quadratic Closure for Compressible Turbulence

    Futterman, J A


    We have investigated a one-point closure model for compressible turbulence based on third- and higher order cumulant discard for systems undergoing rapid deformation, such as might occur downstream of a shock or other discontinuity. In so doing, we find the lowest order contributions of turbulence to the mean flow, which lead to criteria for Adaptive Mesh Refinement. Rapid distortion theory (RDT) as originally applied by Herring closes the turbulence hierarchy of moment equations by discarding third order and higher cumulants. This is similar to the fourth-order cumulant discard hypothesis of Millionshchikov, except that the Millionshchikov hypothesis was taken to apply to incompressible homogeneous isotropic turbulence generally, whereas RDT is applied only to fluids undergoing a distortion that is 'rapid' in the sense that the interaction of the mean flow with the turbulence overwhelms the interaction of the turbulence with itself. It is also similar to Gaussian closure, in which both second and fourth-order cumulants are retained. Motivated by RDT, we develop a quadratic one-point closure for rapidly distorting compressible turbulence, without regard to homogeneity or isotropy, and make contact with two equation turbulence models, especially the K-{var_epsilon} and K-L models, and with linear instability growth. In the end, we arrive at criteria for Adaptive Mesh Refinement in Finite Volume simulations.


    Idris Mohamed El-Mahdi


    Full Text Available This work was aimed at the use of dissolution testing and similarity factor to assess the level of damage taken by active drug microspheres during compression in tablet dosage form. To achieve that, combinations of suitable excipients were used to protect drug microspheres during compression. The excipients were used in the form of powders, granules or placebo pellets prepared by extrusion-spheronization technology. The excipients were evaluated alone, in combinations and post-compression into compacts.  Preliminary experiments included density, hardness, friability and disintegration on all of the selected excipients. Based on such experiments it was found that the flowability of combination powders was more acceptable than individual excipients. Two combinations of microcrystalline -starch and microcrystalline cellulose -calcium carbonate granules were selected to be compressed with active ketoprofen pellets. In all the combinations used there was a significant amount of damage to drug pellets.  The kinetics of drug release appears to follow the zero-order rate and the rate remained unchanged even when a significant degree of damage to pellets occur. It was found that a high level of excipients is required in order to prepare microspheres as a rapid disintegrating tablet. Citation DOI: 10.21502/limuj.002.01.2016  LIMUJ is licensed under a Creative Commons Attribution 4.0 International License

  1. Randomness Testing of Compressed Data

    Chang, Weiling; Yun, Xiaochun; Wang, Shupeng; Yu, Xiangzhan


    Random Number Generators play a critical role in a number of important applications. In practice, statistical testing is employed to gather evidence that a generator indeed produces numbers that appear to be random. In this paper, we reports on the studies that were conducted on the compressed data using 8 compression algorithms or compressors. The test results suggest that the output of compression algorithms or compressors has bad randomness, the compression algorithms or compressors are not suitable as random number generator. We also found that, for the same compression algorithm, there exists positive correlation relationship between compression ratio and randomness, increasing the compression ratio increases randomness of compressed data. As time permits, additional randomness testing efforts will be conducted.

  2. TEM Video Compressive Sensing

    Stevens, Andrew J.; Kovarik, Libor; Abellan, Patricia; Yuan, Xin; Carin, Lawrence; Browning, Nigel D.


    One of the main limitations of imaging at high spatial and temporal resolution during in-situ TEM experiments is the frame rate of the camera being used to image the dynamic process. While the recent development of direct detectors has provided the hardware to achieve frame rates approaching 0.1ms, the cameras are expensive and must replace existing detectors. In this paper, we examine the use of coded aperture compressive sensing methods [1, 2, 3, 4] to increase the framerate of any camera with simple, low-cost hardware modifications. The coded aperture approach allows multiple sub-frames to be coded and integrated into a single camera frame during the acquisition process, and then extracted upon readout using statistical compressive sensing inversion. Our simulations show that it should be possible to increase the speed of any camera by at least an order of magnitude. Compressive Sensing (CS) combines sensing and compression in one operation, and thus provides an approach that could further improve the temporal resolution while correspondingly reducing the electron dose rate. Because the signal is measured in a compressive manner, fewer total measurements are required. When applied to TEM video capture, compressive imaging couled improve acquisition speed and reduce the electron dose rate. CS is a recent concept, and has come to the forefront due the seminal work of Candès [5]. Since the publication of Candès, there has been enormous growth in the application of CS and development of CS variants. For electron microscopy applications, the concept of CS has also been recently applied to electron tomography [6], and reduction of electron dose in scanning transmission electron microscopy (STEM) imaging [7]. To demonstrate the applicability of coded aperture CS video reconstruction for atomic level imaging, we simulate compressive sensing on observations of Pd nanoparticles and Ag nanoparticles during exposure to high temperatures and other environmental

  3. Equilibrium states of homogeneous sheared compressible turbulence

    Riahi, M.; Lili, T.


    Equilibrium states of homogeneous compressible turbulence subjected to rapid shear is studied using rapid distortion theory (RDT). The purpose of this study is to determine the numerical solutions of unsteady linearized equations governing double correlations spectra evolution. In this work, RDT code developed by authors solves these equations for compressible homogeneous shear flows. Numerical integration of these equations is carried out using a second-order simple and accurate scheme. The two Mach numbers relevant to homogeneous shear flow are the turbulent Mach number Mt, given by the root mean square turbulent velocity fluctuations divided by the speed of sound, and the gradient Mach number Mg which is the mean shear rate times the transverse integral scale of the turbulence divided by the speed of sound. Validation of this code is performed by comparing RDT results with direct numerical simulation (DNS) of [A. Simone, G.N. Coleman, and C. Cambon, Fluid Mech. 330, 307 (1997)] and [S. Sarkar, J. Fluid Mech. 282, 163 (1995)] for various values of initial gradient Mach number Mg0. It was found that RDT is valid for small values of the non-dimensional times St (St 10) in particular for large values of Mg0. This essential feature justifies the resort to RDT in order to determine equilibrium states in the compressible regime.

  4. Equilibrium states of homogeneous sheared compressible turbulence

    M. Riahi


    Full Text Available Equilibrium states of homogeneous compressible turbulence subjected to rapid shear is studied using rapid distortion theory (RDT. The purpose of this study is to determine the numerical solutions of unsteady linearized equations governing double correlations spectra evolution. In this work, RDT code developed by authors solves these equations for compressible homogeneous shear flows. Numerical integration of these equations is carried out using a second-order simple and accurate scheme. The two Mach numbers relevant to homogeneous shear flow are the turbulent Mach number Mt, given by the root mean square turbulent velocity fluctuations divided by the speed of sound, and the gradient Mach number Mg which is the mean shear rate times the transverse integral scale of the turbulence divided by the speed of sound. Validation of this code is performed by comparing RDT results with direct numerical simulation (DNS of [A. Simone, G.N. Coleman, and C. Cambon, Fluid Mech. 330, 307 (1997] and [S. Sarkar, J. Fluid Mech. 282, 163 (1995] for various values of initial gradient Mach number Mg0. It was found that RDT is valid for small values of the non-dimensional times St (St 10 in particular for large values of Mg0. This essential feature justifies the resort to RDT in order to determine equilibrium states in the compressible regime.

  5. Tree compression with top trees

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


    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...

  6. Tree compression with top trees

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


    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...

  7. Tree compression with top trees

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


    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...

  8. Reinterpreting Compression in Infinitary Rewriting

    Ketema, J.; Tiwari, Ashish


    Departing from a computational interpretation of compression in infinitary rewriting, we view compression as a degenerate case of standardisation. The change in perspective comes about via two observations: (a) no compression property can be recovered for non-left-linear systems and (b) some standar

  9. Lossless Compression of Broadcast Video

    Martins, Bo; Eriksen, N.; Faber, E.


    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...

  10. An epidemiological study on pattern of thoraco-abdominal injuries sustained in fatal road traffic accidents of Bangalore: Autopsy-based study.

    Reddy, N Bayapa; Hanumantha; Madithati, Pallavi; Reddy, N Nagarjuna; Reddy, C Sainarasimha


    The statistical profile reflects a global estimate of 5.1 million deaths in 2000, which was due to injuries that accounted for 10% of deaths due to all causes. Out of this, a quarter of injury-related deaths occurred in the South-East Asian region. Road Traffic Accident (RTA) is one among the top 5 causes of morbidity and mortality in South-East Asian countries. Most common cause of blunt abdominal trauma in India is road traffic accident followed by pedestrian accidents, abdominal blows, and fall from heights. To analyze the epidemiology and pattern of fatal thoraco-abdominal injuries in road traffic accidents. An autopsy-based cross-sectional study conducted. A purposive sampling technique was applied to select the study sample of 100 post-mortems of road traffic accident between November 2008 and May 2010 subjected to medico-legal autopsy at the department of Forensic Medicine, KIMS Hospital Bangalore. The majority of the victims were aged 21 to 40 years, 50 (50.0%), most of the victims were male 92 (92.0%); and male/female ratio was 11.5:1. Commonest offending agents in heavy motor vehicles were 54 (54.0%). Bony cage sustained injuries were observed in 71; out of this, fractures of ribs were observed in 45 (63.3%) victims, clavicle in 14 (19.7%), sternum was 6 (8.4%), and vertebrae 6 (8.4%) of fatal road traffic accidents. Internal thoracic injuries were observed in 26 cases. Among internal thoracic injuries, lungs were the most commonly involved organ 24 (92.3%) followed by the heart 2 (7.6%). Lung sustained more lacerations 19 (79.1%) than contusions 5 (20.8%). Internal abdominal injuries were observed in 49 cases. In road traffic accidents, the most commonly injured abdominal organs were solid organs such as liver 16 (32.6%) followed by spleen 9 (18.3%). Majority of the times in road traffic accidents, young and productive males were injured or lost their life. This study may help the planners to take safety measures, to implement strict traffic rules, to

  11. A Novel Off-the-Shelf Technique for Endovascular Repair of Type III and IV Thoracoabdominal Aortic Aneurysms Using the Gore Excluder and Viabahn Branches.

    Wooster, Mathew; Tanious, Adam; Jones, R Wesley; Armstrong, Paul; Shames, Murray


    The aim of this study is to describe the use of a novel off-the-shelf technique to repair type III and type IV thoracoabdominal aortic aneurysms (TAAAs) in the absence of available prefabricated branched devices. All patients undergoing endovascular repair of type III and IV TAAAs using this technique were included from a prospectively maintained registry at a regional aortic referral center. The proximal bifurcated Gore C3 Excluder device is positioned in the descending thoracic aorta with the contralateral gate 2-3 cm above the celiac artery. From an axillary approach, the contralateral gate renovisceral branches are sequentially cannulated and simultaneously stented using Viabahn covered stents. In cases were the celiac artery could not be excluded, a parallel stent (snorkel) was added adjacent to the proximal endograft. All branches are simultaneously balloon dilated to ensure proximal gutter seal in the contralateral gate. Via the ipsilateral limb, the device can then be extended with a flared iliac extension and/or additional bifurcated device to obtain seal in the distal aorta (previous open repair) or common iliac arteries. Eight patients (male = 6, mean 78 years of age) were treated in this manner since January 2015. All patients underwent repair using Gore C3 device with 3 (n = 5) or 4 (n = 3) renovisceral branches. The celiac artery was sacrificed in 4 patients and 1 renal artery in 1 patient. Mean fluoroscopy time was 88.7 min with a mean of 92.3 cc contrast utilized. Median length of stay was 7 days with 3 days spent in the intensive care unit. No major cardiac, respiratory, renal, neurologic, or wound complications occurred. Three patients had early endoleaks treated with additional endovascular techniques (n = 2) or open surgical ligation (n = 1) during the index hospitalization. Two late endoleaks were identified; 1 type II with stable sac size and 1 type III requiring iliac limb relining. All limbs and branches remain patent at the

  12. Visceral hybrid reconstruction of thoracoabdominal aortic aneurysm after open repair of type a aortic dissection by the Bentall procedure with the elephant trunk technique: A case report

    Marjanović Ivan


    Full Text Available Introduction. Reconstruction of chronic type B dissection and thoracoabdominal aortic aneurysm (TAAA remaining after the emergency reconstruction of the ascending thoracic aorta and aortic arch for acute type A dissection represents one of the major surgical challenges. Complications of chronic type B dissection are aneurysmal formation and rupture of an aortic aneurysm with a high mortality rate. We presented a case of visceral hybrid reconstruction of TAAA secondary to chronic dissection type B after the Bentall procedure with the elephant trunk technique due to acute type A aortic dissection in a high-risk patient. Case report. A 62 year-old woman was admitted to our institution for reconstruction of Crawford type I TAAA secondary to chronic dissection. The patient had had an acute type A aortic dissection 3 years before and undergone reconstruction by the Bentall procedure with the elephant trunk technique with valve replacement. On admission the patient had coronary artery disease (myocardial infarction, two times in the past 3 years, congestive heart disease with ejection fraction of 25% and chronic obstructive pulmonary disease. On computed tomography (CT of the aorta TAAA was revealed with a maximum diameter of 93 mm in the descending thoracic aorta secondary to chronic dissection. All the visceral arteries originated from the true lumen with exception of the celiac artery (CA, and the end of chronic dissection was below the origin of the superior mesenteric artery (SMA. The patient was operated on using surgical visceral reconstruction of the SMA, CA and the right renal artery (RRA as the first procedure. Postoperative course was without complications. Endovascular TAAA reconstruction was performed as the second procedure one month later, when the elephant trunk was used as the proximal landing zone for the endograft, and distal landing zone was the level of origin of the RRA. Postoperatively, the patient had no neurological deficit and

  13. Double jeopardy revisited: clinical decision making in unstable patients with, thoraco-abdominal stab wounds and, potential injuries in multiple body cavities.

    Clarke, Damian L; Gall, Tamara M H; Thomson, Sandie R


    In the setting of the hypovolaemic patient with a thoraco-abdominal stab wound and potential injuries in both the chest and abdomen, deciding which cavity to explore first may be difficult.Opening the incorrect body cavity can delay control of tamponade or haemorrhage and exacerbate hypothermia and fluid shifts. This situation has been described as one of double jeopardy. All stab victims from July 2007 to July 2009 requiring a thoracotomy and laparotomy at the same operation were identified from a database. Demographics, site and nature of injuries, admission observations and investigations as well as operative sequence were recorded. Correct sequencing was defined as first opening the cavity with most lethal injury. Incorrect sequencing was defined as opening a cavity and finding either no injury or an injury of less severity than a simultaneous injury in the unopened cavity. The primary outcome was survival or death. Sixteen stab victims underwent thoracotomy and laparotomy during the same operation. All were male with an age range of 18–40 (mean/median 27). Median systolic blood pressure on presentation was 90 mm Hg. (quartile range 80–90 mm Hg). Median base excess was 6.5 (quartile range 12 to 2.2). All the deaths were the result of cardiac injuries. Incorrect sequencing occurred in four patients (25%). In this group there were four negative abdominal explorations prior to thoracotomy with two deaths. There was one death in the correct sequencing group. Incorrect sequencing in stab victims who require both thoracotomy and laparotomy at the same sitting is associated with a high mortality. This is especially true when the abdomen is incorrectly entered first whilst the life threatening pathology is in the chest. Clinical signs may be confusing, leading to incorrect sequencing of exploration. The common causes for confusion include failure to appreciate that cardiac tamponade does not present with bleeding and difficulty in assessing peritonism in an

  14. An epidemiological study on pattern of thoraco-abdominal injuries sustained in fatal road traffic accidents of Bangalore: Autopsy-based study

    N Bayapa Reddy


    Full Text Available Background: The statistical profile reflects a global estimate of 5.1 million deaths in 2000, which was due to injuries that accounted for 10% of deaths due to all causes. Out of this, a quarter of injury-related deaths occurred in the South-East Asian region. Road Traffic Accident (RTA is one among the top 5 causes of morbidity and mortality in South-East Asian countries. Most common cause of blunt abdominal trauma in India is road traffic accident followed by pedestrian accidents, abdominal blows, and fall from heights. Aims: To analyze the epidemiology and pattern of fatal thoraco-abdominal injuries in road traffic accidents. Materials and Methods: An autopsy-based cross-sectional study conducted. A purposive sampling technique was applied to select the study sample of 100 post-mortems of road traffic accident between November 2008 and May 2010 subjected to medico-legal autopsy at the department of Forensic Medicine, KIMS Hospital Bangalore. Results: The majority of the victims were aged 21 to 40 years, 50 (50.0%, most of the victims were male 92 (92.0%; and male/female ratio was 11.5:1. Commonest offending agents in heavy motor vehicles were 54 (54.0%. Bony cage sustained injuries were observed in 71; out of this, fractures of ribs were observed in 45 (63.3% victims, clavicle in 14 (19.7%, sternum was 6 (8.4%, and vertebrae 6 (8.4% of fatal road traffic accidents. Internal thoracic injuries were observed in 26 cases. Among internal thoracic injuries, lungs were the most commonly involved organ 24 (92.3% followed by the heart 2 (7.6%. Lung sustained more lacerations 19 (79.1% than contusions 5 (20.8%. Internal abdominal injuries were observed in 49 cases. In road traffic accidents, the most commonly injured abdominal organs were solid organs such as liver 16 (32.6% followed by spleen 9 (18.3%. Conclusions: Majority of the times in road traffic accidents, young and productive males were injured or lost their life. This study may help the

  15. Clinical features and early management of combined thoracoabdominal injury%胸腹联合伤迅速诊断和紧急处理的探讨

    白黎智; 邢嵘; 路小光; 康新; 康利民


    目的 探讨胸腹联合伤的特点,为迅速诊断和及时救治提供参考.方法 回顾性分析经手术证实的胸腹联合伤29例,其中开放性损伤21例,闭合性损伤8例.29例患者均有不同程度的血胸和(或)气胸,其中13例合并休克.经胸部手术17例,开腹手术6例,开胸+开腹5例,胸腹联合切口1例.结果 全组损伤严重度评分(ISS)为(40.16±15.23)分,死亡4例,其中2例死于失血性休克,1例死于心包填塞,1例死于多器官功能衰竭.结论 胸腹联合伤病情严重,病死率高,最常见的死亡原因是失血性休克及呼吸衰竭.抢救及治疗措施应视具体伤情而定,挽救危重患者生命的关键是及早正确的诊断、正确的抢救措施和及时手术.%Objective To evaluate the clinical features and early management of combined thoracoabdominal injury (CTI).Methods A retrospective study was carried out in 29 cases with CTI treated surgically.There were 21 cases with penetrating injuries and 8 cases with blunt injuries.All cases were associated with penumothorax and/or hernothorax at various degrees and 13 cases complicated with shock.In this study thoracotomy was performed in 17 cases,laparotomy in 6 cases,thoracotomy plus laparotomy in 5 cases and combined thoraco-laparotomy in 1 case.Results The injury severity score in this series was (40.16±15.23) scores.Four cases were died from hemorrhagic shock (2 cases),pericardial tampenade(1 case) and multiple organ failure(1 case).Conclusions CTI has high mortality rate,and the most frequent cause of death is hypovolemic shock.The operative approach is based on individual injury condition.Early diagnosis and timely surgical intervention are key to improving the cure rate and reducing mortality in severe CTI.

  16. Building indifferentiable compression functions from the PGV compression functions

    Gauravaram, P.; Bagheri, Nasour; Knudsen, Lars Ramkilde


    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...... cipher is ideal. We address the problem of building indifferentiable compression functions from the PGV compression functions. We consider a general form of 64 PGV compression functions and replace the linear feed-forward operation in this generic PGV compression function with an ideal block cipher...... independent of the one used in the generic PGV construction. This modified construction is called a generic modified PGV (MPGV). We analyse indifferentiability of the generic MPGV construction in the ideal cipher model and show that 12 out of 64 MPGV compression functions in this framework...

  17. Compressive Principal Component Pursuit

    Wright, John; Min, Kerui; Ma, Yi


    We consider the problem of recovering a target matrix that is a superposition of low-rank and sparse components, from a small set of linear measurements. This problem arises in compressed sensing of structured high-dimensional signals such as videos and hyperspectral images, as well as in the analysis of transformation invariant low-rank recovery. We analyze the performance of the natural convex heuristic for solving this problem, under the assumption that measurements are chosen uniformly at random. We prove that this heuristic exactly recovers low-rank and sparse terms, provided the number of observations exceeds the number of intrinsic degrees of freedom of the component signals by a polylogarithmic factor. Our analysis introduces several ideas that may be of independent interest for the more general problem of compressed sensing and decomposing superpositions of multiple structured signals.

  18. On Network Functional Compression

    Feizi, Soheil


    In this paper, we consider different aspects of the network functional compression problem where computation of a function (or, some functions) of sources located at certain nodes in a network is desired at receiver(s). The rate region of this problem has been considered in the literature under certain restrictive assumptions, particularly in terms of the network topology, the functions and the characteristics of the sources. In this paper, we present results that significantly relax these assumptions. Firstly, we consider this problem for an arbitrary tree network and asymptotically lossless computation. We show that, for depth one trees with correlated sources, or for general trees with independent sources, a modularized coding scheme based on graph colorings and Slepian-Wolf compression performs arbitrarily closely to rate lower bounds. For a general tree network with independent sources, optimal computation to be performed at intermediate nodes is derived. We introduce a necessary and sufficient condition...

  19. Hamming Compressed Sensing

    Zhou, Tianyi


    Compressed sensing (CS) and 1-bit CS cannot directly recover quantized signals and require time consuming recovery. In this paper, we introduce \\textit{Hamming compressed sensing} (HCS) that directly recovers a k-bit quantized signal of dimensional $n$ from its 1-bit measurements via invoking $n$ times of Kullback-Leibler divergence based nearest neighbor search. Compared with CS and 1-bit CS, HCS allows the signal to be dense, takes considerably less (linear) recovery time and requires substantially less measurements ($\\mathcal O(\\log n)$). Moreover, HCS recovery can accelerate the subsequent 1-bit CS dequantizer. We study a quantized recovery error bound of HCS for general signals and "HCS+dequantizer" recovery error bound for sparse signals. Extensive numerical simulations verify the appealing accuracy, robustness, efficiency and consistency of HCS.

  20. Compressive Spectral Renormalization Method

    Bayindir, Cihan


    In this paper a novel numerical scheme for finding the sparse self-localized states of a nonlinear system of equations with missing spectral data is introduced. As in the Petviashivili's and the spectral renormalization method, the governing equation is transformed into Fourier domain, but the iterations are performed for far fewer number of spectral components (M) than classical versions of the these methods with higher number of spectral components (N). After the converge criteria is achieved for M components, N component signal is reconstructed from M components by using the l1 minimization technique of the compressive sampling. This method can be named as compressive spectral renormalization (CSRM) method. The main advantage of the CSRM is that, it is capable of finding the sparse self-localized states of the evolution equation(s) with many spectral data missing.

  1. Speech Compression and Synthesis


    phonological rules combined with diphone improved the algorithms used by the phonetic synthesis prog?Im for gain normalization and time... phonetic vocoder, spectral template. i0^Th^TreprtTörc"u’d1sTuV^ork for the past two years on speech compression’and synthesis. Since there was an...from Block 19: speech recognition, pnoneme recogmtion. initial design for a phonetic recognition program. We also recorded ana partially labeled a

  2. Sensitivity of bronchial responsiveness measurements in young infants

    Loland, Lotte; Buchvald, Frederik F; Halkjaer, Liselotte Brydensholt


    of 402 infants (median age, 6 weeks). Forced flow-volume measurements were obtained by the raised volume rapid thoracoabdominal compression technique and were compared with indexes of tidal breathing, measurements of transcutaneous oxygen (Ptco(2)), and auscultation during methacholine challenge testing...

  3. Shock compression of nitrobenzene

    Kozu, Naoshi; Arai, Mitsuru; Tamura, Masamitsu; Fujihisa, Hiroshi; Aoki, Katsutoshi; Yoshida, Masatake; Kondo, Ken-Ichi


    The Hugoniot (4 - 30 GPa) and the isotherm (1 - 7 GPa) of nitrobenzene have been investigated by shock and static compression experiments. Nitrobenzene has the most basic structure of nitro aromatic compounds, which are widely used as energetic materials, but nitrobenzene has been considered not to explode in spite of the fact its calculated heat of detonation is similar to TNT, about 1 kcal/g. Explosive plane-wave generators and diamond anvil cell were used for shock and static compression, respectively. The obtained Hugoniot consists of two linear lines, and the kink exists around 10 GPa. The upper line agrees well with the Hugoniot of detonation products calculated by KHT code, so it is expected that nitrobenzene detonates in that area. Nitrobenzene solidifies under 1 GPa of static compression, and the isotherm of solid nitrobenzene was obtained by X-ray diffraction technique. Comparing the Hugoniot and the isotherm, nitrobenzene is in liquid phase under experimented shock condition. From the expected phase diagram, shocked nitrobenzene seems to remain metastable liquid in solid phase region on that diagram.

  4. Compressed sensing electron tomography

    Leary, Rowan, E-mail: [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Saghi, Zineb; Midgley, Paul A. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Holland, Daniel J. [Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge CB2 3RA (United Kingdom)


    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.

  5. Ultraspectral sounder data compression review

    Bormin HUANG; Hunglung HUANG


    Ultraspectral sounders provide an enormous amount of measurements to advance our knowledge of weather and climate applications. The use of robust data compression techniques will be beneficial for ultraspectral data transfer and archiving. This paper reviews the progress in lossless compression of ultra-spectral sounder data. Various transform-based, pre-diction-based, and clustering-based compression methods are covered. Also studied is a preprocessing scheme for data reordering to improve compression gains. All the coding experiments are performed on the ultraspectral compression benchmark dataset col-lected from the NASA Atmospheric Infrared Sounder (AIRS) observations.

  6. Engineering Relative Compression of Genomes

    Grabowski, Szymon


    Technology progress in DNA sequencing boosts the genomic database growth at faster and faster rate. Compression, accompanied with random access capabilities, is the key to maintain those huge amounts of data. In this paper we present an LZ77-style compression scheme for relative compression of multiple genomes of the same species. While the solution bears similarity to known algorithms, it offers significantly higher compression ratios at compression speed over a order of magnitude greater. One of the new successful ideas is augmenting the reference sequence with phrases from the other sequences, making more LZ-matches available.

  7. Padrão respiratório e movimento toracoabdominal de crianças respiradoras orais Breathing pattern and thoracoabdominal motion in mouth-breathing children

    TCS Brant


    Full Text Available OBJETIVO: Caracterizar o padrão respiratório e o movimento toracoabdominal de crianças respiradoras orais, na faixa etária entre oito e dez anos, e compará-lo ao de seus pares respiradoras nasais. MÉTODOS: Estudo observacional realizado em laboratório universitário. O número amostral calculado com base em um estudo piloto com dez crianças em cada grupo, perfazendo um total de 20 crianças, foi de 50 para um nível de significância de 0,05 e um poder estatístico de 0,80. Participaram do estudo 26 crianças respiradoras orais e 25 respiradoras nasais. A pletismografia respiratória por indutância calibrada foi o instrumento utilizado para a análise das seguintes variáveis, entre outras: freqüência respiratória (FR, contribuição da caixa torácica para o volume corrente (%CT/Vc, ângulo de fase (Angfase e a razão entre o tempo para alcançar o pico de fluxo inspiratório e o tempo inspiratório (PifT/Ti. A saturação periférica da hemoglobia em oxigênio (SpO2 foi medida pela oximetria de pulso. A análise estatística foi realizada por meio do teste t de Student para grupos independentes e do teste U de Mann-Whitney, em função da distribuição das variáveis. RESULTADOS: No total, 4.816 ciclos respiratórios foram analisados, sendo 2.455 de respiradores orais e 2.361 de respiradores nasais, com média de 94 ciclos por criança. Não houve diferença significativa entre os grupos nas variáveis estudadas (FR=20,00±2,68 versus 20,73±2,58, p=0,169; %CT/Vc=39,30±11,86 versus 38,36±10,93, p=0,769; Angfase=14,53±7,97 versus 13,31±7,74, p=0,583; PifT/Ti=57,40±7,16 versus 58,35±5,99, p=0,610; SpO2=96,42±1,52% versus 96,88±1,01%, p=0,208; respectivamente. CONCLUSÕES: Estes resultados sugerem que as crianças respiradoras orais apresentam padrão respiratório e movimento toracoabdominal semelhantes às de respiradores nasais de mesma faixa etária.OBJECTIVE: To characterize the breathing pattern and thoracoabdominal

  8. Damage control surgery for severe thoracoabdominal injuries dominated by abdominal trauma%损伤控制手术在以腹部损伤为主的严重胸腹联合伤中的应用

    周正武; 韩圣瑾; 丁锐; 吴文涛


    目的:探讨损伤控制手术(DCO)在治疗以腹部损伤为主的严重胸腹联合伤中的应用.方法:回顾性分析2008年3月-2011年6月收治的71例严重胸腹联合伤患者的临床资料,其中,行损伤控制手术41例,另外30例患者行一期确定性手术.结果:损伤控制手术组患者复苏后乳酸水平,pH值,体温,凝血酶原时间(PT)与一期确定性手术组的患者无统计学差异(均P>0.05).71例患者均治愈后安全出院,但损伤控制手术组患者粘连性肠梗阻、感染的发生率明显低于一期确定性手术组(均P<0.05).结论:在正确掌握适应证的前提下,损伤控制性手术对于严重胸腹部损伤患者是理想的治疗策略.%Objective: To investigate the utilization of damage control operation (DCO) in treatment of the severe thoracoabdominal injuries dominated by abdominal trauma.Methods: The clinical data of 71 patients with severe thoracoabdominal wounds admitted from March 2008 to June 2011 were retrospectively analyzed. Of the patients, 41 cases received DCO procedure, and another 30 cases underwent primary definitive surgery.Results: There were no significant differences in the lactate levels, pH value, body temperature, and prothrombin time (PT) between the DCO patients after resuscitation and patients undergoing primary definitive surgery (all P>0.05). All of the 71 patients were cured and discharged from hospital, while the patients receiving DCO had significantly lower incidence of adhesive ileus and infection compared with those undergoing primary definitive surgery (both P<0.05).Conclusion: DCO is a better treatment strategy for patients with severe thoracoabdominal injuries under the condition of a correct understanding of its indications.

  9. Accurate Element of Compressive Bar considering the Effect of Displacement

    Lifeng Tang


    Full Text Available By constructing the compressive bar element and developing the stiffness matrix, most issues about the compressive bar can be solved. In this paper, based on second derivative to the equilibrium differential governing equations, the displacement shape functions are got. And then the finite element formula of compressive bar element is developed by using the potential energy principle and analytical shape function. Based on the total potential energy variation principle, the static and geometrical stiffness matrices are proposed, in which the large deformation of compressive bar is considered. To verify the accurate and validity of the analytical trial function element proposed in this paper, a number of the numerical examples are presented. Comparisons show that the proposed element has high calculation efficiency and rapid speed of convergence.

  10. The compression of liquids

    Whalley, E.

    The compression of liquids can be measured either directly by applying a pressure and noting the volume change, or indirectly, by measuring the magnitude of the fluctuations of the local volume. The methods used in Ottawa for the direct measurement of the compression are reviewed. The mean-square deviation of the volume from the mean at constant temperature can be measured by X-ray and neutron scattering at low angles, and the meansquare deviation at constant entropy can be measured by measuring the speed of sound. The speed of sound can be measured either acoustically, using an acoustic transducer, or by Brillouin spectroscopy. Brillouin spectroscopy can also be used to study the shear waves in liquids if the shear relaxation time is > ∼ 10 ps. The relaxation time of water is too short for the shear waves to be studied in this way, but they do occur in the low-frequency Raman and infrared spectra. The response of the structure of liquids to pressure can be studied by neutron scattering, and recently experiments have been done at Atomic Energy of Canada Ltd, Chalk River, on liquid D 2O up to 15.6 kbar. They show that the near-neighbor intermolecular O-D and D-D distances are less spread out and at shorter distances at high pressure. Raman spectroscopy can also provide information on the structural response. It seems that the O-O distance in water decreases much less with pressure than it does in ice. Presumably, the bending of O-O-O angles tends to increase the O-O distance, and so to largely compensate the compression due to the direct effect of pressure.

  11. Compressive Transient Imaging

    Sun, Qilin


    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.

  12. Statistical Mechanical Analysis of Compressed Sensing Utilizing Correlated Compression Matrix

    Takeda, Koujin


    We investigate a reconstruction limit of compressed sensing for a reconstruction scheme based on the L1-norm minimization utilizing a correlated compression matrix with a statistical mechanics method. We focus on the compression matrix modeled as the Kronecker-type random matrix studied in research on multi-input multi-output wireless communication systems. We found that strong one-dimensional correlations between expansion bases of original information slightly degrade reconstruction performance.

  13. Cold compression residual stress reduction in aluminium alloy 7010

    Tanner, D.A. [Limerick Univ. (Ireland). Materials Research Centre; Robinson, J.S. [Dept. of Materials Science and Technology, Univ. of Limerick (Ireland); Cudd, R.L. [HDA Forgings Ltd., Redditch, Worchestershire (United Kingdom)


    7010 is one of the high strength aluminium alloys used mainly as plate and forgings in the aerospace industry. Its high strength is achieved through a quenching operation where the material is rapidly cooled from the solution heat treatment temperature (475 C) to room temperature. As with all rapid quenching operations, residual stresses develop, leaving the material unsuitable for further machining operations and for service. Regular shaped forgings are generally cold compressed after quenching to relieve residual stresses. The effect of friction, increasing/decreasing the amount of cold compression and applying cold compression in 'bites' on residual stress magnitudes is unknown. This paper aims to study the effect that these variables have on final residual stress patterns through use of a finite element model. (orig.)

  14. Compressive full waveform lidar

    Yang, Weiyi; Ke, Jun


    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.

  15. Metal Hydride Compression

    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)


    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

  16. Beamforming using compressive sensing.

    Edelmann, Geoffrey F; Gaumond, Charles F


    Compressive sensing (CS) is compared with conventional beamforming using horizontal beamforming of at-sea, towed-array data. They are compared qualitatively using bearing time records and quantitatively using signal-to-interference ratio. Qualitatively, CS exhibits lower levels of background interference than conventional beamforming. Furthermore, bearing time records show increasing, but tolerable, levels of background interference when the number of elements is decreased. For the full array, CS generates signal-to-interference ratio of 12 dB, but conventional beamforming only 8 dB. The superiority of CS over conventional beamforming is much more pronounced with undersampling.

  17. Saccadic compression of symbolic numerical magnitude.

    Paola Binda

    Full Text Available Stimuli flashed briefly around the time of saccadic eye movements are subject to complex distortions: compression of space and time; underestimate of numerosity. Here we show that saccadic distortions extend to abstract quantities, affecting the representation of symbolic numerical magnitude. Subjects consistently underestimated the results of rapidly computed mental additions and subtractions, when the operands were briefly displayed before a saccade. However, the recognition of the number symbols was unimpaired. These results are consistent with the hypothesis of a common, abstract metric encoding magnitude along multiple dimensions. They suggest that a surprising link exists between the preparation of action and the representation of abstract quantities.

  18. Simulation of inviscid compressible multi-phase flow with condensation

    Kelleners, P.H.


    Condensation of vapours in rapid expansions of compressible gases is investigated. In the case of high temperature gradients the condensation will start at conditions well away from thermodynamic equilibrium of the fluid. In those cases homogeneous condensation is dominant over heterogeneous

  19. Cirurgia da aorta descendente e tóraco-abdominal com técnica de oclusão proximal isolada da aorta ("open distal" Surgical treatment of descending thoracic and thoracoabdominal aorta with the "open distal" technique

    Bayard Gontijo Filho


    Full Text Available O presente relato apresenta a experiência obtida em um período de 4 anos (jan/91 - jan/95 com a técnica "open distal" descrita por Cooley, em 1990³, para tratamento cirúrgico de doenças da aorta torácica descendente e aorta tóraco-abdominal. Nesse período foram realizadas 35 operações (25 para aorta descendente e 10 para aorta tóraco-abdominal. Os aneurismas de origem degenerativa e as dissecções aórticas ocorreram em freqüência semelhante (48,5% e 40%, respectivamente; em 8 pacientes havia rotura da aorta, parcialmente tamponada pelo pulmão (5 casos, órgãos abdominais (2 casos e esófago (1 caso. O acesso cirúrgico foi obtido por toracotomia póstero-lateral esquerda ou tóraco-freno-laparotomia. Heparina foi usada na dose de 1,5 mg/kg e todo sangue do campo cirúrgico foi coletado a um reservatório e reinfundido pela veia femoral. Houve 4 (11.4% óbitos hospitalares e 2 (5,8% pacientes portadores de aneurisma tóraco-abdominal desenvolveram paraplegia. A morbi-mortalidade do grupo foi diretamente relacionada à condição clínica per-operatória e à extensão do segmento aórtico acometido. Na nossa opinião, a técnica "open distal" é um método alternativo simples e eficaz no tratamento cirúrgico das doenças da aorta descendente e tóraco-abdominal. Em casos de ressecções extensas com períodos longos de oclusão aórtica, métodos para proteção medular deverão ser avaliadosSince Jan/91 we have been using the "open distal" technique (ODT described by Cooley, for surgical treatment of diseases of the descending thoracic and thoracoabdominal aorta. From jan/91 to jan/95, the technique was used in 35 instances (25 for descending aorta and 10 for thoracoabdominal aorta. Degenerative aneurysms and aortic dissections had similar incidence in this group (48.5% and 40.0%, respectively. In 8 patients the aorta was ruptured which was partially occluded by the lung (5 cases, abdominal organs (2 cases and esophagus (1

  20. Compressive sensing in medical imaging.

    Graff, Christian G; Sidky, Emil Y


    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.

  1. Speech Compression Using Multecirculerletet Transform

    Sulaiman Murtadha


    Full Text Available Compressing the speech reduces the data storage requirements, leading to reducing the time of transmitting the digitized speech over long-haul links like internet. To obtain best performance in speech compression, wavelet transforms require filters that combine a number of desirable properties, such as orthogonality and symmetry.The MCT bases functions are derived from GHM bases function using 2D linear convolution .The fast computation algorithm methods introduced here added desirable features to the current transform. We further assess the performance of the MCT in speech compression application. This paper discusses the effect of using DWT and MCT (one and two dimension on speech compression. DWT and MCT performances in terms of compression ratio (CR, mean square error (MSE and peak signal to noise ratio (PSNR are assessed. Computer simulation results indicate that the two dimensions MCT offer a better compression ratio, MSE and PSNR than DWT.

  2. libpolycomp: Compression/decompression library

    Tomasi, Maurizio


    Libpolycomp compresses and decompresses one-dimensional streams of numbers by means of several algorithms. It is well-suited for time-ordered data acquired by astronomical instruments or simulations. One of the algorithms, called "polynomial compression", combines two widely-used ideas (namely, polynomial approximation and filtering of Fourier series) to achieve substantial compression ratios for datasets characterized by smoothness and lack of noise. Notable examples are the ephemerides of astronomical objects and the pointing information of astronomical telescopes. Other algorithms implemented in this C library are well known and already widely used, e.g., RLE, quantization, deflate (via libz) and Burrows-Wheeler transform (via libbzip2). Libpolycomp can compress the timelines acquired by the Planck/LFI instrument with an overall compression ratio of ~9, while other widely known programs (gzip, bzip2) reach compression ratios less than 1.5.

  3. Image Compression using GSOM Algorithm



    Full Text Available compression. Conventional techniques such as Huffman coding and the Shannon Fano method, LZ Method, Run Length Method, LZ-77 are more recent methods for the compression of data. A traditional approach to reduce the large amount of data would be to discard some data redundancy and introduce some noise after reconstruction. We present a neural network based Growing self-organizing map technique that may be a reliable and efficient way to achieve vector quantization. Typical application of such algorithm is image compression. Moreover, Kohonen networks realize a mapping between an input and an output space that preserves topology. This feature can be used to build new compression schemes which allow obtaining better compression rate than with classical method as JPEG without reducing the image quality .the experiment result show that proposed algorithm improve the compression ratio in BMP, JPG and TIFF File.

  4. Data compression on the sphere

    McEwen, J D; Eyers, D M; 10.1051/0004-6361/201015728


    Large data-sets defined on the sphere arise in many fields. In particular, recent and forthcoming observations of the anisotropies of the cosmic microwave background (CMB) made on the celestial sphere contain approximately three and fifty mega-pixels respectively. The compression of such data is therefore becoming increasingly important. We develop algorithms to compress data defined on the sphere. A Haar wavelet transform on the sphere is used as an energy compression stage to reduce the entropy of the data, followed by Huffman and run-length encoding stages. Lossless and lossy compression algorithms are developed. We evaluate compression performance on simulated CMB data, Earth topography data and environmental illumination maps used in computer graphics. The CMB data can be compressed to approximately 40% of its original size for essentially no loss to the cosmological information content of the data, and to approximately 20% if a small cosmological information loss is tolerated. For the topographic and il...

  5. Energy transfer in compressible turbulence

    Bataille, Francoise; Zhou, YE; Bertoglio, Jean-Pierre


    This letter investigates the compressible energy transfer process. We extend a methodology developed originally for incompressible turbulence and use databases from numerical simulations of a weak compressible turbulence based on Eddy-Damped-Quasi-Normal-Markovian (EDQNM) closure. In order to analyze the compressible mode directly, the well known Helmholtz decomposition is used. While the compressible component has very little influence on the solenoidal part, we found that almost all of the compressible turbulence energy is received from its solenoidal counterpart. We focus on the most fundamental building block of the energy transfer process, the triadic interactions. This analysis leads us to conclude that, at low turbulent Mach number, the compressible energy transfer process is dominated by a local radiative transfer (absorption) in both inertial and energy containing ranges.

  6. Compressive Sensing DNA Microarrays

    Richard G. Baraniuk


    Full Text Available Compressive sensing microarrays (CSMs are DNA-based sensors that operate using group testing and compressive sensing (CS principles. In contrast to conventional DNA microarrays, in which each genetic sensor is designed to respond to a single target, in a CSM, each sensor responds to a set of targets. We study the problem of designing CSMs that simultaneously account for both the constraints from CS theory and the biochemistry of probe-target DNA hybridization. An appropriate cross-hybridization model is proposed for CSMs, and several methods are developed for probe design and CS signal recovery based on the new model. Lab experiments suggest that in order to achieve accurate hybridization profiling, consensus probe sequences are required to have sequence homology of at least 80% with all targets to be detected. Furthermore, out-of-equilibrium datasets are usually as accurate as those obtained from equilibrium conditions. Consequently, one can use CSMs in applications in which only short hybridization times are allowed.

  7. Compressive light field sensing.

    Babacan, S Derin; Ansorge, Reto; Luessi, Martin; Matarán, Pablo Ruiz; Molina, Rafael; Katsaggelos, Aggelos K


    We propose a novel design for light field image acquisition based on compressive sensing principles. By placing a randomly coded mask at the aperture of a camera, incoherent measurements of the light passing through different parts of the lens are encoded in the captured images. Each captured image is a random linear combination of different angular views of a scene. The encoded images are then used to recover the original light field image via a novel Bayesian reconstruction algorithm. Using the principles of compressive sensing, we show that light field images with a large number of angular views can be recovered from only a few acquisitions. Moreover, the proposed acquisition and recovery method provides light field images with high spatial resolution and signal-to-noise-ratio, and therefore is not affected by limitations common to existing light field camera designs. We present a prototype camera design based on the proposed framework by modifying a regular digital camera. Finally, we demonstrate the effectiveness of the proposed system using experimental results with both synthetic and real images.

  8. Splines in Compressed Sensing

    S. Abhishek


    Full Text Available It is well understood that in any data acquisition system reduction in the amount of data reduces the time and energy, but the major trade-off here is the quality of outcome normally, lesser the amount of data sensed, lower the quality. Compressed Sensing (CS allows a solution, for sampling below the Nyquist rate. The challenging problem of increasing the reconstruction quality with less number of samples from an unprocessed data set is addressed here by the use of representative coordinate selected from different orders of splines. We have made a detailed comparison with 10 orthogonal and 6 biorthogonal wavelets with two sets of data from MIT Arrhythmia database and our results prove that the Spline coordinates work better than the wavelets. The generation of two new types of splines such as exponential and double exponential are also briefed here .We believe that this is one of the very first attempts made in Compressed Sensing based ECG reconstruction problems using raw data.  

  9. q-ary compressive sensing

    Mroueh, Youssef; Rosasco, Lorenzo


    We introduce q-ary compressive sensing, an extension of 1-bit compressive sensing. We propose a novel sensing mechanism and a corresponding recovery procedure. The recovery properties of the proposed approach are analyzed both theoretically and empirically. Results in 1-bit compressive sensing are recovered as a special case. Our theoretical results suggest a tradeoff between the quantization parameter q, and the number of measurements m in the control of the error of the resulting recovery a...

  10. Introduction to compressible fluid flow

    Oosthuizen, Patrick H


    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

  11. Compressive sensing of sparse tensors.

    Friedland, Shmuel; Li, Qun; Schonfeld, Dan


    Compressive sensing (CS) has triggered an enormous research activity since its first appearance. CS exploits the signal's sparsity or compressibility in a particular domain and integrates data compression and acquisition, thus allowing exact reconstruction through relatively few nonadaptive linear measurements. While conventional CS theory relies on data representation in the form of vectors, many data types in various applications, such as color imaging, video sequences, and multisensor networks, are intrinsically represented by higher order tensors. Application of CS to higher order data representation is typically performed by conversion of the data to very long vectors that must be measured using very large sampling matrices, thus imposing a huge computational and memory burden. In this paper, we propose generalized tensor compressive sensing (GTCS)-a unified framework for CS of higher order tensors, which preserves the intrinsic structure of tensor data with reduced computational complexity at reconstruction. GTCS offers an efficient means for representation of multidimensional data by providing simultaneous acquisition and compression from all tensor modes. In addition, we propound two reconstruction procedures, a serial method and a parallelizable method. We then compare the performance of the proposed method with Kronecker compressive sensing (KCS) and multiway compressive sensing (MWCS). We demonstrate experimentally that GTCS outperforms KCS and MWCS in terms of both reconstruction accuracy (within a range of compression ratios) and processing speed. The major disadvantage of our methods (and of MWCS as well) is that the compression ratios may be worse than that offered by KCS.

  12. Uncommon upper extremity compression neuropathies.

    Knutsen, Elisa J; Calfee, Ryan P


    Hand surgeons routinely treat carpal and cubital tunnel syndromes, which are the most common upper extremity nerve compression syndromes. However, more infrequent nerve compression syndromes of the upper extremity may be encountered. Because they are unusual, the diagnosis of these nerve compression syndromes is often missed or delayed. This article reviews the causes, proposed treatments, and surgical outcomes for syndromes involving compression of the posterior interosseous nerve, the superficial branch of the radial nerve, the ulnar nerve at the wrist, and the median nerve proximal to the wrist. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Image Compression Algorithms Using Dct

    Er. Abhishek Kaushik


    Full Text Available Image compression is the application of Data compression on digital images. The discrete cosine transform (DCT is a technique for converting a signal into elementary frequency components. It is widely used in image compression. Here we develop some simple functions to compute the DCT and to compress images. An image compression algorithm was comprehended using Matlab code, and modified to perform better when implemented in hardware description language. The IMAP block and IMAQ block of MATLAB was used to analyse and study the results of Image Compression using DCT and varying co-efficients for compression were developed to show the resulting image and error image from the original images. Image Compression is studied using 2-D discrete Cosine Transform. The original image is transformed in 8-by-8 blocks and then inverse transformed in 8-by-8 blocks to create the reconstructed image. The inverse DCT would be performed using the subset of DCT coefficients. The error image (the difference between the original and reconstructed image would be displayed. Error value for every image would be calculated over various values of DCT co-efficients as selected by the user and would be displayed in the end to detect the accuracy and compression in the resulting image and resulting performance parameter would be indicated in terms of MSE , i.e. Mean Square Error.

  14. TPC data compression

    Berger, Jens; Frankenfeld, Ulrich; Lindenstruth, Volker; Plamper, Patrick; Roehrich, Dieter; Schaefer, Erich; W. Schulz, Markus; M. Steinbeck, Timm; Stock, Reinhard; Sulimma, Kolja; Vestboe, Anders; Wiebalck, Arne E-mail:


    In the collisions of ultra-relativistic heavy ions in fixed-target and collider experiments, multiplicities of several ten thousand charged particles are generated. The main devices for tracking and particle identification are large-volume tracking detectors (TPCs) producing raw event sizes in excess of 100 Mbytes per event. With increasing data rates, storage becomes the main limiting factor in such experiments and, therefore, it is essential to represent the data in a way that is as concise as possible. In this paper, we present several compression schemes, such as entropy encoding, modified vector quantization, and data modeling techniques applied on real data from the CERN SPS experiment NA49 and on simulated data from the future CERN LHC experiment ALICE.

  15. TPC data compression

    Berger, Jens; Lindenstruth, Volker; Plamper, Patrick; Röhrich, Dieter; Schafer, Erich; Schulz, M W; Steinbeck, T M; Stock, Reinhard; Sulimma, Kolja; Vestbo, Anders S; Wiebalck, Arne


    In the collisions of ultra-relativistic heavy ions in fixed-target and collider experiments, multiplicities of several ten thousand charged particles are generated. The main devices for tracking and particle identification are large-volume tracking detectors (TPCs) producing raw event sizes in excess of 100 Mbytes per event. With increasing data rates, storage becomes the main limiting factor in such experiments and, therefore, it is essential to represent the data in a way that is as concise as possible. In this paper, we present several compression schemes, such as entropy encoding, modified vector quantization, and data modeling techniques applied on real data from the CERN SPS experiment NA49 and on simulated data from the future CERN LHC experiment ALICE.

  16. TPC data compression

    Berger, Jens; Frankenfeld, Ulrich; Lindenstruth, Volker; Plamper, Patrick; Röhrich, Dieter; Schäfer, Erich; Schulz, Markus W.; Steinbeck, Timm M.; Stock, Reinhard; Sulimma, Kolja; Vestbø, Anders; Wiebalck, Arne


    In the collisions of ultra-relativistic heavy ions in fixed-target and collider experiments, multiplicities of several ten thousand charged particles are generated. The main devices for tracking and particle identification are large-volume tracking detectors (TPCs) producing raw event sizes in excess of 100 Mbytes per event. With increasing data rates, storage becomes the main limiting factor in such experiments and, therefore, it is essential to represent the data in a way that is as concise as possible. In this paper, we present several compression schemes, such as entropy encoding, modified vector quantization, and data modeling techniques applied on real data from the CERN SPS experiment NA49 and on simulated data from the future CERN LHC experiment ALICE.

  17. Waves and compressible flow

    Ockendon, Hilary


    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, ...

  18. Central cooling: compressive chillers

    Christian, J.E.


    Representative cost and performance data are provided in a concise, useable form for three types of compressive liquid packaged chillers: reciprocating, centrifugal, and screw. The data are represented in graphical form as well as in empirical equations. Reciprocating chillers are available from 2.5 to 240 tons with full-load COPs ranging from 2.85 to 3.87. Centrifugal chillers are available from 80 to 2,000 tons with full load COPs ranging from 4.1 to 4.9. Field-assemblied centrifugal chillers have been installed with capacities up to 10,000 tons. Screw-type chillers are available from 100 to 750 tons with full load COPs ranging from 3.3 to 4.5.

  19. Compressive Fatigue in Wood

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


    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...... is observed between stiffness reduction and accumulated creep. A failure model based on the total work during the fatigue life is rejected, and a modified work model based on elastic, viscous and non-recovered viscoelastic work is experimentally supported, and an explanation at a microstructural level...

  20. Compression-based Similarity

    Vitanyi, Paul M B


    First we consider pair-wise distances for literal objects consisting of finite binary files. These files are taken to contain all of their meaning, like genomes or books. The distances are based on compression of the objects concerned, normalized, and can be viewed as similarity distances. Second, we consider pair-wise distances between names of objects, like "red" or "christianity." In this case the distances are based on searches of the Internet. Such a search can be performed by any search engine that returns aggregate page counts. We can extract a code length from the numbers returned, use the same formula as before, and derive a similarity or relative semantics between names for objects. The theory is based on Kolmogorov complexity. We test both similarities extensively experimentally.

  1. Adaptively Compressed Exchange Operator

    Lin, Lin


    The Fock exchange operator plays a central role in modern quantum chemistry. The large computational cost associated with the Fock exchange operator hinders Hartree-Fock calculations and Kohn-Sham density functional theory calculations with hybrid exchange-correlation functionals, even for systems consisting of hundreds of atoms. We develop the adaptively compressed exchange operator (ACE) formulation, which greatly reduces the computational cost associated with the Fock exchange operator without loss of accuracy. The ACE formulation does not depend on the size of the band gap, and thus can be applied to insulating, semiconducting as well as metallic systems. In an iterative framework for solving Hartree-Fock-like systems, the ACE formulation only requires moderate modification of the code, and can be potentially beneficial for all electronic structure software packages involving exchange calculations. Numerical results indicate that the ACE formulation can become advantageous even for small systems with tens...

  2. Adaptive compressive sensing camera

    Hsu, Charles; Hsu, Ming K.; Cha, Jae; Iwamura, Tomo; Landa, Joseph; Nguyen, Charles; Szu, Harold


    We have embedded Adaptive Compressive Sensing (ACS) algorithm on Charge-Coupled-Device (CCD) camera based on the simplest concept that each pixel is a charge bucket, and the charges comes from Einstein photoelectric conversion effect. Applying the manufactory design principle, we only allow altering each working component at a minimum one step. We then simulated what would be such a camera can do for real world persistent surveillance taking into account of diurnal, all weather, and seasonal variations. The data storage has saved immensely, and the order of magnitude of saving is inversely proportional to target angular speed. We did design two new components of CCD camera. Due to the matured CMOS (Complementary metal-oxide-semiconductor) technology, the on-chip Sample and Hold (SAH) circuitry can be designed for a dual Photon Detector (PD) analog circuitry for changedetection that predicts skipping or going forward at a sufficient sampling frame rate. For an admitted frame, there is a purely random sparse matrix [Φ] which is implemented at each bucket pixel level the charge transport bias voltage toward its neighborhood buckets or not, and if not, it goes to the ground drainage. Since the snapshot image is not a video, we could not apply the usual MPEG video compression and Hoffman entropy codec as well as powerful WaveNet Wrapper on sensor level. We shall compare (i) Pre-Processing FFT and a threshold of significant Fourier mode components and inverse FFT to check PSNR; (ii) Post-Processing image recovery will be selectively done by CDT&D adaptive version of linear programming at L1 minimization and L2 similarity. For (ii) we need to determine in new frames selection by SAH circuitry (i) the degree of information (d.o.i) K(t) dictates the purely random linear sparse combination of measurement data a la [Φ]M,N M(t) = K(t) Log N(t).

  3. Developing an artificial neural network model for predicting concrete’s compression strength and electrical resistivity

    Juan Manuel Lizarazo Marriaga


    Full Text Available The present study was conducted for predicting the compressive strength of concrete based on unit weight ultrasonic and pulse velocity (UPV for 41 different concrete mixtures. This research emerged from the need for a rapid test for predicting concrete’s compressive strength. The research was also conducted for predicting concrete’s electrical resistivity based on unit weight ultrasonic, pulse velocity (UPV and compressive strength with the same mixes. The prediction was made using simple regression analysis and artificial neural networks. The results revealed that artificial neural networks can be used for effectively predicting compressive strength and electrical resistivity.

  4. Application specific compression : final report.

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


    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.

  5. Streaming Compression of Hexahedral Meshes

    Isenburg, M; Courbet, C


    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.

  6. Data Compression with Linear Algebra

    Etler, David


    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.

  7. Prevalence of Vertebral Compression Fractures on Routine CT Scans According to L1 Trabecular Attenuation: Determining Relevant Thresholds for Opportunistic Osteoporosis Screening.

    Graffy, Peter M; Lee, Scott J; Ziemlewicz, Timothy J; Pickhardt, Perry J


    Radiologists interpreting body CT scans may be the first to identify osteoporosis and associated vertebral fractures. This study correlates L1 trabecular attenuation measurements with prevalent vertebral body fractures in older adults undergoing routine CT. Mean L1 trabecular attenuation was measured at thoracoabdominal CT in 1966 consecutive adults (983 men and 983 women) 65 years and older (mean age, 74.1 ± 6.6 [SD] years). Sagittal reconstructions and lateral scouts were analyzed for moderate or severe thoracolumbar vertebral compression fractures according to the Genant semiquantitative assessment method. The diagnostic performance of L1 attenuation for the evaluation of prevalent vertebral fractures was assessed, including ROC curve analysis. A total of 162 (8.2%) individuals (mean age, 78.3 years; 66 men, 96 women) had at least one moderate or severe vertebral fracture. The mean L1 attenuation was 70.2 HU among patients with a prevalent fracture, whereas it was 132.3 HU among patients without fracture (p < 0.001). The prevalence of moderate or severe vertebral compression fractures was 32.5% when L1 attenuation was ≤ 90 HU. Prevalence increased to 49.2% with L1 attenuation of ≤ 50 HU. ROC curve analysis determined an optimal threshold of 90 HU (sensitivity = 86.9%, specificity = 83.9%), with a corresponding AUC of 0.895. The odds ratio of having a moderate or severe vertebral compression fracture was 31.9 for L1 attenuation ≤ 90 HU (95% CI, 20.2-50.5; p < 0.001). Patients with moderate or severe vertebral compression fractures have significantly lower L1 attenuation values than patients who do not. L1 attenuation ≤ 90 HU may represent an optimal threshold for determining risk for osteoporotic vertebral fractures.

  8. Compressible Quasi-geostrophic Convection without the Anelastic Approximation

    Calkins, M. A.; Marti, P.; Julien, K. A.


    Fluid compressibility is known to be an important, non-negligible component of the dynamics of many planetary atmospheres and stellar convection zones, yet imposes severe computational constraints on numerical simulations of the compressible Navier-Stokes equations (NSE). An often employed reduced form of the NSE are the anelastic equations, which maintain fluid compressibility in the form of a depth varying, adiabatic background state onto which the perturbations cannot feed back. We present the linear theory of compressible rotating convection in a local-area, plane layer geometry. An important dimensionless parameter in convection is the ratio of kinematic viscosity to thermal diffusivity, or the Prandtl number, Pr. It is shown that the anelastic approximation cannot capture the linear instability of gases with Prandtl numbers less than approximately 0.5 in the limit of rapid rotation; the time derivative of the density fluctuation appearing in the conservation of mass equation remains important for these cases and cannot be neglected. An alternative compressible, geostrophically balanced equation set has been derived and preliminary results utilizing this new equation set are presented. Notably, this new set of equations satisfies the Proudman-Taylor theorem on small axial scales even for strongly compressible flows, does not require the flow to be nearly adiabatic, and thus allows for feedback onto the background state.

  9. Compression Maps and Stable Relations

    Price, Kenneth L


    Balanced relations were defined by G. Abrams to extend the convolution product used in the construction of incidence rings. We define stable relations,which form a class between balanced relations and preorders. We also define a compression map to be a surjective function between two sets which preserves order, preserves off-diagonal relations, and has the additional property every transitive triple is the image of a transitive triple. We show a compression map preserves the balanced and stable properties but the compression of a preorder may be stable and not transitive. We also cover an example of a stable relation which is not the compression of a preorder. In our main theorem we provide necessary and sufficient conditions for a finite stable relation to be the compression of a preorder.

  10. Compressive Sensing for Quantum Imaging

    Howland, Gregory A.

    This thesis describes the application of compressive sensing to several challenging problems in quantum imaging with practical and fundamental implications. Compressive sensing is a measurement technique that compresses a signal during measurement such that it can be dramatically undersampled. Compressive sensing has been shown to be an extremely efficient measurement technique for imaging, particularly when detector arrays are not available. The thesis first reviews compressive sensing through the lens of quantum imaging and quantum measurement. Four important applications and their corresponding experiments are then described in detail. The first application is a compressive sensing, photon-counting lidar system. A novel depth mapping technique that uses standard, linear compressive sensing is described. Depth maps up to 256 x 256 pixel transverse resolution are recovered with depth resolution less than 2.54 cm. The first three-dimensional, photon counting video is recorded at 32 x 32 pixel resolution and 14 frames-per-second. The second application is the use of compressive sensing for complementary imaging---simultaneously imaging the transverse-position and transverse-momentum distributions of optical photons. This is accomplished by taking random, partial projections of position followed by imaging the momentum distribution on a cooled CCD camera. The projections are shown to not significantly perturb the photons' momenta while allowing high resolution position images to be reconstructed using compressive sensing. A variety of objects and their diffraction patterns are imaged including the double slit, triple slit, alphanumeric characters, and the University of Rochester logo. The third application is the use of compressive sensing to characterize spatial entanglement of photon pairs produced by spontaneous parametric downconversion. The technique gives a theoretical speedup N2/log N for N-dimensional entanglement over the standard raster scanning technique

  11. Advances in compressible turbulent mixing

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


    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.

  12. A new compression design that increases proximal locking screw bending resistance in femur compression nails.

    Karaarslan, Ahmet Adnan; Karakaşli, Ahmet; Karci, Tolga; Aycan, Hakan; Yildirim, Serhat; Sesli, Erhan


    The aim is to present our new method of compression, a compression tube instead of conventional compression screw and to investigate the difference of proximal locking screw bending resistance between compression screw application (6 mm wide contact) and compression tube (two contact points with 13 mm gap) application. We formed six groups each consisting of 10 proximal locking screws. On metal cylinder representing lesser trochanter level, we performed 3-point bending tests with compression screw and with compression tube. We determined the yield points of the screws in 3-point bending tests using an axial compression testing machine. We determined the yield point of 5 mm screws as 1963±53 N (mean±SD) with compression screw, and as 2929±140 N with compression tubes. We found 51% more locking screw bending resistance with compression tube than with compression screw (p=0,000). Therefore compression tubes instead of compression screw must be preferred at femur compression nails.

  13. Compressed Submanifold Multifactor Analysis.

    Luu, Khoa; Savvides, Marios; Bui, Tien; Suen, Ching


    Although widely used, Multilinear PCA (MPCA), one of the leading multilinear analysis methods, still suffers from four major drawbacks. First, it is very sensitive to outliers and noise. Second, it is unable to cope with missing values. Third, it is computationally expensive since MPCA deals with large multi-dimensional datasets. Finally, it is unable to maintain the local geometrical structures due to the averaging process. This paper proposes a novel approach named Compressed Submanifold Multifactor Analysis (CSMA) to solve the four problems mentioned above. Our approach can deal with the problem of missing values and outliers via SVD-L1. The Random Projection method is used to obtain the fast low-rank approximation of a given multifactor dataset. In addition, it is able to preserve the geometry of the original data. Our CSMA method can be used efficiently for multiple purposes, e.g. noise and outlier removal, estimation of missing values, biometric applications. We show that CSMA method can achieve good results and is very efficient in the inpainting problem as compared to [1], [2]. Our method also achieves higher face recognition rates compared to LRTC, SPMA, MPCA and some other methods, i.e. PCA, LDA and LPP, on three challenging face databases, i.e. CMU-MPIE, CMU-PIE and Extended YALE-B.

  14. Tratamento do aneurisma da aorta toracoabdominal com endoprótese ramificada para as artérias viscerais Branched endovascular stent graft for thoracoabdominal aortic aneurysm repair

    André Simi


    AATA com endoprótese ramificada é factível. A melhora dos recursos técnicos e da qualidade dos materiais poderá ampliar a indicação desse procedimento como alternativa à cirurgia aberta.We report a case of branched stent graft system for endovascular repair of thoracoabdominal aortic aneurysm (TAAA. A 68-year-old female patient, smoker, hypertensive, with a large TAAA and multiple comorbid conditions that restricted indication for conventional surgery. The aneurysm originated from the descending thoracic aorta, extending until the infrarenal abdominal aorta, involving the emergence of visceral arteries, celiac trunk, superior and renal mesenteric arteries. The TAAA was treated with the endovascular technique using a branched stent graft. This stent graft was customized based on the anatomical characteristics of the aorta and on the position of visceral branches, which were obtained by tomographic angiography, with the aim of excluding the aneurysm and maintaining perfusion of visceral arteries. The procedure was performed under regional and general anesthesia in the surgical room, preceded by cerebrospinal fluid drainage under fluoroscopic guidance. The femoral arteries, which were previously dissected, were used to implement the branched stent graft and for radiological control. Through the stent graft branches, secondary extensions were implanted, with covered stents, to the respective visceral arteries, which were approached via left axillary artery. Total operative time was 14 hours, 4 hours and 30 minutes of fluoroscopy time and 120 mL of iodinated contrast. The patient became hemodynamically unstable after the surgery. Transesophageal echocardiogram showed a type A retrograde dissection of the thoracic aorta, followed by spontaneous thrombosis of the false lumen. Control tomography showed exclusion of the TAAA and patency of the bypasses to visceral branches, with no endoleaks. The patient was discharged on the 13th postoperative day. Branched

  15. The OMV Data Compression System Science Data Compression Workshop

    Lewis, Garton H., Jr.


    The Video Compression Unit (VCU), Video Reconstruction Unit (VRU), theory and algorithms for implementation of Orbital Maneuvering Vehicle (OMV) source coding, docking mode, channel coding, error containment, and video tape preprocessed space imagery are presented in viewgraph format.

  16. Wearable EEG via lossless compression.

    Dufort, Guillermo; Favaro, Federico; Lecumberry, Federico; Martin, Alvaro; Oliver, Juan P; Oreggioni, Julian; Ramirez, Ignacio; Seroussi, Gadiel; Steinfeld, Leonardo


    This work presents a wearable multi-channel EEG recording system featuring a lossless compression algorithm. The algorithm, based in a previously reported algorithm by the authors, exploits the existing temporal correlation between samples at different sampling times, and the spatial correlation between different electrodes across the scalp. The low-power platform is able to compress, by a factor between 2.3 and 3.6, up to 300sps from 64 channels with a power consumption of 176μW/ch. The performance of the algorithm compares favorably with the best compression rates reported up to date in the literature.

  17. Context-Aware Image Compression.

    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.

  18. Compressive sensing for urban radar

    Amin, Moeness


    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

  19. Designing experiments through compressed sensing.

    Young, Joseph G.; Ridzal, Denis


    In the following paper, we discuss how to design an ensemble of experiments through the use of compressed sensing. Specifically, we show how to conduct a small number of physical experiments and then use compressed sensing to reconstruct a larger set of data. In order to accomplish this, we organize our results into four sections. We begin by extending the theory of compressed sensing to a finite product of Hilbert spaces. Then, we show how these results apply to experiment design. Next, we develop an efficient reconstruction algorithm that allows us to reconstruct experimental data projected onto a finite element basis. Finally, we verify our approach with two computational experiments.

  20. Compressive myelopathy in fluorosis: MRI

    Gupta, R.K. [MR Section, Department of Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow-226014 (India); Agarwal, P. [MR Section, Department of Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow-226014 (India); Kumar, S. [MR Section, Department of Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow-226014 (India); Surana, P.K. [Department of Neurology, SGPGIMS, Lucknow-226014 (India); Lal, J.H. [MR Section, Department of Radiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow-226014 (India); Misra, U.K. [Department of Neurology, SGPGIMS, Lucknow-226014 (India)


    We examined four patients with fluorosis, presenting with compressive myelopathy, by MRI, using spin-echo and fast low-angle shot sequences. Cord compression due to ossification of the posterior longitudinal ligament (PLL) and ligamentum flavum (LF) was demonstrated in one and ossification of only the LF in one. Marrow signal was observed in the PLL and LF in all the patients on all pulse sequences. In patients with compressive myelopathy secondary to ossification of PLL and/or LF, fluorosis should be considered as a possible cause, especially in endemic regions. (orig.). With 2 figs., 1 tab.

  1. Partial transparency of compressed wood

    Sugimoto, Hiroyuki; Sugimori, Masatoshi


    We have developed novel wood composite with optical transparency at arbitrary region. Pores in wood cells have a great variation in size. These pores expand the light path in the sample, because the refractive indexes differ between constituents of cell and air in lumen. In this study, wood compressed to close to lumen had optical transparency. Because the condition of the compression of wood needs the plastic deformation, wood was impregnated phenolic resin. The optimal condition for high transmission is compression ratio above 0.7.

  2. Compressive phase-only filtering at extreme compression rates

    Pastor-Calle, David; Pastuszczak, Anna; Mikołajczyk, Michał; Kotyński, Rafał


    We introduce an efficient method for the reconstruction of the correlation between a compressively measured image and a phase-only filter. The proposed method is based on two properties of phase-only filtering: such filtering is a unitary circulant transform, and the correlation plane it produces is usually sparse. Thanks to these properties, phase-only filters are perfectly compatible with the framework of compressive sensing. Moreover, the lasso-based recovery algorithm is very fast when phase-only filtering is used as the compression matrix. The proposed method can be seen as a generalization of the correlation-based pattern recognition technique, which is hereby applied directly to non-adaptively acquired compressed data. At the time of measurement, any prior knowledge of the target object for which the data will be scanned is not required. We show that images measured at extremely high compression rates may still contain sufficient information for target classification and localization, even if the compression rate is high enough, that visual recognition of the target in the reconstructed image is no longer possible. The method has been applied by us to highly undersampled measurements obtained from a single-pixel camera, with sampling based on randomly chosen Walsh-Hadamard patterns.

  3. Effects of errors in velocity tilt on maximum longitudinal compression during neutralized drift compression of intense beam pulses: I. general description

    Kaganovich, Igor D., E-mail: [Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States); Massidda, Scott; Startsev, Edward A.; Davidson, Ronald C. [Plasma Physics Laboratory, Princeton University, Princeton, NJ 08543 (United States); Vay, Jean-Luc [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Friedman, Alex [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA 94550 (United States)


    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

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

    Xiangwei Li


    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.

  5. Efficient lossy compression for compressive sensing acquisition of images in compressive sensing imaging systems.

    Li, Xiangwei; Lan, Xuguang; Yang, Meng; Xue, Jianru; Zheng, Nanning


    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. Compressive Phase Contrast Tomography

    Maia, F R N C; Marchesini, S; Padmore, H A; Parkinson, D Y; Pien, J; Schirotzek, A; Yang, C; 10.1117/12.861946


    When x-rays penetrate soft matter, their phase changes more rapidly than their amplitude. In- terference 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 con- trast 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).

  7. Compressive Acquisition of Dynamic Scenes

    Sankaranarayanan, Aswin C; Chellappa, Rama; Baraniuk, Richard G


    Compressive sensing (CS) is a new approach for the acquisition and recovery of sparse signals and images that enables sampling rates significantly below the classical Nyquist rate. Despite significant progress in the theory and methods of CS, little headway has been made in compressive video acquisition and recovery. Video CS is complicated by the ephemeral nature of dynamic events, which makes direct extensions of standard CS imaging architectures and signal models difficult. In this paper, we develop a new framework for video CS for dynamic textured scenes that models the evolution of the scene as a linear dynamical system (LDS). This reduces the video recovery problem to first estimating the model parameters of the LDS from compressive measurements, and then reconstructing the image frames. We exploit the low-dimensional dynamic parameters (the state sequence) and high-dimensional static parameters (the observation matrix) of the LDS to devise a novel compressive measurement strategy that measures only the...

  8. Normalized Compression Distance of Multiples

    Cohen, Andrew R


    Normalized compression distance (NCD) is a parameter-free similarity measure based on compression. The NCD between pairs of objects is not sufficient for all applications. We propose an NCD of finite multisets (multiples) of objacts that is metric and is better for many applications. Previously, attempts to obtain such an NCD failed. We use the theoretical notion of Kolmogorov complexity that for practical purposes is approximated from above by the length of the compressed version of the file involved, using a real-world compression program. We applied the new NCD for multiples to retinal progenitor cell questions that were earlier treated with the pairwise NCD. Here we get significantly better results. We also applied the NCD for multiples to synthetic time sequence data. The preliminary results are as good as nearest neighbor Euclidean classifier.

  9. Compression fractures of the back

    Taking steps to prevent and treat osteoporosis is the most effective way to prevent compression or insufficiency fractures. Getting regular load-bearing exercise (such as walking) can help you avoid bone loss.

  10. Compressed sensing for distributed systems

    Coluccia, Giulio; Magli, Enrico


    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...

  11. Preprocessing of compressed digital video

    Segall, C. Andrew; Karunaratne, Passant V.; Katsaggelos, Aggelos K.


    Pre-processing algorithms improve on the performance of a video compression system by removing spurious noise and insignificant features from the original images. This increases compression efficiency and attenuates coding artifacts. Unfortunately, determining the appropriate amount of pre-filtering is a difficult problem, as it depends on both the content of an image as well as the target bit-rate of compression algorithm. In this paper, we explore a pre- processing technique that is loosely coupled to the quantization decisions of a rate control mechanism. This technique results in a pre-processing system that operates directly on the Displaced Frame Difference (DFD) and is applicable to any standard-compatible compression system. Results explore the effect of several standard filters on the DFD. An adaptive technique is then considered.

  12. Compressed gas fuel storage system

    Wozniak, John J. (Columbia, MD); Tiller, Dale B. (Lincoln, NE); Wienhold, Paul D. (Baltimore, MD); Hildebrand, Richard J. (Edgemere, MD)


    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.

  13. Shock compression of polyvinyl chloride

    Neogi, Anupam; Mitra, Nilanjan


    This study presents shock compression simulation of atactic polyvinyl chloride (PVC) using ab-initio and classical molecular dynamics. The manuscript also identifies the limits of applicability of classical molecular dynamics based shock compression simulation for PVC. The mechanism of bond dissociation under shock loading and its progression is demonstrated in this manuscript using the density functional theory based molecular dynamics simulations. The rate of dissociation of different bonds at different shock velocities is also presented in this manuscript.

  14. Bridgman's concern (shock compression science)

    Graham, R. A.


    In 1956 P. W. Bridgman published a letter to the editor in the Journal of Applied Physics reporting results of electrical resistance measurements on iron under static high pressure. The work was undertaken to verify the existence of a polymorphic phase transition at 130 kbar (13 GPa) reported in the same journal and year by the Los Alamos authors, Bancroft, Peterson, and Minshall for high pressure, shock-compression loading. In his letter, Bridgman reported that he failed to find any evidence for the transition. Further, he raised some fundamental concerns as to the state of knowledge of shock-compression processes in solids. Later it was determined that Bridgman's static pressure scale was in error, and the shock observations became the basis for calibration of pressure values in static high pressure apparatuses. In spite of the error in pressure scales, Bridgman's concerns on descriptions of shock-compression processes were perceptive and have provided the basis for subsequent fundamental studies of shock-compressed solids. The present paper, written in response to receipt of the 1993 American Physical Society Shock-Compression Science Award, provides a brief contemporary assessment of those shock-compression issues which were the basis of Bridgman's 1956 concerns.

  15. Hidden force opposing ice compression

    Sun, Chang Q; Zheng, Weitao


    Coulomb repulsion between the unevenly-bound bonding and nonbonding electron pairs in the O:H-O hydrogen-bond is shown to originate the anomalies of ice under compression. Consistency between experimental observations, density functional theory and molecular dynamics calculations confirmed that the resultant force of the compression, the repulsion, and the recovery of electron-pair dislocations differentiates ice from other materials in response to pressure. The compression shortens and strengthens the longer-and-softer intermolecular O:H lone-pair virtual-bond; the repulsion pushes the bonding electron pair away from the H+/p and hence lengthens and weakens the intramolecular H-O real-bond. The virtual-bond compression and the real-bond elongation symmetrize the O:H-O as observed at ~60 GPa and result in the abnormally low compressibility of ice. The virtual-bond stretching phonons ( 3000 cm-1) softened upon compression. The cohesive energy of the real-bond dominates and its loss lowers the critical temperat...

  16. Lavado de la cavidad pleural en pacientes con heridas toracoabdominales: comparación entre toracoscopia y toracotomía Thoracoscopic vs. thoracotomy cleaning of the preural cavity in patients with thoracoabdominal wounds

    Sergio Hernández


    Full Text Available

    Se estudiaron 32 pacientes con contaminación de la cavidad pleural después de heridas toracoabdominales. Para propósitos del lavado de la cavidad la mitad fueron sometidos a toracoscopia y los restantes a toracotomía. Se halló que la primera, en comparación con la segunda, ofrece las ventajas de ser más fácil de realizar, requerir menor tiempo operatorio (20.3 vs. 60 minutos; p < 0.01 y menor estancia hospitalaria (3.5 contra 8.1 días; p < 0.01 y acompañarse de menor morbilidad postoperatoria (1 complicación vs. 4. No hubo diferencia significativa en la proporción en que se logró limpieza adecuada de la cavidad (87.5% en los casos de toracoscopia y 81.3% en los de toracotomía.

    A study was performed on 32 patients with pleural cavity contamination after thoracoabdominal wounds. Sixteen patients were treated by thoracoscopic pleural cleaning while In the remaining 16 thoracotomy was employed for that purpose; thoracoscopy was easler to perform and allowed adequate cleaning of the cavity In 87.5% of the cases (81.3% in cases of thoracotomy; It requlred less operatory time (20.3 vs. 60 minutes of the thoracotomy; p < 0.01 and a shorter hospital stay (3.5 vs 8.1 days with thoracotomy; p < 0.01; morbidity was lower In the toracoscopy group (1 complication vs. 4 with thoracotomy but this difference was not significant; p > 0.05. In view of these results we propose the use of thoracoscopic cleaning of the pleural cavity in cases of thoracoabdominal wounds

  17. Full-frame compression of discrete wavelet and cosine transforms

    Lo, Shih-Chung B.; Li, Huai; Krasner, Brian; Freedman, Matthew T.; Mun, Seong K.


    At the foreground of computerized radiology and the filmless hospital are the possibilities for easy image retrieval, efficient storage, and rapid image communication. This paper represents the authors' continuous efforts in compression research on full-frame discrete wavelet (FFDWT) and full-frame discrete cosine transforms (FFDCT) for medical image compression. Prior to the coding, it is important to evaluate the global entropy in the decomposed space. It is because of the minimum entropy, that a maximum compression efficiency can be achieved. In this study, each image was split into the top three most significant bit (MSB) and the remaining remapped least significant bit (RLSB) images. The 3MSB image was compressed by an error-free contour coding and received an average of 0.1 bit/pixel. The RLSB image was either transformed to a multi-channel wavelet or the cosine transform domain for entropy evaluation. Ten x-ray chest radiographs and ten mammograms were randomly selected from our clinical database and were used for the study. Our results indicated that the coding scheme in the FFDCT domain performed better than in FFDWT domain for high-resolution digital chest radiographs and mammograms. From this study, we found that decomposition efficiency in the DCT domain for relatively smooth images is higher than that in the DWT. However, both schemes worked just as well for low resolution digital images. We also found that the image characteristics of the `Lena' image commonly used in the compression literature are very different from those of radiological images. The compression outcome of the radiological images can not be extrapolated from the compression result based on the `Lena.'

  18. An Efficient Image Compression Technique Based on Arithmetic Coding

    Prof. Rajendra Kumar Patel


    Full Text Available The rapid growth of digital imaging applications, including desktop publishing, multimedia, teleconferencing, and high visual definition has increased the need for effective and standardized image compression techniques. Digital Images play a very important role for describing the detailed information. The key obstacle for many applications is the vast amount of data required to represent a digital image directly. The various processes of digitizing the images to obtain it in the best quality for the more clear and accurate information leads to the requirement of more storage space and better storage and accessing mechanism in the form of hardware or software. In this paper we concentrate mainly on the above flaw so that we reduce the space with best quality image compression. State-ofthe-art techniques can compress typical images from 1/10 to 1/50 their uncompressed size without visibly affecting image quality. From our study I observe that there is a need of good image compression technique which provides better reduction technique in terms of storage and quality. Arithmetic coding is the best way to reducing encoding data. So in this paper we propose arithmetic coding with walsh transformation based image compression technique which is an efficient way of reduction

  19. Frequency extrapolation by nonconvex compressive sensing

    Chartrand, Rick [Los Alamos National Laboratory; Sidky, Emil Y [UNIV OF CHICAGO; Pan, Xiaochaun [UNIV OF CHICAGO


    Tomographic imaging modalities sample subjects with a discrete, finite set of measurements, while the underlying object function is continuous. Because of this, inversion of the imaging model, even under ideal conditions, necessarily entails approximation. The error incurred by this approximation can be important when there is rapid variation in the object function or when the objects of interest are small. In this work, we investigate this issue with the Fourier transform (FT), which can be taken as the imaging model for magnetic resonance imaging (MRl) or some forms of wave imaging. Compressive sensing has been successful for inverting this data model when only a sparse set of samples are available. We apply the compressive sensing principle to a somewhat related problem of frequency extrapolation, where the object function is represented by a super-resolution grid with many more pixels than FT measurements. The image on the super-resolution grid is obtained through nonconvex minimization. The method fully utilizes the available FT samples, while controlling aliasing and ringing. The algorithm is demonstrated with continuous FT samples of the Shepp-Logan phantom with additional small, high-contrast objects.

  20. Analysis of coalescence behavior for compressed droplets

    Choi, Sung Woong; Lee, Dong Eon; Lee, Woo Il; Kim, Han Sang


    Coalescence of droplets is a significant phenomenon, and it has been adapted to many applications such as raindrop formation, emulsion polymerization, ink-jet printing, coating, and multiphase flows. In this study, the morphological characteristics of two compressed adjacent droplets between two parallel plates were investigated to study the phenomenon of coalescence of droplets. By controlling the distance of the dispensed droplets, various results for coalescence of droplets were evaluated, especially, from the view of the minor axis, major axis, and meniscus liquid bridge of the coalesced droplet. Experimental results show that the length of the meniscus liquid bridge rapidly increases and then the rate of increase slows with time. The increase rate of the major and minor axes is largely influenced by the meniscus liquid bridge, which is mainly due to the curvature between the droplets. The numerical modeling of the coalescence of the two compressed droplets between two parallel plates was presented and simulation was conducted to realize the coalescence behavior. Comparison with numerical simulation showed that there was a good agreement with the experimental results.

  1. Comparing image compression methods in biomedical applications

    Libor Hargas


    Full Text Available Compression methods suitable for image processing are described in this article in biomedical applications. The compression is often realized by reduction of irrelevance or redundancy. There are described lossless and lossy compression methods which can be use for compress of images in biomedical applications and comparison of these methods based on fidelity criteria.

  2. 29 CFR 1917.154 - Compressed air.


    ... 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...

  3. Shock wave compression behavior of aluminum foam

    程和法; 黄笑梅; 薛国宪; 韩福生


    The shock wave compression behavior of the open cell aluminum foam with relative density of 0. 396 was studied through planar impact experiments. Using polyvinylidene fluoride(PVDF) piezoelectric gauge technique, the stress histories and propagation velocities of shock wave in the aluminum foam were measured and analyzed. The results show that the amplitude of shock wave attenuates rapidly with increasing the propagation distance in the aluminum foam, and an exponential equation of the normalized peak stress vs propagation distance of shock wave is established, the attenuation factor in the equation is 0. 286. Furthermore, the Hugoniot relation, νs = 516.85+ 1.27νp,for the aluminum foam is determined by empirical fit to the experimental Hugoniot data.

  4. Selectivity estimation using compressed spatial information

    JEONG Jae-hyuck; CHI Jeong-hee; RYU Keun-ho


    Spatial selectivity estimation is one of the essential studies to get query responses rapidly and accurately with the limitation of memory space. Currently, there exist several spatial selectivity estimation techniques such as random sampling, histogram, and parametric. Especially, Cumulative Density Histogram guarantees accurate estimation for rectangle object which has multiple-count problem. However, it requires large memory space because of retaining four sub-histograms for spatial data. Therefore in this paper,we propose a new technique Cumulative Density Wavelet Histogram, called CDWH, which is the combination of Cumulative Density Histogram and Haar Wavelet Transform, a compressed technique. The proposed method simultaneously takes full advantage of their strong points, high accuracy provided by the former and economization of memory space supported by the latter. Consequently, our technique is able to support estimates with relatively low error and retain similar estimates even if memory space is small.

  5. High-Frequency Chest Compression: A Summary of the Literature

    Dosman, Cara F; Jones, Richard L


    The purpose of the present literature summary is to describe high-frequency chest compression (HFCC), summarize its history and outline study results on its effect on mucolysis, mucus transport, pulmonary function and quality of life. HFCC is a mechanical method of self-administered chest physiotherapy, which induces rapid air movement in and out of the lungs. This mean oscillated volume is an effective method of mucolysis and mucus clearance. HFCC can increase independence. Some studies have...

  6. Adiabatic Compression Sensitivity of AF-M315E


    is pressurized to specific driving pressures into an accumulator tank above a rapid-opening valve. This valve is placed directly above the burst disc...this mission. Of particular interest is the sensitivity of the propellant at elevated temperatures and the resulting system peak pressures and...dynamic response characteristics. For this study, an adiabatic compression U-tube apparatus was used to determine the driving pressure threshold levels

  7. Compressibility, turbulence and high speed flow

    Gatski, Thomas B


    Compressibility, Turbulence and High Speed Flow introduces the reader to the field of compressible turbulence and compressible turbulent flows across a broad speed range, through a unique complimentary treatment of both the theoretical foundations and the measurement and analysis tools currently used. The book provides the reader with the necessary background and current trends in the theoretical and experimental aspects of compressible turbulent flows and compressible turbulence. Detailed derivations of the pertinent equations describing the motion of such turbulent flows is provided and

  8. 30 CFR 75.1730 - Compressed air; general; compressed air systems.


    ... Compressed air; general; compressed air systems. (a) All pressure vessels shall be constructed, installed... pressure has been relieved from that part of the system to be repaired. (d) At no time shall compressed air... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressed air; general; compressed air systems...

  9. Adult-like processing of time-compressed speech by newborns: A NIRS study

    Cécile Issard


    Full Text Available Humans can adapt to a wide range of variations in the speech signal, maintaining an invariant representation of the linguistic information it contains. Among them, adaptation to rapid or time-compressed speech has been well studied in adults, but the developmental origin of this capacity remains unknown. Does this ability depend on experience with speech (if yes, as heard in utero or as heard postnatally, with sounds in general or is it experience-independent? Using near-infrared spectroscopy, we show that the newborn brain can discriminate between three different compression rates: normal, i.e. 100% of the original duration, moderately compressed, i.e. 60% of original duration and highly compressed, i.e. 30% of original duration. Even more interestingly, responses to normal and moderately compressed speech are similar, showing a canonical hemodynamic response in the left temporoparietal, right frontal and right temporal cortex, while responses to highly compressed speech are inverted, showing a decrease in oxyhemoglobin concentration. These results mirror those found in adults, who readily adapt to moderately compressed, but not to highly compressed speech, showing that adaptation to time-compressed speech requires little or no experience with speech, and happens at an auditory, and not at a more abstract linguistic level.

  10. Word-Based Text Compression

    Platos, Jan


    Today there are many universal compression algorithms, but in most cases is for specific data better using specific algorithm - JPEG for images, MPEG for movies, etc. For textual documents there are special methods based on PPM algorithm or methods with non-character access, e.g. word-based compression. In the past, several papers describing variants of word-based compression using Huffman encoding or LZW method were published. The subject of this paper is the description of a word-based compression variant based on the LZ77 algorithm. The LZ77 algorithm and its modifications are described in this paper. Moreover, various ways of sliding window implementation and various possibilities of output encoding are described, as well. This paper also includes the implementation of an experimental application, testing of its efficiency and finding the best combination of all parts of the LZ77 coder. This is done to achieve the best compression ratio. In conclusion there is comparison of this implemented application wi...

  11. 非体外循环全胸腹主动脉置换术的麻醉处理%Anesthetic management for patients undergoing total thoracoabdominal aorta replacement without cardiopulmonary bypass

    李军; 石佳; 陈雷; 李立环; 纪宏文


    Objective To summarize the experience in anesthetic management for total thoracoabdominal aorta replacement without cardiopulmonary bypass.Methods From October 2009 to September 2010,10 patients of Fuwai Hospital received off-pump total thoracoabdominal aorta replacement.Of these patients,5 were subjected to Standford B aortic dissection,2 were Standford A aortic dissection received total aortic arch replacement combined with transaortic stented graft implantation into the descending aorta.1 were Marfan's syndrome,and 2 were thoracoabdominal aorta.All operations used the technique which preserved blood was transfused back by pump via the femoral artery.Results The average surgery time was (7.4 ± 1.2) h and extubation time was (14.1 ± 2.5) h,the descending thoracic aorta crossclamp time was (11.5 ± 3.6) min,the intercostal artery reconstruction time was (16.4 ± 5.5) min,the required amount of blood products was fresh frozen plasma(600.5 ±-542.8) ml,platelet(1.7 ± 0.8) U,red blood cell(4.3 ± 2.4) U,autoblood salvage(465.7 ± 242.3) ml.Three patients occured atelectasis and one patient occurred seroperitoneum postoperation.All of the 10 patients were discharged from hospital without any neurologic complications.Conclusion The anesthetic management for total thoracoabdominal aortareplacement without cardiopulmonary bypass is feasible.It can reduce the side effects of deep hypothermia circulatory arrest and had a good effect.%目的 探讨非体外循环全胸腹主动脉置换手术的麻醉处理经验.方法 选择中国协和医科大学阜外医院血管外科2009年10月至2010年9月非体外循环下全胸腹主动脉置换术患者10例,其中男6例,女4例,慢性Stanford B型主动脉夹层动脉瘤5例,慢性Stanford A型夹层动脉瘤2例(一期已行Bentall加全弓及象鼻手术),马凡综合征合并慢性Stanford B型夹层动脉瘤1例,胸腹主动脉瘤2例.所有病例术中均采用血泵法联合自体血液回收技术.记录手术时间

  12. Very Long Segment Congenital Thoracoabdominal Aortic Coarctation (Diffuse Aortic Dysplasia) with Infrarenal Aortobi-Iliac and Cavobi-Iliac Aplasia in a 30-Year-Old Patient.

    Mamopoulos, Apostolos; Luther, Bernd


    Congenital dysplastic aortic syndromes range from coarctation at the aortic isthmus to more extended aortic disease (midaortic syndrome). The latter is usually restricted to dysplastic aortic segments of up to 15 cm. Long segment dysplasia of the entire abdominal or thoracic aorta is extremely rare. This case of a 30-year-old patient with a very long segment congenital thoracoabdominal aortic coarctation and infrarenal aortobi-iliac and cavobi-iliac aplasia represents to our knowledge the most extended congenital vascular malformation in a surviving adult patient. The developed extensive collateral pathways ensured the survival of the patient, so that the main clinical manifestation was a refractory hypertension. Because of the extent of the disease, open surgery represented the only viable option. Interestingly, after 30 years of uncontrollable hypertension, the patient's blood pressure promptly responded to surgical treatment. A concomitant infrarenal aplasia of both the aorta and cava vein is also very unusual and points to a major developmental deficit during vascular embryogenesis. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Morphological Transform for Image Compression

    Luis Pastor Sanchez Fernandez


    Full Text Available A new method for image compression based on morphological associative memories (MAMs is presented. We used the MAM to implement a new image transform and applied it at the transformation stage of image coding, thereby replacing such traditional methods as the discrete cosine transform or the discrete wavelet transform. Autoassociative and heteroassociative MAMs can be considered as a subclass of morphological neural networks. The morphological transform (MT presented in this paper generates heteroassociative MAMs derived from image subblocks. The MT is applied to individual blocks of the image using some transformation matrix as an input pattern. Depending on this matrix, the image takes a morphological representation, which is used to perform the data compression at the next stages. With respect to traditional methods, the main advantage offered by the MT is the processing speed, whereas the compression rate and the signal-to-noise ratio are competitive to conventional transforms.

  14. Compressive Sensing in Communication Systems

    Fyhn, Karsten


    Wireless communication is omnipresent today, but this development has led to frequency spectrum becoming a limited resource. Furthermore, wireless devices become more and more energy-limited, due to the demand for continual wireless communication of higher and higher amounts of information....... 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...

  15. Compressive Sensing for MIMO Radar

    Yu, Yao; Poor, H Vincent


    Multiple-input multiple-output (MIMO) radar systems have been shown to achieve superior resolution as compared to traditional radar systems with the same number of transmit and receive antennas. This paper considers a distributed MIMO radar scenario, in which each transmit element is a node in a wireless network, and investigates the use of compressive sampling for direction-of-arrival (DOA) estimation. According to the theory of compressive sampling, a signal that is sparse in some domain can be recovered based on far fewer samples than required by the Nyquist sampling theorem. The DOA of targets form a sparse vector in the angle space, and therefore, compressive sampling can be applied for DOA estimation. The proposed approach achieves the superior resolution of MIMO radar with far fewer samples than other approaches. This is particularly useful in a distributed scenario, in which the results at each receive node need to be transmitted to a fusion center for further processing.

  16. Compressive Sensing with Optical Chaos

    Rontani, D.; Choi, D.; Chang, C.-Y.; Locquet, A.; Citrin, D. S.


    Compressive sensing (CS) is a technique to sample a sparse signal below the Nyquist-Shannon limit, yet still enabling its reconstruction. As such, CS permits an extremely parsimonious way to store and transmit large and important classes of signals and images that would be far more data intensive should they be sampled following the prescription of the Nyquist-Shannon theorem. CS has found applications as diverse as seismology and biomedical imaging. In this work, we use actual optical signals generated from temporal intensity chaos from external-cavity semiconductor lasers (ECSL) to construct the sensing matrix that is employed to compress a sparse signal. The chaotic time series produced having their relevant dynamics on the 100 ps timescale, our results open the way to ultrahigh-speed compression of sparse signals.

  17. Compressive behavior of fine sand.

    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)


    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.

  18. Instability of ties in compression

    Buch-Hansen, Thomas Cornelius


    Masonry cavity walls are loaded by wind pressure and vertical load from upper floors. These loads results in bending moments and compression forces in the ties connecting the outer and the inner wall in a cavity wall. Large cavity walls are furthermore loaded by differential movements from...... the temperature gradient between the outer and the inner wall, which results in critical increase of the bending moments in the ties. Since the ties are loaded by combined compression and moment forces, the loadbearing capacity is derived from instability equilibrium equations. Most of them are iterative, since......-connectors in cavity walls was developed. The method takes into account constraint conditions limiting the free length of the wall tie, and the instability in case of pure compression which gives an optimal load bearing capacity. The model is illustrated with examples from praxis....

  19. SRComp: short read sequence compression using burstsort and Elias omega coding.

    Jeremy John Selva

    Full Text Available Next-generation sequencing (NGS technologies permit the rapid production of vast amounts of data at low cost. Economical data storage and transmission hence becomes an increasingly important challenge for NGS experiments. In this paper, we introduce a new non-reference based read sequence compression tool called SRComp. It works by first employing a fast string-sorting algorithm called burstsort to sort read sequences in lexicographical order and then Elias omega-based integer coding to encode the sorted read sequences. SRComp has been benchmarked on four large NGS datasets, where experimental results show that it can run 5-35 times faster than current state-of-the-art read sequence compression tools such as BEETL and SCALCE, while retaining comparable compression efficiency for large collections of short read sequences. SRComp is a read sequence compression tool that is particularly valuable in certain applications where compression time is of major concern.

  20. Fast, efficient lossless data compression

    Ross, Douglas


    This paper presents lossless data compression and decompression algorithms which can be easily implemented in software. The algorithms can be partitioned into their fundamental parts which can be implemented at various stages within a data acquisition system. This allows for efficient integration of these functions into systems at the stage where they are most applicable. The algorithms were coded in Forth to run on a Silicon Composers Single Board Computer (SBC) using the Harris RTX2000 Forth processor. The algorithms require very few system resources and operate very fast. The performance of the algorithms with the RTX enables real time data compression and decompression to be implemented for a wide range of applications.

  1. [Vascular compression of the duodenum].

    Acosta, B; Guachalla, G; Martínez, C; Felce, S; Ledezma, G


    The acute vascular compression of the duodenum is a well-recognized clinical entity, characterized by recurrent vomiting, abdominal distention, weight loss, post prandial distress. The cause of compression is considered to be effect produced as a result of the angle formed by the superior mesenteric vessels and sometimes by one of its first two branches, and vertebrae and paravertebral muscles, when the angle between superior mesenteric vessels and the aorta it's lower than 18 degrees we can saw this syndrome. The duodenojejunostomy is the best treatment, as well as in our patient.

  2. GPU-accelerated compressive holography.

    Endo, Yutaka; Shimobaba, Tomoyoshi; Kakue, Takashi; Ito, Tomoyoshi


    In this paper, we show fast signal reconstruction for compressive holography using a graphics processing unit (GPU). We implemented a fast iterative shrinkage-thresholding algorithm on a GPU to solve the ℓ1 and total variation (TV) regularized problems that are typically used in compressive holography. Since the algorithm is highly parallel, GPUs can compute it efficiently by data-parallel computing. For better performance, our implementation exploits the structure of the measurement matrix to compute the matrix multiplications. The results show that GPU-based implementation is about 20 times faster than CPU-based implementation.

  3. Compressing the Inert Doublet Model

    Blinov, Nikita; Morrissey, David E; de la Puente, Alejandro


    The Inert Doublet Model relies on a discrete symmetry to prevent couplings of the new scalars to Standard Model fermions. This stabilizes the lightest inert state, which can then contribute to the observed dark matter density. In the presence of additional approximate symmetries, the resulting spectrum of exotic scalars can be compressed. Here, we study the phenomenological and cosmological implications of this scenario. We derive new limits on the compressed Inert Doublet Model from LEP, and outline the prospects for exclusion and discovery of this model at dark matter experiments, the LHC, and future colliders.

  4. Spinal cord compression in {beta}-thalassemia: follow-up after radiotherapy

    Fonseca, Silvana Fahel da; Figueiredo, Maria Stella; Cancado, Rodolfo Delfini; Nakadakare, Fernando; Segreto, Roberto; Kerbauy, Jose [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Escola Paulista de Medicina


    Spinal cord compression due to extramedullary hematopoiesis is a well-described bu rare syndrome encountered in several hematologic disorders, including {beta}-thalassemia. We report a case of a patient with intermediate {beta}-thalassemia and crural paraparesis due to spinal cord compression by a paravertebral extramedullary mass. She was successfully treated with low-dose radiotherapy and transfusions. After splenectomy, she was regularly followed up for over four years without transfusion or recurrence of spinal cord compression. Extramedullary hematopoiesis should be investigated in patients with hematologic disorders and spinal cord symptoms. The rapid recognition and treatment with radiotherapy can dramatically alleviate symptoms. (author)

  5. Spinal cord compression in b-thalassemia: follow-up after radiotherapy

    Silvana Fahel da Fonseca

    Full Text Available CONTEXT: Spinal cord compression due to extramedullary hematopoiesis is a well-described but rare syndrome encountered in several clinical hematologic disorders, including b-thalassemia. CASE REPORT: We report the case of a patient with intermediate b-thalassemia and crural paraparesis due to spinal cord compression by a paravertebral extramedullary mass. She was successfully treated with low-dose radiotherapy and transfusions. After splenectomy, she was regularly followed up for over four years without transfusion or recurrence of spinal cord compression. DISCUSSION: Extramedullary hematopoiesis should be investigated in patients with hematologic disorders and spinal cord symptoms. The rapid recognition and treatment with radiotherapy can dramatically alleviate symptoms.

  6. Chunk formation in immediate memory and how it relates to data compression.

    Chekaf, Mustapha; Cowan, Nelson; Mathy, Fabien


    This paper attempts to evaluate the capacity of immediate memory to cope with new situations in relation to the compressibility of information likely to allow the formation of chunks. We constructed a task in which untrained participants had to immediately recall sequences of stimuli with possible associations between them. Compressibility of information was used to measure the chunkability of each sequence on a single trial. Compressibility refers to the recoding of information in a more compact representation. Although compressibility has almost exclusively been used to study long-term memory, our theory suggests that a compression process relying on redundancies within the structure of the list materials can occur very rapidly in immediate memory. The results indicated a span of about three items when the list had no structure, but increased linearly as structure was added. The amount of information retained in immediate memory was maximal for the most compressible sequences, particularly when information was ordered in a way that facilitated the compression process. We discuss the role of immediate memory in the rapid formation of chunks made up of new associations that did not already exist in long-term memory, and we conclude that immediate memory is the starting place for the reorganization of information. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Wavelet and wavelet packet compression of electrocardiograms.

    Hilton, M L


    Wavelets and wavelet packets have recently emerged as powerful tools for signal compression. Wavelet and wavelet packet-based compression algorithms based on embedded zerotree wavelet (EZW) coding are developed for electrocardiogram (ECG) signals, and eight different wavelets are evaluated for their ability to compress Holter ECG data. Pilot data from a blind evaluation of compressed ECG's by cardiologists suggest that the clinically useful information present in original ECG signals is preserved by 8:1 compression, and in most cases 16:1 compressed ECG's are clinically useful.

  8. Maxwell's Demon and Data Compression

    Hosoya, Akio; Shikano, Yutaka


    In an asymmetric Szilard engine model of Maxwell's demon, we show the equivalence between information theoretical and thermodynamic entropies when the demon erases information optimally. The work gain by the engine can be exactly canceled out by the work necessary to reset demon's memory after optimal data compression a la Shannon before the erasure.

  9. Grid-free compressive beamforming

    Xenaki, Angeliki; Gerstoft, Peter


    The direction-of-arrival (DOA) estimation problem involves the localization of a few sources from a limited number of observations on an array of sensors, thus it can be formulated as a sparse signal reconstruction problem and solved efficiently with compressive sensing (CS) to achieve high...

  10. LIDAR data compression using wavelets

    Pradhan, B.; Mansor, Shattri; Ramli, Abdul Rahman; Mohamed Sharif, Abdul Rashid B.; Sandeep, K.


    The lifting scheme has been found to be a flexible method for constructing scalar wavelets with desirable properties. In this paper, it is extended to the LIDAR data compression. A newly developed data compression approach to approximate the LIDAR surface with a series of non-overlapping triangles has been presented. Generally a Triangulated Irregular Networks (TIN) are the most common form of digital surface model that consists of elevation values with x, y coordinates that make up triangles. But over the years the TIN data representation has become a case in point for many researchers due its large data size. Compression of TIN is needed for efficient management of large data and good surface visualization. This approach covers following steps: First, by using a Delaunay triangulation, an efficient algorithm is developed to generate TIN, which forms the terrain from an arbitrary set of data. A new interpolation wavelet filter for TIN has been applied in two steps, namely splitting and elevation. In the splitting step, a triangle has been divided into several sub-triangles and the elevation step has been used to 'modify' the point values (point coordinates for geometry) after the splitting. Then, this data set is compressed at the desired locations by using second generation wavelets. The quality of geographical surface representation after using proposed technique is compared with the original LIDAR data. The results show that this method can be used for significant reduction of data set.

  11. Compressed Blind De-convolution

    Saligrama, V


    Suppose the signal x is realized by driving a k-sparse signal u through an arbitrary unknown stable discrete-linear time invariant system H. These types of processes arise naturally in Reflection Seismology. In this paper we are interested in several problems: (a) Blind-Deconvolution: Can we recover both the filter $H$ and the sparse signal $u$ from noisy measurements? (b) Compressive Sensing: Is x compressible in the conventional sense of compressed sensing? Namely, can x, u and H be reconstructed from a sparse set of measurements. We develop novel L1 minimization methods to solve both cases and establish sufficient conditions for exact recovery for the case when the unknown system H is auto-regressive (i.e. all pole) of a known order. In the compressed sensing/sampling setting it turns out that both H and x can be reconstructed from O(k log(n)) measurements under certain technical conditions on the support structure of u. Our main idea is to pass x through a linear time invariant system G and collect O(k lo...

  12. Compressing spatio-temporal trajectories

    Gudmundsson, Joachim; Katajainen, Jyrki; Merrick, Damian


    A trajectory is a sequence of locations, each associated with a timestamp, describing the movement of a point. Trajectory data is becoming increasingly available and the size of recorded trajectories is getting larger. In this paper we study the problem of compressing planar trajectories such tha...

  13. Range Compressed Holographic Aperture Ladar


    digital holography, laser, active imaging, remote sensing, laser imaging 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT: SAR 8...slow speed tunable lasers, while relaxing the need to precisely track the transceiver or target motion. In the following section we describe a scenario...contrast targets. As shown in Figure 28, augmenting holographic ladar with range compression relaxes the dependence of image reconstruction on

  14. Compressive passive millimeter wave imager

    Gopalsami, Nachappa; Liao, Shaolin; Elmer, Thomas W; Koehl, Eugene R; Heifetz, Alexander; Raptis, Apostolos C


    A compressive scanning approach for millimeter wave imaging and sensing. A Hadamard mask is positioned to receive millimeter waves from an object to be imaged. A subset of the full set of Hadamard acquisitions is sampled. The subset is used to reconstruct an image representing the object.

  15. Excluded volume effects in compressed polymer brushes: A density functional theory

    Chen, Cangyi; Tang, Ping; Qiu, Feng; Shi, An-Chang


    A classical density functional theory (DFT) is applied to investigate the behavior of compressed polymer brushes composed of hard-sphere chains. The excluded volume interactions among the chain segments are explicitly treated. Two compression systems are used to study the behavior of brush-wall and brush-brush interactions. For the brush-brush systems, an obvious interpenetration zone has been observed. The extent of the interpenetration depends strongly on the grafting density. Furthermore, the repulsive force between the brush and wall or between the two brushes has been obtained as a function of the compression distance. Compared to the prediction of the analytic self-consistent field theory, such force increases more rapidly in the brush-wall compression with high polymer grafting densities or at higher compressions. In the brush-brush compression system, the interpenetration between the two compressed brushes creates a "softer" interaction. The influence of hard-sphere solvents on the behavior of compressed brushes is also discussed.

  16. Semantic Source Coding for Flexible Lossy Image Compression

    Phoha, Shashi; Schmiedekamp, Mendel


    Semantic Source Coding for Lossy Video Compression investigates methods for Mission-oriented lossy image compression, by developing methods to use different compression levels for different portions...

  17. Compressibility effects in the shear layer over a rectangular cavity

    Beresh, Steven J.; Wagner, Justin; Casper, Katya Marie


    we studied the influence of compressibility on the shear layer over a rectangular cavity of variable width in a free stream Mach number range of 0.6–2.5 using particle image velocimetry data in the streamwise centre plane. As the Mach number increases, the vertical component of the turbulence intensity diminishes modestly in the widest cavity, but the two narrower cavities show a more substantial drop in all three components as well as the turbulent shear stress. Furthermore, this contrasts with canonical free shear layers, which show significant reductions in only the vertical component and the turbulent shear stress due to compressibility. The vorticity thickness of the cavity shear layer grows rapidly as it initially develops, then transitions to a slower growth rate once its instability saturates. When normalized by their estimated incompressible values, the growth rates prior to saturation display the classic compressibility effect of suppression as the convective Mach number rises, in excellent agreement with comparable free shear layer data. The specific trend of the reduction in growth rate due to compressibility is modified by the cavity width.

  18. Infraspinatus muscle atrophy from suprascapular nerve compression.

    Cordova, Christopher B; Owens, Brett D


    Muscle weakness without pain may signal a nerve compression injury. Because these injuries should be identified and treated early to prevent permanent muscle weakness and atrophy, providers should consider suprascapular nerve compression in patients with shoulder muscle weakness.


    Danny M. Deffenbaugh; Klaus Brun; Ralph E. Harris; J. Pete Harrell; Robert J. Mckee; J. Jeffrey Moore; Steven J. Svedeman; Anthony J. Smalley; Eugene L. Broerman; Robert A Hart; Marybeth G. Nored; Ryan S. Gernentz; Shane P. Siebenaler


    The U.S. natural gas pipeline industry is facing the twin challenges of increased flexibility and capacity expansion. To meet these challenges, the industry requires improved choices in gas compression to address new construction and enhancement of the currently installed infrastructure. The current fleet of installed reciprocating compression is primarily slow-speed integral machines. Most new reciprocating compression is and will be large, high-speed separable units. The major challenges with the fleet of slow-speed integral machines are: limited flexibility and a large range in performance. In an attempt to increase flexibility, many operators are choosing to single-act cylinders, which are causing reduced reliability and integrity. While the best performing units in the fleet exhibit thermal efficiencies between 90% and 92%, the low performers are running down to 50% with the mean at about 80%. The major cause for this large disparity is due to installation losses in the pulsation control system. In the better performers, the losses are about evenly split between installation losses and valve losses. The major challenges for high-speed machines are: cylinder nozzle pulsations, mechanical vibrations due to cylinder stretch, short valve life, and low thermal performance. To shift nozzle pulsation to higher orders, nozzles are shortened, and to dampen the amplitudes, orifices are added. The shortened nozzles result in mechanical coupling with the cylinder, thereby, causing increased vibration due to the cylinder stretch mode. Valve life is even shorter than for slow speeds and can be on the order of a few months. The thermal efficiency is 10% to 15% lower than slow-speed equipment with the best performance in the 75% to 80% range. The goal of this advanced reciprocating compression program is to develop the technology for both high speed and low speed compression that will expand unit flexibility, increase thermal efficiency, and increase reliability and integrity

  20. Magnetic Flux Compression Experiments Using Plasma Armatures

    Turner, M. W.; Hawk, C. W.; Litchford, R. J.


    Magnetic flux compression reaction chambers offer considerable promise for controlling the plasma flow associated with various micronuclear/chemical pulse propulsion and power schemes, primarily because they avoid thermalization with wall structures and permit multicycle operation modes. The major physical effects of concern are the diffusion of magnetic flux into the rapidly expanding plasma cloud and the development of Rayleigh-Taylor instabilities at the plasma surface, both of which can severely degrade reactor efficiency and lead to plasma-wall impact. A physical parameter of critical importance to these underlying magnetohydrodynamic (MHD) processes is the magnetic Reynolds number (R(sub m), the value of which depends upon the product of plasma electrical conductivity and velocity. Efficient flux compression requires R(sub m) less than 1, and a thorough understanding of MHD phenomena at high magnetic Reynolds numbers is essential to the reliable design and operation of practical reactors. As a means of improving this understanding, a simplified laboratory experiment has been constructed in which the plasma jet ejected from an ablative pulse plasma gun is used to investigate plasma armature interaction with magnetic fields. As a prelude to intensive study, exploratory experiments were carried out to quantify the magnetic Reynolds number characteristics of the plasma jet source. Jet velocity was deduced from time-of-flight measurements using optical probes, and electrical conductivity was measured using an inductive probing technique. Using air at 27-inHg vacuum, measured velocities approached 4.5 km/s and measured conductivities were in the range of 30 to 40 kS/m.

  1. Considerations and Algorithms for Compression of Sets

    Larsson, Jesper

    compression algorithm that allows transparent incorporation of various estimates for probability distribution. Our experimental results allow the conclusion that set compression can benefit from incorporat- ing statistics, using our method or variants of previously known techniques.......We consider compression of unordered sets of distinct elements. After a discus- sion of the general problem, we focus on compressing sets of fixed-length bitstrings in the presence of statistical information. We survey techniques from previous work, suggesting some adjustments, and propose a novel...

  2. Cascaded quadratic soliton compression at 800 nm

    Bache, Morten; Bang, Ole; Moses, Jeffrey;


    We study soliton compression in quadratic nonlinear materials at 800 nm, where group-velocity mismatch dominates. We develop a nonlocal theory showing that efficient compression depends strongly on characteristic nonlocal time scales related to pulse dispersion.......We study soliton compression in quadratic nonlinear materials at 800 nm, where group-velocity mismatch dominates. We develop a nonlocal theory showing that efficient compression depends strongly on characteristic nonlocal time scales related to pulse dispersion....

  3. Still image and video compression with MATLAB

    Thyagarajan, K


    This book describes the principles of image and video compression techniques and introduces current and popular compression standards, such as the MPEG series. Derivations of relevant compression algorithms are developed in an easy-to-follow fashion. Numerous examples are provided in each chapter to illustrate the concepts. The book includes complementary software written in MATLAB SIMULINK to give readers hands-on experience in using and applying various video compression methods. Readers can enhance the software by including their own algorithms.

  4. Simultaneous denoising and compression of multispectral images

    Hagag, Ahmed; Amin, Mohamed; Abd El-Samie, Fathi E.


    A new technique for denoising and compression of multispectral satellite images to remove the effect of noise on the compression process is presented. One type of multispectral images has been considered: Landsat Enhanced Thematic Mapper Plus. The discrete wavelet transform (DWT), the dual-tree DWT, and a simple Huffman coder are used in the compression process. Simulation results show that the proposed technique is more effective than other traditional compression-only techniques.

  5. Image quality (IQ) guided multispectral image compression

    Zheng, Yufeng; Chen, Genshe; Wang, Zhonghai; Blasch, Erik


    Image compression is necessary for data transportation, which saves both transferring time and storage space. In this paper, we focus on our discussion on lossy compression. There are many standard image formats and corresponding compression algorithms, for examples, JPEG (DCT -- discrete cosine transform), JPEG 2000 (DWT -- discrete wavelet transform), BPG (better portable graphics) and TIFF (LZW -- Lempel-Ziv-Welch). The image quality (IQ) of decompressed image will be measured by numerical metrics such as root mean square error (RMSE), peak signal-to-noise ratio (PSNR), and structural Similarity (SSIM) Index. Given an image and a specified IQ, we will investigate how to select a compression method and its parameters to achieve an expected compression. Our scenario consists of 3 steps. The first step is to compress a set of interested images by varying parameters and compute their IQs for each compression method. The second step is to create several regression models per compression method after analyzing the IQ-measurement versus compression-parameter from a number of compressed images. The third step is to compress the given image with the specified IQ using the selected compression method (JPEG, JPEG2000, BPG, or TIFF) according to the regressed models. The IQ may be specified by a compression ratio (e.g., 100), then we will select the compression method of the highest IQ (SSIM, or PSNR). Or the IQ may be specified by a IQ metric (e.g., SSIM = 0.8, or PSNR = 50), then we will select the compression method of the highest compression ratio. Our experiments tested on thermal (long-wave infrared) images (in gray scales) showed very promising results.

  6. Brain image Compression, a brief survey

    Saleha Masood


    Full Text Available Brain image compression is known as a subfield of image compression. It allows the deep analysis and measurements of brain images in different modes. Brain images are compressed to analyze and diagnose in an effective manner while reducing the image storage space. This survey study describes the different existing techniques regarding brain image compression. The techniques come under different categories. The study also discusses these categories.

  7. Position index preserving compression of text data

    Akhtar, Nasim; Rashid, Mamunur; Islam, Shafiqul; Kashem, Mohammod Abul; Kolybanov, Cyrll Y.


    Data compression offers an attractive approach to reducing communication cost by using available bandwidth effectively. It also secures data during transmission for its encoded form. In this paper an index based position oriented lossless text compression called PIPC ( Position Index Preserving Compression) is developed. In PIPC the position of the input word is denoted by ASCII code. The basic philosopy of the secure compression is to preprocess the text and transform it into some intermedia...

  8. Rapid shallow breathing

    Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... Shallow, rapid breathing has many possible medical causes, including: Asthma Blood clot in an artery in the lung Choking Chronic obstructive ...

  9. H.264/AVC Video Compression on Smartphones

    Sharabayko, M. P.; Markov, N. G.


    In this paper, we studied the usage of H.264/AVC video compression tools by the flagship smartphones. The results show that only a subset of tools is used, meaning that there is still a potential to achieve higher compression efficiency within the H.264/AVC standard, but the most advanced smartphones are already reaching the compression efficiency limit of H.264/AVC.

  10. BPCS steganography using EZW lossy compressed images

    Spaulding, Jeremiah; Noda, Hideki; Shirazi, Mahdad N.; Kawaguchi, Eiji


    This paper presents a steganography method based on an embedded zerotree wavelet (EZW) compression scheme and bit-plane complexity segmentation (BPCS) steganography. The proposed steganography enables us to use lossy compressed images as dummy files in bit-plane-based steganographic algorithms. Large embedding rates of around 25% of the compressed image size were achieved with little noticeable degradation in image quality.

  11. Short-pulse, compressed ion beams at the Neutralized Drift Compression Experiment

    Seidl, P. A.; Barnard, J. J.; Davidson, R. C.; Friedman, A.; Gilson, E. P.; Grote, D.; Ji, Q.; Kaganovich, I. D.; Persaud, A.; Waldron, W. L.; Schenkel, T.


    We have commenced experiments with intense short pulses of ion beams on the Neutralized Drift Compression Experiment (NDCX-II) at Lawrence Berkeley National Laboratory, with 1-mm beam spot size within 2.5 ns full-width at half maximum. The ion kinetic energy is 1.2 MeV. To enable the short pulse duration and mm-scale focal spot radius, the beam is neutralized in a 1.5-meter-long drift compression section following the last accelerator cell. A short-focal-length solenoid focuses the beam in the presence of the volumetric plasma that is near the target. In the accelerator, the line-charge density increases due to the velocity ramp imparted on the beam bunch. The scientific topics to be explored are warm dense matter, the dynamics of radiation damage in materials, and intense beam and beam-plasma physics including select topics of relevance to the development of heavy-ion drivers for inertial fusion energy. Below the transition to melting, the short beam pulses offer an opportunity to study the multi-scale dynamics of radiation-induced damage in materials with pump-probe experiments, and to stabilize novel metastable phases of materials when short-pulse heating is followed by rapid quenching. First experiments used a lithium ion source; a new plasma-based helium ion source shows much greater charge delivered to the target.

  12. Stability of compressible boundary layers

    Nayfeh, Ali H.


    The stability of compressible 2-D and 3-D boundary layers is reviewed. The stability of 2-D compressible flows differs from that of incompressible flows in two important features: There is more than one mode of instability contributing to the growth of disturbances in supersonic laminar boundary layers and the most unstable first mode wave is 3-D. Whereas viscosity has a destabilizing effect on incompressible flows, it is stabilizing for high supersonic Mach numbers. Whereas cooling stabilizes first mode waves, it destabilizes second mode waves. However, second order waves can be stabilized by suction and favorable pressure gradients. The influence of the nonparallelism on the spatial growth rate of disturbances is evaluated. The growth rate depends on the flow variable as well as the distance from the body. Floquet theory is used to investigate the subharmonic secondary instability.

  13. Conservative regularization of compressible flow

    Krishnaswami, Govind S; Thyagaraja, Anantanarayanan


    Ideal Eulerian flow may develop singularities in vorticity w. Navier-Stokes viscosity provides a dissipative regularization. We find a local, conservative regularization - lambda^2 w times curl(w) of compressible flow and compressible MHD: a three dimensional analogue of the KdV regularization of the one dimensional kinematic wave equation. The regulator lambda is a field subject to the constitutive relation lambda^2 rho = constant. Lambda is like a position-dependent mean-free path. Our regularization preserves Galilean, parity and time-reversal symmetries. We identify locally conserved energy, helicity, linear and angular momenta and boundary conditions ensuring their global conservation. Enstrophy is shown to remain bounded. A swirl velocity field is identified, which transports w/rho and B/rho generalizing the Kelvin-Helmholtz and Alfven theorems. A Hamiltonian and Poisson bracket formulation is given. The regularized equations are used to model a rotating vortex, channel flow, plane flow, a plane vortex ...

  14. Compressing DNA sequence databases with coil

    Hendy Michael D


    Full Text Available Abstract Background Publicly available DNA sequence databases such as GenBank are large, and are growing at an exponential rate. The sheer volume of data being dealt with presents serious storage and data communications problems. Currently, sequence data is usually kept in large "flat files," which are then compressed using standard Lempel-Ziv (gzip compression – an approach which rarely achieves good compression ratios. While much research has been done on compressing individual DNA sequences, surprisingly little has focused on the compression of entire databases of such sequences. In this study we introduce the sequence database compression software coil. Results We have designed and implemented a portable software package, coil, for compressing and decompressing DNA sequence databases based on the idea of edit-tree coding. coil is geared towards achieving high compression ratios at the expense of execution time and memory usage during compression – the compression time represents a "one-off investment" whose cost is quickly amortised if the resulting compressed file is transmitted many times. Decompression requires little memory and is extremely fast. We demonstrate a 5% improvement in compression ratio over state-of-the-art general-purpose compression tools for a large GenBank database file containing Expressed Sequence Tag (EST data. Finally, coil can efficiently encode incremental additions to a sequence database. Conclusion coil presents a compelling alternative to conventional compression of flat files for the storage and distribution of DNA sequence databases having a narrow distribution of sequence lengths, such as EST data. Increasing compression levels for databases having a wide distribution of sequence lengths is a direction for future work.

  15. Antiproton compression and radial measurements

    Andresen, G. B.; Bertsche, W.; Bowe, P. D.; Bray, C. C.; Butler, E.; Cesar, C. L.; Chapman, S.; Charlton, M.; Fajans, J.; Fujiwara, M. C.; Funakoshi, R.; Gill, D. R.; Hangst, J. S.; Hardy, W. N.; Hayano, R. S.; Hayden, M. E.; Humphries, A. J.; Hydomako, R.; Jenkins, M. J.; Jørgensen, L. V.; Kurchaninov, L.; Lambo, R.; Madsen, N.; Nolan, P.; Olchanski, K.; Olin, A.; Page, R. D.; Povilus, A.; Pusa, P.; Robicheaux, F.; Sarid, E.; El Nasr, S. Seif; Silveira, D. M.; Storey, J. W.; Thompson, R. I.; van der Werf, D. P.; Wurtele, J. S.; Yamazaki, Y.


    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, achieved by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile, and its relation to that of the electron plasma. We also measure the outer radial profile by ejecting antiprotons to the trap wall using an octupole magnet.

  16. Direct compression properties of melt-extruded isomalt.

    Ndindayino, F; Henrist, D; Kiekens, F; Van den Mooter, G; Vervaet, C; Remon, J P


    Isomalt, a sugar alcohol, was melt-extruded prior to compression in order to improve its tabletting properties. After fusion, crystalline isomalt was transformed into an amorphous form as shown by X-ray diffraction and differential scanning calorimetry (DSC). The tabletting properties of amorphous isomalt were dramatically improved. Mixtures formulated with paracetamol (50%) and extruded isomalt yielded hard tablets. However, extruded isomalt powder showed agglomeration problems due to recrystallization of the amorphous phase into a stable crystalline form in the presence of atmospheric moisture. The evolution of the moisture content correlated well with the compressibility data. The tablets made of extruded isomalt powder had a lower friability in comparison to the tablets formulated with non-extruded isomalt powder. Their disintegration was fast and a rapid dissolution rate was recorded. Extruded isomalt displayed excellent tabletting properties; however, further experiments should be conducted to delay or even prevent recrystallization of amorphous isomalt.

  17. Compressibility effects on turbulent mixing

    Panickacheril John, John; Donzis, Diego


    We investigate the effect of compressibility on passive scalar mixing in isotropic turbulence with a focus on the fundamental mechanisms that are responsible for such effects using a large Direct Numerical Simulation (DNS) database. The database includes simulations with Taylor Reynolds number (Rλ) up to 100, turbulent Mach number (Mt) between 0.1 and 0.6 and Schmidt number (Sc) from 0.5 to 1.0. We present several measures of mixing efficiency on different canonical flows to robustly identify compressibility effects. We found that, like shear layers, mixing is reduced as Mach number increases. However, data also reveal a non-monotonic trend with Mt. To assess directly the effect of dilatational motions we also present results with both dilatational and soleniodal forcing. Analysis suggests that a small fraction of dilatational forcing decreases mixing time at higher Mt. Scalar spectra collapse when normalized by Batchelor variables which suggests that a compressive mechanism similar to Batchelor mixing in incompressible flows might be responsible for better mixing at high Mt and with dilatational forcing compared to pure solenoidal mixing. We also present results on scalar budgets, in particular on production and dissipation. Support from NSF is gratefully acknowledged.

  18. Laser Compression of Nanocrystalline Metals

    Meyers, M. A.; Jarmakani, H. N.; Bringa, E. M.; Earhart, P.; Remington, B. A.; Vo, N. Q.; Wang, Y. M.


    Shock compression in nanocrystalline nickel is simulated over a range of pressures (10-80 GPa) and compared with experimental results. Laser compression carried out at Omega and Janus yields new information on the deformation mechanisms of nanocrystalline Ni. Although conventional deformation does not produce hardening, the extreme regime imparted by laser compression generates an increase in hardness, attributed to the residual dislocations observed in the structure by TEM. An analytical model is applied to predict the critical pressure for the onset of twinning in nanocrystalline nickel. The slip-twinning transition pressure is shifted from 20 GPa, for polycrystalline Ni, to 80 GPa, for Ni with g. s. of 10 nm. Contributions to the net strain from the different mechanisms of plastic deformation (partials, perfect dislocations, twinning, and grain boundary shear) were quantified in the nanocrystalline samples through MD calculations. The effect of release, a phenomenon often neglected in MD simulations, on dislocation behavior was established. A large fraction of the dislocations generated at the front are annihilated.

  19. Image Compression Using Discrete Wavelet Transform

    Mohammad Mozammel Hoque Chowdhury


    Full Text Available Image compression is a key technology in transmission and storage of digital images because of vast data associated with them. This research suggests a new image compression scheme with pruning proposal based on discrete wavelet transformation (DWT. The effectiveness of the algorithm has been justified over some real images, and the performance of the algorithm has been compared with other common compression standards. The algorithm has been implemented using Visual C++ and tested on a Pentium Core 2 Duo 2.1 GHz PC with 1 GB RAM. Experimental results demonstrate that the proposed technique provides sufficient high compression ratios compared to other compression techniques.

  20. Compression Waves and Phase Plots: Simulations

    Orlikowski, Daniel


    Compression wave analysis started nearly 50 years ago with Fowles.[1] Coperthwaite and Williams [2] gave a method that helps identify simple and steady waves. We have been developing a method that gives describes the non-isentropic character of compression waves, in general.[3] One result of that work is a simple analysis tool. Our method helps clearly identify when a compression wave is a simple wave, a steady wave (shock), and when the compression wave is in transition. This affects the analysis of compression wave experiments and the resulting extraction of the high-pressure equation of state.

  1. Mathematical theory of compressible fluid flow

    Von Mises, Richard


    Mathematical Theory of Compressible Fluid Flow covers the conceptual and mathematical aspects of theory of compressible fluid flow. This five-chapter book specifically tackles the role of thermodynamics in the mechanics of compressible fluids. This text begins with a discussion on the general theory of characteristics of compressible fluid with its application. This topic is followed by a presentation of equations delineating the role of thermodynamics in compressible fluid mechanics. The discussion then shifts to the theory of shocks as asymptotic phenomena, which is set within the context of

  2. Video compressive sensing using Gaussian mixture models.

    Yang, Jianbo; Yuan, Xin; Liao, Xuejun; Llull, Patrick; Brady, David J; Sapiro, Guillermo; Carin, Lawrence


    A Gaussian mixture model (GMM)-based algorithm is proposed for video reconstruction from temporally compressed video measurements. The GMM is used to model spatio-temporal video patches, and the reconstruction can be efficiently computed based on analytic expressions. The GMM-based inversion method benefits from online adaptive learning and parallel computation. We demonstrate the efficacy of the proposed inversion method with videos reconstructed from simulated compressive video measurements, and from a real compressive video camera. We also use the GMM as a tool to investigate adaptive video compressive sensing, i.e., adaptive rate of temporal compression.

  3. Compression therapy in elderly and overweight patients.

    Reich-Schupke, Stefanie; Murmann, Friederike; Altmeyer, Peter; Stücker, Markus


    According to the current demography of the western population, age and weight will have increasing impact on medical therapies. The aim of the analysis was to examine if there are differences in the use of compression therapy depending on age and BMI. Questioning of 200 consecutive phlebological patients (C2-C6) with a compression therapy time of > 2 weeks. Analysis of 110 returned questionnaires. Sub-analysis according to age (≥ 60 years vs. 60 years even need the help of another person to apply compression. Patients ≥ 25 kg/m2 have an ulcer stocking significantly more often (15 % vs. 4.3 %, p = 0.05) and need the help of family members to put on the compression therapy (11.7 % vs. 2.1 %, p = 0.04). There is a tendency of patients ≥ 25 kg/m2 to complain more often about a constriction of compression therapy (35 % vs. 19.2 %, p = 0.06). There are special aspects that have to be regarded for compression therapy in elderly and overweight patients. Data should encourage prescribers, sellers and manufacturers of compression therapy to use compression in a very differentiated way for these patients and to consider: Is the recommended compression therapy right for this patient (pressure, material, type)? What advice and adjuvants do the patients need to get along more easily with the compression therapy? Are there any new materials or adjuvants that allow those increasing groups of people to get along with compression therapy alone?

  4. Chapter 22: Compressed Air Evaluation Protocol

    Benton, N.


    Compressed-air systems are used widely throughout industry for many operations, including pneumatic tools, packaging and automation equipment, conveyors, and other industrial process operations. Compressed-air systems are defined as a group of subsystems composed of air compressors, air treatment equipment, controls, piping, pneumatic tools, pneumatically powered machinery, and process applications using compressed air. A compressed-air system has three primary functional subsystems: supply, distribution, and demand. Air compressors are the primary energy consumers in a compressed-air system and are the primary focus of this protocol. The two compressed-air energy efficiency measures specifically addressed in this protocol are: high-efficiency/variable speed drive (VSD) compressor replacing modulating compressor; compressed-air leak survey and repairs. This protocol provides direction on how to reliably verify savings from these two measures using a consistent approach for each.

  5. Binary-phase compression of stretched pulses

    Lozovoy, Vadim V.; Nairat, Muath; Dantus, Marcos


    Pulse stretching and compression are essential for the energy scale-up of ultrafast lasers. Here, we consider a radical approach using spectral binary phases, containing only two values (0 and π) for stretching and compressing laser pulses. We numerically explore different strategies and present results for pulse compression of factors up to a million back to the transform limit and experimentally obtain results for pulse compression of a factor of one hundred, in close agreement with numerical calculations. Imperfections resulting from binary-phase compression are addressed by considering cross-polarized wave generation filtering, and show that this approach leads to compressed pulses with contrast ratios greater than ten orders of magnitude. This new concept of binary-phase stretching and compression, if implemented in a multi-layer optic, could eliminate the need for traditional pulse stretchers and more importantly expensive compressors.

  6. Bit-Optimal Lempel-Ziv compression

    Ferragina, Paolo; Venturini, Rossano


    One of the most famous and investigated lossless data-compression scheme is the one introduced by Lempel and Ziv about 40 years ago. This compression scheme is known as "dictionary-based compression" and consists of squeezing an input string by replacing some of its substrings with (shorter) codewords which are actually pointers to a dictionary of phrases built as the string is processed. Surprisingly enough, although many fundamental results are nowadays known about upper bounds on the speed and effectiveness of this compression process and references therein), ``we are not aware of any parsing scheme that achieves optimality when the LZ77-dictionary is in use under any constraint on the codewords other than being of equal length'' [N. Rajpoot and C. Sahinalp. Handbook of Lossless Data Compression, chapter Dictionary-based data compression. Academic Press, 2002. pag. 159]. Here optimality means to achieve the minimum number of bits in compressing each individual input string, without any assumption on its ge...

  7. Rapid natural resolution of intracranial hematoma

    吴明灿; 刘建雄; 罗国才; 张志文; 闵杰; 余辉; 姚远


    Objective:To investigate the clinical characteristics of intracranial hematoma and the mechanism involved in its rapid natural resolution. Methods:Seventeen cases of intracranial hematoma with typical clinical and CT manifestations were retrospectively studied. Results: Intracranial hematoma was found obviously decreased in size within 72 h after its occurrence in 8 cases. The rest 9 cases presented complete resolution. Conclusions: Rapid natural resolution of acute epidural hematoma is mostly found in teenagers and the resolution is correlated with cranial fracture at the hematoma site. As for acute subdural hematoma, its rapid resolution is associated with the transfer of cerebrospinal fluid toward subdural space, the lavage effect, and the compression caused by the increased intracranial pressure or the space left resulting from redistribution of the hematoma in brain atrophy.

  8. Envera Variable Compression Ratio Engine

    Charles Mendler


    Aggressive engine downsizing, variable compression ratio and use of the Atkinson cycle are being combined to improve fuel economy by up to 40 percent relative to port fuel injected gasoline engines, while maintaining full engine power. Approach Engine downsizing is viewed by US and foreign automobile manufacturers as one of the best options for improving fuel economy. While this strategy has already demonstrated a degree of success, downsizing and fuel economy gains are currently limited. With new variable compression ratio technology however, the degree of engine downsizing and fuel economy improvement can be greatly increased. A small variable compression ratio (VCR) engine has the potential to return significantly higher vehicle fuel economy while also providing high power. Affordability and potential for near term commercialization are key attributes of the Envera VCR engine. VCR Technology To meet torque and power requirements, a smaller engine needs to do more work per stroke. This is typically accomplished by boosting the incoming charge with either a turbo or supercharger so that more energy is present in the cylinder per stroke to do the work. With current production engines the degree of engine boosting (which correlates to downsizing) is limited by detonation (combustion knock) at high boost levels. Additionally, the turbo or supercharger needs to be responsive and efficient while providing the needed boost. VCR technology eliminates the limitation of engine knock at high load levels by reducing compression ratio to {approx}9:1 (or whatever level is appropriate) when high boost pressures are needed. By reducing the compression ratio during high load demand periods there is increased volume in the cylinder at top dead center (TDC) which allows more charge (or energy) to be present in the cylinder without increasing the peak pressure. Cylinder pressure is thus kept below the level at which the engine would begin to knock. When loads on the engine are low

  9. Digital image compression in dermatology: format comparison.

    Guarneri, F; Vaccaro, M; Guarneri, C


    Digital image compression (reduction of the amount of numeric data needed to represent a picture) is widely used in electronic storage and transmission devices. Few studies have compared the suitability of the different compression algorithms for dermatologic images. We aimed at comparing the performance of four popular compression formats, Tagged Image File (TIF), Portable Network Graphics (PNG), Joint Photographic Expert Group (JPEG), and JPEG2000 on clinical and videomicroscopic dermatologic images. Nineteen (19) clinical and 15 videomicroscopic digital images were compressed using JPEG and JPEG2000 at various compression factors and TIF and PNG. TIF and PNG are "lossless" formats (i.e., without alteration of the image), JPEG is "lossy" (the compressed image has a lower quality than the original), JPEG2000 has a lossless and a lossy mode. The quality of the compressed images was assessed subjectively (by three expert reviewers) and quantitatively (by measuring, point by point, the color differences from the original). Lossless JPEG2000 (49% compression) outperformed the other lossless algorithms, PNG and TIF (42% and 31% compression, respectively). Lossy JPEG2000 compression was slightly less efficient than JPEG, but preserved image quality much better, particularly at higher compression factors. For its good quality and compression ratio, JPEG2000 appears to be a good choice for clinical/videomicroscopic dermatologic image compression. Additionally, its diffusion and other features, such as the possibility of embedding metadata in the image file and to encode various parts of an image at different compression levels, make it perfectly suitable for the current needs of dermatology and teledermatology.

  10. Rapid-fire improvement with short-cycle kaizen.

    Heard, E


    Continuous improvement is an attractive idea, but it is typically more myth than reality. SCK is no myth. It delivers dramatic improvements in traditional measures quickly. SCK accomplishes this via kaizens: rapid, repeated, time-compressed changes for the better in bite-sized chunks of the business.

  11. Effect of cooling rate on microstructure and compressive performance of AZ91 magnesium alloy

    YANG Lin; FENG Hui; QIU Ke-qiang; CHEN Li-jia; LIU Zheng


    Effect of cooling rate on both microstructure and room temperature compressive performance of the AZ91 magnesium alloy was investigated. The experimental results show that with increasing cooling rate, the quantity of the solid solution phase increases and the fraction of secondary phase Mg17Al12 decreases. The almost single solid solution phase can be obtained with using liquid nitrogen as a coolant. The compressive strengths of the rapid solidified AZ91 magnesium alloys are higher than those of normal cast alloy, and decrease with increasing cooling rate. After artificial aging treatment for 14 h at 168 ℃, the compressive strength of the rapidly solidified AZ91 magnesium alloy cooled in liquid nitrogen increases from 253.5 to 335.3 MPa, while the compressive yield strength increases from 138.1 to 225.91 MPa. The improvement in the compressive strength of the rapidly solidified AZ91magnesium alloys can be attributed to the hardening effect from fine secondary phase.

  12. Fast Plasma Instrument for MMS: Data Compression Simulation Results

    Barrie, A.; Adrian, M. L.; Yeh, P.; Winkert, G.; Lobell, J.; Vinas, A. F.; Simpson, D. G.


    Magnetospheric Multiscale (MMS) mission will study small-scale reconnection structures and their rapid motions from closely spaced platforms using instruments capable of high angular, energy, and time resolution measurements. To meet these requirements, the Fast Plasma Instrument (FPI) consists of eight (8) identical half top-hat electron sensors and eight (8) identical ion sensors and an Instrument Data Processing Unit (IDPU). The sensors (electron or ion) are grouped into pairs whose 6° x 180° fields-of-view (FOV) are set 90° apart. Each sensor is equipped with electrostatic aperture steering to allow the sensor to scan a 45° x 180° fan about the its nominal viewing (0° deflection) direction. Each pair of sensors, known as the Dual Electron Spectrometer (DES) and the Dual Ion Spectrometer (DIS), occupies a quadrant on the MMS spacecraft and the combination of the eight electron/ion sensors, employing aperture steering, image the full-sky every 30-ms (electrons) and 150-ms (ions), respectively. To probe the diffusion regions of reconnection, the highest temporal/spatial resolution mode of FPI results in the DES complement of a given spacecraft generating 6.5-Mb s-1 of electron data while the DIS generates 1.1-Mb s-1 of ion data yielding an FPI total data rate of 6.6-Mb s-1. The FPI electron/ion data is collected by the IDPU then transmitted to the Central Data Instrument Processor (CIDP) on the spacecraft for science interest ranking. Only data sequences that contain the greatest amount of temporal/spatial structure will be intelligently down-linked by the spacecraft. Currently, the FPI data rate allocation to the CIDP is 1.5-Mb s-1. Consequently, the FPI-IDPU must employ data/image compression to meet this CIDP telemetry allocation. Here, we present updated simulations of the CCSDS 122.0-B-1 algorithm-based compression of the FPI-DES electron data as well as the FPI-DIS ion data. Compression analysis is based upon a seed of re-processed Cluster

  13. Does an Arithmetic Coding Followed by Run-length Coding Enhance the Compression Ratio?

    Mohammed Otair


    Full Text Available Compression is a technique to minimize the quantity of image without excessively decreasing the quality of the image. Then, the translating of compressed image is much more efficient and rapidly than original image. Arithmetic and Huffman coding are mostly used techniques in the entropy coding. This study tries to prove that RLC may be added after Arithmetic coding as an extra processing step which may therefore be coded efficiently without any further degradation of the image quality. So, the main purpose of this study is to answer the following question "Which entropy coding, arithmetic with RLC or Huffman with RLC, is more suitable from the compression ratio perspective?" Finally, experimental results show that an Arithmetic followed by RLC coding yields better compression performance than Huffman with RLC coding.

  14. Thermal compression waves. 2: Mass adjustment and vertical transfer of the total energy

    Nicholls, Melville E.; Pielke, Roger A.


    A fully compressible model is used to simulate the mass adjustment that occurs in response to a prescribed heat source. Results illustrate the role that thermal compression waves have in this process. The vertical mass transport associated with compression waves decreases rapidly with height. Most of the mass transport occurs in the horizontal, with the vertical structure of the disturbance similar to that of a Lamb wave. The vertical transfer of total energy in a thermally driven mixed layer is also examined. It is shown that the upward transport of total energy is accomplished by a compression effect rather than by the exchange of warm and cold air by buoyant thermals. Model results are analyzed to determine budgets of total energy, mass and entropy. It is demonstrated that buoyant thermals are predominantly responsible for a transfer of entropy, rather than total energy. In the light of these results the notion of 'heat transport' in a fluid is discussed.

  15. Compression failure mechanisms of single-ply, unidirectional, carbon-fiber composites

    Ha, Jong-Bae; Nairn, John A.


    A single-ply composite compression test was used to study compression failure mechanisms as a function of fiber type, matrix type, and interfacial strength. Composites made with low- and intermediate-modulus fibers (Hercules AS4 and IM7) in either an epoxy (Hercules 3501-6) or a thermoplastic (ULTEM and LARC-TPI) matrix failed by kink banding and out-of-plane slip. The failures proceeded by rapid and catastrophic damage propagation across the specimen width. Composites made with high-modulus fibers (Hercules HMS4/3501-6) had a much lower compression strength. Their failures were characterized by kink banding and longitudinal splitting. The damage propagated slowly across the specimen width. Composites made with fibers treated to give low interfacial strength had low compression strength. These composites typically failed near the specimen ends and had long kink bands.

  16. The Lateral Compressive Buckling Performance of Aluminum Honeycomb Panels for Long-Span Hollow Core Roofs

    Caiqi Zhao


    Full Text Available To solve the problem of critical buckling in the structural analysis and design of the new long-span hollow core roof architecture proposed in this paper (referred to as a “honeycomb panel structural system” (HSSS, lateral compression tests and finite element analyses were employed in this study to examine the lateral compressive buckling performance of this new type of honeycomb panel with different length-to-thickness ratios. The results led to two main conclusions: (1 Under the experimental conditions that were used, honeycomb panels with the same planar dimensions but different thicknesses had the same compressive stiffness immediately before buckling, while the lateral compressive buckling load-bearing capacity initially increased rapidly with an increasing honeycomb core thickness and then approached the same limiting value; (2 The compressive stiffnesses of test pieces with the same thickness but different lengths were different, while the maximum lateral compressive buckling loads were very similar. Overall instability failure is prone to occur in long and flexible honeycomb panels. In addition, the errors between the lateral compressive buckling loads from the experiment and the finite element simulations are within 6%, which demonstrates the effectiveness of the nonlinear finite element analysis and provides a theoretical basis for future analysis and design for this new type of spatial structure.

  17. Drift compression and final focus systems for heavy ion inertial fusion

    de Hoon, Michiel Jan Laurens [Univ. of California, Berkeley, CA (United States)


    Longitudinal compression of space-charge dominated beams can be achieved by imposing a head-to-tail velocity tilt on the beam. This tilt has to be carefully tailored, such that it is removed by the longitudinal space-charge repulsion by the time the beam reaches the end of the drift compression section. The transverse focusing lattice should be designed such that all parts of the beam stay approximately matched, while the beam smoothly expands transversely to the larger beam radius needed in the final focus system following drift compression. In this thesis, several drift compression systems were designed within these constraints, based on a given desired pulse shape at the end of drift compression systems were designed within these constraints, based on a given desired pulse shape at the end of drift compression. The occurrence of mismatches due to a rapidly increasing current was analyzed. In addition, the sensitivity of drift compression to errors in the initial velocity tilt and current profile was studied. These calculations were done using a new computer code that accurately calculates the longitudinal electric field in the space-charge dominated regime.

  18. Algorithmic height compression of unordered trees.

    Ben-Naoum, Farah; Godin, Christophe


    By nature, tree structures frequently present similarities between their sub-parts. Making use of this redundancy, different types of tree compression techniques have been designed in the literature to reduce the complexity of tree structures. A popular and efficient way to compress a tree consists of merging its isomorphic subtrees, which produces a directed acyclic graph (DAG) equivalent to the original tree. An important property of this method is that the compressed structure (i.e. the DAG) has the same height as the original tree, thus limiting partially the possibility of compression. In this paper we address the problem of further compressing this DAG in height. The difficulty is that compression must be carried out on substructures that are not exactly isomorphic as they are strictly nested within each-other. We thus introduced a notion of quasi-isomorphism between subtrees that makes it possible to define similar patterns along any given path in a tree. We then proposed an algorithm to detect these patterns and to merge them, thus leading to compressed structures corresponding to DAGs augmented with return edges. In this way, redundant information is removed from the original tree in both width and height, thus achieving minimal structural compression. The complete compression algorithm is then illustrated on the compression of various plant-like structures.

  19. Instability of ties in compression

    Buch-Hansen, Thomas Cornelius


    Masonry cavity walls are loaded by wind pressure and vertical load from upper floors. These loads results in bending moments and compression forces in the ties connecting the outer and the inner wall in a cavity wall. Large cavity walls are furthermore loaded by differential movements from...... exact instability solutions are complex to derive, not to mention the extra complexity introducing dimensional instability from the temperature gradients. Using an inverse variable substitution and comparing an exact theory with an analytical instability solution a method to design tie...

  20. Ab initio compressive phase retrieval

    Marchesini, S


    Any object on earth has two fundamental properties: it is finite, and it is made of atoms. Structural information about an object can be obtained from diffraction amplitude measurements that account for either one of these traits. Nyquist-sampling of the Fourier amplitudes is sufficient to image single particles of finite size at any resolution. Atomic resolution data is routinely used to image molecules replicated in a crystal structure. Here we report an algorithm that requires neither information, but uses the fact that an image of a natural object is compressible. Intended applications include tomographic diffractive imaging, crystallography, powder diffraction, small angle x-ray scattering and random Fourier amplitude measurements.

  1. Lossless Compression of Digital Images

    Martins, Bo

    Presently, tree coders are the best bi-level image coders. The currentISO standard, JBIG, is a good example.By organising code length calculations properly a vast number of possible models (trees) can be investigated within reasonable time prior to generating code.A number of general-purpose coders...... version that is substantially faster than its precursorsand brings it close to the multi-pass coders in compression performance.Handprinted characters are of unequal complexity; recent work by Singer and Tishby demonstrates that utilizing the physiological process of writing one can synthesize cursive...

  2. Antiproton compression and radial measurements

    Andresen, G B; Bowe, P D; Bray, C C; Butler, E; Cesar, C L; Chapman, S; Charlton, M; Fajans, J; Fujiwara, M C; Funakoshi, R; Gill, D R; Hangst, J S; Hardy, W N; Hayano, R S; Hayden, M E; Humphries, A J; Hydomako, R; Jenkins, M J; Jorgensen, L V; Kurchaninov, L; Lambo, R; Madsen, N; Nolan, P; Olchanski, K; Olin, A; Page R D; Povilus, A; Pusa, P; Robicheaux, F; Sarid, E; Seif El Nasr, S; Silveira, D M; Storey, J W; Thompson, R I; Van der Werf, D P; Wurtele, J S; Yamazaki, Y


    Control of the radial profile of trapped antiproton clouds is critical to trapping antihydrogen. We report detailed measurements of the radial manipulation of antiproton clouds, including areal density compressions by factors as large as ten, achieved by manipulating spatially overlapped electron plasmas. We show detailed measurements of the near-axis antiproton radial profile, and its relation to that of the electron plasma. We also measure the outer radial profile by ejecting antiprotons to the trap wall using an octupole magnet.

  3. Lossless Compression of Broadcast Video

    Martins, Bo; Eriksen, N.; Faber, E.


    complexity, difficult but natural material is compressed up to 20\\% better than with coding using lossless JPEG-LS. More complex schemes lower the bit rate even further. A real-time implementation of JPEG-LS may be carried out in a DSP environment or a FPGA environment. Conservative analysis supported...... with actual measurements on a DSP suggests that a real-time implementation may be carried out using about 5 DSPs. An FPGA based solution is estimated to demand 4 or 6 FPGAs (each 40.000 gate equivalent)...

  4. Image Quality Meter Using Compression

    Muhammad Ibrar-Ul-Haque


    Full Text Available This paper proposed a new technique to compressed image blockiness/blurriness in frequency domain through edge detection method by applying Fourier transform. In image processing, boundaries are characterized by edges and thus, edges are the problems of fundamental importance. The edges have to be identified and computed thoroughly in order to retrieve the complete illustration of the image. Our novel edge detection scheme for blockiness and blurriness shows improvement of 60 and 100 blocks for high frequency components respectively than any other detection technique.

  5. Photovoltaic driven vapor compression cycles

    Anand, D. K.

    Since the vast majority of heat pumps, air conditioning and refrigeration equipment employs the vapor compression cycle (VCC), the use of renewable energy represents a significant opportunity. As discussed in this report, it is clear that the use of photovoltaics (PV) to drive the VCC has more potential than any other active solar cooling approach. This potential exists due to improvements in not only the PV cells but VCC machinery and control algorithms. It is estimated that the combined improvements will result in reducing the PV cell requirements by as much as one half.

  6. Initial results for compressive sensing in electronic support receiver systems

    Du Plessis, WP


    Full Text Available of 80 Gb/s which is 25% more than the optimistic assumption of 64 Gb/s for the fastest Serial RapidIO line. This means that data will take 25% longer to read from memory than it took to write into memory, so the above example will only be sampling 44... of compressive sensing are considered in Section V showing that real-time operation is possible. Finally, a brief conclusion and suggestions for future research are provided in Section VI. II. DATA RATES OF MODERN ES SYSTEMS AND THEIR EFFECT ON SYSTEM...

  7. Mechanical Properties and Compression Sensibility of Ironstone Aggregate Concrete

    DING Shijing; GE Debiao; ZHAO Yuezhi; YANG Jixiang


    Radiation-shielding concrete was made with ironstone aggregate.The compressive strength is affected by multi factors.The electrical conductive properties and smart performance was discovered and investigated.Experimental results show that concrete conductivity rapidly declines with increasing loading,and the conductivity is much lower than the initial value of conductive aggregate of concrete,which may be related to special characters of ironstone.This kind of concrete has widely potential applications due to its special characters and low cost.

  8. Compressibility effects in the Kemp-Sears Problem

    Mani, R.


    The effects of including compressibility in the Kemp-Sears problem of aerodynamic interference between moving blade rows are examined. Methods of linearized, subsonic, plane, unsteady flow are adopted. The major new effect is that a resonance appears at certain combinations of flow Mach number, tip Mach number, and blade vane ratios. The resonance is at exactly the Tyler-Sofrin cutoff condition for rotor-stator interaction. At such conditions the unsteady lift on a blade row due to externally imposed nonstationary upwash vanishes. However, the resonance appears to be very sharp and seems to be more significant as an indication that around this condition the unsteady lift changes very rapidly.

  9. A 50 cc Two-Stroke DI Compression Ignition Engine Fuelled by DME

    Hansen, Kim Rene; Nielsen, Claus Suldrup; Sorenson, Spencer C


    The low auto-ignition temperature, rapid evaporation and high cetane number of dimethyl ether (DME) enables the use of low-pressure direct injection in compression ignition engines, thus potentially bringing the cost of the injection system down. This in turn holds the promise of bringing CI effi...

  10. Hayman uterine compression stitch for arresting atonic postpartum hemorrhage: 5 years experience

    Smiti Nanda


    Conclusion: Two parallel vertical compression sutures (Hayman stitch placed in the uterus controls bleeding effectively. The technique is easy, rapid and requires less skill and this simple procedure be tried first before other complex measures like uterine artery ligation are undertaken particularly for those obstetricians who lack sufficient training and skill.

  11. Compression des fichiers son de type wave.

    BAKLI, Meriem


    Ce travail de projet de fin d’étude s’intéresse à une étude comparative sur la compression d’un fichier son. La compression est l'action utilisée pour réduire la taille physique d'un bloc d'information.. Il existe plusieurs algorithmes pour la compression comme HUFFMAN, …etc. Nous avons fait la compression d’un fichier son de format WAVE non compressé à un fichier MP3 compressé avec différent format de codage, différent frame et quelque soit le fichier mono où stéréo. A partir ...

  12. Direct numerical simulation of compressible isotropic turbulence

    LI; Xinliang(李新亮); FU; Dexun(傅德薰); MAYanwen(马延文)


    Direct numerical simulation (DNS) of decaying compressible isotropic turbulence at tur-bulence Mach numbers of Mt = 0.2-0.7 and Taylor Reynolds numbers of 72 and 153 is per-formed by using the 7th order upwind-biased difference and 8th order center difference schemes.Results show that proper upwind-biased difference schemes can release the limit of "start-up"problem to Mach numbers.Compressibility effects on the statistics of turbulent flow as well as the mechanics of shockletsin compressible turbulence are also studied, and the conclusion is drawn that high Mach numberleads to more dissipation. Scaling laws in compressible turbulence are also analyzed. Evidence isobtained that scaling laws and extended self similarity (ESS) hold in the compressible turbulentflow in spite of the presence of shocklets, and compressibility has little effect on scaling exponents.

  13. Accelerating Lossless Data Compression with GPUs

    Cloud, R L; Ward, H L; Skjellum, A; Bangalore, P


    Huffman compression is a statistical, lossless, data compression algorithm that compresses data by assigning variable length codes to symbols, with the more frequently appearing symbols given shorter codes than the less. This work is a modification of the Huffman algorithm which permits uncompressed data to be decomposed into indepen- dently compressible and decompressible blocks, allowing for concurrent compression and decompression on multiple processors. We create implementations of this modified algorithm on a current NVIDIA GPU using the CUDA API as well as on a current Intel chip and the performance results are compared, showing favorable GPU performance for nearly all tests. Lastly, we discuss the necessity for high performance data compression in today's supercomputing ecosystem.

  14. Image Compression Using Harmony Search Algorithm

    Ryan Rey M. Daga


    Full Text Available Image compression techniques are important and useful in data storage and image transmission through the Internet. These techniques eliminate redundant information in an image which minimizes the physical space requirement of the image. Numerous types of image compression algorithms have been developed but the resulting image is still less than the optimal. The Harmony search algorithm (HSA, a meta-heuristic optimization algorithm inspired by the music improvisation process of musicians, was applied as the underlying algorithm for image compression. Experiment results show that it is feasible to use the harmony search algorithm as an algorithm for image compression. The HSA-based image compression technique was able to compress colored and grayscale images with minimal visual information loss.

  15. Industrial Compressed Air System Energy Efficiency Guidebook.

    United States. Bonneville Power Administration.


    Energy efficient design, operation and maintenance of compressed air systems in industrial plants can provide substantial reductions in electric power and other operational costs. This guidebook will help identify cost effective, energy efficiency opportunities in compressed air system design, re-design, operation and maintenance. The guidebook provides: (1) a broad overview of industrial compressed air systems, (2) methods for estimating compressed air consumption and projected air savings, (3) a description of applicable, generic energy conservation measures, and, (4) a review of some compressed air system demonstration projects that have taken place over the last two years. The primary audience for this guidebook includes plant maintenance supervisors, plant engineers, plant managers and others interested in energy management of industrial compressed air systems.

  16. LDPC Codes for Compressed Sensing

    Dimakis, Alexandros G; Vontobel, Pascal O


    We present a mathematical connection between channel coding and compressed sensing. In particular, we link, on the one hand, \\emph{channel coding linear programming decoding (CC-LPD)}, which is a well-known relaxation of maximum-likelihood channel decoding for binary linear codes, and, on the other hand, \\emph{compressed sensing linear programming decoding (CS-LPD)}, also known as basis pursuit, which is a widely used linear programming relaxation for the problem of finding the sparsest solution of an under-determined system of linear equations. More specifically, we establish a tight connection between CS-LPD based on a zero-one measurement matrix over the reals and CC-LPD of the binary linear channel code that is obtained by viewing this measurement matrix as a binary parity-check matrix. This connection allows the translation of performance guarantees from one setup to the other. The main message of this paper is that parity-check matrices of "good" channel codes can be used as provably "good" measurement ...

  17. Hemifacial spasm and neurovascular compression.

    Lu, Alex Y; Yeung, Jacky T; Gerrard, Jason L; Michaelides, Elias M; Sekula, Raymond F; Bulsara, Ketan R


    Hemifacial spasm (HFS) is characterized by involuntary unilateral contractions of the muscles innervated by the ipsilateral facial nerve, usually starting around the eyes before progressing inferiorly to the cheek, mouth, and neck. Its prevalence is 9.8 per 100,000 persons with an average age of onset of 44 years. The accepted pathophysiology of HFS suggests that it is a disease process of the nerve root entry zone of the facial nerve. HFS can be divided into two types: primary and secondary. Primary HFS is triggered by vascular compression whereas secondary HFS comprises all other causes of facial nerve damage. Clinical examination and imaging modalities such as electromyography (EMG) and magnetic resonance imaging (MRI) are useful to differentiate HFS from other facial movement disorders and for intraoperative planning. The standard medical management for HFS is botulinum neurotoxin (BoNT) injections, which provides low-risk but limited symptomatic relief. The only curative treatment for HFS is microvascular decompression (MVD), a surgical intervention that provides lasting symptomatic relief by reducing compression of the facial nerve root. With a low rate of complications such as hearing loss, MVD remains the treatment of choice for HFS patients as intraoperative technique and monitoring continue to improve.

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

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


    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.

  19. Efficiency of Compressed Air Energy Storage

    Elmegaard, Brian; Brix, Wiebke


    The simplest type of a Compressed Air Energy Storage (CAES) facility would be an adiabatic process consisting only of a compressor, a storage and a turbine, compressing air into a container when storing and expanding when producing. This type of CAES would be adiabatic and would if the machines were reversible have a storage efficiency of 100%. However, due to the specific capacity of the storage and the construction materials the air is cooled during and after compression in practice, making...

  20. Technique for chest compressions in adult CPR

    Rajab Taufiek K


    Full Text Available Abstract Chest compressions have saved the lives of countless patients in cardiac arrest as they generate a small but critical amount of blood flow to the heart and brain. This is achieved by direct cardiac massage as well as a thoracic pump mechanism. In order to optimize blood flow excellent chest compression technique is critical. Thus, the quality of the delivered chest compressions is a pivotal determinant of successful resuscitation. If a patient is found unresponsive without a definite pulse or normal breathing then the responder should assume that this patient is in cardiac arrest, activate the emergency response system and immediately start chest compressions. Contra-indications to starting chest compressions include a valid Do Not Attempt Resuscitation Order. Optimal technique for adult chest compressions includes positioning the patient supine, and pushing hard and fast over the center of the chest with the outstretched arms perpendicular to the patient's chest. The rate should be at least 100 compressions per minute and any interruptions should be minimized to achieve a minimum of 60 actually delivered compressions per minute. Aggressive rotation of compressors prevents decline of chest compression quality due to fatigue. Chest compressions are terminated following return of spontaneous circulation. Unconscious patients with normal breathing are placed in the recovery position. If there is no return of spontaneous circulation, then the decision to terminate chest compressions is based on the clinical judgment that the patient's cardiac arrest is unresponsive to treatment. Finally, it is important that family and patients' loved ones who witness chest compressions be treated with consideration and sensitivity.

  1. Compression Techniques for Improved Algorithm Computational Performance

    Zalameda, Joseph N.; Howell, Patricia A.; Winfree, William P.


    Analysis of thermal data requires the processing of large amounts of temporal image data. The processing of the data for quantitative information can be time intensive especially out in the field where large areas are inspected resulting in numerous data sets. By applying a temporal compression technique, improved algorithm performance can be obtained. In this study, analysis techniques are applied to compressed and non-compressed thermal data. A comparison is made based on computational speed and defect signal to noise.

  2. Wavelet transform approach to video compression

    Li, Jin; Cheng, Po-Yuen; Kuo, C.-C. Jay


    In this research, we propose a video compression scheme that uses the boundary-control vectors to represent the motion field and the embedded zerotree wavelet (EZW) to compress the displacement frame difference. When compared to the DCT-based MPEG, the proposed new scheme achieves a better compression performance in terms of the MSE (mean square error) value and visual perception for the same given bit rate.

  3. Quantum Data Compression of a Qubit Ensemble

    Rozema, Lee A.; Mahler, Dylan H.; Hayat, Alex; Turner, Peter S.; Steinberg, Aephraim M.


    Data compression is a ubiquitous aspect of modern information technology, and the advent of quantum information raises the question of what types of compression are feasible for quantum data, where it is especially relevant given the extreme difficulty involved in creating reliable quantum memories. We present a protocol in which an ensemble of quantum bits (qubits) can in principle be perfectly compressed into exponentially fewer qubits. We then experimentally implement our algorithm, compre...

  4. Image Processing by Compression: An Overview


    International audience; This article aims to present the various applications of data compression in image processing. Since some time ago, several research groups have been developing methods based on different data compression techniques to classify, segment, filter and detect digital images fakery. It is necessary to analyze the relationship between different methods and put them into a framework to better understand and better exploit the possibilities that compression provides us respect...

  5. New Theory and Algorithms for Compressive Sensing


    are compressed by a factor of 10 or more when expressed in terms of their largest Fourier or wavelet coefficients. The usual approach to acquiring a...information conversion 2.2.1 Compressive sensing background Compressive Sensing (CS) provides a framework for acquisition of an N × 1 discrete -time signal...1) This optimization problem, also known as Basis Pursuit with Denoising (BPDN) [10] can be solved with tradi- tional convex programming techniques

  6. Rapid response systems update.

    Winterbottom, Fiona; Castex, Julie; Campbell, Anita


    Rapid response is a mature concept that is undergoing metamorphosis. The ideal structure and function of these safety teams has not yet been realized but new developments in the field of rapid response systems are evolving.

  7. Effects of chest compressions on cardiorespiratory function in a non-arrested porcine model

    CONG Lu-hong; LI Chun-sheng; GUO Zhi-jun; WANG Shuo; WU Jun-yuan; YUAN Wei


    Background The effects of chest compressions to hemodynamic and respiratory parameters during hands-only cardiopulmonary resuscitation (CPR) in a non-arrested patient who suddenly collapses are confusing.In this research,we investigated the effects of chest compressions in a non-arrested porcine model.Methods Fourteen male domestic pigs were randomized into sham control group (SHAM group,only anesthetized and instrumented without chest compression,n=6) or chest compression group (CC group,2 minutes of chest compressions,n=8).Continuous hemodynamic parameters,dynamic lung compliance (Cdyn),and blood gas analysis outcomes were recorded.Serum levels of catecholamine were measured at baseline and 2 minutes,30 minutes,4 hours,and 24 hours after chest compressions.Chest computed tomography (CT) was performed at 30 minutes and 24 hours.Conventional histopathology evaluation was performed.Results After two minutes of chest compressions in the CC group,heart rate and extravascular lung water increased significantly; mean arterial pressure,stroke volume,and global ejection fraction significantly decreased.Cdyn significantly decreased to valley levels at 30 minutes and slowly recovered.Compared with the baseline,serum levels of catecholamine significantly increased at 2 minutes and rapidly decreased 24 hours later.At 30 minutes after chest compressions,chest CT showed local exudation,which was absorbed 24 hours later.Conclusions This research showed that 2 minutes of chest compressions causes various heart and lung tissue damage in the normal a normal porcine model.It also impacts the hemodynamic and Cdyn.

  8. Compression of structured high-throughput sequencing data.

    Fabien Campagne

    Full Text Available Large biological datasets are being produced at a rapid pace and create substantial storage challenges, particularly in the domain of high-throughput sequencing (HTS. Most approaches currently used to store HTS data are either unable to quickly adapt to the requirements of new sequencing or analysis methods (because they do not support schema evolution, or fail to provide state of the art compression of the datasets. We have devised new approaches to store HTS data that support seamless data schema evolution and compress datasets substantially better than existing approaches. Building on these new approaches, we discuss and demonstrate how a multi-tier data organization can dramatically reduce the storage, computational and network burden of collecting, analyzing, and archiving large sequencing datasets. For instance, we show that spliced RNA-Seq alignments can be stored in less than 4% the size of a BAM file with perfect data fidelity. Compared to the previous compression state of the art, these methods reduce dataset size more than 40% when storing exome, gene expression or DNA methylation datasets. The approaches have been integrated in a comprehensive suite of software tools ( that support common analyses for a range of high-throughput sequencing assays.

  9. Second Order Model for Strongly Sheared Compressible Turbulence

    marzougui hamed


    Full Text Available In this paper, we propose a model designed to describe a strongly sheared compressible homogeneous turbulent flows. Such flows are far from equilibrium and are well represented by the A3 and A4 cases of the DNS of Sarkar. Speziale and Xu developed a relaxation model in incompressible turbulence able to take into account significant departures from equilibrium. In a previous paper, Radhia et al. proposed a relaxation model similar to that of Speziale and Xu .This model is based on an algebraic representation of the Reynolds stress tensor, much simpler than that of Speziale and Xu and it gave a good result for rapid axisymetric contraction. In this work, we propose to extend the Radhia et al’s. model to compressible homogenous turbulence. This model is based on the pressure-strain model of Launder et al., where we incorporate turbulent Mach number in order to take into account compressibility effects. To assess this model, two numerical simulations were performed which are similar to the cases A3 and A4 of the DNS of Sarkar.

  10. Comparing biological networks via graph compression

    Hayashida Morihiro


    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.

  11. Stability of compressible reacting mixing layer

    Shin, D. S.; Ferziger, J. H.


    Linear instability of compressible reacting mixing layers is analyzed with emphasis on the effects of heat release and compressibility. Laminar solutions of the compressible boundary-layer equations are used as the base flows. The parameters of this study are the adiabatic flame temperature, the Mach number of the upper stream, frequency, wavenumber, and the direction of propagation of the disturbance wave. Stability characteristics of the flow are presented. Three groups of unstable modes are found when the Mach number and/or heat release are large. Finally, it is shown that the unstable modes are two-dimensional for large heat release even in highly compressible flow.

  12. Compression Properties of Polyester Needlepunched Fabric

    Sanjoy Debnath, Ph.D.


    Full Text Available In the present paper, a study of the effects of fabricweight, fiber cross-sectional shapes (round, hollowand trilobal and presence of reinforcing materialon the compression properties (initial thickness,percentage compression, percentage thickness lossand percentage compression resilience of polyesterneedle punched industrial nonwoven fabrics ispresented. It was found that for fabrics with noreinforcing material, the initial thickness,compression, and thickness loss were higher thanfabrics with reinforcing material, irrespectiveoffiber cross-section. Compression resilience datashowed the reverse trend. Initial thickness fortrilobal cross-sectional fabric sample was highestfollowed by round and hollow cross-sectionedpolyester needle punched fabrics. The polyesterfabric made from hollow cross-sectioned fibersshowed the least percentage compression at everylevel of fabric weights. The trilobal cross-sectionedpolyester fabric sample showed higher thicknessloss followed by round and hollow cross-sectionedpolyester fabric samples respectively. The hollowcross-sectioned polyester fabric samples showedmaximum compression resilience followed byround and trilobal cross-sectioned polyestersamples irrespective of fabric weights. The initialthickness increases, but percentage compression,thickness loss and compression resilience decreaseswith the increase in fabric weight irrespective offiber cross-sectional shapes.

  13. Spinal cord compression due to ethmoid adenocarcinoma.

    Johns, D R; Sweriduk, S T


    Adenocarcinoma of the ethmoid sinus is a rare tumor which has been epidemiologically linked to woodworking in the furniture industry. It has a low propensity to metastasize and has not been previously reported to cause spinal cord compression. A symptomatic epidural spinal cord compression was confirmed on magnetic resonance imaging (MRI) scan in a former furniture worker with widely disseminated metastases. The clinical features of ethmoid sinus adenocarcinoma and neoplastic spinal cord compression, and the comparative value of MRI scanning in the neuroradiologic diagnosis of spinal cord compression are reviewed.

  14. Efficient compression of molecular dynamics trajectory files.

    Marais, Patrick; Kenwood, Julian; Smith, Keegan Carruthers; Kuttel, Michelle M; Gain, James


    We investigate whether specific properties of molecular dynamics trajectory files can be exploited to achieve effective file compression. We explore two classes of lossy, quantized compression scheme: "interframe" predictors, which exploit temporal coherence between successive frames in a simulation, and more complex "intraframe" schemes, which compress each frame independently. Our interframe predictors are fast, memory-efficient and well suited to on-the-fly compression of massive simulation data sets, and significantly outperform the benchmark BZip2 application. Our schemes are configurable: atomic positional accuracy can be sacrificed to achieve greater compression. For high fidelity compression, our linear interframe predictor gives the best results at very little computational cost: at moderate levels of approximation (12-bit quantization, maximum error ≈ 10(-2) Å), we can compress a 1-2 fs trajectory file to 5-8% of its original size. For 200 fs time steps-typically used in fine grained water diffusion experiments-we can compress files to ~25% of their input size, still substantially better than BZip2. While compression performance degrades with high levels of quantization, the simulation error is typically much greater than the associated approximation error in such cases.

  15. Memory hierarchy using row-based compression

    Loh, Gabriel H.; O'Connor, James M.


    A system includes a first memory and a device coupleable to the first memory. The device includes a second memory to cache data from the first memory. The second memory includes a plurality of rows, each row including a corresponding set of compressed data blocks of non-uniform sizes and a corresponding set of tag blocks. Each tag block represents a corresponding compressed data block of the row. The device further includes decompression logic to decompress data blocks accessed from the second memory. The device further includes compression logic to compress data blocks to be stored in the second memory.

  16. Rapid Reading, Yes

    Frommer, Harvey


    Recommends instruction in rapid reading fo high school and college students and asserts that flexibility of speed and reasoning provide the foundation for effective rapid reading. Describes the components of rapid reading as orientation, selection, clarification, arrangement, review, and study. (RW)

  17. Comparative compressibility of hydrous wadsleyite

    Chang, Y.; Jacobsen, S. D.; Thomas, S.; Bina, C. R.; Smyth, J. R.; Frost, D. J.; Hauri, E. H.; Meng, Y.; Dera, P. K.


    Determining the effects of hydration on the density and elastic properties of wadsleyite, β-Mg2SiO4, is critical to constraining Earth’s global geochemical water cycle. Whereas previous studies of the bulk modulus (KT) have studied either hydrous Mg-wadsleyite, or anhydrous Fe-bearing wadsleyite, the combined effects of hydration and iron are under investigation. Also, whereas KT from compressibility studies is relatively well constrained by equation of state fitting to P-V data, the pressure derivative of the bulk modulus (K’) is usually not well constrained either because of poor data resolution, uncertainty in pressure calibrations, or narrow pressure ranges of previous single-crystal studies. Here we report the comparative compressibility of dry versus hydrous wadsleyite with Fo90 composition containing 1.9(2) wt% H2O, nearly the maximum water storage capacity of this phase. The composition was characterized by EMPA and nanoSIMS. The experiments were carried out using high-pressure, single-crystal diffraction up to 30 GPa at HPCAT, Advanced Photon Source. By loading three crystals each of hydrous and anhydrous wadsleyite together in the same diamond-anvil cell, we achieve good hkl coverage and eliminate the pressure scale as a variable in comparing the relative value of K’ between the dry and hydrous samples. We used MgO as an internal diffraction standard, in addition to recording ruby fluorescence pressures. By using neon as a pressure medium and about 1 GPa pressure steps up to 30 GPa, we obtain high-quality diffraction data for constraining the effect of hydration on the density and K’ of hydrous wadsleyite. Due to hydration, the initial volume of hydrous Fo90 wadsleyite is larger than anhydrous Fo90 wadsleyite, however the higher compressibility of hydrous wadsleyite leads to a volume crossover at 6 GPa. Hydration to 2 wt% H2O reduces the bulk modulus of Fo90 wadsleyite from 170(2) to 157(2) GPa, or about 7.6% reduction. In contrast to previous

  18. Blind compressive sensing dynamic MRI.

    Lingala, Sajan Goud; Jacob, Mathews


    We propose a novel blind compressive sensing (BCS) frame work to recover dynamic magnetic resonance images from undersampled measurements. This scheme models the dynamic signal as a sparse linear combination of temporal basis functions, chosen from a large dictionary. In contrast to classical compressed sensing, the BCS scheme simultaneously estimates the dictionary and the sparse coefficients from the undersampled measurements. Apart from the sparsity of the coefficients, the key difference of the BCS scheme with current low rank methods is the nonorthogonal nature of the dictionary basis functions. Since the number of degrees-of-freedom of the BCS model is smaller than that of the low-rank methods, it provides improved reconstructions at high acceleration rates. We formulate the reconstruction as a constrained optimization problem; the objective function is the linear combination of a data consistency term and sparsity promoting l1 prior of the coefficients. The Frobenius norm dictionary constraint is used to avoid scale ambiguity. We introduce a simple and efficient majorize-minimize algorithm, which decouples the original criterion into three simpler subproblems. An alternating minimization strategy is used, where we cycle through the minimization of three simpler problems. This algorithm is seen to be considerably faster than approaches that alternates between sparse coding and dictionary estimation, as well as the extension of K-SVD dictionary learning scheme. The use of the l1 penalty and Frobenius norm dictionary constraint enables the attenuation of insignificant basis functions compared to the l0 norm and column norm constraint assumed in most dictionary learning algorithms; this is especially important since the number of basis functions that can be reliably estimated is restricted by the available measurements. We also observe that the proposed scheme is more robust to local minima compared to K-SVD method, which relies on greedy sparse coding. Our

  19. Magnetic Flux Compression in Plasmas

    Velikovich, A. L.


    Magnetic flux compression (MFC) as a method for producing ultra-high pulsed magnetic fields had been originated in the 1950s by Sakharov et al. at Arzamas in the USSR (now VNIIEF, Russia) and by Fowler et al. at Los Alamos in the US. The highest magnetic field produced by explosively driven MFC generator, 28 MG, was reported by Boyko et al. of VNIIEF. The idea of using MFC to increase the magnetic field in a magnetically confined plasma to 3-10 MG, relaxing the strict requirements on the plasma density and Lawson time, gave rise to the research area known as MTF in the US and MAGO in Russia. To make a difference in ICF, a magnetic field of ˜100 MG should be generated via MFC by a plasma liner as a part of the capsule compression scenario on a laser or pulsed power facility. This approach was first suggested in mid-1980s by Liberman and Velikovich in the USSR and Felber in the US. It has not been obvious from the start that it could work at all, given that so many mechanisms exist for anomalously fast penetration of magnetic field through plasma. And yet, many experiments stimulated by this proposal since 1986, mostly using pulsed-power drivers, demonstrated reasonably good flux compression up to ˜42 MG, although diagnostics of magnetic fields of such magnitude in HED plasmas is still problematic. The new interest of MFC in plasmas emerged with the advancement of new drivers, diagnostic methods and simulation tools. Experiments on MFC in a deuterium plasma filling a cylindrical plastic liner imploded by OMEGA laser beam led by Knauer, Betti et al. at LLE produced peak fields of 36 MG. The novel MagLIF approach to low-cost, high-efficiency ICF pursued by Herrmann, Slutz, Vesey et al. at Sandia involves pulsed-power-driven MFC to a peak field of ˜130 MG in a DT plasma. A review of the progress, current status and future prospects of MFC in plasmas is presented.

  20. Experimental and Numerical Study of Jet Controlled Compression Ignition on Combustion Phasing Control in Diesel Premixed Compression Ignition Systems

    Qiang Zhang


    Full Text Available In order to directly control the premixed combustion phasing, a Jet Controlled Compression Ignition (JCCI for diesel premixed compression ignition systems is investigated. Experiments were conducted on a single cylinder natural aspirated diesel engine without EGR at 3000 rpm. Numerical models were validated by load sweep experiments at fixed spark timing. Detailed combustion characteristics were analyzed based on the BMEP of 2.18 bar. The simulation results showed that the high temperature jets of reacting active radical species issued from the ignition chamber played an important role on the onset of combustion in the JCCI system. The combustion of diesel pre-mixtures was initiated rapidly by the combustion products issued from the ignition chamber. Moreover, the flame propagation was not obvious, similar to that in Pre-mixed Charge Compression Ignition (PCCI. Consequently, spark timing sweep experiments were conducted. The results showed a good linear relationship between spark timing in the ignition chamber and CA10 and CA50, which indicated the ability for direct combustion phasing control in diesel PCCI. The NOx and soot emissions gradually changed with the decrease of spark advance angle. The maximum reduction of NOx and soot were both over 90%, and HC and CO emissions were increased.

  1. Real-time imaging of complex nanoscale mechanical responses of carbon nanotubes in highly compressible porous monoliths

    Whitby, Raymond L D; Mikhalovsky, Sergey V [Brighton Nanoscience and Nanotechnology Group, PABS, University of Brighton, Lewes Road, Brighton, BN2 4GJ (United Kingdom); Fukuda, Takahiro; Maekawa, Toru [Bio-Nano Electronics Research Centre, Toyo University, 2100 Kujirai, Kawagoe Saitama 350-8585 (Japan); Cundy, Andrew B, E-mail: [School of Environment and Technology, University of Brighton, Lewes Road, Brighton, BN2 4GJ (United Kingdom)


    A facile and rapid assembly of powdered carbon nanotubes (CNTs) into compressible, porous, macroscale monoliths is reported. Despite a Poisson's ratio just above zero, we found that the sample under compression inside a scanning electron microscope (SEM) revealed CNT regions behaving in auxetic and vortex-like rotational modes as well as standard collapse responses. This method is crucial in understanding the macroscale behaviour based on the accumulation of nanoscale responses to an applied force.

  2. Real-time imaging of complex nanoscale mechanical responses of carbon nanotubes in highly compressible porous monoliths

    Whitby, Raymond L. D.; Fukuda, Takahiro; Maekawa, Toru; Mikhalovsky, Sergey V.; Cundy, Andrew B.


    A facile and rapid assembly of powdered carbon nanotubes (CNTs) into compressible, porous, macroscale monoliths is reported. Despite a Poisson's ratio just above zero, we found that the sample under compression inside a scanning electron microscope (SEM) revealed CNT regions behaving in auxetic and vortex-like rotational modes as well as standard collapse responses. This method is crucial in understanding the macroscale behaviour based on the accumulation of nanoscale responses to an applied force.

  3. A New Approach for Fingerprint Image Compression

    Mazieres, Bertrand


    The FBI has been collecting fingerprint cards since 1924 and now has over 200 million of them. Digitized with 8 bits of grayscale resolution at 500 dots per inch, it means 2000 terabytes of information. Also, without any compression, transmitting a 10 Mb card over a 9600 baud connection will need 3 hours. Hence we need a compression and a compression as close to lossless as possible: all fingerprint details must be kept. A lossless compression usually do not give a better compression ratio than 2:1, which is not sufficient. Compressing these images with the JPEG standard leads to artefacts which appear even at low compression rates. Therefore the FBI has chosen in 1993 a scheme of compression based on a wavelet transform, followed by a scalar quantization and an entropy coding : the so-called WSQ. This scheme allows to achieve compression ratios of 20:1 without any perceptible loss of quality. The publication of the FBI specifies a decoder, which means that many parameters can be changed in the encoding process: the type of analysis/reconstruction filters, the way the bit allocation is made, the number of Huffman tables used for the entropy coding. The first encoder used 9/7 filters for the wavelet transform and did the bit allocation using a high-rate bit assumption. Since the transform is made into 64 subbands, quite a lot of bands receive only a few bits even at an archival quality compression rate of 0.75 bit/pixel. Thus, after a brief overview of the standard, we will discuss a new approach for the bit-allocation that seems to make more sense where theory is concerned. Then we will talk about some implementation aspects, particularly for the new entropy coder and the features that allow other applications than fingerprint image compression. Finally, we will compare the performances of the new encoder to those of the first encoder.

  4. Spectral compression of single photons

    Lavoie, Jonathan; Wright, Logan G; Fedrizzi, Alessandro; Resch, Kevin J


    Photons are critical to quantum technologies since they can be used for virtually all quantum information tasks: in quantum metrology, as the information carrier in photonic quantum computation, as a mediator in hybrid systems, and to establish long distance networks. The physical characteristics of photons in these applications differ drastically; spectral bandwidths span 12 orders of magnitude from 50 THz for quantum-optical coherence tomography to 50 Hz for certain quantum memories. Combining these technologies requires coherent interfaces that reversibly map centre frequencies and bandwidths of photons to avoid excessive loss. Here we demonstrate bandwidth compression of single photons by a factor 40 and tunability over a range 70 times that bandwidth via sum-frequency generation with chirped laser pulses. This constitutes a time-to-frequency interface for light capable of converting time-bin to colour entanglement and enables ultrafast timing measurements. It is a step toward arbitrary waveform generatio...

  5. Genetic disorders producing compressive radiculopathy.

    Corey, Joseph M


    Back pain is a frequent complaint seen in neurological practice. In evaluating back pain, neurologists are asked to evaluate patients for radiculopathy, determine whether they may benefit from surgery, and help guide management. Although disc herniation is the most common etiology of compressive radiculopathy, there are many other causes, including genetic disorders. This article is a discussion of genetic disorders that cause or contribute to radiculopathies. These genetic disorders include neurofibromatosis, Paget's disease of bone, and ankylosing spondylitis. Numerous genetic disorders can also lead to deformities of the spine, including spinal muscular atrophy, Friedreich's ataxia, Charcot-Marie-Tooth disease, familial dysautonomia, idiopathic torsional dystonia, Marfan's syndrome, and Ehlers-Danlos syndrome. However, the extent of radiculopathy caused by spine deformities is essentially absent from the literature. Finally, recent investigation into the heritability of disc degeneration and lumbar disc herniation suggests a significant genetic component in the etiology of lumbar disc disease.

  6. Photon counting compressive depth mapping

    Howland, Gregory A; Ware, Matthew R; Howell, John C


    We demonstrate a compressed sensing, photon counting lidar system based on the single-pixel camera. Our technique recovers both depth and intensity maps from a single under-sampled set of incoherent, linear projections of a scene of interest at ultra-low light levels around 0.5 picowatts. Only two-dimensional reconstructions are required to image a three-dimensional scene. We demonstrate intensity imaging and depth mapping at 256 x 256 pixel transverse resolution with acquisition times as short as 3 seconds. We also show novelty filtering, reconstructing only the difference between two instances of a scene. Finally, we acquire 32 x 32 pixel real-time video for three-dimensional object tracking at 14 frames-per-second.

  7. Compressed Encoding for Rank Modulation

    Gad, Eyal En; Jiang,; Bruck, Jehoshua


    Rank modulation has been recently proposed as a scheme for storing information in flash memories. While rank modulation has advantages in improving write speed and endurance, the current encoding approach is based on the "push to the top" operation that is not efficient in the general case. We propose a new encoding procedure where a cell level is raised to be higher than the minimal necessary subset - instead of all - of the other cell levels. This new procedure leads to a significantly more compressed (lower charge levels) encoding. We derive an upper bound for a family of codes that utilize the proposed encoding procedure, and consider code constructions that achieve that bound for several special cases.

  8. Construction and compression of Dwarf

    XIANG Long-gang; FENG Yu-cai; GUI Hao


    There exists an inherent difficulty in the original algorithm for the construction of Dwarf, which prevents it from constructing true Dwarfs. We explained when and why it introduces suffix redundancies into the Dwarf structure. To solve this problem, we proposed a completely new algorithm called PID. It bottom-up computes partitions of a fact table, and inserts them into the Dwarf structure. Ifa partition is an MSV partition, coalesce its sub-Dwarf; otherwise create necessary nodes and cells. Our performance study showed that PID is efficient. For further condensing of Dwarf, we proposed Condensed Dwarf, a more compressed structure, combining the strength of Dwarf and Condensed Cube. By eliminating unnecessary stores of "ALL" cells from the Dwarf structure, Condensed Dwarf could effectively reduce the size of Dwarf, especially for Dwarfs of the real world, which was illustrated by our experiments. Its query processing is still simple and, only two minor modifications to PID are required for the construction of Condensed Dwarf.

  9. Fragment separator momentum compression schemes

    Bandura, Laura, E-mail: [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); National Superconducting Cyclotron Lab, Michigan State University, 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Erdelyi, Bela [Argonne National Laboratory, Argonne, IL 60439 (United States); Northern Illinois University, DeKalb, IL 60115 (United States); Hausmann, Marc [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Kubo, Toshiyuki [RIKEN Nishina Center, RIKEN, Wako (Japan); Nolen, Jerry [Argonne National Laboratory, Argonne, IL 60439 (United States); Portillo, Mauricio [Facility for Rare Isotope Beams (FRIB), 1 Cyclotron, East Lansing, MI 48824-1321 (United States); Sherrill, Bradley M. [National Superconducting Cyclotron Lab, Michigan State University, 1 Cyclotron, East Lansing, MI 48824-1321 (United States)


    We present a scheme to use a fragment separator and profiled energy degraders to transfer longitudinal phase space into transverse phase space while maintaining achromatic beam transport. The first order beam optics theory of the method is presented and the consequent enlargement of the transverse phase space is discussed. An interesting consequence of the technique is that the first order mass resolving power of the system is determined by the first dispersive section up to the energy degrader, independent of whether or not momentum compression is used. The fragment separator at the Facility for Rare Isotope Beams is a specific application of this technique and is described along with simulations by the code COSY INFINITY.

  10. Fragment separator momentum compression schemes.

    Bandura, L.; Erdelyi, B.; Hausmann, M.; Kubo, T.; Nolen, J.; Portillo, M.; Sherrill, B.M. (Physics); (MSU); (Northern Illinois Univ.); (RIKEN)


    We present a scheme to use a fragment separator and profiled energy degraders to transfer longitudinal phase space into transverse phase space while maintaining achromatic beam transport. The first order beam optics theory of the method is presented and the consequent enlargement of the transverse phase space is discussed. An interesting consequence of the technique is that the first order mass resolving power of the system is determined by the first dispersive section up to the energy degrader, independent of whether or not momentum compression is used. The fragment separator at the Facility for Rare Isotope Beams is a specific application of this technique and is described along with simulations by the code COSY INFINITY.

  11. Isotropic polarization of compressible flows

    Zhu, Jian-Zhou


    The helical absolute equilibrium of a compressible adiabatic flow presents not only the polarization between the two purely helical modes of opposite chiralities but also that between the vortical and acoustic modes, deviating from the equipartition predicted by {\\sc Kraichnan, R. H.} [1955 The Journal of the Acoustical Society of America {\\bf 27}, 438--441.] Due to the existence of the acoustic mode, even if all Fourier modes of one chiral sector in the sharpened Helmholtz decomposition [{\\sc Moses, H. E.} 1971 SIAM ~(Soc. Ind. Appl. Math.) J. Appl. Math. {\\bf 21}, 114--130] are thoroughly truncated, negative temperature and the corresponding large-scale concentration of vortical modes are not allowed, unlike the incompressible case.

  12. Compression molding of aerogel microspheres

    Pekala, Richard W. (Pleasant Hill, CA); Hrubesh, Lawrence W. (Pleasanton, CA)


    An aerogel composite material produced by compression molding of aerogel microspheres (powders) mixed together with a small percentage of polymer binder to form monolithic shapes in a cost-effective manner. The aerogel composites are formed by mixing aerogel microspheres with a polymer binder, placing the mixture in a mold and heating under pressure, which results in a composite with a density of 50-800 kg/m.sup.3 (0.05-0.80 g/cc). The thermal conductivity of the thus formed aerogel composite is below that of air, but higher than the thermal conductivity of monolithic aerogels. The resulting aerogel composites are attractive for applications such as thermal insulation since fabrication thereof does not require large and expensive processing equipment. In addition to thermal insulation, the aerogel composites may be utilized for filtration, ICF target, double layer capacitors, and capacitive deionization.

  13. Compression molding of aerogel microspheres

    Pekala, R.W.; Hrubesh, L.W.


    An aerogel composite material produced by compression molding of aerogel microspheres (powders) mixed together with a small percentage of polymer binder to form monolithic shapes in a cost-effective manner is disclosed. The aerogel composites are formed by mixing aerogel microspheres with a polymer binder, placing the mixture in a mold and heating under pressure, which results in a composite with a density of 50--800 kg/m{sup 3} (0.05--0.80 g/cc). The thermal conductivity of the thus formed aerogel composite is below that of air, but higher than the thermal conductivity of monolithic aerogels. The resulting aerogel composites are attractive for applications such as thermal insulation since fabrication thereof does not require large and expensive processing equipment. In addition to thermal insulation, the aerogel composites may be utilized for filtration, ICF target, double layer capacitors, and capacitive deionization. 4 figs.

  14. Nonrepetitive Colouring via Entropy Compression

    Dujmović, Vida; Wood, David R


    A vertex colouring of a graph is \\emph{nonrepetitive} if there is no path whose first half receives the same sequence of colours as the second half. A graph is nonrepetitively $k$-choosable if given lists of at least $k$ colours at each vertex, there is a nonrepetitive colouring such that each vertex is coloured from its own list. It is known that every graph with maximum degree $\\Delta$ is $c\\Delta^2$-choosable, for some constant $c$. We prove this result with $c=4$. We then prove that every subdivision of a graph with sufficiently many division vertices per edge is nonrepetitively 6-choosable. The proofs of both these results are based on the Moser-Tardos entropy-compression method, and a recent extension by Grytczuk, Kozik and Micek for the nonrepetitive choosability of paths. Finally, we prove that every graph with pathwidth $k$ is nonrepetitively ($2k^2+6k+1$)-colourable.

  15. MIMO Radar Using Compressive Sampling

    Yu, Yao; Poor, H Vincent


    A MIMO radar system is proposed for obtaining angle and Doppler information on potential targets. Transmitters and receivers are nodes of a small scale wireless network and are assumed to be randomly scattered on a disk. The transmit nodes transmit uncorrelated waveforms. Each receive node applies compressive sampling to the received signal to obtain a small number of samples, which the node subsequently forwards to a fusion center. Assuming that the targets are sparsely located in the angle- Doppler space, based on the samples forwarded by the receive nodes the fusion center formulates an l1-optimization problem, the solution of which yields target angle and Doppler information. The proposed approach achieves the superior resolution of MIMO radar with far fewer samples than required by other approaches. This implies power savings during the communication phase between the receive nodes and the fusion center. Performance in the presence of a jammer is analyzed for the case of slowly moving targets. Issues rel...

  16. Compressed sensing traction force microscopy.

    Brask, Jonatan Bohr; Singla-Buxarrais, Guillem; Uroz, Marina; Vincent, Romaric; Trepat, Xavier


    Adherent cells exert traction forces on their substrate, and these forces play important roles in biological functions such as mechanosensing, cell differentiation and cancer invasion. The method of choice to assess these active forces is traction force microscopy (TFM). Despite recent advances, TFM remains highly sensitive to measurement noise and exhibits limited spatial resolution. To improve the resolution and noise robustness of TFM, here we adapt techniques from compressed sensing (CS) to the reconstruction of the traction field from the substrate displacement field. CS enables the recovery of sparse signals at higher resolution from lower resolution data. Focal adhesions (FAs) of adherent cells are spatially sparse implying that traction fields are also sparse. Here we show, by simulation and by experiment, that the CS approach enables circumventing the Nyquist-Shannon sampling theorem to faithfully reconstruct the traction field at a higher resolution than that of the displacement field. This allows reaching state-of-the-art resolution using only a medium magnification objective. We also find that CS improves reconstruction quality in the presence of noise. A great scientific advance of the past decade is the recognition that physical forces determine an increasing list of biological processes. Traction force microscopy which measures the forces that cells exert on their surroundings has seen significant recent improvements, however the technique remains sensitive to measurement noise and severely limited in spatial resolution. We exploit the fact that the force fields are sparse to boost the spatial resolution and noise robustness by applying ideas from compressed sensing. The novel method allows high resolution on a larger field of view. This may in turn allow better understanding of the cell forces at the multicellular level, which are known to be important in wound healing and cancer invasion. Copyright © 2015 Acta Materialia Inc. Published by Elsevier

  17. Survey of data compression techniques

    Gryder, R.; Hake, K.


    PM-AIM must provide to customers in a timely fashion information about Army acquisitions. This paper discusses ways that PM-AIM can reduce the volume of data that must be transmitted between sites. Although this paper primarily discusses techniques of data compression, it also briefly discusses other options for meeting the PM-AIM requirements. The options available to PM-AIM, in addition to hardware and software data compression, include less-frequent updates, distribution of partial updates, distributed data base design, and intelligent network design. Any option that enhances the performance of the PM-AIM network is worthy of consideration. The recommendations of this paper apply to the PM-AIM project in three phases: the current phase, the target phase, and the objective phase. Each recommendation will be identified as (1) appropriate for the current phase, (2) considered for implementation during the target phase, or (3) a feature that should be part of the objective phase of PM-AIM's design. The current phase includes only those measures that can be taken with the installed leased lines. The target phase includes those measures that can be taken in transferring the traffic from the leased lines to the DSNET environment with minimal changes in the current design. The objective phase includes all the things that should be done as a matter of course. The objective phase for PM-AIM appears to be a distributed data base with data for each site stored locally and all sites having access to all data.

  18. Survey of data compression techniques

    Gryder, R.; Hake, K.


    PM-AIM must provide to customers in a timely fashion information about Army acquisitions. This paper discusses ways that PM-AIM can reduce the volume of data that must be transmitted between sites. Although this paper primarily discusses techniques of data compression, it also briefly discusses other options for meeting the PM-AIM requirements. The options available to PM-AIM, in addition to hardware and software data compression, include less-frequent updates, distribution of partial updates, distributed data base design, and intelligent network design. Any option that enhances the performance of the PM-AIM network is worthy of consideration. The recommendations of this paper apply to the PM-AIM project in three phases: the current phase, the target phase, and the objective phase. Each recommendation will be identified as (1) appropriate for the current phase, (2) considered for implementation during the target phase, or (3) a feature that should be part of the objective phase of PM-AIM`s design. The current phase includes only those measures that can be taken with the installed leased lines. The target phase includes those measures that can be taken in transferring the traffic from the leased lines to the DSNET environment with minimal changes in the current design. The objective phase includes all the things that should be done as a matter of course. The objective phase for PM-AIM appears to be a distributed data base with data for each site stored locally and all sites having access to all data.

  19. Experimental Study of Fractal Image Compression Algorithm

    Chetan R. Dudhagara


    Full Text Available Image compression applications have been increasing in recent years. Fractal compression is a lossy compression method for digital images, based on fractals. The method is best suited for textures and natural images, relying on the fact that parts of an image often resemble other parts of the same image. In this paper, a study on fractal-based image compression and fixed-size partitioning will be made, analyzed for performance and compared with a standard frequency domain based image compression standard, JPEG. Sample images will be used to perform compression and decompression. Performance metrics such as compression ratio, compression time and decompression time will be measured in JPEG cases. Also the phenomenon of resolution/scale independence will be studied and described with examples. Fractal algorithms convert these parts into mathematical data called "fractal codes" which are used to recreate the encoded image. Fractal encoding is a mathematical process used to encode bitmaps containing a real-world image as a set of mathematical data that describes the fractal properties of the image. Fractal encoding relies on the fact that all natural, and most artificial, objects contain redundant information in the form of similar, repeating patterns called fractals.

  20. Bioimpedance of soft tissue under compression.

    Dodde, R E; Bull, J L; Shih, A J


    In this paper compression-dependent bioimpedance measurements of porcine spleen tissue are presented. Using a Cole-Cole model, nonlinear compositional changes in extracellular and intracellular makeup; related to a loss of fluid from the tissue, are identified during compression. Bioimpedance measurements were made using a custom tetrapolar probe and bioimpedance circuitry. As the tissue is increasingly compressed up to 50%, both intracellular and extracellular resistances increase while bulk membrane capacitance decreases. Increasing compression to 80% results in an increase in intracellular resistance and bulk membrane capacitance while extracellular resistance decreases. Tissues compressed incrementally to 80% show a decreased extracellular resistance of 32%, an increased intracellular resistance of 107%, and an increased bulk membrane capacitance of 64% compared to their uncompressed values. Intracellular resistance exhibits double asymptotic curves when plotted against the peak tissue pressure during compression, possibly indicating two distinct phases of mechanical change in the tissue during compression. Based on these findings, differing theories as to what is happening at a cellular level during high tissue compression are discussed, including the possibility of cell rupture and mass exudation of cellular material.

  1. College Students' Preference for Compressed Speech Lectures.

    Primrose, Robert A.

    To test student reactions to compressed-speech lectures, tapes for a general education course in oral communication were compressed to 49 to 77 percent of original time. Students were permitted to check them out via a dial access retrieval system. Checkouts and use of tapes were compared with student grades at semester's end. No significant…

  2. Triceps skinfold compressibility in hospitalized patients

    Sousa, Ana Sofia; Pichel, Fernando; Amaral, Teresa F


    To explore triceps skinfold (TSF) compressibility and its associated factors among hospitalized patients. A cross-sectional study was conducted among hospitalized adult patients. Evolution of tissue compressibility during two seconds was registered and 120 TSF values were obtained using a digital calliper. Compressibility was determined according to the difference between the initial value and the final value (TSF difference) and according to time (τ). Multivariable linear regression models were performed in order to identify factors associated with TSF compressibility. One hundred and six patients (30.2% aged ≥ 65 years) composed the study sample. Compressibility based on TSF difference was independently associated with TSF thickness (regression coefficient, 95% confidence interval [CI] = 0.38, 0.01-0.05, p = 0.002) and nutritional risk (regression coefficient, 95% CI = 0.23, 0.12-1.23, p = 0.018), but time of compressibility (τ) was not significantly associated with any of the studied variables. Among a sample of hospitalized patients, undernutrition risk and higher TSF thickness were factors independently associated with higher compressibility assessed by the difference between the initial and final TSF value. Time of compressibility (τ) was not affected by any of the studied factors.

  3. Hardware compression using common portions of data

    Chang, Jichuan; Viswanathan, Krishnamurthy


    Methods and devices are provided for data compression. Data compression can include receiving a plurality of data chunks, sampling at least some of the plurality of data chunks extracting a common portion from a number of the plurality of data chunks based on the sampling, and storing a remainder of the plurality of data chunks in memory.

  4. Lossless Compression on MRI Images Using SWT.

    Anusuya, V; Raghavan, V Srinivasa; Kavitha, G


    Medical image compression is one of the growing research fields in biomedical applications. Most medical images need to be compressed using lossless compression as each pixel information is valuable. With the wide pervasiveness of medical imaging applications in health-care settings and the increased interest in telemedicine technologies, it has become essential to reduce both storage and transmission bandwidth requirements needed for archival and communication of related data, preferably by employing lossless compression methods. Furthermore, providing random access as well as resolution and quality scalability to the compressed data has become of great utility. Random access refers to the ability to decode any section of the compressed image without having to decode the entire data set. The system proposes to implement a lossless codec using an entropy coder. 3D medical images are decomposed into 2D slices and subjected to 2D-stationary wavelet transform (SWT). The decimated coefficients are compressed in parallel using embedded block coding with optimized truncation of the embedded bit stream. These bit streams are decoded and reconstructed using inverse SWT. Finally, the compression ratio (CR) is evaluated to prove the efficiency of the proposal. As an enhancement, the proposed system concentrates on minimizing the computation time by introducing parallel computing on the arithmetic coding stage as it deals with multiple subslices.

  5. Efficiency of Compressed Air Energy Storage

    Elmegaard, Brian; Brix, Wiebke


    The simplest type of a Compressed Air Energy Storage (CAES) facility would be an adiabatic process consisting only of a compressor, a storage and a turbine, compressing air into a container when storing and expanding when producing. This type of CAES would be adiabatic and would if the machines...

  6. A singular limit for compressible rotating fluids

    Feireisl, Eduard; Novotny, Antonin


    We consider a singular limit problem for the Navier-Stokes system of a rotating compressible fluid, where the Rossby and Mach numbers tend simultaneously to zero. The limit problem is identified as the 2-D Navier-Stokes system in the ``horizontal'' variables containing an extra term that accounts for compressibility in the original system.

  7. Compression of Short Text on Embedded Systems

    Rein, S.; Gühmann, C.; Fitzek, Frank


    The paper details a scheme for lossless compression of a short data series larger than 50 bytes. The method uses arithmetic coding and context modelling with a low-complexity data model. A data model that takes 32 kBytes of RAM already cuts the data size in half. The compression scheme just takes...

  8. RNACompress: Grammar-based compression and informational complexity measurement of RNA secondary structure

    Chen Chun


    Full Text Available Abstract Background With the rapid emergence of RNA databases and newly identified non-coding RNAs, an efficient compression algorithm for RNA sequence and structural information is needed for the storage and analysis of such data. Although several algorithms for compressing DNA sequences have been proposed, none of them are suitable for the compression of RNA sequences with their secondary structures simultaneously. This kind of compression not only facilitates the maintenance of RNA data, but also supplies a novel way to measure the informational complexity of RNA structural data, raising the possibility of studying the relationship between the functional activities of RNA structures and their complexities, as well as various structural properties of RNA based on compression. Results RNACompress employs an efficient grammar-based model to compress RNA sequences and their secondary structures. The main goals of this algorithm are two fold: (1 present a robust and effective way for RNA structural data compression; (2 design a suitable model to represent RNA secondary structure as well as derive the informational complexity of the structural data based on compression. Our extensive tests have shown that RNACompress achieves a universally better compression ratio compared with other sequence-specific or common text-specific compression algorithms, such as Gencompress, winrar and gzip. Moreover, a test of the activities of distinct GTP-binding RNAs (aptamers compared with their structural complexity shows that our defined informational complexity can be used to describe how complexity varies with activity. These results lead to an objective means of comparing the functional properties of heteropolymers from the information perspective. Conclusion A universal algorithm for the compression of RNA secondary structure as well as the evaluation of its informational complexity is discussed in this paper. We have developed RNACompress, as a useful tool

  9. Social and Economic Space Compression in Border Areas: the Case of the Northwestern Federal District

    Romanova E.


    Full Text Available The so-called “compression” of social and economic space has been the subject of quite a few studies in the past decades. There are two principle types of compression: communicative, that is, associated with the development of transport and information systems, and physical, manifested in the rapid decrease of the number of new territories to explore. While physical and communicative compression are interrelated, they have different spatial expressions depending on geographical conditions, economic, environmental, historical, and political characteristics of the re-gion. The authors identify the patterns of communicative and physical space com-pression using comparative mapping, statistical and historical research methods, and a model showing the spatial differentiation of regional socioeconomic charac-teristics in the Northwestern Federal District. The study focuses on border areas, where the following key manifestations of compression have been identified: trans-port connectivity, level of agriculture development, and depopulation. All these indicators of space compression process are studied at the municipal level. The authors identify the key features of socioeconomic space compression for the border areas of the Russian Northwest.

  10. Social and Economic Space Compression in Border Areas: the Case of the Northwestern Federal District

    Romanova E.


    Full Text Available The so-called “compression” of social and economic space has been the subject of quite a few studies in the past decades. There are two principle types of compression: communicative, that is, associated with the development of transport and information systems, and physical, manifested in the rapid decrease of the number of new territories to explore. While physical and communicative compression are interrelated, they have different spatial expressions depending on geographical conditions, economic, environmental, historical, and political characteristics of the re-gion. The authors identify the patterns of communicative and physical space com-pression using comparative mapping, statistical and historical research methods, and a model showing the spatial differentiation of regional socioeconomic charac-teristics in the Northwestern Federal District. The study focuses on border areas, where the following key manifestations of compression have been identified: trans-port connectivity, level of agriculture development, and depopulation. All these indicators of space compression process are studied at the municipal level. The authors identify the key features of socioeconomic space compression for the border areas of the Russian Northwest.

  11. Social and Economic Space Compression in Border Areas: the Case of the Northwestern Federal District

    Romanova Elena


    Full Text Available The so-called “compression” of social and economic space has been the subject of quite a few studies in the past decades. There are two principle types of compression: communicative, that is, associated with the development of transport and information systems, and physical, manifested in the rapid decrease of the number of new territories to explore. While physical and communicative compression are interrelated, they have different spatial expressions depending on geographical conditions, economic, environmental, historical, and political characteristics of the re-gion. The authors identify the patterns of communicative and physical space com-pression using comparative mapping, statistical and historical research methods, and a model showing the spatial differentiation of regional socioeconomic charac-teristics in the Northwestern Federal District. The study focuses on border areas, where the following key manifestations of compression have been identified: trans-port connectivity, level of agriculture development, and depopulation. All these indicators of space compression process are studied at the municipal level. The authors identify the key features of socioeconomic space compression for the border areas of the Russian Northwest.

  12. Solid iron compressed up to 560 GPa.

    Ping, Y; Coppari, F; Hicks, D G; Yaakobi, B; Fratanduono, D E; Hamel, S; Eggert, J H; Rygg, J R; Smith, R F; Swift, D C; Braun, D G; Boehly, T R; Collins, G W


    Dynamic compression by multiple shocks is used to compress iron up to 560 GPa (5.6 Mbar), the highest solid-state pressure yet attained for iron in the laboratory. Extended x-ray absorption fine structure (EXAFS) spectroscopy offers simultaneous density, temperature, and local-structure measurements for the compressed iron. The data show that the close-packed structure of iron is stable up to 560 GPa, the temperature at peak compression is significantly higher than expected from pure compressive work, and the dynamic strength of iron is many times greater than the static strength based on lower pressure data. The results provide the first constraint on the melting line of iron above 400 GPa.

  13. Quantum data compression of a qubit ensemble.

    Rozema, Lee A; Mahler, Dylan H; Hayat, Alex; Turner, Peter S; Steinberg, Aephraim M


    Data compression is a ubiquitous aspect of modern information technology, and the advent of quantum information raises the question of what types of compression are feasible for quantum data, where it is especially relevant given the extreme difficulty involved in creating reliable quantum memories. We present a protocol in which an ensemble of quantum bits (qubits) can in principle be perfectly compressed into exponentially fewer qubits. We then experimentally implement our algorithm, compressing three photonic qubits into two. This protocol sheds light on the subtle differences between quantum and classical information. Furthermore, since data compression stores all of the available information about the quantum state in fewer physical qubits, it could allow for a vast reduction in the amount of quantum memory required to store a quantum ensemble, making even today's limited quantum memories far more powerful than previously recognized.

  14. Image compression algorithm using wavelet transform

    Cadena, Luis; Cadena, Franklin; Simonov, Konstantin; Zotin, Alexander; Okhotnikov, Grigory


    Within the multi-resolution analysis, the study of the image compression algorithm using the Haar wavelet has been performed. We have studied the dependence of the image quality on the compression ratio. Also, the variation of the compression level of the studied image has been obtained. It is shown that the compression ratio in the range of 8-10 is optimal for environmental monitoring. Under these conditions the compression level is in the range of 1.7 - 4.2, depending on the type of images. It is shown that the algorithm used is more convenient and has more advantages than Winrar. The Haar wavelet algorithm has improved the method of signal and image processing.

  15. A Novel Fractal Wavelet Image Compression Approach

    SONG Chun-lin; FENG Rui; LIU Fu-qiang; CHEN Xi


    By investigating the limitation of existing wavelet tree based image compression methods, we propose a novel wavelet fractal image compression method in this paper. Briefly, the initial errors are appointed given the different levels of importance accorded the frequency sublevel band wavelet coefficients. Higher frequency sublevel bands would lead to larger initial errors. As a result, the sizes of sublevel blocks and super blocks would be changed according to the initial errors. The matching sizes between sublevel blocks and super blocks would be changed according to the permitted errors and compression rates. Systematic analyses are performed and the experimental results demonstrate that the proposed method provides a satisfactory performance with a clearly increasing rate of compression and speed of encoding without reducing SNR and the quality of decoded images. Simulation results show that our method is superior to the traditional wavelet tree based methods of fractal image compression.

  16. Video Coding Technique using MPEG Compression Standards

    A. J. Falade


    Full Text Available Digital video compression technologies have become part of life, in the way visual information is created, communicated and consumed. Some application areas of video compression focused on the problem of optimizing storage space and transmission bandwidth (BW. The two dimensional discrete cosine transform (2-D DCT is an integral part of video and image compression, which is used in Moving Picture Expert Group (MPEG encoding standards. Thus, several video compression algorithms had been developed to reduce the data quantity and provide the acceptable quality standard. In the proposed study, the Matlab Simulink Model (MSM has been used for video coding/compression. The approach is more modern and reduces error resilience image distortion.

  17. Adiabatic Liquid Piston Compressed Air Energy Storage

    Petersen, Tage; Elmegaard, Brian; Pedersen, Allan Schrøder

    the mechanical energy into electricity at times of high electricity demand. Two such systems are currently in operation; one in Germany (Huntorf) and one in the USA (Macintosh, Alabama). In both cases, an underground cavern is used as a pressure vessel for the storage of the compressed air. Both systems...... are in the range of 100 MW electrical power output with several hours of production stored as compressed air. In this range, enormous volumes are required, which make underground caverns the only economical way to design the pressure vessel. Both systems use axial turbine compressors to compress air when charging......), but no such units are in operation at present. The CAES system investigated in this project uses a different approach to avoid compression heat loss. The system uses a pre-compressed pressure vessel full of air. A liquid is pumped into the bottom of the vessel when charging and the same liquid is withdrawn through...

  18. Mathematical transforms and image compression: A review

    Satish K. Singh


    Full Text Available It is well known that images, often used in a variety of computer and other scientific and engineering applications, are difficult to store and transmit due to their sizes. One possible solution to overcome this problem is to use an efficient digital image compression technique where an image is viewed as a matrix and then the operations are performed on the matrix. All the contemporary digital image compression systems use various mathematical transforms for compression. The compression performance is closely related to the performance by these mathematical transforms in terms of energy compaction and spatial frequency isolation by exploiting inter-pixel redundancies present in the image data. Through this paper, a comprehensive literature survey has been carried out and the pros and cons of various transform-based image compression models have also been discussed.

  19. Compressed Sensing with Rank Deficient Dictionaries

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


    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....../A) step in a GPS receiver. Simulations show that for this application the proposed choice of measurement matrix yields an increase in SNR performance of up to 5 − 10 dB, compared to the conventional choice of a fully random measurement matrix. Furthermore, the compressed sensing based C/A step is compared...

  20. Adaptive Remote Sensing Texture Compression on GPU

    Xiao-Xia Lu


    Full Text Available Considering the properties of remote sensing texture such as strong randomness and weak local correlation, a novel adaptive compression method based on vector quantizer is presented and implemented on GPU. Utilizing the property of Human Visual System (HVS, a new similarity measurement function is designed instead of using Euclid distance. Correlated threshold between blocks can be obtained adaptively according to the property of different images without artificial auxiliary. Furthermore, a self-adaptive threshold adjustment during the compression is designed to improve the reconstruct quality. Experiments show that the method can handle various resolution images adaptively. It can achieve satisfied compression rate and reconstruct quality at the same time. Index is coded to further increase the compression rate. The coding way is designed to guarantee accessing the index randomly too. Furthermore, the compression and decompression process is speed up with the usage of GPU, on account of their parallelism.

  1. Compressed classification learning with Markov chain samples.

    Cao, Feilong; Dai, Tenghui; Zhang, Yongquan; Tan, Yuanpeng


    In this article, we address the problem of compressed classification learning. A generalization bound of the support vector machines (SVMs) compressed classification algorithm with uniformly ergodic Markov chain samples is established. This bound indicates that the accuracy of the SVM classifier in the compressed domain is close to that of the best classifier in the data domain. In a sense, the fact that the compressed learning can avoid the curse of dimensionality in the learning process is shown. In addition, we show that compressed classification learning reduces the learning time at the price of decreasing the classification accuracy, but the decrement can be controlled. The numerical experiments further verify the results claimed in this article.

  2. An efficient medical image compression scheme.

    Li, Xiaofeng; Shen, Yi; Ma, Jiachen


    In this paper, a fast lossless compression scheme is presented for the medical image. This scheme consists of two stages. In the first stage, a Differential Pulse Code Modulation (DPCM) is used to decorrelate the raw image data, therefore increasing the compressibility of the medical image. In the second stage, an effective scheme based on the Huffman coding method is developed to encode the residual image. This newly proposed scheme could reduce the cost for the Huffman coding table while achieving high compression ratio. With this algorithm, a compression ratio higher than that of the lossless JPEG method for image can be obtained. At the same time, this method is quicker than the lossless JPEG2000. In other words, the newly proposed algorithm provides a good means for lossless medical image compression.

  3. Temporal Resolution Enhancement in Compressed Video Sequences

    Robert L. Stevenson


    Full Text Available Compressed video may possess a number of artifacts, both spatial and temporal. Spatial compression artifacts arise as a result of quantization of the transform-domain coefficients, and are often manifested as blocking and ringing artifacts. Temporal limitations in compressed video occur when the encoder, in an effort to reduce bandwidth, drops frames. Omitting frames decreases the reconstructed frame rate, which can cause motion to appear jerky and uneven. This paper discusses a method to increase the frame rate of video compressed with the DCT by inserting images between received frames of the sequence. The Bayesian formulation of the restoration prevents spatial compression artifacts in the received frames from propagating to the reconstructed frames.

  4. Isostatic compression of buffer blocks. Middle scale

    Ritola, J.; Pyy, E. [VTT Technical Research Centre of Finland, Espoo (Finland)


    Manufacturing of buffer components using isostatic compression method has been studied in small scale in 2008 (Laaksonen 2010). These tests included manufacturing of buffer blocks using different bentonite materials and different compression pressures. Isostatic mould technology was also tested, along with different methods to fill the mould, such as vibration and partial vacuum, as well as a stepwise compression of the blocks. The development of manufacturing techniques has continued with small-scale (30 %) blocks (diameter 600 mm) in 2009. This was done in a separate project: Isostatic compression, manufacturing and testing of small scale (D = 600 mm) buffer blocks. The research on the isostatic compression method continued in 2010 in a project aimed to test and examine the isostatic manufacturing process of buffer blocks at 70 % scale (block diameter 1200 to 1300 mm), and the aim was to continue in 2011 with full-scale blocks (diameter 1700 mm). A total of nine bentonite blocks were manufactured at 70 % scale, of which four were ring-shaped and the rest were cylindrical. It is currently not possible to manufacture full-scale blocks, because there is no sufficiently large isostatic press available. However, such a compression unit is expected to be possible to use in the near future. The test results of bentonite blocks, produced with an isostatic pressing method at different presses and at different sizes, suggest that the technical characteristics, for example bulk density and strength values, are somewhat independent of the size of the block, and that the blocks have fairly homogenous characteristics. Water content and compression pressure are the two most important properties determining the characteristics of the compressed blocks. By adjusting these two properties it is fairly easy to produce blocks at a desired density. The commonly used compression pressure in the manufacturing of bentonite blocks is 100 MPa, which compresses bentonite to approximately

  5. Effects of compression ratio on the combustion characteristics of a homogeneous charge compression ignition engine

    SONG Ruizhi; HU Tiegang; ZHOU Longbao; LIU Shenghua; LI Wei


    The effects of homogeneous charge compression ignition (HCCI) engine compression ratio on its combustion characteristics were studied experimentally on a modified TY1100 single cylinder engine fueled with dimethyl ether.The results show that dimethyl ether (DME) HCCI engine can work stably and can realize zero nitrogen oxides (NOx)emission and smokeless combustion under the compression ratio of both 10.7 and 14.The combustion process has obvious two stage combustion characteristics at ε = 10.7(εrefers to compression ratio),and the combustion beginning point is decided by the compression temperature,which varies very little with the engine load;the combustion beginning point is closely related to the engine load (concentration of mixture) with the increase in the compression temperature,and it moves forward versus crank angle with the increase in the engine load at ε = 14;the combustion durations are shortened with the increase in the engine load under both compression ratios.

  6. Beam manipulation and compression using broadband rf systems in the Fermilab Main Injector and Recycler

    G William Foster et al.


    A novel method for beam manipulation, compression, and stacking using a broad band RF system in circular accelerators is described. The method uses a series of linear voltage ramps in combination with moving barrier pulses to azimuthally compress, expand, or cog the beam. Beam manipulations can be accomplished rapidly and, in principle, without emittance growth. The general principle of the method is discussed using beam dynamics simulations. Beam experiments in the Fermilab Recycler Ring convincingly validate the concept. Preliminary experiments in the Fermilab Main Injector to investigate its potential for merging two ''booster batches'' to produce high intensity proton beams for neutrino and antiproton production are described.

  7. Compressive sensing reconstruction of feed-forward connectivity in pulse-coupled nonlinear networks

    Barranca, Victor J.; Zhou, Douglas; Cai, David


    Utilizing the sparsity ubiquitous in real-world network connectivity, we develop a theoretical framework for efficiently reconstructing sparse feed-forward connections in a pulse-coupled nonlinear network through its output activities. Using only a small ensemble of random inputs, we solve this inverse problem through the compressive sensing theory based on a hidden linear structure intrinsic to the nonlinear network dynamics. The accuracy of the reconstruction is further verified by the fact that complex inputs can be well recovered using the reconstructed connectivity. We expect this Rapid Communication provides a new perspective for understanding the structure-function relationship as well as compressive sensing principle in nonlinear network dynamics.

  8. Compressive sensing reconstruction of feed-forward connectivity in pulse-coupled nonlinear networks.

    Barranca, Victor J; Zhou, Douglas; Cai, David


    Utilizing the sparsity ubiquitous in real-world network connectivity, we develop a theoretical framework for efficiently reconstructing sparse feed-forward connections in a pulse-coupled nonlinear network through its output activities. Using only a small ensemble of random inputs, we solve this inverse problem through the compressive sensing theory based on a hidden linear structure intrinsic to the nonlinear network dynamics. The accuracy of the reconstruction is further verified by the fact that complex inputs can be well recovered using the reconstructed connectivity. We expect this Rapid Communication provides a new perspective for understanding the structure-function relationship as well as compressive sensing principle in nonlinear network dynamics.

  9. Rapid Prototyping Laboratory

    Federal Laboratory Consortium — The ARDEC Rapid Prototyping (RP) Laboratory was established in December 1992 to provide low cost RP capabilities to the ARDEC engineering community. The Stratasys,...

  10. Reducing the Disk IO Bandwidth Bottleneck through Fast Floating Point Compression using Accelerators

    Ajith Padyana


    Full Text Available Compute-intensive tasks in high-end high performance computing (HPC systems often generate large amounts of data, especially floating-point data that need to be transmitted over the network. Although computation speeds are very high, the overall performance of these applications is affected by the data transfer overhead. Moreover, as data sets are growing in size rapidly, bandwidth limitations pose a serious bottleneck in several scientific applications. Fast floating point compression can ameliorate the bandwidth limitations. If data is compressed well, then the amount of data transfer is reduced. This reduction in data transfer time comes at the expense of the increased computation required by compression and decompression. It is important for compression and decompression rates to be greater than the network bandwidth; otherwise, it will be faster to transmit uncompressed data directly [1]. Accelerators such as Graphics Processing Units (GPU provide much computational power. In this paper, we show that the computational power of GPUs and CellBE processor can be harnessed to provide sufficiently fast compression and decompression for this approach to be effective for data produced by many practical applications. In particularly, we use Holt`s Exponential smoothing algorithm from time series analysis, and encode the difference between its predictions and the actual data. This yields a lossless compression scheme. We show that it can be implemented efficiently on GPUs and CellBE to provide an effective compression scheme for the purpose of saving on data transfer overheads The primary contribution of this work lies in demonstrating the potential of floating point compression in reducing the I/O bandwidth bottleneck on modern hardware for important classes of scientific applications.

  11. Non-US data compression and coding research. FASAC Technical Assessment Report

    Gray, R.M.; Cohn, M.; Craver, L.W.; Gersho, A.; Lookabaugh, T.; Pollara, F.; Vetterli, M.


    This assessment of recent data compression and coding research outside the United States examines fundamental and applied work in the basic areas of signal decomposition, quantization, lossless compression, and error control, as well as application development efforts in image/video compression and speech/audio compression. Seven computer scientists and engineers who are active in development of these technologies in US academia, government, and industry carried out the assessment. Strong industrial and academic research groups in Western Europe, Israel, and the Pacific Rim are active in the worldwide search for compression algorithms that provide good tradeoffs among fidelity, bit rate, and computational complexity, though the theoretical roots and virtually all of the classical compression algorithms were developed in the United States. Certain areas, such as segmentation coding, model-based coding, and trellis-coded modulation, have developed earlier or in more depth outside the United States, though the United States has maintained its early lead in most areas of theory and algorithm development. Researchers abroad are active in other currently popular areas, such as quantizer design techniques based on neural networks and signal decompositions based on fractals and wavelets, but, in most cases, either similar research is or has been going on in the United States, or the work has not led to useful improvements in compression performance. Because there is a high degree of international cooperation and interaction in this field, good ideas spread rapidly across borders (both ways) through international conferences, journals, and technical exchanges. Though there have been no fundamental data compression breakthroughs in the past five years--outside or inside the United State--there have been an enormous number of significant improvements in both places in the tradeoffs among fidelity, bit rate, and computational complexity.

  12. Effects of deformation temperature and rate on compressive deformation behaviour of Y 112 die cast aluminum alloy in semi-solid state

    YANG Ming-bo; HU Hong-jun; TANG Li-wen; DAI Bing


    The semi-solid compression deformation behaviour of Y112 die casting aluminum alloy with nondendritic structure obtained under the semi-solid isothermal treatment condition of 570 ℃ and 120 min, was investigated by means of Gleeble-1500 thermal-mechanical simulator. The results show that, when the strain is lower than 0.8, along with the compression strain increasing,the compression stress firstly increases rapidly, then decreases gradually. Under the condition of different deformation temperatures and deformation rates, the maximium compression stress is obtained simultaneously when the strain is 0.07 approximately.Furthermore, when the deformation rate keeps a constant, the compression stress decreases along with the deformation temperature increasing, and when the deformation temperature keeps a constant, the compression stress increases along with the deformation rate increasing.

  13. Cascaded Soliton Compression of Energetic Femtosecond Pulses at 1030 nm

    Bache, Morten; Zhou, Binbin


    We discuss soliton compression with cascaded second-harmonic generation of energetic femtosecond pulses at 1030 nm. We discuss problems encountered with soliton compression of long pulses and show that sub-10 fs compressed pulses can be achieved.......We discuss soliton compression with cascaded second-harmonic generation of energetic femtosecond pulses at 1030 nm. We discuss problems encountered with soliton compression of long pulses and show that sub-10 fs compressed pulses can be achieved....

  14. Backpropagation Neural Network Implementation for Medical Image Compression

    Kamil Dimililer


    Full Text Available Medical images require compression, before transmission or storage, due to constrained bandwidth and storage capacity. An ideal image compression system must yield high-quality compressed image with high compression ratio. In this paper, Haar wavelet transform and discrete cosine transform are considered and a neural network is trained to relate the X-ray image contents to their ideal compression method and their optimum compression ratio.

  15. MAFCO: a compression tool for MAF files.

    Luís M O Matos

    Full Text Available In the last decade, the cost of genomic sequencing has been decreasing so much that researchers all over the world accumulate huge amounts of data for present and future use. These genomic data need to be efficiently stored, because storage cost is not decreasing as fast as the cost of sequencing. In order to overcome this problem, the most popular general-purpose compression tool, gzip, is usually used. However, these tools were not specifically designed to compress this kind of data, and often fall short when the intention is to reduce the data size as much as possible. There are several compression algorithms available, even for genomic data, but very few have been designed to deal with Whole Genome Alignments, containing alignments between entire genomes of several species. In this paper, we present a lossless compression tool, MAFCO, specifically designed to compress MAF (Multiple Alignment Format files. Compared to gzip, the proposed tool attains a compression gain from 34% to 57%, depending on the data set. When compared to a recent dedicated method, which is not compatible with some data sets, the compression gain of MAFCO is about 9%. Both source-code and binaries for several operating systems are freely available for non-commercial use at:

  16. Cloud Optimized Image Format and Compression

    Becker, P.; Plesea, L.; Maurer, T.


    Cloud based image storage and processing requires revaluation of formats and processing methods. For the true value of the massive volumes of earth observation data to be realized, the image data needs to be accessible from the cloud. Traditional file formats such as TIF and NITF were developed in the hay day of the desktop and assumed fast low latency file access. Other formats such as JPEG2000 provide for streaming protocols for pixel data, but still require a server to have file access. These concepts no longer truly hold in cloud based elastic storage and computation environments. This paper will provide details of a newly evolving image storage format (MRF) and compression that is optimized for cloud environments. Although the cost of storage continues to fall for large data volumes, there is still significant value in compression. For imagery data to be used in analysis and exploit the extended dynamic range of the new sensors, lossless or controlled lossy compression is of high value. Compression decreases the data volumes stored and reduces the data transferred, but the reduced data size must be balanced with the CPU required to decompress. The paper also outlines a new compression algorithm (LERC) for imagery and elevation data that optimizes this balance. Advantages of the compression include its simple to implement algorithm that enables it to be efficiently accessed using JavaScript. Combing this new cloud based image storage format and compression will help resolve some of the challenges of big image data on the internet.

  17. GPU Lossless Hyperspectral Data Compression System

    Aranki, Nazeeh I.; Keymeulen, Didier; Kiely, Aaron B.; Klimesh, Matthew A.


    Hyperspectral imaging systems onboard aircraft or spacecraft can acquire large amounts of data, putting a strain on limited downlink and storage resources. Onboard data compression can mitigate this problem but may require a system capable of a high throughput. In order to achieve a high throughput with a software compressor, a graphics processing unit (GPU) implementation of a compressor was developed targeting the current state-of-the-art GPUs from NVIDIA(R). The implementation is based on the fast lossless (FL) compression algorithm reported in "Fast Lossless Compression of Multispectral-Image Data" (NPO- 42517), NASA Tech Briefs, Vol. 30, No. 8 (August 2006), page 26, which operates on hyperspectral data and achieves excellent compression performance while having low complexity. The FL compressor uses an adaptive filtering method and achieves state-of-the-art performance in both compression effectiveness and low complexity. The new Consultative Committee for Space Data Systems (CCSDS) Standard for Lossless Multispectral & Hyperspectral image compression (CCSDS 123) is based on the FL compressor. The software makes use of the highly-parallel processing capability of GPUs to achieve a throughput at least six times higher than that of a software implementation running on a single-core CPU. This implementation provides a practical real-time solution for compression of data from airborne hyperspectral instruments.

  18. Segmentation-based CT image compression

    Thammineni, Arunoday; Mukhopadhyay, Sudipta; Kamath, Vidya


    The existing image compression standards like JPEG and JPEG 2000, compress the whole image as a single frame. This makes the system simple but inefficient. The problem is acute for applications where lossless compression is mandatory viz. medical image compression. If the spatial characteristics of the image are considered, it can give rise to a more efficient coding scheme. For example, CT reconstructed images have uniform background outside the field of view (FOV). Even the portion within the FOV can be divided as anatomically relevant and irrelevant parts. They have distinctly different statistics. Hence coding them separately will result in more efficient compression. Segmentation is done based on thresholding and shape information is stored using 8-connected differential chain code. Simple 1-D DPCM is used as the prediction scheme. The experiments show that the 1st order entropies of images fall by more than 11% when each segment is coded separately. For simplicity and speed of decoding Huffman code is chosen for entropy coding. Segment based coding will have an overhead of one table per segment but the overhead is minimal. Lossless compression of image based on segmentation resulted in reduction of bit rate by 7%-9% compared to lossless compression of whole image as a single frame by the same prediction coder. Segmentation based scheme also has the advantage of natural ROI based progressive decoding. If it is allowed to delete the diagnostically irrelevant portions, the bit budget can go down as much as 40%. This concept can be extended to other modalities.

  19. Lossless compression of VLSI layout image data.

    Dai, Vito; Zakhor, Avideh


    We present a novel lossless compression algorithm called Context Copy Combinatorial Code (C4), which integrates the advantages of two very disparate compression techniques: context-based modeling and Lempel-Ziv (LZ) style copying. While the algorithm can be applied to many lossless compression applications, such as document image compression, our primary target application has been lossless compression of integrated circuit layout image data. These images contain a heterogeneous mix of data: dense repetitive data better suited to LZ-style coding, and less dense structured data, better suited to context-based encoding. As part of C4, we have developed a novel binary entropy coding technique called combinatorial coding which is simultaneously as efficient as arithmetic coding, and as fast as Huffman coding. Compression results show C4 outperforms JBIG, ZIP, BZIP2, and two-dimensional LZ, and achieves lossless compression ratios greater than 22 for binary layout image data, and greater than 14 for gray-pixel image data.


    Y. Venkataramani


    Full Text Available The amount of digital contents grows at a faster speed as a result does the demand for communicate them. On the other hand, the amount of storage and bandwidth increases at a slower rate. Thus powerful and efficient compression methods are required. The repetition of words and phrases cause the reordered text much more compressible than the original text. On the whole system is fast and achieves close to the best result on the test files. In this study a novel fast dictionary based text compression technique MBRH (Multidictionary with burrows wheeler transforms, Run length coding and Huffman coding is proposed for the purpose of obtaining improved performance on various document sizes. MBRH algorithm comprises of two stages, the first stage is concerned with the conversion of input text into dictionary based compression .The second stage deals mainly with reduction of the redundancy in multidictionary based compression by using BWT, RLE and Huffman coding. Bib test files of input size of 111, 261 bytes achieves compression ratio of 0.192, bit rate of 1.538 and high speed using MBRH algorithm. The algorithm has attained a good compression ratio, reduction of bit rate and the increase in execution speed.

  1. On the compressibility effects in mixing layers

    Khlifi Hechmi


    Full Text Available Previous studies of compressible flows carried out in the past few years have shown that the pressure-strain is the main indicator of the structural compressibility effects. Undoubtedly, this terms plays a key role toward strongly changing magnitude of the turbulent Reynolds stress anisotropy. On the other hand, the incompressible models of the pressure-strain correlation have not correctly predicted compressible turbulence at high speed shear flow. Consequently, a correction of these models is needed for precise prediction of compressibility effects. In the present work, a compressibility correction of the widely used incompressible Launder Reece and Rodi model making their standard coefficients dependent on the turbulent and convective Mach numbers is proposed. The ability of the model to predict the developed mixing layers in different cases from experiments of Goebel and Dutton is examined. The predicted results with the proposed model are compared with DNS and experimental data and those obtained by the compressible model of Adumitroiae et al. and the original LRR model. The results show that the essential compressibility effects on mixing layers are well captured by the proposed model.

  2. Compressive sensing for nuclear security.

    Gestner, Brian Joseph


    Special nuclear material (SNM) detection has applications in nuclear material control, treaty verification, and national security. The neutron and gamma-ray radiation signature of SNMs can be indirectly observed in scintillator materials, which fluoresce when exposed to this radiation. A photomultiplier tube (PMT) coupled to the scintillator material is often used to convert this weak fluorescence to an electrical output signal. The fluorescence produced by a neutron interaction event differs from that of a gamma-ray interaction event, leading to a slightly different pulse in the PMT output signal. The ability to distinguish between these pulse types, i.e., pulse shape discrimination (PSD), has enabled applications such as neutron spectroscopy, neutron scatter cameras, and dual-mode neutron/gamma-ray imagers. In this research, we explore the use of compressive sensing to guide the development of novel mixed-signal hardware for PMT output signal acquisition. Effectively, we explore smart digitizers that extract sufficient information for PSD while requiring a considerably lower sample rate than conventional digitizers. Given that we determine the feasibility of realizing these designs in custom low-power analog integrated circuits, this research enables the incorporation of SNM detection into wireless sensor networks.

  3. Review Article: An Overview of Image Compression Techniques

    M. Marimuthu


    Full Text Available To store an image, large quantities of digital data are required. Due to limited bandwidth, image must be compressed before transmission. However, image compression reduces the image fidelity, when an image is compressed at low bitrates. Hence, the compressed images suffer from block artifacts. To meet this, several compression schemes have been developed in image processing. This study presents an overview of compression techniques for image applications. It covers the lossy and lossless compression algorithm used for still image and other applications. The focus of this article is based on the overview of VLSI DCT architecture for image compression. Further, this new approach may provide better results.

  4. Properties of Compressive Strength and Heating Value of Compressed Semi-Carbonized Sugi thinning

    Sawai, Toru; Kajimoto, Takeshi; Akasaka, Motofumi; Kaji, Masuo; Ida, Tamio; Fuchihata, Manabu; Honjyo, Takako; Sano, Hiroshi

    Sugi thinnings with small diameter that are not suitable for lumber can be considered as important domestic energy resources. To utilize Sugi thinnings as alternative fuel of coal cokes, properties of compressive strength and heating value of compressed semi-carbonized wood fuel are investigated. To enhance the heating value, "semi-carbonization", that is the pyrolysis in the temperature range between 200 and 400 degree, is conducted. From the variation of heating value and energy yield of char with pyrolysis temperature, the semi-carbonization pyrolysis is found to be the upgrading technology to convert the woody biomass into the high energy density fuel at high energy yield. To increase the compressive strength, "Cold Isostatic Pressing" method is adopted. The compressive strength of the compressed wood fuel decreases with pyrolysis temperature, while the heating value increases. The drastic decrease in the compressive strength is observed at temperature of 250 degree. The increase in the hydrostatic compression pressure improves the compressive strength for an entire range of semi-carbonization pyrolysis. The alternative fuel with high heating value and high compressive strength can be produced by the semi-carbonization processing at temperature of 280 degree for wood fuel compressed at hydrostatic pressure of 200MPa.

  5. Digital Image Compression Using Artificial Neural Networks

    Serra-Ricart, M.; Garrido, L.; Gaitan, V.; Aloy, A.


    The problem of storing, transmitting, and manipulating digital images is considered. Because of the file sizes involved, large amounts of digitized image information are becoming common in modern projects. Our goal is to described an image compression transform coder based on artificial neural networks techniques (NNCTC). A comparison of the compression results obtained from digital astronomical images by the NNCTC and the method used in the compression of the digitized sky survey from the Space Telescope Science Institute based on the H-transform is performed in order to assess the reliability of the NNCTC.

  6. Simulation of Compressive Failure in Fiber Composites

    Veluri, Badrinath; Jensen, Henrik Myhre

    Kinkband formation is a non-linear phenomenon involving interacting effects of non-linear material behavior of the matrix materials and fiber buckling including fiber misalignment in fiber composites under compressive loading. Taking into account the non-linearties of the constituents...... understanding of the influence of the macro-geometry and micro-geometry. In addition studying the mechanics of kinkband formation, focus is also directed in computing the critical compressive stress for steady state kinkband broadening under compression in the fiber direction. The present theory demonstrates...

  7. An efficient compression scheme for bitmap indices

    Wu, Kesheng; Otoo, Ekow J.; Shoshani, Arie


    When using an out-of-core indexing method to answer a query, it is generally assumed that the I/O cost dominates the overall query response time. Because of this, most research on indexing methods concentrate on reducing the sizes of indices. For bitmap indices, compression has been used for this purpose. However, in most cases, operations on these compressed bitmaps, mostly bitwise logical operations such as AND, OR, and NOT, spend more time in CPU than in I/O. To speedup these operations, a number of specialized bitmap compression schemes have been developed; the best known of which is the byte-aligned bitmap code (BBC). They are usually faster in performing logical operations than the general purpose compression schemes, but, the time spent in CPU still dominates the total query response time. To reduce the query response time, we designed a CPU-friendly scheme named the word-aligned hybrid (WAH) code. In this paper, we prove that the sizes of WAH compressed bitmap indices are about two words per row for large range of attributes. This size is smaller than typical sizes of commonly used indices, such as a B-tree. Therefore, WAH compressed indices are not only appropriate for low cardinality attributes but also for high cardinality attributes.In the worst case, the time to operate on compressed bitmaps is proportional to the total size of the bitmaps involved. The total size of the bitmaps required to answer a query on one attribute is proportional to the number of hits. These indicate that WAH compressed bitmap indices are optimal. To verify their effectiveness, we generated bitmap indices for four different datasets and measured the response time of many range queries. Tests confirm that sizes of compressed bitmap indices are indeed smaller than B-tree indices, and query processing with WAH compressed indices is much faster than with BBC compressed indices, projection indices and B-tree indices. In addition, we also verified that the average query response time

  8. 17 Pseudoaneurysms Treated by Padding and Compression

    WANGLu-ping; MEIXiao-rong; XUYu-lan; LIUYi; ZHENGCheng-fei; WANGGang


    To introduce the method and curative effect of treating pseudoaneurysms by padding and compression. Method: retrospectively analyze the curative effect of treating 17 pseudoaneurysms bypadding hard things and compression. Result: 15 of them was completely recovered by doing so,murmur disappeared and the local skin became even, there was no recurrences and complications after 0.5-3year's following up,but the other two were the same as before the therapy. Conclusion: pseudoaneurysms can be treated effectively by padding and compression

  9. ECG data compression using Jacobi polynomials.

    Tchiotsop, Daniel; Wolf, Didier; Louis-Dorr, Valérie; Husson, René


    Data compression is a frequent signal processing operation applied to ECG. We present here a method of ECG data compression utilizing Jacobi polynomials. ECG signals are first divided into blocks that match with cardiac cycles before being decomposed in Jacobi polynomials bases. Gauss quadratures mechanism for numerical integration is used to compute Jacobi transforms coefficients. Coefficients of small values are discarded in the reconstruction stage. For experimental purposes, we chose height families of Jacobi polynomials. Various segmentation approaches were considered. We elaborated an efficient strategy to cancel boundary effects. We obtained interesting results compared with ECG compression by wavelet decomposition methods. Some propositions are suggested to improve the results.

  10. Compression of a bundle of light rays.

    Marcuse, D


    The performance of ray compression devices is discussed on the basis of a phase space treatment using Liouville's theorem. It is concluded that the area in phase space of the input bundle of rays is determined solely by the required compression ratio and possible limitations on the maximum ray angle at the output of the device. The efficiency of tapers and lenses as ray compressors is approximately equal. For linear tapers and lenses the input angle of the useful rays must not exceed the compression ratio. The performance of linear tapers and lenses is compared to a particular ray compressor using a graded refractive index distribution.

  11. Face Tracking in the Compressed Domain

    Fonseca Pedro Miguel


    Full Text Available A compressed domain generic object tracking algorithm offers, in combination with a face detection algorithm, a low-compu-tational-cost solution to the problem of detecting and locating faces in frames of compressed video sequences (such as MPEG-1 or MPEG-2. Objects such as faces can thus be tracked through a compressed video stream using motion information provided by existing forward and backward motion vectors. The described solution requires only low computational resources on CE devices and offers at one and the same time sufficiently good location rates.

  12. Face Tracking in the Compressed Domain

    Fonseca, Pedro Miguel; Nesvadba, Jan


    A compressed domain generic object tracking algorithm offers, in combination with a face detection algorithm, a low-compu-tational-cost solution to the problem of detecting and locating faces in frames of compressed video sequences (such as MPEG-1 or MPEG-2). Objects such as faces can thus be tracked through a compressed video stream using motion information provided by existing forward and backward motion vectors. The described solution requires only low computational resources on CE devices and offers at one and the same time sufficiently good location rates.

  13. Compressed Gas Safety for Experimental Fusion Facilities

    Lee C. Cadwallader


    Experimental fusion facilities present a variety of hazards to the operators and staff. There are unique or specialized hazards, including magnetic fields, cryogens, radio frequency emissions, and vacuum reservoirs. There are also more general industrial hazards, such as a wide variety of electrical power, pressurized air, and cooling water systems in use, there are crane and hoist loads, working at height, and handling compressed gas cylinders. This paper outlines the projectile hazard assoicated with compressed gas cylinders and mthods of treatment to provide for compressed gas safety. This information should be of interest to personnel at both magnetic and inertial fusion experiments.

  14. Compressed sensing and sparsity in photoacoustic tomography

    Haltmeier, Markus; Moon, Sunghwan; Burgholzer, Peter


    Increasing the imaging speed is a central aim in photoacoustic tomography. In this work we address this issue using techniques of compressed sensing. We demonstrate that the number of measurements can significantly be reduced by allowing general linear measurements instead of point wise pressure values. A main requirement in compressed sensing is the sparsity of the unknowns to be recovered. For that purpose we develop the concept of sparsifying temporal transforms for three dimensional photoacoustic tomography. Reconstruction results for simulated and for experimental data verify that the proposed compressed sensing scheme allows to significantly reducing the number of spatial measurements without reducing the spatial resolution.

  15. Compressive sensing with a microwave photonic filter

    Chen, Ying; Yu, Xianbin; Chi, Hao


    In this letter, we present a novel approach to realizing photonics-assisted compressive sensing (CS) with the technique of microwave photonic fi ltering. In the proposed system, an input spectrally sparse signal to be captured and a random sequence are modulated on an optical carrier via two Mach...... to a frequency- dependent power fading, low-pass fi ltering required in the CS is then realized. A proof-of-concept ex- periment for compressive sampling and recovery of a signal containing three tones at 310 MHz, 1 GHz and 2 GHz with a compression factor up to 10 is successfully demonstrated. More simulation...

  16. Combined Sparsifying Transforms for Compressive Image Fusion

    ZHAO, L.


    Full Text Available In this paper, we present a new compressive image fusion method based on combined sparsifying transforms. First, the framework of compressive image fusion is introduced briefly. Then, combined sparsifying transforms are presented to enhance the sparsity of images. Finally, a reconstruction algorithm based on the nonlinear conjugate gradient is presented to get the fused image. The simulations demonstrate that by using the combined sparsifying transforms better results can be achieved in terms of both the subjective visual effect and the objective evaluation indexes than using only a single sparsifying transform for compressive image fusion.

  17. Spectral Compressive Sensing with Polar Interpolation

    Fyhn, Karsten; Dadkhahi, Hamid; F. Duarte, Marco


    Existing approaches to compressive sensing of frequency-sparse signals focuses on signal recovery rather than spectral estimation. Furthermore, the recovery performance is limited by the coherence of the required sparsity dictionaries and by the discretization of the frequency parameter space....... In this paper, we introduce a greedy recovery algorithm that leverages a band-exclusion function and a polar interpolation function to address these two issues in spectral compressive sensing. Our algorithm is geared towards line spectral estimation from compressive measurements and outperforms most existing...

  18. Lossless wavelet compression on medical image

    Zhao, Xiuying; Wei, Jingyuan; Zhai, Linpei; Liu, Hong


    An increasing number of medical imagery is created directly in digital form. Such as Clinical image Archiving and Communication Systems (PACS), as well as telemedicine networks require the storage and transmission of this huge amount of medical image data. Efficient compression of these data is crucial. Several lossless and lossy techniques for the compression of the data have been proposed. Lossless techniques allow exact reconstruction of the original imagery, while lossy techniques aim to achieve high compression ratios by allowing some acceptable degradation in the image. Lossless compression does not degrade the image, thus facilitating accurate diagnosis, of course at the expense of higher bit rates, i.e. lower compression ratios. Various methods both for lossy (irreversible) and lossless (reversible) image compression are proposed in the literature. The recent advances in the lossy compression techniques include different methods such as vector quantization. Wavelet coding, neural networks, and fractal coding. Although these methods can achieve high compression ratios (of the order 50:1, or even more), they do not allow reconstructing exactly the original version of the input data. Lossless compression techniques permit the perfect reconstruction of the original image, but the achievable compression ratios are only of the order 2:1, up to 4:1. In our paper, we use a kind of lifting scheme to generate truly loss-less non-linear integer-to-integer wavelet transforms. At the same time, we exploit the coding algorithm producing an embedded code has the property that the bits in the bit stream are generated in order of importance, so that all the low rate codes are included at the beginning of the bit stream. Typically, the encoding process stops when the target bit rate is met. Similarly, the decoder can interrupt the decoding process at any point in the bit stream, and still reconstruct the image. Therefore, a compression scheme generating an embedded code can

  19. Plasma heating by electric field compression.

    Avinash, K; Kaw, P K


    Plasma heating by compression of electric fields is proposed. It is shown that periodic cycles of external compression followed by the free expansion of electric fields in the plasma cause irreversible, collisionless plasma heating and corresponding entropy generation. As a demonstration of general ideas and scalings, the heating is shown in the case of a dusty plasma, where electric fields are created due to the presence of charged dust. The method is expected to work in the cases of compression of low frequency or dc electric fields created by other methods. Applications to high power laser heating of plasmas using this scheme are discussed.

  20. Compressed Gas Safety for Experimental Fusion Facilities

    Lee C. Cadwallader


    Experimental fusion facilities present a variety of hazards to the operators and staff. There are unique or specialized hazards, including magnetic fields, cryogens, radio frequency emissions, and vacuum reservoirs. There are also more general industrial hazards, such as a wide variety of electrical power, pressurized air, and cooling water systems in use, there are crane and hoist loads, working at height, and handling compressed gas cylinders. This paper outlines the projectile hazard assoicated with compressed gas cylinders and mthods of treatment to provide for compressed gas safety. This information should be of interest to personnel at both magnetic and inertial fusion experiments.

  1. Spinal epidural compression in chronic lymphocytic leukemia.

    Michalevicz, R; Burstein, A; Razon, N; Reider, I; Ilie, B


    Spinal epidural compression is a rare neurologic complication in patients with lymphoma. It occurs mostly in those with intermediate-grade to high-grade malignancy disease. This type of neurologic involvement has not been described in chronic lymphocytic leukemia (CLL). A patient with a long, stable CLL course developed spinal epidural compression and consequently died. The frequency of spinal epidural compression in lymphoma, according to the histologic subtypes and the considerations in making the right choice of therapy are discussed in light of the presented case.

  2. Pulse Compression Technique of Radio Fuze

    HU Xiu-juan; DENG Jia-hao; SANG Hui-ping


    The advantages of using phase-coded pulse compression technique for radio fuze systems are evaluated. With building mathematical models a matched filter has be en implemented successfully. Various simulations for pulse compression waveform coding were done to evaluate the performance of fuze system under noisy environment. The results of the simulation and the data analysis show that the phase-coded pulse compression gets a good result in the signal identification of the radio fuze with matched filter. Simultaneously, a suitable sidelobe suppression filter is established by simulation, the suppressed sidelobe level is acceptable to radio fuze application.

  3. Comparison of different Fingerprint Compression Techniques

    Ms.Mansi Kambli


    Full Text Available The important features of wavelet transform and different methods in compression of fingerprint images have been implemented. Image quality is measured objectively using peak signal to noise ratio (PSNR and mean square error (MSE.A comparative study using discrete cosine transform based Joint Photographic Experts Group(JPEG standard , wavelet based basic Set Partitioning in Hierarchical trees(SPIHT and Modified SPIHT is done. The comparison shows that Modified SPIHT offers better compression than basic SPIHT and JPEG. The results will help application developers to choose a good wavelet compression system for their applications.

  4. Fluid Compressibility Effects on the Dynamic Response of Hydrostatic Journal Bearings

    Sanandres, Luis A.


    A theoretical analysis for the dynamic performance characteristics of laminar flow, capillar/orifice compensated hydrostatic journal bearings is presented. The analysis considers in detail the effect of fluid compressibility in the bearing recesses. At high frequency excitations beyond a break frequency, the bearing hydrostatic stiffness increases sharply and it is accompanied by a rapid decrease in direct damping. Also, the potential of pneumatic hammer instability (negative damping) at low frequencies is likely to occur in hydrostatic bearing applications handling highly compressible fluids. Useful design criteria to avoid undesirable dynamic operating conditions at low and high frequencies are determined. The effect of fluid recess compressibility is brought into perspective, and found to be of utmost importance on the entire frequency spectrum response and stability characteristics of hydrostatic/hybrid journal bearings.

  5. Excimer Laser Pulse Compress With Pulse Feedback


    <正>To attain a shorter laser pulse, a compressing technique called pulse feedback was developed from the saturation gain switch applied to the amplification in a discharge pumping excimer laser cavity. It can

  6. Defocus cue and saliency preserving video compression

    Khanna, Meera Thapar; Chaudhury, Santanu; Lall, Brejesh


    There are monocular depth cues present in images or videos that aid in depth perception in two-dimensional images or videos. Our objective is to preserve the defocus depth cue present in the videos along with the salient regions during compression application. A method is provided for opportunistic bit allocation during the video compression using visual saliency information comprising both the image features, such as color and contrast, and the defocus-based depth cue. The method is divided into two steps: saliency computation followed by compression. A nonlinear method is used to combine pure and defocus saliency maps to form the final saliency map. Then quantization values are assigned on the basis of these saliency values over a frame. The experimental results show that the proposed scheme yields good results over standard H.264 compression as well as pure and defocus saliency methods.

  7. Pulse compression and prepulse suppression apparatus

    Dane, C.B.; Hackel, L.A.; George, E.V.; Miller, J.L.; Krupke, W.F.


    A pulse compression and prepulse suppression apparatus (10) for time compressing the output of a laser (14). A pump pulse (46) is separated from a seed pulse (48) by a first polarized beam splitter (20) according to the orientation of a half wave plate (18). The seed pulse (48) is directed into an SBS oscillator (44) by two plane mirrors (22, 26) and a corner mirror (24), the corner mirror (24) being movable to adjust timing. The pump pulse (46) is directed into an SBS amplifier 34 wherein SBS occurs. The seed pulse (48), having been propagated from the SBS oscillator (44), is then directed through the SBS amplifier (34) wherein it sweeps the energy of the pump pulse (46) out of the SBS amplifier (34) and is simultaneously compressed, and the time compressed pump pulse (46) is emitted as a pulse output (52). A second polarized beam splitter (38) directs any undepleted pump pulse 58 away from the SBS oscillator (44).

  8. Improve Compressed Air System Performance with AIRMaster+



    AIRMaster+ provides a systematic apporach for assessing the supply-side performance of compressed air systems. Using plant-specific data, the software effectively evaluates supply-side operational costs for various equipment configurations and system pro

  9. Compressive multi-mode superresolution display

    Heide, Felix


    Compressive displays are an emerging technology exploring the co-design of new optical device configurations and compressive computation. Previously, research has shown how to improve the dynamic range of displays and facilitate high-quality light field or glasses-free 3D image synthesis. In this paper, we introduce a new multi-mode compressive display architecture that supports switching between 3D and high dynamic range (HDR) modes as well as a new super-resolution mode. The proposed hardware consists of readily-available components and is driven by a novel splitting algorithm that computes the pixel states from a target high-resolution image. In effect, the display pixels present a compressed representation of the target image that is perceived as a single, high resolution image. © 2014 Optical Society of America.

  10. Seneca Compressed Air Energy Storage (CAES) Project



    This document provides specifications for the process air compressor for a compressed air storage project, requests a budgetary quote, and provides supporting information, including compressor data, site specific data, water analysis, and Seneca CAES value drivers.

  11. Hyperspectral image data compression based on DSP

    Fan, Jiming; Zhou, Jiankang; Chen, Xinhua; Shen, Weimin


    The huge data volume of hyperspectral image challenges its transportation and store. It is necessary to find an effective method to compress the hyperspectral image. Through analysis and comparison of current various algorithms, a mixed compression algorithm based on prediction, integer wavelet transform and embedded zero-tree wavelet (EZW) is proposed in this paper. We adopt a high-powered Digital Signal Processor (DSP) of TMS320DM642 to realize the proposed algorithm. Through modifying the mixed algorithm and optimizing its algorithmic language, the processing efficiency of the program was significantly improved, compared the non-optimized one. Our experiment show that the mixed algorithm based on DSP runs much faster than the algorithm on personal computer. The proposed method can achieve the nearly real-time compression with excellent image quality and compression performance.

  12. Smoking and the compression of morbidity

    W.J. Nusselder (Wilma); C.W.N. Looman (Caspar); P.J. Marang-van de Mheen; H. van de Mheen (Dike); J.P. Mackenbach (Johan)


    textabstractOBJECTIVE: To examine whether eliminating smoking will lead to a reduction in the number of years lived with disability (that is, absolute compression of morbidity). DESIGN: Multistate life table calculations based on the longitudinal GLOBE study (the Nether

  13. Compression of Short Text on Embedded Systems

    Rein, S.; Gühmann, C.; Fitzek, Frank


    The paper details a scheme for lossless compression of a short data series larger than 50 bytes. The method uses arithmetic coding and context modelling with a low-complexity data model. A data model that takes 32 kBytes of RAM already cuts the data size in half. The compression scheme just takes...... a few pages of source code,is scaleablein memory size, and may be useful in sensor or cellular networks to spare bandwidth. As we demonstrate the method allows for battery savings when applied to mobile phones.......The paper details a scheme for lossless compression of a short data series larger than 50 bytes. The method uses arithmetic coding and context modelling with a low-complexity data model. A data model that takes 32 kBytes of RAM already cuts the data size in half. The compression scheme just takes...

  14. 3D MHD Simulations of Spheromak Compression

    Stuber, James E.; Woodruff, Simon; O'Bryan, John; Romero-Talamas, Carlos A.; Darpa Spheromak Team


    The adiabatic compression of compact tori could lead to a compact and hence low cost fusion energy system. The critical scientific issues in spheromak compression relate both to confinement properties and to the stability of the configuration undergoing compression. We present results from the NIMROD code modified with the addition of magnetic field coils that allow us to examine the role of rotation on the stability and confinement of the spheromak (extending prior work for the FRC). We present results from a scan in initial rotation, from 0 to 100km/s. We show that strong rotational shear (10km/s over 1cm) occurs. We compare the simulation results with analytic scaling relations for adiabatic compression. Work performed under DARPA grant N66001-14-1-4044.

  15. Compression therapy after ankle fracture surgery

    Winge, R; Bayer, L; Gottlieb, H


    PURPOSE: The main purpose of this systematic review was to investigate the effect of compression treatment on the perioperative course of ankle fractures and describe its effect on edema, pain, ankle joint mobility, wound healing complication, length of stay (LOS) and time to surgery (TTS). The aim...... undergoing surgery, testing either intermittent pneumatic compression, compression bandage and/or compression stocking and reporting its effect on edema, pain, ankle joint mobility, wound healing complication, LOS and TTS. To conclude on data a narrative synthesis was performed. RESULTS: The review included...... eight studies (451 patients). Seven studies found a significant effect on edema, two studies described a significant reduction in pain, one a positive effect on ankle movement, two a positive effect on wound healing, one a reduction in LOS and finally two studies reported reduction in TTS. A systematic...

  16. Magnetic compression of an FRC plasma

    Okada, S.; Kitano, K.; Matsumoto, H. [Plasma Physics Laboratory, Faculty of Engineering, Osaka Univ., Suita, Osaka (JP)] [and others


    Confinement of a plasma with field-reversed configuration (FRC) is predicted to be improved if it is compressed only axially, keeping the magnetic flux between the separatrix and the confining chamber (flux conserver) wall unchanged, while allowing the plasma to expand radially. The prediction is based on an empirical scaling law of FRC confinement and on the assumption that the compression is done adiabatically. The apparatus for this axial compression was developed and the axial compression experiment was actually carried out by decreasing the distance of the mirror fields between which the FRC plasma is confined by 30% and the plasma life time of about 500 {mu}s was increased by about 50 {mu}s. (author)

  17. Flight Lossless Data Compression Electronics Project

    National Aeronautics and Space Administration — The proposed work seeks to drastically increase the capability of the lossless data compression technology embedded in the currently used flight part known as USES...

  18. Compression asphyxia from a human pyramid.

    Tumram, Nilesh Keshav; Ambade, Vipul Namdeorao; Biyabani, Naushad


    In compression asphyxia, respiration is stopped by external forces on the body. It is usually due to an external force compressing the trunk such as a heavy weight on the chest or abdomen and is associated with internal injuries. In present case, the victim was trapped and crushed under the falling persons from a human pyramid formation for a "Dahi Handi" festival. There was neither any severe blunt force injury nor any significant pathological natural disease contributing to the cause of death. The victim was unable to remove himself from the situation because his cognitive responses and coordination were impaired due to alcohol intake. The victim died from asphyxia due to compression of his chest and abdomen. Compression asphyxia resulting from the collapse of a human pyramid and the dynamics of its impact force in these circumstances is very rare and is not reported previously to the best of our knowledge.

  19. Fully compressive tides in galaxy mergers

    Renaud, Florent; Naab, Thorsten; Theis, Christian


    The disruptive effect of galactic tides is a textbook example of gravitational dynamics. However, depending on the shape of the potential, tides can also become fully compressive. When that is the case, they might trigger or strengthen the formation of galactic substructures (star clusters, tidal dwarf galaxies), instead of destroying them. We perform N-body simulations of interacting galaxies to quantify this effect. We demonstrate that tidal compression occurs repeatedly during a galaxy merger, independently of the specific choice of parameterization. With a model tailored to the Antennae galaxies, we show that the distribution of compressive tides matches the locations and timescales of observed substructures. After extending our study to a broad range of parameters, we conclude that neither the importance of the compressive tides (~15% of the stellar mass) nor their duration (~ 10 Myr) are strongly affected by changes in the progenitors' configurations and orbits. Moreover, we show that individual clumps ...

  20. optimizing compressive strength characteristics of hollow building ...


    This paper evaluates the compressive strength of sandcrete hollow building blocks when its sand fraction is partially replaced ... defines sandcrete blocks as composite materials made .... industry as well as the economy of Nigeria, if there is no.