Direct Lift Research Articles

Direction-Adaptive Discrete Wavelet Transform for Image Compression

We propose a direction-adaptive DWT (DA-DWT) that locally adapts the filtering directions to image content based on directional lifting. With the adaptive transform, energy compaction is improved for sharp image features. A mathematical analysis based on an anisotropic statistical image model is presented to quantify the theoretical gain achieved by adapting the filtering directions. The analysis indicates that the proposed DA-DWT is more effective than other lifting-based approaches. Experimental results report a gain of up to 2.5 dB in PSNR over the conventional DWT for typical test images. Subjectively, the reconstruction from the DA-DWT better represents the structure in the image and is visually more pleasing.

Evolution in Techniques for Endsocopic Brow Lift with Deep Temporal Fixation Only and Lower Blepharoplasty-Transconjunctival Fat Repositioning

As we become more confident with our surgical skills following our fellowship training, some of our approaches and techniques will be modified or changed. My primary evolutionary change involves procedures of the upper third of the face, primarily the brow lift and treatment of lower eyelid fat techniques. Traditional methods of forehead and brow rejuvenation, such as coronal, pretrichal, and direct brow lifts, have provided facial plastic surgeons with effective brow elevation for many years. In the past decade, the endoscopic brow lift has rapidly become accepted as part of the surgical armamentarium and is frequently the technique of choice. In general, the temporal dissection, temporal fixation, forehead subperiosteal or subgaleal dissection with release, and treatment to the brow depressor musculature have been standardized. Methods of bony fixation remain a controversial topic as there are numerous methods. We advocate deep temporal fixation only without bone fixation to achieve effective, long-term brow elevation. Traditionally, lower eyelid herniated fat is removed, which may cause a sunken or hollow lid appearance, especially in patients with a tear trough deformity (nasojugal groove). Lower eyelid transconjunctival fat repositioning, defined as the subperiosteal repositioning of the medial and central lower eyelid herniated orbital fat into the nasojugal fold, may prevent the surgical, hollow lower eyelid appearance while treating the herniated fat. Fat repositioning may be combined with an endoscopic subperiosteal midface-lift, transcutaneous skin pinch, and transconjunctival orbicularis oculi excision. This technique offers a powerful tool in the surgical armamentarium of the facial plastic surgeon.

Adaptive Directional Lifting-Based Wavelet Transform for Image Coding

We present a novel 2-D wavelet transform scheme of adaptive directional lifting (ADL) in image coding. Instead of alternately applying horizontal and vertical lifting, as in present practice, ADL performs lifting-based prediction in local windows in the direction of high pixel correlation. Hence, it adapts far better to the image orientation features in local windows. The ADL transform is achieved by existing 1-D wavelets and is seamlessly integrated into the global wavelet transform. The predicting and updating signals of ADL can be derived even at the fractional pixel precision level to achieve high directional resolution, while still maintaining perfect reconstruction. To enhance the ADL performance, a rate-distortion optimized directional segmentation scheme is also proposed to form and code a hierarchical image partition adapting to local features. Experimental results show that the proposed ADL-based image coding technique outperforms JPEG 2000 in both PSNR and visual quality, with the improvement up to 2.0 dB on images with rich orientation features.

Response of the non-premixed lifted flame to coaxial jet mixing layers

The influence of an air coflow on a non-premixed flame is studied. The purpose is to gradually disorganize the fuel (methane) jet by acting on the mixing layer while controlling the oxidizer (air) supply. For methane flow rate velocity ranging between 1 and 25 m/s, the flame adapts its behavior according to the value of the air co-flow rate velocity ranging between 0 and 1 m/s. First, two distinct processes are noticed in the flame lifting: a break point lifting process and a direct lifting process. By simultaneous measurements based on direct CH ∗-imaging and laser tomography, a criterion based on a thermal thickness, characteristic of the direct lifting process, is determined. Second, three lifted flame aspects are identifiable: a laminarized flame with a lobe-shaped base, a turbulent flame with a tubular base and a laminar flame with a totally rounded base. In particular, the two former flames are quantified by their lift-off height measured by CH ∗-imaging. To characterize the lifted flame behavior as a response to the mixing layers, the analysis introduces some global jet parameters able to take into account the local scale phenomena due to the jets’ vortices: the inner and the outer potential cores, characterizing the central and coflowing jets, respectively and the spreading of the methane jet. It is shown how much the relative organization of the mixing layers characterized by the ratio of the outer to inner potential core, is of paramount importance for the lifting process as well as for the lifted flame response (flame aspect, lift-off height, …). So, ‘macro’ parameters, introduced here, appear efficient to describe the lifted flame behavior.

Bounded differential games guidance law for dual-controlled missiles

A new guidance law tailored for an interceptor missile having forward and aft controls is proposed. The guidance law is derived using a differential games formulation with bounded controls. For the derivation, the interceptor closed-loop dynamics is represented by two first-order bi-proper transfer functions. Possible game-space structures are investigated, including a new one with two closed singular regions. The effect of the direct lift associated with the canard and tail controls is investigated, and it is proved that zero miss distance can always be guaranteed for some initial conditions. It is also shown that for the tail control a switching surface at some constant time before interception exists in the game-space, resulting from its nonminimum-phase nature.

Chromospheric Prolateness: Solar Cycle Variations

The solar prolateness (also known as Ovalisation, a french origin name) of the extended dynamical chromosphere is established from measurements performed above 2 Mm heights during the years of solar minimum, using the H and linear jets seen in SXR and EUV as well as in W-L (eclipses). Some kind of dynamical dissipation of the newly emerged magnetic field is needed. More systematic measurements should be done to build a more complete, possibly 3D, picture to explain the extended in the horizontal direction lifting effect of a large part of the polar chromosphere.

Brow Lift via the Direct and Trans-Blepharoplasty Approaches

Brow ptosis occurs as part of the aging process, and as a complication of facial nerve paresis. The article addresses the options available for correction of brow ptosis. The direct brow lift is effective for medial and central brow ptosis, and additional lift laterally may occasionally be needed. This is achieved with either a temporal external lift or an internal lift combined with blepharoplasty. The direct brow lift is suitable for any degree and pattern of brow ptosis, usually in males. It is also suitable for older females as well as male patients with facial paresis or marked involutional brow ptosis. The trans-blepharoplasty brow lift is suitable for relatively small degrees of brow ptosis affecting mainly the lateral two-thirds of the brow in any age group. It is often combined with upper lid blepharoplasty and is performed through the same incision. Complications associated with the direct brow lift include a cosmetically disturbing scar, granuloma formation due to the use of braided absorbable sutures rather than monofilament sutures, and the brow descending again. There may be temporary patches of reduced sensation in the forehead which normally recover in a few months. Complications associated with the trans-blepharoplasty brow lift include less lift than desired, and sutures causing dimpling of the skin. These two techniques are useful additions to the approaches for patients with brow ptosis.

Aircraft maneuverability improvement by direct lift control system application

The handling qualities of an aircraft will be improved if the Direct Lift Control (DLC) system is applied. In this paper, an attempt has been made to evaluate the influence of DLC-type system parameters on the aircraft's maneuverability and to determine the desired values of these parameters for the purpose of obtaining required values of the handling maneuverability criteria. Published papers which deal with direct lift control do not list requirements for evaluating handling qualities and maneuverability of aircraft equipped with DLC system. In this paper, three new criteria permitting the evaluation of results of employing DLC have been defined. Analysis of influence of DLC system parameters on selected known handling qualities criteria (for example CAP, C ∗ ), as well as new DLC efficiency coefficients, have been illustrated with a numeric example of A4D “Skyhawk” fighter aircraft and PZL M-18 “Dromader” agricultural airplane control system modification.

Selective Delayed Management of Blunt Traumatic Left Common Carotid Artery Injury Using Hypothermic Circulatory Arrest

Most traumatic carotid artery aneurysms occur at or close to its bifurcation, and traumatic aneurysm of the intrathoracic carotid arteries are rare. We describe a case of false aneurysm at the origin of the left common carotid artery (LCCA) after blunt trauma. A 53-year-old man suffered a blow from a broken steel plate, which flew from a working concrete crusher over his neck when he looked down the machine. Chest computed tomography revealed aneurysm of the LCCA, and aortic arch arteriography demonstrated a false aneurysm of about 3 x 5 cm at the origin of the LCCA, with loss of arterial continuity and abnormal tortuosity above the aneurysm. An ascending aorta to LCCA bypass graft was placed during the cooling period of cardiopulmonary bypass, and mattress sutures were placed in the normal aorta to close the origin of the LCCA under hypothermic circulatory arrest because of the extreme danger of dissection. The LCCA was transected partially at its origin from the aorta. We speculated that the direct lifting force which caused the carotid artery to move upward might produce a tear at the junction of the LCCA and the aortic arch.

Breaking the mass/anisotropy degeneracy in the Coma cluster

We provide the first direct lifting of the mass/anisotropy degeneracy for a cluster of galaxies, by jointly fitting the line of sight velocity dispersion and kurtosis profiles of the Coma cluster, assuming an NFW tracer density profile, a generalized-NFW dark matter profile and a constant anisotropy profile. We find that the orbits in Coma must be quasi-isotropic, and find a mass consistent with previous analyses, but a concentration parameter 50% higher than expected in cosmological ) for the concentration parameter, with decreased accuracy and efficiency when the projected mean velocity is not constant with radius.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Role of TEP in the microbial food web structure. I. Grazing behavior of a bacterivorous pelagic ciliate

We studied the ingestion of picoplankton-size particles by the oligotrich Strombidium sulcatum as a function of transparent exopolymeric particle (TEP) concentration. Fluorescent micro- spheres of 1 µm (FMS) were used as prey-item analogs. TEP-FMS aggregates were formed by bub- bling seawater solutions containing different TEP concentrations in the presence of FMS. After bub- bling, concentrations of TEP-FMS aggregates ranged from 0.5 to 1.7 ppm and from 11.9 to 17.9 ppm in the low and high TEP treatments, respectively. When the ciliates were exposed to similar FMS con- centrations, but different TEP concentrations, ingestion rates were higher for the low TEP treatments (14.1 FMS ciliate -1 h -1 ) than for the high TEP treatments (5.2 FMS ciliate -1 h -1 ). The number of FMS in- gested in the low TEP treatments was 2.7 times higher than in the high TEP treatments and ingestion rates were inversely correlated to TEP volume concentration. Our results suggest that the formation of TEP-FMS reduces FMS availability for micro-grazers by modifying the food size spectra and redistri- buting FMS to larger size classes, and that at a critical TEP concentration picoplankton-size prey items may become unavailable for the ciliate S. sulcatum, while concomitantly they may become available for large-particle grazers. Therefore, one role of TEP in the microbial food web would be to act as a trophic elevator, thus creating a direct lift for picoplankton-size prey items to higher trophic levels.

Control of Supersonic Impinging Jet Flows Using Supersonic Microjets

Supersonic impinging jets, such as those occurring in the next generation of short takeoff and vertical landing aircraft, generate a highly oscillatory e ow with very high unsteady loads on the nearby aircraft structures and the landing surfaces. These high-pressure and acoustic loads are also accompanied by a dramatic loss in lift during hover.Previousstudies of supersonic impinging jets suggestthatthehighly unsteady behavioroftheimpinging jets is due to a feedback loop between the e uid and acoustic e elds, which leads to these adverse effects. A unique active control technique was attempted with the aim of disrupting the feedback loop, diminishing the e ow unsteadiness, and ultimatelyreducing theadverseeffectsofthise ow.Flowcontrolwasimplementedbyplacingacirculararray of 400-πm-diamsupersonicmicrojetsaroundtheperipheryofthemainjet.Thiscontrolapproachwasverysuccessful in disrupting the feedback loop in that the activation of the microjets led to dramatic reductions in the lift loss (40%), unsteady pressure loads (11 dB), and near-e eld noise (8 dB). This relatively simple and highly effective control technique makes it a suitable candidate for implementation in practical aircraft systems. NUNDERSTANDINGoftheimpingingjete owe eld isnecessary for the design of efe cient short takeoff and vertical landing (STOVL) aircraft. When such STOVL aircraft are operating in hovermode,thatis,in closeproximityto theground,thedownwardpointing lift jets produce high-speed, hot e ow that impinges on the landing surface and generates the direct lift force. It is well known that in this cone guration several e ow-induced effects can emerge, which substantially diminish the performance of the aircraft. In particular, a signie cant lift loss can be induced due to e ow entrainment bytheliftingjetsfromtheambientenvironmentinthe vicinityofthe airframe. Other adverse phenomena include severe ground erosion on the landing surface and hot gas ingestion into the engine inlets. In addition, the impinging e owe eld usually generates signie cantly highernoiselevelsrelativetothatofafreejetoperatingundersimilar conditions. Increased overall sound pressure levels (OASPL) associated with the high-speed impinging jets can pose an environment pollution problem and adversely affect the integrity of structural elements in the vicinity of the nozzle exhaust due to acoustic loading. Moreover, the noise and the highly unsteady pressure e eld are frequently dominated by high-amplitude discrete tones, which may match the resonant frequencies of the aircraft panels, thus further exacerbating the sonic fatigue problem. These problems become more pronounced when the impinging jets are supersonic, the operating regime of the STOVL version of the future joint strike e ghter. In addition, the presence of multiple impinging jets can potentially further aggravate these effects due to the strong coupling between the jets and the emergence of an upward-moving fountain e ow e owing opposite to the lift jets. 1 A

The initiation of orogenic margin reverse faulting

Laboratory values of rock friction coefficients suggest that reverse faulting should be very difficult to initiate by simple horizontal compression of the crust. Values of stresses required by Andersonian faulting may be an order of magnitude higher than those actually present in orogenic margins. A simple stress balance calculation shows that the effect of the excess lithostatic pressure under an elevated orogen, if transmitted laterally through a crustal ductile layer to the orogenic margin, is to provide sufficient hydraulic lift under the orogen flanks to initiate reverse faulting by direct lift, even with rock friction coefficients of order 0.8. The required orogenic elevation above surrounding “normal” lithosphere is about one fifth of the thickness of the brittle crust of the orogen. This elevation may be as small as 2 km in tectonically active regions. The mechanism works even in the absence of regional lithospheric compressive stresses.

Observed versus forecasted precipitation in the South East Alps

Intense precipitation events are common on the SE slopes of the Alps and the climatological maximum of precipitation is located in the area of the Julian and Carnic Alps. Mesoscale intensification of rainfall in the area is explained. Two cases of intense precipitation were studied with fine mesh mesometeorological modelling using the ALADIN-SI model and verifying its results with all available ground-based raingauge measurements. For the first case of 5-8 November 1997 mesoscale topographically induced direct lifting was the main reason for precipitation intensification in the area. For the second case of 3-5 November 1998 this forcing was further modified by a mesofront moving along the eastern edge of the Alps in the opposite direction to the flow at upper levels. In the predicted precipitation the most noticeable feature was the shift of the forecasted precipitation fields by some 20 km with respect to the measured one leading to overestimation at the SW side, and underestimation at the NE side of the mountain ridge. The role of discrepancy sources of differences between the forecasted and raingauge precipitation are evaluated.

NEW TECHNIQUES IN EYEBROW SURGERY

Significant advances in eyebrow elevation surgery have occurred over the past 10 years spurred on in part by the public's general desire for less invasive procedures with faster healing times. 15 Standard eyebrow elevation techniques include the direct, midforehead, and coronal lift, with incisions of varying length and location. 18 Performed for both functional and aesthetic reasons, the endoscopic brow lift represents the most advanced eyebrow and forehead elevation technique. Brow muscle dissection and release can be carried out through significantly smaller incisions and with endoscopic visualization, resulting in less potential morbidity. 2 A thorough understanding of the regional anatomy, the importance of brow position in eyelid surgery, and proper patient selection are crucial to the success of the endoscopic brow lift.

Initial growth of Cu on Ir(100)-(5×1)

The structure of the clean and Cu covered Ir(100)-(5×1) surface has been studied with scanning tunneling microscopy and spectroscopy (STM/STS), low energy electron diffraction (LEED) and ion scattering spectroscopy (ISS). STM images of the reconstructed Ir surface with atomic resolution directly reveal a two-bridge registry configuration of the quasi-hexagonal layer. Growth of Cu starts with the formation of strongly anisotropic islands induced by the lateral asymmetry of the (5×1) reconstruction. The Cu island formation is accompanied by direct lifting of the Ir reconstruction. The lifting process is not limited to the area beneath the islands but continues onto the Ir terraces. Two-dimensional layer growth occurs at room temperature for a coverage below 0.6 ML. Upon annealing, the anisotropic Cu areas coalesce into larger islands of laterally more compact shape. The excess Ir atoms originating from the lifted reconstruction create a well-separated two-dimensional Ir phase inside the Cu islands. STS local barrier-height measurements exhibit strong chemical contrast between Cu and Ir areas. Phase separation between Ir and Cu is visible in the entire investigated coverage and temperature range; neither intermixing nor segregation has been found.

Optical ionization of DX center in AlGaAs : Se by inner-shell excitation

DX state is strongly localized. This nature could be investigated by observing relaxation process of localized electrons to emptied inner shells. We have found two different optical ionization processes of the DX center in AlxGa1−xAs:Se (x=0.33, NSe=5×1017(cm−3)) by using synchrotron radiation (SR). They are tentatively assigned to be a direct lift of an inner-shell electron to the conduction band (CB) followed by a capture of an electron at the DX center to the emptied inner shell (DX−+hν(L, K-edge)→DX0+eCB) and the Auger ionization of one electron of the DX center to the CB followed by a capture of another electron to the emptied inner shell (DX−+hν(L, K-edge)→DX++eCB+evacuum).

The combined method: A novel access technique for fetal endoscopic surgery

Background/Purpose: To develop practical and less invasive techniques for fetal endoscopic surgery, new methods of lifting the uterine wall to allow fetal surgery without maternal laparotomy were developed and assessed. Methods: Fetal endoscopic surgical procedures, including tracheostomy and umbilical vascular cannulation, were performed using one of the three methods to enter the uterus without maternal laparotomy in pregnant goats (n = 6; 105 to 115 days' gestation): (1) direct uterine lifting with an air-cushion device; (2) indirect uterine lifting, in which the uterine wall was fixed to the maternal abdominal wall using balloon tip ports inserted percutaneously by Seldinger's method, then the maternal abdomen was lifted mechanically; and (3) combined method, in which low pressure CO 2 (5 mm Hg for initial inflation and 2 mm Hg for maintenance) was insufflated into the uterus in addition to the indirect uterine lifting cited above. Results: The direct uterine lifting caused massive injury of myometrium and uterine membranes. The creation of intrauterine space and the protection of the membranes were not accomplished effectively by the indirect uterine lifting only. The combined method provided the adequate intrauterine space and excellent endoscopic visibility for completion of the endoscopic procedures with minimal uterine injury. Conclusion: The fetal endoscopic surgery may be accomplished simply and safely by the combined method, a novel technique of uterine lifting to allow fetal surgery without maternal laparotomy.

Design of an autoland controller for an F-14 aircraft using H-infinity synthesis

Our purpose is to present the results of a design effort to incorporate direct lift control into the F-14 aircraft automatic carrier landing system. This was accomplished using a new design methodology whereby typical single input/single output design specifications were translated into the weighting functions of an T^oo output-feedback synthesis problem. Next, robustness of the Tioo controller was analyzed using the structured singular value concept (JJL). A simplified uncertainty model for air vehicles based on flight test data was developed for this analysis. Finally, the resulting controller was successfully validated on the nonlinear simulation.

Brow lift by flap transposition in the glabrous brow area.

In brow lift, if a direct approach is utilized, the suture line medially is placed in a normal frontalis crease, and then the lateral part of the suture line, by lateral transfer of a small superiorly based flap, is caused to fall into a natural "laugh line" or "crow's feet" crease, three improvements result: 1. Greater control and predictability of shaping and position than with other techniques; 2. A more normal appearance, including better lateral lift and a much more inconspicuous scar than with supraciliary direct lift; 3. A longer-lasting result. In approximately 150 patients, scar appearance has been very gratifying indeed, with only 3 limited segmental scar revisions and 2 secondary midforehead elliptical excisions. It is believed that the principle exhibited in the tightening of the upper suture line by flap transfer, referred to by analogy as the worm principle, accounts for much of the improvement, especially in durability. This principle is seen as an aid in thinking through the mechanics of several other plastic surgical situations as well.