Search

ObjectivesIntracranial pressure over 20 mm Hg is associated with poor neurologic prognosis, but measuring intracranial pressure directly requires an invasive procedure. Dilation of the optic nerve sheath on axial ultrasound of the eye has been correlated with elevated intracranial pressure, but optimal cutoffs have been inconsistent possibly related to the measurement technique. A coronal technique has been studied on healthy volunteers but not on patients with high intracranial pressure. We compared two measurement techniques (axial and coronal) in patients with suspected high intracranial pressure due to trauma, bleeding, tumor, or infection.DesignProspective blinded observational study.SettingTwo tertiary referral center ICUs.PatientsTwenty adults admitted to the ICU at risk for increased intracranial pressure expected to receive invasive intracranial monitoring.InterventionsUltrasound measurements of the optic nerve sheath in axial and coronal views either averaged between eyes or the highest in either eye.Measurements and main resultsCoronal measurements showed less variability between each eye than axial measurements (mean difference 0.5 mm vs 1 mm; p = 0.03) and were associated with high intracranial pressure at first measurement and over 24 hours (area under the receiver operating characteristic range 0.7-0.8). Mean and highest axial measurements showed improved association with first (area under the receiver operating characteristic 0.87-0.94) and highest intracranial pressure measurement (area under the receiver operating characteristic 0.89-0.96) within 24 hours. A cutoff of highest axial measurement in either eye greater than 6.2 mm or mean axial measurement between eyes of 5.6 mm had a sensitivity of 100% in predicting high intracranial pressure over the following 24 hours.ConclusionsThe highest axial measurement of optic nerve sheath diameter in either eye is the most predictive of patients with high intracranial pressure in our population. This comparison of measurement techniques has not previously been described and should be further explored to set test cutoffs for ultrasound of the optic nerve sheath diameter.

Currently, there is a lack of direct design provisions in structural codes and literature that address design temperatures in tunnel structures and thus it is common practice for designers to resort to bridge codes. The main focus of this paper is the study of the temperature distribution in concrete road tunnels due to ambient temperature. In this context, the temperature distributions of the Airport Trail Tunnel in Calgary, Alberta is studied using numerical modelling and long-term temperature monitoring data collected from the tunnel. The overall aim is to evaluate findings from the numerical analysis and sensor data with current Canadian structural code provisions considered in tunnel design in regards to temperature loads. From the investigation, it is determined that the design temperature range was within CSA S6, however CSA S6 underestimates the temperature gradient effect in the walls and slabs of the tunnel under study.Key words: road tunnels, thermal loads, heat transfer analysis, numerical modelling, long-term monitoring, CSA S6.Actuellement, il y a un manque de dispositions de conception directes au niveau des codes structurels et de la litterature qui aborde la determination des temperatures dans les structures de tunnel et ainsi, c'est pratique courante que les concepteurs aient recours aux codes des ponts. L'objectif principal de ce travail est d'etudier la repartition de la temperature dans les tunnels de route en beton en raison de la temperature ambiante. Dans ce contexte, les repartitions de temperature du <> a Calgary en Alberta sont etudiees utilisant la modelisation numerique et les donnees de temperature du tunnel provenant du suivi a long terme. Le but global est d'evaluer les resultats de l'analyse numerique et les donnees de capteur avec les dispositions des codes structurelles canadiennes actuelles considerees dans la conception de tunnel en lien avec les charges de temperature. A partir de l'examen, il est determine que les variations de temperature de conception etaient dans les limites de la norme S6 de la CSA, cependant la norme S6 de la CSA sous-estime l'effet de gradient de temperature dans les murs et les dalles du tunnel a l'etude. [Traduit par la Redaction]Mots-cles : tunnels routiers, charges thermiques, analyse du transfert thermique, modelisation numerique, suivi a long terme, norme S6 de la CSA., IntroductionThermal loads are considered in the design of many types of structures including buildings, dams, bridges, and tunnels. Determining the thermal load is a complex problem since it depends on [...]

A brief review of the social and educational context of Hong Kong shows that the publication of the "General guidelines on moral education in schools" in 1981, by the Hong Kong Education Department, marked a milestone in the development of moral education. The "Guidelines" explicitly asserted moral education as one function of schooling, whilst also formally recognizing the home and the community as two main influences. This paper narrates how three moral sources of influence--namely Confucian-parental, Christian-religious and liberal-civic--have shaped the development of moral education in Hong Kong from 1973 to 2003. It then examines in more detail: parental influence at home--the Confucian moral source in Chinese family; schooling influenced by religious sources--taking Christian schools as an example; and the Independent Commission Against Corruption as an official agency for moral education--a liberal source calling for civic morality. In conclusion, the post-colonial emergence of nationalistic influence in the recently constituted Chinese Special Administrative Region, advocating national identity as the new core value, is traced and the implications for future moral education in Hong Kong are considered.

Abstract: Residential construction has changed little in decades. In North America, houses are constructed predominantly with cast-in-place (CIP) concrete basement foundations and 'custom-built' wood platform--framing structures. To improve the productivity [...]

Abstract: This paper presents a study on the interfacial behavior of carbon fiber reinforced polymer (CFRP) sheets when applied to concrete members as external reinforcement. Two bond test methods that [...]

The systematic approach for designing space-time trellis codes, over flat fading channels with full antenna diversity and good coding advantage, is discussed. These kinds of codes are suitable for an arbitrary number of transmit antennas with arbitrary signal constellations.

Coding and modulation for multiple-antenna systems have gained much attention in wireless communications. This paper investigates a noncoherent trellis-coded scheme based on differential unitary space--time modulation when neither the transmitter nor the receiver know the channel. In a time-varying flat Rayleigh fading environment, we derive differentially noncoherent decision metrics and obtain performance measures for systems with either an ideal interleaver or no interleaver. We demonstrate that with an ideal interleaver, the system performance is dominated by the minimum Hamming distance of the trellis code, while without an interleaver, the performance is dominated by the minimum free squared determinant distance (a novel generalization of the Euclidean distance) of the code. For both cases, code construction is described for Ungerboeck-type codes. Several examples that are based on diagonal cyclic group constellations and offer a good tradeoff between the coding advantage and trellis complexity are provided. Simulation results show that, by applying the soft-decision Viterbi decoder, the proposed scheme can achieve very good performance even with few receive antennas. Extensions to trellis-coded differential space-time block codes are also discussed. Index Terms--Antenna diversity, differential detection, multiple-antenna systems, space-time code, trellis-coded modulation, wireless communications.

In this letter, we propose an adaptive rank-estimation method for the additive white or colored Gaussian noise model. The main contribution of this letter has three parts. 1) We investigate the rank mismatch problem in the group-blind multiuser detector of Wang and Host-Madsen, and find that underestimating the rank causes significant performance degradation, whereas, rank overestimation can achieve performance gain in the low signal-to-noise-ratio (SNR) region. However, rank overestimation can lead to inaccurate channel estimation, which degrades the detector performance significantly in the high SNR region. 2) We propose a heuristic criterion for initial rank estimation which is robust for nonwhite noise cases. 3) In order to mitigate the rank mismatch problem, we introduce a hypothesis testing criterion for rank and signal Subspace decisions, which selects the most probable rank for the group-blind detectors. Simulation results show that the performance of the group-blind detector using this adaptive rank estimation algorithm is comparable to the group-blind .with perfect knowledge of the rank, and even better in the low-to-medium SNR region. Index Terms--Blind detector, code-division multiple access (CDMA), multiuser detector, rank estimation.

Background: Patients desire facelifting procedures to look younger, refreshed, and attractive. Unfortunately, there are few objective studies assessing the success of types of facelift procedures and ancillary techniques.Objectives: The authors sought to utilize convolutional neural network algorithms alongside patient-reported FACE-Q outcomes to evaluate perceived age reduction and patient satisfaction following various facelift techniques.Methods: Standardized preoperative and postoperative (1-year) images of patients who underwent facelift procedures were analyzed by 4 neural networks to estimate age reduction after surgery (n = 105). FACE-Q surveys were employed to measure patient-reported facial aesthetic outcome. We compared (1) facelift procedure type: skin-only vs superficial musculoaponeurotic system (SMAS)-plication, vs SMAS-ectomy; and (2) ancillary techniques: fat grafting (malar) vs no fat grafting. Outcomes were based on complications, estimated age-reduction, and patient satisfaction.Results: The neural network preoperative age accuracy score demonstrated that all neural networks were accurate in identifying our patients' ages (mean score = 100.4). SMAS-ectomy and SMAS-plication had significantly greater age-reduction (5.85 and 5.35 years, respectively) compared with skin-only (2.95 years, P < 0.05). Fat grafting compared to no fat grafting demonstrated 2.1 more years of age reduction. Facelift procedure type did not affect FACE-Q scores; however, patients who underwent fat grafting had a higher satisfaction with outcome (78.1 ± 8 vs 69 ± 6, P < 0.05) and decision to have the procedure (83.0 ± 6 vs 72 ± 9, P < 0.05).Conclusions: Artificial intelligence algorithms can reliably estimate the reduction in apparent age after facelift surgery. Facelift technique, like SMAS-ectomy or SMAS-plication, and specific technique, like fat grafting, were found to enhance facelifting outcomes and patient satisfaction. [ABSTRACT FROM AUTHOR]

We consider the symbol-synchronous Gaussian L-out-of-K code-division multiaccess channel, and obtain the capacity region and the upper and lower bounds to the symmetric capacity. The capacity region is found to be the same with or without frame synchronism. The lower bound depends on the signature waveforms through the eigenvalues of the SNR-weighted crosscorrelation matrix. We find a sufficient condition for the signature waveform set to maximize this lower bound and give an algorithm to construct a set of signature waveforms satisfying the sufficient condition. Index Terms - Code-division multiaccess, signal design, information rates.

The capacity region of a two-user Gaussian multiaccess channel with intersymbol interference (ISI), where the inputs pass through respective linear systems and are then superimposed before being corrupted by an additive Gaussian noise process, is found. A novel geometrical method is given to obtain the optimal input power spectral densities and the capacity region. This method can be viewed as a nontrivial generalization of the single-user water-filling argument. We show that as in the traditional memoryless multiaccess channel, frequency-division multiaccess (FDMA), with optimally selected frequency bands for each user, achieves the total capacity of the K-user Gaussian multiaccess channel with ISI. However, the capacity region of the two-user channel with memory is, in general, not a pentagon unless the channel transfer functions for both users are identical.

The restriction to Gaussian inputs in the limiting expression for the capacity regions of memoryless Gaussian interference and multiple-access channels is shown to fall short of achieving capacity even if the inputs are allowed to be dependent and nonstationary. In addition, the equality between the limiting and the single-letter characterizations of memoryless multiple-access channel capacity is established directly, without recourse to independent coding theorems.