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Arising from people's concern on global warming, structural engineers have to pay close attention to the environmental cost component in their structural designs. The structural framework contributes about 20% of the total emissions of the building in the life cycle according to a study in the United Kingdom. In the actual design process, there is no effective method of calculating the environmental cost for structural engineers and structural engineers ignore environmental effects of the structure at most times. This paper introduces the environmental cost index of embodied carbon as well as research and engineering applications. The comprehensive structural system selection method proposed by the paper, which combines life cycle assessment method, Inventory of Carbon and Energy (ICE) database and abatement model, considers both economic and environmental costs that take emission reduction cost into account. The method is applied to a high-rise building in Xi’an to compare structural schemes of frame-cor...

A disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4) can effectively degrade articular cartilage matrix proteoglycan and damage the intervertebral disc of spinal tuberculosis patients, resulting in deterioration of the physical properties of articular cartilage. Transforming growth factor β activated kinase 1 (TAK1) is similar to vascular cell adhesion molecule 1 (VCAM-1) and closely related to a variety of pathophysiological processes. This study intended to explore the expression of ADAMTS-4, VCAM-1, and TAK1 in cartilage tissue obtained from spinal tuberculosis patients and their inter-relationships, aiming to provide new treatment approaches for spinal tuberculosis. Patients with spinal tuberculosis (N = 60) from the department of orthopedics and patients with traumatic spinal fracture (N = 60, controls) were recruited for the study. ADAMTS-4, VCAM-1, and TAK1 expression was detected by immunohistochemistry. SPSS 19.0 software was used for data processing and analysis. The score values of ADAMTS-4, TAK1, and VCAM-1 were 1.45 ± 0.10, 1.33 ± 0.09, and 1.54 ± 0.11, respectively, which were significantly higher than those in normal controls (P < 0.05). ADAMTS-4 showed positive correlation with VCAM-1 and TAK1. ADAMTS-4, TAK1, and VCAM-1 expressions increased in spinal tuberculosis patients. They could provide clinical reference for spinal tuberculosis diagnosis and new treatment strategies can be devised by focusing on their positive correlation.

Selective area epitaxy has been applied to grow GaN stripe templates with side facts, followed by InGaN/GaN multiple quantum well (MQW) structures. Stripes oriented along the direction of [1 1 −2 0] form smooth triangular {1 −1 0 1} facets, while stripes in the [1 −1 0 0] direction produce incomplete coalesced {1 1 −2 2} side facets with planar (0 0 0 1) surface under the same growth conditions. Room-temperature luminescence property is investigated by using photoluminescence (PL) and cathodeluminescence (CL) spectra. It is found that uniform emission at 400 nm has been obtained for triangular MQWs oriented the direction of [1 1 −2 0]. With respect to the MQWs grown along the [1 −1 0 0] direction, large redshift is achieved for the ridge area compared to the sidewall due to the lateral vapor diffusion and surface migration.

According to the ionizing radiation safety regulation approved by the ROC Atomic Energy Council (AEC), personnel dosimeter processors shall be qualified by the Chinese National Laboratory Accreditation (CNLA) program before offering dosimeter services and shall be requalified every two years. The Institute of Nuclear Energy Research (INER) was entrusted by CNLA as the central laboratory to perform the proficiency test of personnel dosimeters for laboratory accreditation in December 1990. Such proficiency tests, based on ANSI N13.11 (1983), have been conducted three times, in 1991, 1993 and 1995, to accommodate for dosimeter processors' need for requalification every two years. The results of the latest proficiency test showed that, among the nine participants, six participants tested with eight categories all passed the test. Of other three participants tested with six categories, two passed the test and one failed this test in two categories. The central laboratory will adopt the new version of HPS N13.11 (1993) to replace ANSI N13.11 (1983) as new criteria for the next proficiency test to be conducted in 1998.

We demonstrate, for the first time, an integration-friendly selective PMOSFET fully silicided (FUSI) gate process. In this process, a millisecond-anneal (MSA) technique is utilized for the nickel silicide phase transformation. A highly tensile FUSI gate electrode is created and hence exerts compressive stress in the underlying channel. The highly flexible integration scheme successfully, and exclusively, implements uniform P+ FUSI gates for PMOSFETs while preserving a FUSI-free N+ poly-Si gate for NMOSFETs with the feature size down to 30 nm. A 20% improvement in FUSI- gated PMOSFET Ion- Ioff is measured, which can be attributed to the enhanced hole mobility and the elimination of P+ poly-gate depletion.

The primary objective of this study is to perform a blinded evaluation of two groups of retrospective image registration techniques, using as a gold standard a prospective marker-based registration method, and to compare the performance of one group with the other. These techniques have already been evaluated individually [27]. In this paper, however, we find that by grouping the techniques as volume based or surface based, we can make some interesting conclusions which were not visible in the earlier study. In order to ensure blindness, all retrospective registrations were performed by participants who had no knowledge of the gold-standard results until after their results had been submitted. Image volumes of three modalities: X-ray computed tomography (CT), magnetic resonance (MR), and positron emission tomography (PET) were obtained from patients undergoing neurosurgery at Vanderbilt University Medical Center on whom bone-implanted fiducial markers were mounted. These volumes had all traces of the markers removed and were provided via the Internet to project collaborators outside Vanderbilt, who then performed retrospective registrations on the volumes, calculating transformations from CT to MR and/or from PET to MR. These investigators communicated their transformations, again via the Internet, to Vanderbilt, where the accuracy of each registration was evaluated. In this evaluation, the accuracy is measured at multiple volumes of interest (VOI's). Our results indicate that the volume-based techniques in this study tended to give substantially more accurate and reliable results than the surface-based ones for the CT-to-MR registration tasks, and slightly more accurate results for the PET-to-MR tasks. Analysis of these results revealed that the rotational component of error was more pronounced for the surface-based group. It was also apparent that all of the registration techniques we examined have the potential to produce satisfactory results much of the time, but that visual inspection is necessary to guard against large errors.

By virtue of its position as the second collection of fibers from the anterior/rostral end of the brain, the optic nerve has been labeled cranial nerve II. The optic nerve is in fact a white matter tract; hence, it is prone to diseases of the central nervous system such as optic neuritis as part of multiple sclerosis. The optic nerve fibers are myelinated but only from the lamina cribrosa back. Given the concentration of fibers required by the demands for high visual resolution, the optic nerve has been estimated to comprise 38% of all fibers entering the brain.

An image processing technique is presented for finding and localizing the centroids of cylindrical markers externally attached to the human head in computed tomography (CT) and magnetic resonance (MR) image volumes. The centroids can be used as control points for image registration. The technique, which is fast, automatic, and knowledge-based, has two major steps. First, it searches the entire image volume to find one voxel inside each marker-like object. The authors call this voxel a "candidate" voxel, and they call the object a candidate marker. Second, it classifies the voxels in a region surrounding the candidate voxel as marker or nonmarker voxels using knowledge-based rules and calculates an intensity-weighted centroid for each true marker. The authors call this final centroid the "fiducial" point of the marker. The technique was developed on 42 scans of six patients-one CT and six MR scans per patient. There are four markers attached to each patient for a total of 168 marker images. For the CT images the false marker rate was zero. For MR the false marker rate was 1.4% (Two out of 144 markers). To evaluate the accuracy of the fiducial points, CT-MR registration was performed after correcting the MR images for geometrical distortion. The fiducial registration accuracy averaged 0.4 mm and was better than 0.6 mm for each of the eighteen image pairs.

A highly scaled, high performance 45 nm CMOS technology utilizing extensive immersion lithography to achieve the industry's highest scaling factor with ELK (k=2.55) BEOL is presented. A record gate density 2.4X higher than that of 65 nm is achieved. Refined strained-CMOS demonstrated 1200/750 μA/μm Idsat at 100 nA/μm Ioff, Vdd=1 V, which has the best Ion-Lg performance reported for bulk CMOS device. The proposed 45 nm technology is not only manufacturing friendly but also has well-controlled leakage and mismatch evidenced by a functional 32 Mb 0.242 μm2 SRAM.

Constructing a robotic control system usually needs much effort. Furthermore, the real time operating environment is required for a teleoperation/telemanipulation system. Work in this paper aims at developing a real time control system using xPC Target for robotic system control. By utilizing the software package MATLAB, Simulink, Real Time Workshop, xPC Target and a C/C++ compiler, the I/O boards are interfaced between the Simulink block and the robotic system such that the physical system is controlled successfully in the manner of hardware-in-the-loop simulation. The presented developing procedure shows a convenient way to implement a real time robotic control system, which does not require any low level language programming. Three case studies, which are single DC motor control, robotic hand control, and telemanipulation system control, are performed to demonstrate the advantages and easiness of developing robotic control system using xPC Target.

We present the novel concept of "bi-layer metal salicidation" by using Co/Ni stacked films, which showed better film chemical and plasma resistance than pure NiSi. NFET device performance demonstrates 5% Idsat/Ioff (100 nA) improvement and no degradation in terms of sheet resistance, junction leakage and isolation than pure NiSi. We also prove the approach can be implemented easily to manufacturing with conventional post salicide process similar to CoSi/sub 2/ for 45 nm gate technology and below.

This paper reports a novel laser processing technique for making channels in the nano regime. A Nd:YAG laser was used to dry fabricate micro channels (25 /spl mu/m-100 /spl mu/m diameter) in a 1 cm/sup 3/ fused silica substrate by thermal-induced processing. By controlling the locations of these initiating micro channels on a silica cube, 1D-controllable self-connecting nano fractures can be formed as rectangular channels. These nano channels are smooth and with extremely high aspect ratio (/spl sim/10/sup 4/ depth to width ratio). The length of the channels is controlled by the separation of the initiating micro channels. This laser-based nano channel fabrication technique is fast and inexpensive, and with potential applications in capillary electrophoresis and electro-osmosis driven nano-filtration.

The architecture and the components design of a compact VLSI model based on the extension of the cellular neural network paradigm is described. Face and image recognition is an important function in future smart, portable multimedia systems. However, it involves many complicated mathematical operations that requires extremely large computing power. Since most operations are in two-dimensional format, the cellular neural network paradigm can be extended for selective tasks in face recognition function. Compact neural network is a suitable computing architecture. It uses the state-constrained neuron model that prevents the state variables becoming unbounded. The clear advantage is that the network will converge to proper solutions quickly. In addition, the hardware annealing technique can be applied to the compact neural network architecture so that the optimized solution can be quickly obtained without the drawback of conventional simulated annealing searching complexity and time penalty.

The integration issue of MOCVD TiN and CVD W has been investigated. The step coverage of tungsten layer was found to depend strongly on the MOCVD TiN layer. An additional thermal cycle can significantly improve step coverage of tungsten. Though the Rc value is not dependent on the step coverage of tungsten, the reliability issue is still a concern.

Describes an extrinsic-point-based, interactive image-guided neurosurgical system designed at Vanderbilt University, Nashville, TN, as part of a collaborative effort among the Departments of Neurological Surgery, Computer Science, and Biomedical Engineering. Multimodal image-to-image (II) and image-to-physical (IP) registration is accomplished using implantable markers. Physical space tracking is accomplished with optical triangulation. The authors investigate the theoretical accuracy of point-based registration using numerical simulations, the experimental accuracy of their system using data obtained with a phantom, and the clinical accuracy of their system using data acquired in a prospective clinical trial by 6 neurosurgeons at 4 medical centers from 158 patients undergoing craniotomies to respect cerebral lesions. The authors can determine the position of their markers with an error of approximately 0.4 mm in X-ray computed tomography (CT) and magnetic resonance (MR) images and 0.3 mm in physical space. The theoretical registration error using 4 such markers distributed around the head in a configuration that is clinically practical is approximately 0.5-0.6 mm. The mean CT-physical registration error for the: phantom experiments is 0.5 mm and for the clinical data obtained with rigid head fixation during scanning is 0.7 mm. The mean CT-MR registration error for the clinical data obtained without rigid head fixation during scanning is 1.4 mm, which is the highest mean error that the authors observed. These theoretical and experimental findings indicate that this system is an accurate navigational aid that can provide real-time feedback to the surgeon about anatomical structures encountered in the surgical field.

In this paper, we describe an extrinsic point-based, interactive image-guided neurosurgical system designed at Vanderbilt University as part of a collaborative effort among the departments of neurological surgery, computer science, and biomedical engineering. Multimodal image-to- image and image-to-physical registration is accomplished using implantable markers. Physical space tracking is accomplished with optical triangulation. We investigate the theoretical accuracy of point-based registration using numerical simulations, the experimental accuracy of our system using data obtained with a phantom, and the clinical accuracy of our system using data acquired in a prospective clinical trial by six neurosurgeons at four medical centers from 158 patients undergoing craniotomies to resect cerebral lesions. We can determine the position of our markers with an error of approximately 0.4 mm in x-ray computed tomography (CT) and magnetic resonance (MR) images and 0.3 mm in physical space. The theoretical registration error using four such markers distributed around the head in a configuration that is clinically practical is approximately 0.5 - 0.6 mm. The mean CT-physical registration error for the phantom experiments is 0.5 mm and for the clinical data obtained with rigid head fixation during scanning is 0.7 mm. The mean CT-MR registration error for the clinical data obtained without rigid head fixation during scanning is 1.4 mm, which is the highest mean error that we observed. These theoretical and experimental findings indicate that this system is an accurate navigational aid that can provide real-time feedback to the surgeon about anatomical structures encountered in the surgical field.

It is becoming increasingly common for surgical navigation systems to be used intraoperatively to enable the surgeon to ascertain his or her position within the patient with respect to features in registered preoperative images. These systems assume that the skull and its contents behave as a rigid body between imaging and surgery, and during surgery. We have used the ACUSTAR I surgical navigation system to measure shifts in the brain surface relative to the skull between imaging and surgery on five patients. The preoperative images are registered to the coordinates of the surgical localizer using four fiducial markers screwed into the outer table of the skull. The brain surface is delineated from preoperative MR images, and the distance between this surface and brain surface points recorded intraoperatively is calculated. The median shift of points on the brain surface ranged from 0.3 mm to 7.4 mm. In all cases, the direction of this shift corresponds to a “sinking” of the brain intraoperatively compared to its preoperative position. We consider possible changes in CNS volume that might account for these shifts.

All retrospective image registration methods have attached to them some intrinsic estimate of registration error. However, this estimate of accuracy may not always be a good indicator of the distance between actual and estimated positions of targets within the cranial cavity. This paper describes a project whose principal goal is to use a prospective method based on fiducial markers as a 'gold standard' to perform an objective, blinded evaluation of the accuracy of several retrospective image-to-image registration techniques. Image volumes of three modalities -- CT, MR, and PET -- were taken of patients undergoing neurosurgery at Vanderbilt University Medical Center. These volumes had all traces of the fiducial markers removed, and were provided to project collaborators outside Vanderbilt, who then performed retrospective registrations on the volumes, calculating transformations from CT to MR and/or from PET to MR, and communicated their transformations to Vanderbilt where the accuracy of each registration was evaluated. In this evaluation the accuracy is measured at multiple 'regions of interest,' i.e. areas in the brain which would commonly be areas of neurological interest. A region is defined in the MR image and its centroid C is determined. Then the prospective registration is used to obtain the corresponding point C' in CT or PET. To this point the retrospective registration is then applied, producing C' in MR. Statistics are gathered on the target registration error (TRE), which is the disparity between the original point C and its corresponding point C'. A second goal of the project is to evaluate the importance of correcting geometrical distortion in MR images, by comparing the retrospective TRE in the rectified images, i.e., those which have had the distortion correction applied, with that of the same images before rectification. This paper presents preliminary results of this study along with a brief description of each registration technique and an estimate of both preparation and execution time needed to perform the registration .

There is an increasing demand for accurate registration of CT and MR images for diagnosis and for surgical planning. One useful technique registers images using externally attached fiducial markers. Previous studies have shown that point-based registration accuracy depends on fiducial localization accuracy, that is, the accuracy with which the position of a marker centroid can be estimated. This paper investigates the dependence of localization accuracy on marker size. The investigation is based on computer simulations. Three shapes are evaluated-- a sphere, a cylinder, and a cube, each with similar dimensions. The results indicate that (1) the accuracy depends strongly on the ratio of marker size to voxel size and (2) the dependence is almost identical among the three shapes tested. The simulation results are shown to agree with results from clinical images.

An image processing technique is presented here for finding centroids of cylindrical fiducial markers attached externally to the human head in CT and MR volume images. The centroids can be used for image registration. The technique, which is fast, automatic, and knowledge-based, has two major steps. First, it searches the whole image volume to find all markerlike objects and gets a position inside each object. We call this position a 'seed' point, and we call the object a candidate marker. Second, it selects the voxels surrounding the seed voxel as marker or non-marker voxels using knowledge-based rules and provides an intensity weighted centroid for each true marker. We call this final centroid the 'fiducial' point of the marker. The technique has been developed on forty-two scans of six patients -- one CT and six MR scans per patient. There were four markers attached to each patient for a total of 168 marker images. On these images the technique exhibits no false positives or false negatives for CT. For MR the false positive rate and the false negative rate are both 1.4%. To evaluate the accuracy of the fiducial points MR-CT registration was performed using geometrical correction for the MR images. The fiducial registration accuracies averaged 0.4 mm and were better that 0.6 mm on each of the eighteen image pairs.