233 research outputs found

    Infelicitous Use of Anaphoric "This" in Undergraduate Academic Writing

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    The objective of this paper is to describe the contexts of misuse of the anaphoric pronoun "this" in paragraphs composed by undergraduate students in their academic writing assignments and account for the infelicities, with the hope that the findings will extend the frame of reference for the analysis of such infelicities for instructional purposes. The study unearthed the following infelicities: (a) Ambiguous coreference; (b) Extensive use of "this':· and (c) Textual distance between "this" and its referent. Practical intervention measures are proposed to help both students and instructors to deal with the problem

    Role of surgery in the treatment of radiation-induced sarcomas of the head and neck

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    Introduction: Radiation-induced sarcoma (RIS) is a well-known complication of radiotherapy. It is an aggressive tumour and the prognosis is often poor, despite radical treatment. We aim to investigate the role of surgery in the treatment of patients with RIS of the head and neck region. Method: We conducted a retrospective review of records of patients whom were treated for radiation-induced sarcoma at Queen Mary Hospital, Hong Kong, between the period 1999 to 2010. Data collected included patient age, gender, latency period for the development of RIS, site of RIS, symptoms, treatment given, pathology and survival. Results: Nineteen patients were included, (M=11, F=8). Eighteen received radiotherapy for treatment of primary nasopharyngeal carcinoma. One received radiotherapy for carcinoma of the parotid. The medial latency period for the development of sarcoma was 11.1 years (range 5.3-25.1). The most common site for development of RIS was the neck (n=8), followed by the oropharynx/oral cavity (n=4), nasopharynx (n=3) nasal cavity (n=2), maxilla (n=1) and mandible (n=1). The most common histology was undifferentiated sarcoma (n=6). Nine patients underwent surgical resection of the RIS with curative intent, three and six patients achieved R0 and R1 resection respectively. Chemotherapy was used in eleven instances after surgery. Radiotherapy was used in seven instances, three through brachytherapy, four through external beam irradiation. Overall medial survival from diagnosis of RIS was 1.74 years (95% CI 0.60-2.87), which improves to 2.47 years (95% CI 0.97-3.97) when only calculating those whom surgery was performed. Conclusions: Patients suffering from radiation-induced sarcomas have a poor prognosis, in keeping with existing literature. Treatment is mainly by surgery aiming at resection with a curative intent. If curative resection is impossible, surgery may still have a role in palliating the patients’ symptoms such as bleeding, fungation, or painpublished_or_final_versio

    Vehicle shape approximation from motion for visual traffic surveillance

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    In this paper, a vehicle shape approximation method based on the vehicle motion in a typical traffic image sequence is proposed. In the proposed method, instead of using the 2D image data directly, the intrinsic 3D data is estimated in a monocular image sequence. Given the binary vehicle mask and the camera parameters, the vehicle shape is estimated by the four stages shape approximation method. These stages include feature point extraction, feature point motion estimation between two consecutive frames, feature point height estimation from motion vector, and the 3D shape estimation based on the feature point height. We have tested our method using real world traffic image sequence and the vehicle height profile and dimensions are estimated to be reasonably close to the actual dimensions.published_or_final_versio

    Camera calibration from road lane markings

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    Three-dimensional computer vision techniques have been actively studied for the purpose of visual traffic surveillance. To determine the 3-D environment, camera calibration is a crucial step to resolve the relationship between the 3-D world coordinates and their corresponding image coordinates. A novel camera calibration using the geometry properties of road lane markings is proposed. A set of equations that computes the camera parameters from the image coordinates of the road lane markings and lane width is derived. The camera parameters include pan angle, tilt angle, swing angle, focal length, and camera distance. Our results show that the proposed method outperforms the others in terms of accuracy and noise sensitivity. The proposed method accurately determines camera parameters using the appropriate camera model and it is insensitive to perturbation of noise on the calibration pattern.published_or_final_versio

    Clustering based 3D level set method for volumetric cardiac segmentation

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    Sect.D Computer modeling and simulations : D-5Multi-slice CT (MSCT) provides dynamic three-dimensional (3D) volumetric data of the whole heart, and is an important medical imaging tool for diagnosis of cardiac diseases. Due to the large size of the dynamic data, manual identification, segmentation and tracking of various parts of the heart will be very labor intensive and inefficient. Alternatively, sophisticated image processing techniques, which require minimal user intervention, can be developed and employed to automate such tasks. In this work, we propose a semi-automatic clustering based 3D level set method to robustly segment the endocardium surface from cardiac MSCT images. The theory of level set defines a flexible and powerful surface which is capable of capturing the complex endocardium anatomical structure. A novel speed function for the level set method using a clustering algorithm is proposed to exploit the non-homogeneous blood pool intensity property by supporting a set of independent intensity samples. To define the intensity clusters for the blood pool region and the surrounding region, only a few lines drawn on the corresponding regions are required as user input. The segmentation result is a level set 3D surface in the whole volume space which can readily be constructed to form a spatial model. Our clustering based 3D level set method can also be used for segmenting other heart wall surfaces by performing appropriate initialization. By ex-tending to a 4D level set method, 4D (3D plus time) dynamic volumetric data could be readily processedpostprintProceedings of BME 2006 Biomedical Engineering Conference : biomedical engineering in education, research and industry, Hong Kong, 21-23 September 2006

    Vehicle type classification from visual-based dimension estimation

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    This paper presents a visual-based dimension estimation method for vehicle type classification. Our method extracts moving vehicles from traffic image sequences and fits them with a simple deformable vehicle model. Using a set of coordination mapping functions derived from a calibrated camera model and relying on a shadow removal method, vehicle's width, length and height are estimated. Our experimental tests show that the modeling method is effective and the estimation accuracy is sufficient for general vehicle type classification.published_or_final_versio

    A novel method to construct taxonomy electrical appliances based on load signatures

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    A load signature is an electrical expression that a load device or appliance distinctly possesses. Load signatures can be applied to produce many useful services and products, such as, determining the energy usage of individual appliances, monitoring the health of critical equipment, monitoring power quality, and developing facility management tools. Load signatures of typical yet extensive loads are needed to be collected before applying them to different services and products. As there are an enormous number of electrical appliances, it is beneficial to classify the appliances for building a well-organized load signature database. The objective of this study is to develop an effective method to classify the loads. A 2-dimensional form of load signatures, voltage-current (V-I) trajectory, is suggested for characterizing the typical household appliances. Hierarchical clustering method was employed to classify the appliances and construct the taxonomy of the appliances. The taxonomy based on V-I trajectory was compared to the taxonomies based on traditional power metrics and eigenvectors in the previous studies. It was found that the groups of appliances in the taxonomy based on V-I trajectory were well-separated and had engineering meanings. © 2007 IEEE.published_or_final_versio

    Stereochemistry of carbon nanotubes for electronic applications

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    Results are presented from studies to prepare carbon nanotubes of single geometry. Carbon nanotubes of certain stereochemistry have been found to be conductive. Others have been found to be excellent transistors, and together nanoelectronic devices have already been formed from them including logic gate circuits. Two synthetic approaches have been tried, namely plasma arcing in the presence of additives and ball milling. In plasma arcing, cathode deposits are altered by the presence of naphthalene in the feed material. The mixture of nanotubes so formed has a larger average void size than that formed in the absence of naphthalene. The results support proposed mechanisms of nanotube formation which involve growth by incorporation of carbon atoms into open tubes. They also show that naphthalene can be directly incorporated into fullerene black and thereby increase the number of hexagonal sheet structures in the carbon deposit. Work so far in ball milling has been confined to studies of the destruction of graphite crystalline phases

    HANDLING NEGOTIATION DEADLOCKS IN SRI LANKAN CONSTRUCTION INDUSTRY

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    Negotiation is identified as first to be used among alternative dispute resolution mechanisms to resolve construction disputes. Further negotiation is identified as most preferred by construction parties. However, it is found parties continuously fail in achieving settlement through negotiation. In every negotiation deadlocks occur where both parties stand still on their stance which stuck negotiations from moving forward. Deadlocks are inevitable but can handle effectively. Existing knowledge identified several techniques used worldwide in handling negotiation deadlocks. This research is targeted to find the applicability of identified negotiation deadlock handling techniques in the Sri Lankan construction industry. A questionnaire survey was carried out among fifty (50) experts in the construction industry. Questionnaire was based on thirty-three (33) identified deadlock handling techniques and respondents were asked to mark their responses on a Likert scale which contained five options. Feedback of the survey was analysed using Relative Importance Index (RII) and found that all the identified techniques are applicable to the Sri Lankan construction industry and found that the industry well recognized them. Further, producing additional information to negotiation table is the key deadlocks handling mechanism using rate negotiation in variation management in construction projects

    Effective moving cast shadow detection for monocular color traffic image sequences

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    For an accurate scene analysis using monocular color traffic image sequences, a robust segmentation of moving vehicles from the stationary background is generally required. However, the presence of moving cast shadow may lead to an inaccurate vehicle segmentation, and as a result, may lead to further erroneous scene analysis. We propose an effective method for the detection of moving cast shadow. By observing the characteristics of cast shadow in the luminance, chrominance, gradient density, and geometry domains, a combined probability map, called a shadow confidence score (SCS), is obtained. From the edge map of the input image, each edge pixel is examined to determine whether it belongs to the vehicle region based on its neighboring SCCs. The cast shadow is identified as those regions with high SCSs, which are outside the convex hull of the selected vehicle edge pixels. The proposed method is tested on 100 vehicle images taken under different lighting conditions (sunny and cloudy), viewing angles (roadside and overhead), vehicle sizes (small, medium, and large), and colors (similar to the road and not). The results indicate that an average error rate of around 14% is obtained while the lowest error rate is around 3% for large vehicles.published_or_final_versio
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