818 research outputs found

    Computing the minimum perimeter triangle enclosing a convex polygon: Theory and implementation.

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    Geometric optimization, an important field of computational geometry, finds the best possible solution to a computational problem that involves geometric objects. An attractive fundamental problem in this area is one of approximating a convex n-gon with a simpler convex k-gon, where k \u3c n, and the area or the perimeter of the approximate object is minimized. This problem arises in a wide range of applications, such as geographic information systems (GIS), spatial databases, pattern recognition, and computer graphics, to name but a few. The approximation of convex polygons with their respective enclosing triangles is a particularly interesting problem; however, finding an optimal linear time solution for computing the minimum perimeter triangle enclosing a convex polygon was a long-standing open problem, which turned out to be more difficult than determining an enclosing triangle of minimal area. In this thesis, we suggest some theoretical and practical justifications for the linear time complexity of a recently proposed optimal solution and provide an efficient and robust implementation of that solution. (Abstract shortened by UMI.) Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2003 .M43. Source: Masters Abstracts International, Volume: 42-02, page: 0618. Adviser: Asish Mukhopadhyay. Thesis (M.Sc.)--University of Windsor (Canada), 2003

    Teaching motor skills by means of biomechanical analysis of the motion: the physiological basis and applied information technologies

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    The article proves the possibility of training athletes using motor skills on the basis of biomechanical analysis of movements with application of information technologies. Motion Tracking – digital single frame shooting photography – is proposed as a method for biomechanical analysis. The relevance of this method is conditioned by the results of the study of a repulsion phase in the performing of the standing jump by athletes of different qualifications. The conclusion about the importance of an optimal model of a jump based on biomechanical analysis is given, and the formation of athletes’ skills, using information technologies and the principle of urgent information, is discussed

    (E)-17β,19-Epoxy­methano-17,23,24-tridemethyl-4-nor-5β,18α-olean-3-one oxime

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    In the penta­cyclic triterpenoide skeleton of the title mol­ecule, C27H43NO2 [systematic name: (3E,3aS,5aR,5bR,7aR,11R,11aR,11bR,13aR,13bR)-5a,5b,10,10,13b-penta­methyl­icosa­hydro-1H-11,7a-(epoxy­methano)cyclo­penta­[a]chrysen-3-one oxime], the five-membered ring A has an envelope conformation, while the six-membered rings B–E adopt chair conformations. Rings A and B are cis-fused. The hydroximino group has an E configuration. Strong inter­molecular O—H⋯O hydrogen bonds link the mol­ecules into helical chains

    Nuclear Medicine in Cancer Diagnosis and Therapy

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    Early cancer diagnosis remains one of the most actual problems of medicine, since it allows using the most effective methods of cancer treating. Unlike most diagnostic methods used in oncology, the methods of nuclear medicine allow assessing not so much the anatomic changes in the organ as the disturbance of metabolic processes in tumors and surrounding tissues. The authors describe the main radiopharmaceuticals used for diagnose and radiotherapy of malignant tumors

    Air purification from process emissions from electroplating baths

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    Electroplating technology is an important technological process at production facilities of various profiles. The electroplating baths are a source of hazardous emissions of toxic vapors and aerosols. In factories with electroplating sites, the crucial task is to eliminate hazardous emissions by applying an effective exhaust ventilation and air purification system for subsequent air discharge into the atmosphere. In this article two basic schemes for cleaning process emissions from electroplating baths were developed: a scheme with purification in scrubbers; a scheme with purification in scrubbers with pre-filtration. The advantages and disadvantages of each scheme were considered. Based on the amount of hazardous emissions and their dispersed composition, the purification efficiency of each scheme was calculated using the probabilistic method. In view of the calculations, a scheme for cleaning process emissions from the electroplating line with the highest purification efficiency has been identified

    Nuclear Medicine in Breast Cancer Diagnostics: Primary Tumor and Lymphatic Metastasis

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    The purpose of the study: to assess the possibility of using nuclear medicine techniques at the stages of diagnosis and treatment of breast cancer. Materials and Methods: The study included 290 patients with breast cancer and 70 patients with benign breast tumors. The study was used as a radiopharmaceutical 99mTc-MIBI, 199Tl for imaging tumors and colloid 99mTc-Aloteh for visualization sentinel lymph nodes (SLN), colloid was injected peritumoral in four points to 80 MBq one day prior to the planned operation. Results: The sensitivity of SPECT using both 99mTc-MIBI and 199Tl for breast cancer detection was shown to be rather high, being 98.5% and 98%, respectively. It should be noted that the sensitivity of SPECT in detection of small tumors (less than 1 cm in diameter) and multicentric tumors was not high irrespective of the radioisotope used (60% and 65% with 99mTc-MIBI and 65% and 59% with 199Tl, respectively). The difference in the sensitivity was found between 99mTc-MIBI and 199T for the detection of regional lymph node metastasis (91% vs 70%). SLN were detected in 31 patients. The most commonly SLN were defined in the axillary region of 96.7%. In 22 (70.9%) patients there was no metastasis SLN. The sensitivity of the method was 91.2%, specificity of 100%. Conclusion: The specificity of SPECT with 199Tl was higher than that with 99mTc-MIBI. The data obtained show that SPECT with 199Tl can be recommended for its use as an additional breast cancer detection method in cases when other imaging techniques and histological findings are not accurate enough. The clinical study of 99mTc-Aloteh, a new radiopharmaceutical agent, has shown that the studied colloid has high uptake level in SLN and can be successfully used for visualization of SLN in patients with breast cancer

    Nuclear Medicine in Breast Cancer Diagnostics: Primary Tumor and Lymphatic Metastasis

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    The purpose of the study: to assess the possibility of using nuclear medicine techniques at the stages of diagnosis and treatment of breast cancer. Materials and Methods: The study included 290 patients with breast cancer and 70 patients with benign breast tumors. The study was used as a radiopharmaceutical 99mTc-MIBI, 199Tl for imaging tumors and colloid 99mTc-Aloteh for visualization sentinel lymph nodes (SLN), colloid was injected peritumoral in four points to 80 MBq one day prior to the planned operation. Results: The sensitivity of SPECT using both 99mTc-MIBI and 199Tl for breast cancer detection was shown to be rather high, being 98.5% and 98%, respectively. It should be noted that the sensitivity of SPECT in detection of small tumors (less than 1 cm in diameter) and multicentric tumors was not high irrespective of the radioisotope used (60% and 65% with 99mTc-MIBI and 65% and 59% with 199Tl, respectively). The difference in the sensitivity was found between 99mTc-MIBI and 199T for the detection of regional lymph node metastasis (91% vs 70%). SLN were detected in 31 patients. The most commonly SLN were defined in the axillary region of 96.7%. In 22 (70.9%) patients there was no metastasis SLN. The sensitivity of the method was 91.2%, specificity of 100%. Conclusion: The specificity of SPECT with 199Tl was higher than that with 99mTc-MIBI. The data obtained show that SPECT with 199Tl can be recommended for its use as an additional breast cancer detection method in cases when other imaging techniques and histological findings are not accurate enough. The clinical study of 99mTc-Aloteh, a new radiopharmaceutical agent, has shown that the studied colloid has high uptake level in SLN and can be successfully used for visualization of SLN in patients with breast cancer

    TEMPO-RHYTHMIC ABILITIES OF THE GYMNASTS AS A FACTOR DETERMINING THE DIFFICULTY OF COMPOSITE SOLUTION OF COMPETITIVE ROUTINE IN GROUP ROUTINES DEPENDING ON THE CHOICE OF MUSICAL ACCOMPANIMENT

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    Starting from 2018 the judges began to evaluate the level of difficulty of the compositions with an open scale according to the rules of the competition. The article is devoted to the evaluation of the compositional difficulty of competitive compositions of group routines in rhythmic gymnastics. One of the factors that determines both the difficulty of the composition and the synchronization of motor interaction execution by sportswomen in group routines is defined. The purpose of this research is to justify the necessity of taking into account tempo-rhythmic abilities of gymnasts that predetermine difficulty of compositional decision of competitive program in group routines. The objective of this study is to reveal the correlational interconnections between tempo-rhythmic abilities and expert evaluations of synchronicity of group motor activity. The methods that were applied in are an expert evaluation that assesses the synchronization of motor actions of gymnasts in group routines and testing that consists of listening to and playing of parts of pieces of music of different rhythmic patterns. The revealed correlational interconnections allow increasing the synchronicity of motor actions of gymnasts in group routines that will make competitive programs more qualitative and spectacular

    Nuclear Medicine Imaging of Locally Advanced Laryngeal and Hypopharyngeal Cancer

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    The diagnostic capabilities of nuclear medicine imaging in the detection and assessment of the spread of laryngeal/hypopharyngeal cancer were studied. A total of 40 patients with histologically verified laryngeal and hypopharyngeal cancer and 20 patients with benign laryngeal lesions were included into the study. Submucosal injections of {99m}Tc-MIBI and {99m}Tc-Alotech were made around the tumor. Single photon emission computed tomography (SPECT) was performed 20 minutes after the injection of {99m}Tc-MIBI. Sentinel lymph nodes (SLNs) were detected in 26 patients. In 18 hours after the injection of {99m}Tc-Alotech, SPECT was performed. In 24 hours after the injection of {99m}Tc-Alotech, intraoperative SLN detection was performed using Gamma Finder II. SPECT with {99m}Tc-MIBI revealed laryngeal and hypopharyngeal tumors in 38 of the 40 patients. The {99m}Tc-MIBI uptake in metastatic lymph nodes was visualized in 2 (17%) of the 12 patients. Twenty eight SLNs were detected by SPECT and 31 SLNs were identified using the intraoperative gamma probe. The percentage of {99m}Tc-Alotech in the SLN was 5-10% of the radioactivity in the injection site by SPECT and 18-33% by intraoperative gamma probe detection. Thus, SPECT with {99m}Tc-MIBI is an effective tool for the diagnosis of laryngeal/hypopharyngeal cancer. The sensitivity, specificity and accuracy of this technique were 95%, 80% and 92%, respectively. The use of {99m}Tc-Alotech for the detection of SLNs in patients with laryngeal/hypopharyngeal cancer is characterized by 92.8% sensitivity

    The use of {99m}Tc-Al[2]O[3] for detection of sentinel lymph nodes in cervical cancer patients

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    The purpose of the study was to evaluate the feasibility of using {99m}Tc-Al[2]O[3]- based radiopharmaceutical, a novel molecular imaging agent for sentinel lymph node detection in patients with invasive cervical cancer. The study included 23 cervical cancer patients (TlaNxMx- T[2]bNxMx) treated at the Tomsk Cancer Research Institute. At 18 hours before surgery, 80 MBq of the {99m}Tc-Al[2]O[3] were injected peritumorally, followed by single-photon emission computed tomography (SPECT) of the pelvis and intraoperative SLN identification. Twenty-seven SLNs were detected by SPECT, and 34 SLNs were identified by intraoperative gamma probe. The total number of identified SLNs per patient ranged from 1 to 3(the mean number of SLNs was 1.4 per patient). The most common site for SLN detection was the external iliac region (57.2%), followed by the internal iliac, obturator, presacral and retrosacral regions (they amounted to 14%, respectively),and the parametrial region (1%). Sensitivity in detecting SLNs was 100% for intraoperative SLN identification and 79% for SPECT image
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