493 research outputs found

    A new methodology called dice game optimizer for capacitor placement in distribution systems

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    Purpose. Shunt capacitors are installed in power system for compensating reactive power. Therefore, feeder capacity releases, voltage profile improves and power loss reduces. However, determination optimal location and size of capacitors in distributionsystems is a complex optimization problem. In order to determine the optimum size and location of the capacitor, an objective function which is generally defined based on capacitor installation costs and power losses should be minimized According to operational limitations. This paper offers a newly developed metaheuristic technique, named dice game optimizerto determine optimal size and location of capacitors in a distribution network. Dice game optimizer is a game based optimization technique that is based on the rules of the dice game.ЦСль. Π¨ΡƒΠ½Ρ‚ΠΈΡ€ΡƒΡŽΡ‰ΠΈΠ΅ кондСнсаторы Π² энСргосистСмС ΡƒΡΡ‚Π°Π½Π°Π²Π»ΠΈΠ²Π°ΡŽΡ‚ΡΡ для компСнсации Ρ€Π΅Π°ΠΊΡ‚ΠΈΠ²Π½ΠΎΠΉ мощности. Π‘Π»Π΅Π΄ΠΎΠ²Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎ, сниТаСтся Π΅ΠΌΠΊΠΎΡΡ‚ΡŒ Ρ„ΠΈΠ΄Π΅Ρ€Π°, ΡƒΠ»ΡƒΡ‡ΡˆΠ°Π΅Ρ‚ΡΡ ΠΏΡ€ΠΎΡ„ΠΈΠ»ΡŒ напряТСния ΠΈ ΡΠ½ΠΈΠΆΠ°ΡŽΡ‚ΡΡ ΠΏΠΎΡ‚Π΅Ρ€ΠΈ мощности. Однако ΠΎΠΏΡ€Π΅Π΄Π΅Π»Π΅Π½ΠΈΠ΅ ΠΎΠΏΡ‚ΠΈΠΌΠ°Π»ΡŒΠ½ΠΎΠ³ΠΎ мСстополоТСния ΠΈ Ρ€Π°Π·ΠΌΠ΅Ρ€Π° кондСнсаторов Π² систСмах распрСдСлСния являСтся слоТной Π·Π°Π΄Π°Ρ‡Π΅ΠΉ ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ†ΠΈΠΈ. Π§Ρ‚ΠΎΠ±Ρ‹ ΠΎΠΏΡ€Π΅Π΄Π΅Π»ΠΈΡ‚ΡŒ ΠΎΠΏΡ‚ΠΈΠΌΠ°Π»ΡŒΠ½Ρ‹ΠΉ Ρ€Π°Π·ΠΌΠ΅Ρ€ ΠΈ располоТСниС кондСнсатора, Ρ†Π΅Π»Π΅Π²ΡƒΡŽ Ρ„ΡƒΠ½ΠΊΡ†ΠΈΡŽ, которая ΠΎΠ±Ρ‹Ρ‡Π½ΠΎ опрСдСляСтся Π½Π° основС Π·Π°Ρ‚Ρ€Π°Ρ‚ Π½Π° установку кондСнсатора ΠΈ ΠΏΠΎΡ‚Π΅Ρ€ΡŒ мощности, слСдуСт ΠΌΠΈΠ½ΠΈΠΌΠΈΠ·ΠΈΡ€ΠΎΠ²Π°Ρ‚ΡŒ Π² соотвСтствии с эксплуатационными ограничСниями. Данная ΡΡ‚Π°Ρ‚ΡŒΡ ΠΏΡ€Π΅Π΄Π»Π°Π³Π°Π΅Ρ‚ Π½Π΅Π΄Π°Π²Π½ΠΎ Ρ€Π°Π·Ρ€Π°Π±ΠΎΡ‚Π°Π½Π½Ρ‹ΠΉ мСтаэвристичСский ΠΌΠ΅Ρ‚ΠΎΠ΄, Π½Π°Π·Ρ‹Π²Π°Π΅ΠΌΡ‹ΠΉ ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ‚ΠΎΡ€ΠΎΠΌ ΠΈΠ³Ρ€Ρ‹ Π² кости, для опрСдСлСния ΠΎΠΏΡ‚ΠΈΠΌΠ°Π»ΡŒΠ½ΠΎΠ³ΠΎ Ρ€Π°Π·ΠΌΠ΅Ρ€Π° ΠΈ располоТСния кондСнсаторов Π² Ρ€Π°ΡΠΏΡ€Π΅Π΄Π΅Π»ΠΈΡ‚Π΅Π»ΡŒΠ½ΠΎΠΉ сСти. ΠžΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ‚ΠΎΡ€ ΠΈΠ³Ρ€Ρ‹ Π² кости – это ΠΈΠ³Ρ€ΠΎΠ²ΠΎΠΉ ΠΌΠ΅Ρ‚ΠΎΠ΄ ΠΎΠΏΡ‚ΠΈΠΌΠΈΠ·Π°Ρ†ΠΈΠΈ, основанный Π½Π° ΠΏΡ€Π°Π²ΠΈΠ»Π°Ρ… ΠΈΠ³Ρ€Ρ‹ Π² кости

    Cyclic Elastoplastic Large Displacement Analysis of Cold-formed Steel Box Columns under Combined Action of Axial and Bidirectional Lateral Loading

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    This paper deals with the cyclic elastoplastic large displacement analysis of cold-formed steel box columns under combined action of axial and bidirectional lateral loading. Cold-formed steel box columns are very useful in highway bridge pier construction as they offer flexible space requirement and provide speedy construction. Behavior of cold-formed steel box columns under earthquake-induced loads is rather complicated as earthquakes occur in an oblique direction. However, modern seismic design philosophies have been based on the behavior of structures under independent actions of uni-directional loading in orthogonal directions. In this study, inelastic cyclic behavior of steel columns subjected to constant axial force together with simultaneous bi-directional cyclic lateral loads is investigated using an advanced finite element analyses procedure. Several types of linear and non-linear idealized loading patte rns are employed to check the strength and ductility. The effects of important structural parameters and loading history on the behavior of cold-formed thin-walled steel box columns are examined using the proposed procedure

    Combined population dynamics and entropy modelling supports patient stratification in chronic myeloid leukemia

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    Modelling the parameters of multistep carcinogenesis is key for a better understanding of cancer progression, biomarker identification and the design of individualized therapies. Using chronic myeloid leukemia (CML) as a paradigm for hierarchical disease evolution we show that combined population dynamic modelling and CML patient biopsy genomic analysis enables patient stratification at unprecedented resolution. Linking CD34+ similarity as a disease progression marker to patientderived gene expression entropy separated established CML progression stages and uncovered additional heterogeneity within disease stages. Importantly, our patient data informed model enables quantitative approximation of individual patients’ disease history within chronic phase (CP) and significantly separates β€œearly” from β€œlate” CP. Our findings provide a novel rationale for personalized and genome-informed disease progression risk assessment that is independent and complementary to conventional measures of CML disease burden and prognosis

    Does knowledge of cancer diagnosis affect quality of life? A methodological challenge

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    BACKGROUND: As part of an assessment of quality of life in lung cancer patients an investigation was carried out to examine whether the knowledge of their diagnosis affected their quality of life. METHODS: Every patient in a defined geographical area with a potential diagnosis of lung cancer was interviewed at first consultation and after a definitive treatment has been given. Quality of life was assessed using three standard measures: the Nottingham Health Profile (NHP), the EORTC quality of life questionnaire (QLQ-C30) and its lung cancer supplementary questionnaire (QLQ-LC13). Comparison was made in quality of life scores between patients who knew their cancer diagnosis and those who did not. RESULTS: In all, 129 lung cancer patients were interviewed. Of these, 30 patients (23%) knew and 99 (78%) did not know their cancer diagnosis at the time of baseline assessment. The patient groups were similar in their characteristics except for age (P = 0.04) and cell type (P < 0.0001). Overall, there were no significant differences between these two groups with regard to their scores on the three instruments used. A major finding was that both group scored almost the same on emotional reactions (P = 0.8) and social isolation (P = 1.0) as measured by the NHP, and emotional (P = 0.7) and social functioning (P = 1.0) as measured by the EORTC QLQ-C30. In addition there were no significant differences in patients' symptom scores between those who knew their diagnosis and those who did not, nor did any consistent pattern emerge. The only significant difference was for sleep difficulties (P = 0.02). CONCLUSION: The findings suggest that the knowledge of cancer diagnosis does not affect the way in which patients respond to quality of life questionnaires

    Quality of life in patients with advanced gastric cancer: a randomized trial comparing docetaxel, cisplatin, 5-FU (TCF) with epirubicin, cisplatin, 5-FU (ECF)

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    BACKGROUND: Health related quality of life (HRQOL) is an important outcome after treatment for upper gastrointestinal carcinoma. This study aimed to compare HRQOL in patients with advanced gastric cancer (GC) receiving either a standard or an experimental treatment. METHODS: Seventy-one patients have been treated in Cancer Institute (Tehran, Iran) with docetaxel, cisplatin, 5 FU (TCF) or epirubicin, cisplatin, 5-FU (ECF) and were followed from Jan 2002 to Jan 2005. End points were response rate, HRQOL and survival. HRQOL was assessed using the EORCT QLQ-C30 at baseline and after the third cycle of chemotherapy. RESULTS: The baseline HRQOL scores were comparable between two groups. After treatment improvement was seen in a number of items and domains except for cognitive functioning, and diarrhoea. Pain decreased and physical functioning improved in both groups. However, only the TCF group showed statistically and clinically meaningful improvement in global QOL (P = 0.001). Surgical and pathologic response was better with TCF but there was no difference in survival rate between two groups. CONCLUSION: Docetaxel based treatment (TCF) showed better palliation and improvement of global QOL as compared with epirubicin based treatment (ECF). However, it seems that regardless of treatment offered, effective chemotherapy was the most important factor affecting QOL in these patients

    Disclosure of cancer diagnosis and quality of life in cancer patients: should it be the same everywhere?

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    <p>Abstract</p> <p>Background</p> <p>Evidence suggests that truth telling and honest disclosure of cancer diagnosis could lead to improved outcomes in cancer patients. To examine such findings in Iran, this trial aimed to study the various dimensions of quality of life in patients with gastrointestinal cancer and to compare these variables among those who knew their diagnosis and those who did not.</p> <p>Methods</p> <p>A consecutive sample of patients with gastrointestinal cancer being treated in Cancer Institute in Tehran, Iran was prospectively evaluated. A psychologist interviewed patients using the Iranian version of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30). Patients were categorized into two groups: those who knew their diagnosis and those who did not. Independent sample t-test was used for group comparisons.</p> <p>Results</p> <p>In all 142 patients were interviewed. A significant proportion (52%) of patients did not know their cancer diagnosis and 48% of patients were aware that they had cancer. They were quite similar in most characteristics. The comparison of quality of life between two groups indicated that those knew their diagnosis showed a significant lower degree of physical (P = 0.001), emotional (P = 0.01) and social functioning (P < 0.001), whereas the global quality of life and other functional scales including role functioning and cognitive functioning did not show significant result. There were no statistically significant differences between symptoms scores between two groups, except for fatigue suggesting a higher score in patients who knew their diagnosis (P = 0.01). The financial difficulties were also significantly higher in patients who knew their cancer diagnosis (P = 0.005). Performing analysis of variance while controlling for age, educational status, cancer site, and knowledge of cancer diagnosis, the results showed that the knowledge of cancer diagnosis independently still contributed to the significant differences observed between two groups.</p> <p>Conclusion</p> <p>Contrary to expectation the findings indicated that patients who did not know their cancer diagnosis had a better physical, social and emotional quality of life. It seems that due to cultural differences between countries cancer disclosure guidelines perhaps should be differing.</p

    Quality of life in patients with breast cancer before and after diagnosis: an eighteen months follow-up study

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    <p>Abstract</p> <p>Background</p> <p>Measuring quality of life in breast cancer patients is of importance in assessing treatment outcomes. This study examined the impact of breast cancer diagnosis and its treatment on quality of life of women with breast cancer.</p> <p>Methods</p> <p>This was a prospective study of quality of life in breast cancer patients. Quality of life was measured using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and its breast cancer supplementary measure (QLQ-BR23) at three points in time: baseline (pre diagnosis), three months after initial treatment and one year after completion of treatment (in all 18 months follow-up). At baseline the questionnaires were administered to all suspected identified patients while both patients and the interviewer were blind to the final diagnosis. Socio-demographic and clinical data included: age, education, marital status, disease stage and initial treatment. Repeated measure analysis was performed to compare quality of life differences over the time.</p> <p>Results</p> <p>In all, 167 patients diagnosed with breast cancer. The mean age of breast cancer patients was 47.2 (SD = 13.5) years and the vast majority (82.6%) underwent mastectomy. At eighteen months follow-up data for 99 patients were available for analysis. The results showed there were significant differences in patients' functioning and global quality of life at three points in time (P < 0.001). Although there were deteriorations in patients' scores for body image and sexual functioning, there were significant improvements for breast symptoms, systematic therapy side effects and patients' future perspective (P < 0.05).</p> <p>Conclusion</p> <p>The findings suggest that overall breast cancer patients perceived benefit from their cancer treatment in long-term. However, patients reported problems with global quality of life, pain, arm symptoms and body image even after 18 months following their treatments. In addition, most of the functional scores did not improve.</p

    Quality of life in patients with gastric cancer: translation and psychometric evaluation of the Iranian version of EORTC QLQ-STO22

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    <p>Abstract</p> <p>Background</p> <p>Disease and treatment related events, can adversely affect the quality of life of patients with cancer. The purpose of this study was to translate and validate a gastric cancer specific health related quality of life questionnaire (EORTC QLQ-STO22) for Iranian patients suffering from gastric cancer.</p> <p>Methods</p> <p>Forward-backward procedure was applied to translate the English language version of the EORTC QLQ-STO22 into Persian (Iranian language). Then, the questionnaire and the EORTC core quality of life instrument (QLQ-C30) were administered to a sample of patients with confirmed diagnosis of gastric cancer. All patients filled in questionnaires before and after one month of treatment. Patients were divided into two groups based on intension of treatment (curative vs. palliative). Reliability and validity of the module was tested by internal consistency and known group comparisons, respectively.</p> <p>Results</p> <p>In all, 105 patients were entered into the study. Cronbach's alpha for multi-item scales (to test reliability) ranged from 0.54 to 0.87. The questionnaire discriminated well between clinically distinct subgroups of patients both before and after treatment lending support to its convergent and clinical validity.</p> <p>Conclusion</p> <p>Overall, the Iranian version of the EORTC QLQ-STO22 demonstrated a good reliability and clinical validity to support its use in combination with core questionnaire in outcome studies of gastric cancer in Iran. However, using the QLQ-STO22 in a wide range of Iranian patients with gastric cancer should allow further confirmation for its psychometric properties.</p

    A spring search algorithm applied to engineering optimization problems

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    At present, optimization algorithms are used extensively. One particular type of such algorithms includes random-based heuristic population optimization algorithms, which may be created by modeling scientific phenomena, like, for example, physical processes. The present article proposes a novel optimization algorithm based on Hooke&rsquo;s law, called the spring search algorithm (SSA), which aims to solve single-objective constrained optimization problems. In the SSA, search agents are weights joined through springs, which, as Hooke&rsquo;s law states, possess a force that corresponds to its length. The mathematics behind the algorithm are presented in the text. In order to test its functionality, it is executed on 38 established benchmark test functions and weighed against eight other optimization algorithms: a genetic algorithm (GA), a gravitational search algorithm (GSA), a grasshopper optimization algorithm (GOA), particle swarm optimization (PSO), teaching&ndash;learning-based optimization (TLBO), a grey wolf optimizer (GWO), a spotted hyena optimizer (SHO), as well as an emperor penguin optimizer (EPO). To test the SSA&rsquo;s usability, it is employed on five engineering optimization problems. The SSA delivered better fitting results than the other algorithms in unimodal objective function, multimodal objective functions, CEC 2015, in addition to the optimization problems in engineering
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