This study deals with the Permutation Flow Shop Scheduling Problem （PFSP） based on the maximum completion time （makespan）. NEH （ the algorithm of Nawaz, Eascore and Ham） is the concluded most efficient construct...This study deals with the Permutation Flow Shop Scheduling Problem （PFSP） based on the maximum completion time （makespan）. NEH （ the algorithm of Nawaz, Eascore and Ham） is the concluded most efficient constructive method in solving this NP-hard problem. The principal features of its strengths are the initial arrangement of jobs and the job insertion phase. In some instances, ties will occur in both the initial permutation and the partial sequences. The problem of ties breaking may have a significant impact on the NEH performance, but evaluate all the ties will be non-polynomial in the worst case. Several kinds of methods are presented in the paper to break the ties in a quick time. Together with the basic one, all 22 methods are tested on the famous Taillard＇s benchmarks and the most suitable ties breaking policy is recommended.展开更多
Gastroparesis refers to abnormal gastric motility characterized by delayed gastric emptying in the absence of mechanical obstruction. The most common etiologies include diabetes, post-surgical and idiopathic. The most...Gastroparesis refers to abnormal gastric motility characterized by delayed gastric emptying in the absence of mechanical obstruction. The most common etiologies include diabetes, post-surgical and idiopathic. The most common symptoms are nausea, vomiting and epigastric pain. Gastroparesis is estimated to affect 4% of the population and symptomatology may range from little effect on daily activity to severe disability and frequent hospitalizations. The gold standard of diagnosis is solid meal gastric scintigraphy. Treatment is multimodal and includes dietary modification, prokinetic and anti-emetic medications, and surgical interventions. New advances in drug therapy, and gastric electrical stimulation techniques have been introduced and might provide new hope to patients with refractory gastroparesis. In this comprehensive review, we discuss gastroparesis with emphasis on the latest developments; from the perspective of the practicing clinician.展开更多
This paper describes a general model for the mechanical behavior studying of general wire rope strand. An exact solution of the deformation characteristics was given when the strands is under tensile and torsional loa...This paper describes a general model for the mechanical behavior studying of general wire rope strand. An exact solution of the deformation characteristics was given when the strands is under tensile and torsional loads. The theoretical results are useful in evaluating the extensional and torsional moduli of rigidity for the strands. Finally, a simple design criterion is establised for the nonrotating ropes.展开更多
The Elekta Precise medical Linac is a typical modern high energy accelerator which uses advanced digital technology and gets acknowledged around the world. It provides both X rays and electrons at various megavoltage ...The Elekta Precise medical Linac is a typical modern high energy accelerator which uses advanced digital technology and gets acknowledged around the world. It provides both X rays and electrons at various megavoltage energies including two photon energies （6 and 15 MV） and several electron energies （e.g. 6, 9, 12, 15, 18 and 22 MeV）. The commonly used dose rate for X rays is 500 MU/min, while that for electors is 400 MU/min. The accelerator is equipped with beam intensity modulation cm2. The width of MLC at 40 pairs of MLC for photon covering fields up to 40 × 40 the isocenter is 10 mm. The maximum leakage is less than 0.3%展开更多
Today＇s industry requires more reliable information on the current status of their hard assets; prognosis for continued usability of systems and better predictability of equipment life cycle maintenance. Therefore, a...Today＇s industry requires more reliable information on the current status of their hard assets; prognosis for continued usability of systems and better predictability of equipment life cycle maintenance. Therefore, an innovative technique for early detection of potential failure and condition monitoring is urgently required by many engineers. This document describes a novel approach to improve industrial equipment safety, reliability and life cycle management. A new field portable instrument called the ＂IMS （indicator of mechanical stresses）＂ utilizes magneto-anisotropic （＂cross＂） transducers to measure anisotropy of magnetic properties in ferromagnetic material. Mechanical stresses including residual stresses in Ferro-magnetic parts, are ＂not visible＂ to most traditional NDT （non-destructive testing） methods; for example, radiography and ultrasonic inspection. Stress build-up can be the first indicator that something is faulty with a structure. This can be the result of a manufacturing defect; or as assets age and fatigue, stress loads can become unevenly distributed throughout the metal. We outline the evaluation of IMS as a fast screening tool to provide structural condition or deterioration feedback in novel applications for pipelines, petrochemical refinery, cranes, and municipal infrastructure.展开更多
The human error mechanism in coal mine safety is analyzed specifically from safety psychological and physiological factors, worker＇ s quality, safety management, safety education, mechanical equipment, and working en...The human error mechanism in coal mine safety is analyzed specifically from safety psychological and physiological factors, worker＇ s quality, safety management, safety education, mechanical equipment, and working environment, and also a human error＇ dominant factors classification model playing a great effect on the safety production of coal mine is established with the application of ant clustering algorithm. The experimental results show that management is the key in the human errors of coal mine.展开更多
This paper presents a design theory and dynamic mechanical characterizations of the composite tape-spring hinge made by two parallel single tape springs.First,the theoretical models of moment-rotation angle on anisotr...This paper presents a design theory and dynamic mechanical characterizations of the composite tape-spring hinge made by two parallel single tape springs.First,the theoretical models of moment-rotation angle on anisotropy tape springs with antisymmetric laminates are proposed.Second,the relationships of moment-rotation angle for tape-spring hinges with different sizes are simulated and analyzed by means of the finite element method (FEM),which is in good agreement with the results from theoretical predictions.Finally,the dynamic vibration analysis for deployable composite tube hinges with different dampings is done during the process of deployment.展开更多
Delirium is an acute and fluctuating change in mental status, with inattention and altered levels of consciousness. It is a common comorbidity in intensive care units （ICU）, resulting in delayed withdrawal of mechan...Delirium is an acute and fluctuating change in mental status, with inattention and altered levels of consciousness. It is a common comorbidity in intensive care units （ICU）, resulting in delayed withdrawal of mechanical ventilation, prolonged length of stay in ICU, increased ICU mortality and impaired long-term cognitive function of the survivors. Narcotic or psychoactive medication is one of the major risk factors that contribute to ICU delirium. Surveys conducted in several countries indicated that delirium in ICU was inad- equately monitored, underdiagnosed and lacked standardized treatment. In order to improve the prevention and treatment of ICU delirium, it is imperative that the ICU professionals should enrich their knowledge about this comorbidity, familiarize themselves with its screening and management, as well as standardize the administration of narcotic and psychoactive medications.展开更多
基金Programfor New Century Excellent Talents in University,China(NO.NCET04-0383)Science and Technology Phosphor Program of Shanghai,China(NO.04QMH1405)
文摘This study deals with the Permutation Flow Shop Scheduling Problem （PFSP） based on the maximum completion time （makespan）. NEH （ the algorithm of Nawaz, Eascore and Ham） is the concluded most efficient constructive method in solving this NP-hard problem. The principal features of its strengths are the initial arrangement of jobs and the job insertion phase. In some instances, ties will occur in both the initial permutation and the partial sequences. The problem of ties breaking may have a significant impact on the NEH performance, but evaluate all the ties will be non-polynomial in the worst case. Several kinds of methods are presented in the paper to break the ties in a quick time. Together with the basic one, all 22 methods are tested on the famous Taillard＇s benchmarks and the most suitable ties breaking policy is recommended.
文摘Gastroparesis refers to abnormal gastric motility characterized by delayed gastric emptying in the absence of mechanical obstruction. The most common etiologies include diabetes, post-surgical and idiopathic. The most common symptoms are nausea, vomiting and epigastric pain. Gastroparesis is estimated to affect 4% of the population and symptomatology may range from little effect on daily activity to severe disability and frequent hospitalizations. The gold standard of diagnosis is solid meal gastric scintigraphy. Treatment is multimodal and includes dietary modification, prokinetic and anti-emetic medications, and surgical interventions. New advances in drug therapy, and gastric electrical stimulation techniques have been introduced and might provide new hope to patients with refractory gastroparesis. In this comprehensive review, we discuss gastroparesis with emphasis on the latest developments; from the perspective of the practicing clinician.
文摘This paper describes a general model for the mechanical behavior studying of general wire rope strand. An exact solution of the deformation characteristics was given when the strands is under tensile and torsional loads. The theoretical results are useful in evaluating the extensional and torsional moduli of rigidity for the strands. Finally, a simple design criterion is establised for the nonrotating ropes.
文摘The Elekta Precise medical Linac is a typical modern high energy accelerator which uses advanced digital technology and gets acknowledged around the world. It provides both X rays and electrons at various megavoltage energies including two photon energies （6 and 15 MV） and several electron energies （e.g. 6, 9, 12, 15, 18 and 22 MeV）. The commonly used dose rate for X rays is 500 MU/min, while that for electors is 400 MU/min. The accelerator is equipped with beam intensity modulation cm2. The width of MLC at 40 pairs of MLC for photon covering fields up to 40 × 40 the isocenter is 10 mm. The maximum leakage is less than 0.3%
文摘Today＇s industry requires more reliable information on the current status of their hard assets; prognosis for continued usability of systems and better predictability of equipment life cycle maintenance. Therefore, an innovative technique for early detection of potential failure and condition monitoring is urgently required by many engineers. This document describes a novel approach to improve industrial equipment safety, reliability and life cycle management. A new field portable instrument called the ＂IMS （indicator of mechanical stresses）＂ utilizes magneto-anisotropic （＂cross＂） transducers to measure anisotropy of magnetic properties in ferromagnetic material. Mechanical stresses including residual stresses in Ferro-magnetic parts, are ＂not visible＂ to most traditional NDT （non-destructive testing） methods; for example, radiography and ultrasonic inspection. Stress build-up can be the first indicator that something is faulty with a structure. This can be the result of a manufacturing defect; or as assets age and fatigue, stress loads can become unevenly distributed throughout the metal. We outline the evaluation of IMS as a fast screening tool to provide structural condition or deterioration feedback in novel applications for pipelines, petrochemical refinery, cranes, and municipal infrastructure.
文摘The human error mechanism in coal mine safety is analyzed specifically from safety psychological and physiological factors, worker＇ s quality, safety management, safety education, mechanical equipment, and working environment, and also a human error＇ dominant factors classification model playing a great effect on the safety production of coal mine is established with the application of ant clustering algorithm. The experimental results show that management is the key in the human errors of coal mine.
文摘This paper presents a design theory and dynamic mechanical characterizations of the composite tape-spring hinge made by two parallel single tape springs.First,the theoretical models of moment-rotation angle on anisotropy tape springs with antisymmetric laminates are proposed.Second,the relationships of moment-rotation angle for tape-spring hinges with different sizes are simulated and analyzed by means of the finite element method (FEM),which is in good agreement with the results from theoretical predictions.Finally,the dynamic vibration analysis for deployable composite tube hinges with different dampings is done during the process of deployment.
文摘Delirium is an acute and fluctuating change in mental status, with inattention and altered levels of consciousness. It is a common comorbidity in intensive care units （ICU）, resulting in delayed withdrawal of mechanical ventilation, prolonged length of stay in ICU, increased ICU mortality and impaired long-term cognitive function of the survivors. Narcotic or psychoactive medication is one of the major risk factors that contribute to ICU delirium. Surveys conducted in several countries indicated that delirium in ICU was inad- equately monitored, underdiagnosed and lacked standardized treatment. In order to improve the prevention and treatment of ICU delirium, it is imperative that the ICU professionals should enrich their knowledge about this comorbidity, familiarize themselves with its screening and management, as well as standardize the administration of narcotic and psychoactive medications.
