SIMULATION ON DISTRIBUTED CONTROL SYSTEM TIME DELAY

One of the fastest growing market segments among control and automation technologies is the introduction and development of network control systems. Even though, fieldbus systems have been used for several years, functional and performance validation is an important issue addressed by fieldbus network design. Simulation support is needed for early functional validation and performance as an evaluation tool for the network design and operation performance analysis in early engineering stages. The delay time which is a random variable produced in the essence of the networked control system transmission process can greatly reduce the performance of control systems such as rising time and overshoot increasing, and situation where the control system become unstable. Therefore, this project briefly explains about the study on the fieldbus real time performance in term of time delay. Delay analysis on a designed cascaded control tank system with the case study of with and without controller have been performed to observe the severity of time delay on fieldbus system. The scope of study covered includes study on methodology to perform analysis on the fieldbus system of a plant using SIMULINK. From the findings, it can be observed that induced delay in complex fieldbus system is very prominent. Complex plant system has a high network delay and response time. Thus, these drawbacks can be overcome using simulation environment to forecast system behaviour and find the best suited network solutions beforehand to minimize engineering and hardware costs

SIMULATION ON DISTRIBUTED CONTROL SYSTEM TIME DELAY

One of the fastest growing market segments among control and automation technologies is the introduction and development of network control systems. Even though, fieldbus systems have been used for several years, functional and performance validation is an important issue addressed by fieldbus network design. Simulation support is needed for early functional validation and performance as an evaluation tool for the network design and operation performance analysis in early engineering stages. The delay time which is a random variable produced in the essence of the networked control system transmission process can greatly reduce the performance of control systems such as rising time and overshoot increasing, and situation where the control system become unstable. Therefore, this project briefly explains about the study on the fieldbus real time performance in term of time delay. Delay analysis on a designed cascaded control tank system with the case study of with and without controller have been performed to observe the severity of time delay on fieldbus system. The scope of study covered includes study on methodology to perform analysis on the fieldbus system of a plant using SIMULINK. From the findings, it can be observed that induced delay in complex fieldbus system is very prominent. Complex plant system has a high network delay and response time. Thus, these drawbacks can be overcome using simulation environment to forecast system behaviour and find the best suited network solutions beforehand to minimize engineering and hardware costs

Reduction of hand transmitted and whole body vibrations experienced by tractor operators by using piezo crystal material

 A study was proposed to investigate the effects of vibration on tractor operator’s health attempting a biodynamic and physiological approach.  The source vibration levels at steering wheel and seat for the hand transmitted and whole body vibration during different tractor operations were measured.  Two isolators, one commercially available, made of styrene butadiene rubber (SBR) and the other custom designed, made of piezo-electric material embedded in SBR were tested for attenuation of vibration.  It was observed that an average 40% reduction in vibration intensity was experienced with installation of custom-designed isolator underneath the tractor operator’s seat.  The measured values of vertical vibration at operator’s seat were found to be within 8 h fatigue decreased proficiency boundary limit.  Incorporation of custom-designed isolator reduced the muscle load to a maximum of 44.37% in erector spinae muscle during first tilling operation, while flexor carpi radialis in transport attained 23.03% reduction.   Keywords: Piezo crystal, vibration, transmissibility, accelerometer, isolators

Immunohistochemical and Molecular Features of Melanomas Exhibiting Intratumor and Intertumor Histomorphologic Heterogeneity

Melanoma is a heterogeneous neoplasm at the histomorphologic, immunophenotypic, and molecular levels. Melanoma with extreme histomorphologic heterogeneity can pose a diagnostic challenge in which the diagnosis may predominantly rely on its immunophenotypic profile. However, tumor survival and response to therapy are linked to tumor genetic heterogeneity rather than tumor morphology. Therefore, understating the molecular characteristics of such melanomas become indispensable. In this study, DNA was extracted from 11 morphologically distinct regions in eight formalin-fixed, paraffin-embedded melanomas. In each region, mutations in 50 cancer-related genes were tested using next-generation sequencing (NGS). A tumor was considered genetically heterogeneous if at least one non-overlapping mutation was identified either between the histologically distinct regions of the same tumor (intratumor heterogeneity) or among the histologically distinct regions of the paired primary and metastatic tumors within the same patient (intertumor heterogeneity). Our results revealed that genetic heterogeneity existed in all tumors as non-overlapping mutations were detected in every tested tumor (n = 5, 100%; intratumor: n = 2, 40%; intertumor: n = 3, 60%). Conversely, overlapping mutations were also detected in all the tested regions (n = 11, 100%). Melanomas exhibiting histomorphologic heterogeneity are often associated with genetic heterogeneity, which might contribute to tumor survival and poor response to therapy

Immunohistochemical and Molecular Features of Melanomas Exhibiting Intratumor and Intertumor Histomorphologic Heterogeneity

Melanoma is a heterogeneous neoplasm at the histomorphologic, immunophenotypic, and molecular levels. Melanoma with extreme histomorphologic heterogeneity can pose a diagnostic challenge in which the diagnosis may predominantly rely on its immunophenotypic profile. However, tumor survival and response to therapy are linked to tumor genetic heterogeneity rather than tumor morphology. Therefore, understating the molecular characteristics of such melanomas become indispensable. In this study, DNA was extracted from 11 morphologically distinct regions in eight formalin-fixed, paraffin-embedded melanomas. In each region, mutations in 50 cancer-related genes were tested using next-generation sequencing (NGS). A tumor was considered genetically heterogeneous if at least one non-overlapping mutation was identified either between the histologically distinct regions of the same tumor (intratumor heterogeneity) or among the histologically distinct regions of the paired primary and metastatic tumors within the same patient (intertumor heterogeneity). Our results revealed that genetic heterogeneity existed in all tumors as non-overlapping mutations were detected in every tested tumor (n = 5, 100%; intratumor: n = 2, 40%; intertumor: n = 3, 60%). Conversely, overlapping mutations were also detected in all the tested regions (n = 11, 100%). Melanomas exhibiting histomorphologic heterogeneity are often associated with genetic heterogeneity, which might contribute to tumor survival and poor response to therapy