Neural units with higher-order synaptic operations with applications to edge detection and control systems

The biological sense organ contains infinite potential. The artificial neural structures have emulated the potential of the central nervous system; however, most of the researchers have been using the linear combination of synaptic operation. In this thesis, this neural structure is referred to as the neural unit with linear synaptic operation (LSO). The objective of the research reported in this thesis is to develop novel neural units with higher-order synaptic operations (HOSO), and to explore their potential applications. The neural units with quadratic synaptic operation (QSO) and cubic synaptic operation (CSO) are developed and reported in this thesis. A comparative analysis is done on the neural units with LSO, QSO, and CSO. It is to be noted that the neural units with lower order synaptic operations are the subsets of the neural units with higher-order synaptic operations. It is found that for much more complex problems the neural units with higher-order synaptic operations are much more efficient than the neural units with lower order synaptic operations. Motivated by the intensity of the biological neural systems, the dynamic nature of the neural structure is proposed and implemented using the neural unit with CSO. The dynamic structure makes the system response relatively insensitive to external disturbances and internal variations in system parameters. With the success of these dynamic structures researchers are inclined to replace the recurrent (feedback) neural networks (NNs) in their present systems with the neural units with CSO. Applications of these novel dynamic neural structures are gaining potential in the areas of image processing for the machine vision and motion controls. One of the machine vision emulations from the biological attribution is edge detection. Edge detection of images is a significant component in the field of computer vision, remote sensing and image analysis. The neural units with HOSO do replicate some of the biological attributes for edge detection. Further more, the developments in robotics are gaining momentum in neural control applications with the introduction of mobile robots, which in turn use the neural units with HOSO; a CCD camera for the vision is implemented, and several photo-sensors are attached on the machine. In summary, it was demonstrated that the neural units with HOSO present the advanced control capability for the mobile robot with neuro-vision and neuro-control systems

Design and fabrication of novel microfluidic systems for microsphere generation

In this thesis, a study of the rational design and fabrication of microfluidic systems for microsphere generation is presented. The required function of microfluidic systems is to produce microspheres with the following attributes: (i) the microsphere size being around one micron or less, (ii) the size uniformity (in particular coefficient of variation (CV)) being less than 5%, and (iii) the size range being adjustable as widely as possible. Micro-electro-mechanical system (MEMS) technology, largely referring to various micro-fabrication techniques in the context of this thesis, has been applied for decades to develop microfluidic systems that can fulfill the foregoing required function of microsphere generation; however, this goal has yet to be achieved. To change this situation was a motivation of the study presented in this thesis. The philosophy behind this study stands on combining an effective design theory and methodology called Axiomatic Design Theory (ADT) with advanced micro-fabrication techniques for the microfluidic systems development. Both theoretical developments and experimental validations were carried out in this study. Consequently, the study has led to the following conclusions: (i) Existing micro-fluidic systems are coupled designs according to ADT, which is responsible for a limited achievement of the required function; (ii) Existing micro-fabrication techniques, especially for pattern transfer, have difficulty in producing a typical feature of micro-fluidic systems - that is, a large overall size (~ mm) of the device but a small channel size (~nm); and (iii) Contemporary micro-fabrication techniques to the silicon-based microfluidic system may have reached a size limit for microspheres, i.e., ~1 micron. Through this study, the following contributions to the field of the microfluidic system technology have been made: (i) Producing three rational designs of microfluidic systems, device 1 (perforated silicon membrane), device 2 (integration of hydrodynamic flow focusing and crossflow principles), and device 3 (liquid chopper using a piezoelectric actuator), with each having a distinct advantage over the others and together having achieved the requirements, size uniformity (CV ≤ 5%) and size controllability (1-186 µm); (ii) Proposing a new pattern transfer technique which combines a photolithography process with a direct writing lithography process (e.g., focused ion beam process); (iii) Proposing a decoupled design principle for micro-fluidic systems, which is effective in improving microfluidic systems for microsphere generation and is likely applicable to microfluidic systems for other applications; and (iv) Developing the mathematical models for the foregoing three devices, which can be used to further optimize the design and the microsphere generation process

Design of an Error-Based Adaptive Controller for a Flexible Robot Arm Using Dynamic Pole Motion Approach

Design of an adaptive controller for complex dynamic systems is a big challenge faced by the researchers. In this paper, we introduce a novel concept of dynamic pole motion (DPM) for the design of an error-based adaptive controller (E-BAC). The purpose of this novel design approach is to make the system response reasonably fast with no overshoot, where the system may be time varying and nonlinear with only partially known dynamics. The E-BAC is implanted in a system as a nonlinear controller with two dominant dynamic parameters: the dynamic position feedback and the dynamic velocity feedback. For illustrating the strength of this new approach, in this paper we give an example of a flexible robot with nonlinear dynamics. In the design of this feedback adaptive controller, parameters of the controller are designed as a function of the system error. The position feedback Kp(e,t) and the velocity feedback Kv(e,t) are continuously varying and formulated as a function of the system error e(t). This approach for formulating the adaptive controller yields a very fast response with no overshoot

Public Transportation Service Evaluations Utilizing Seoul Transportation Card Data

AbstractThis study evaluated transit service performance in Seoul using data collected from the Automatic Fare Collection (AFC) system in Seoul. The distance-based fare system in Seoul allows a maximum of four transfers with no additional charges to encourage transit ridership. In order to analyze the transit transfers, this study developed quantitative indicators for public transportation evaluations differentiated from those of previous studies by the fact that it utilizes data mining techniques which incorporate massive amounts of data (over 10 million transits per day) derived from the smart card system. This study not only carried out an evaluation to improve public transportation quality but provided comparative analysis of the mobility handicapped and an evaluation of public transportation users’ regional equity. This evaluative analysis of Level of Services (LOS) for various items is expected to be adopted for analyzing LOS status and generating improvement priorities and to be utilized as an objective database for public transportation policy decisions

The effects of a 12-week jump rope exercise program on abdominal adiposity, vasoactive substances, inflammation, and vascular function in adolescent girls with prehypertension

Introduction Childhood obesity is strongly associated with cardiovascular disease (CVD) development. It is necessary to combat unfavorable outcomes of obesity at a young age by utilizing effective interventions, such as exercise. Purpose We sought to examine the effects of a jump rope exercise program on CVD risk factors, including body composition, vasoactive substances, inflammation, and vascular function in prehypertensive adolescent girls. Methods Forty girls (age 14–16) were recruited and randomly assigned to a jump rope exercise group (EX, n = 20) or control group (CON, n = 20). Body composition, nitrate and nitrite levels, endothelin-1 (ET-1), C-reactive protein (CRP), systolic blood pressure and diastolic blood pressure (SBP, DBP), and arterial stiffness were measured before and after 12 weeks. Results There were significant group by time interactions following the 12-week program for body composition (from 33.8 ± 3.6 to 30.2 ± 3.1%), central adiposity (from 86.4 ± 4 to 83.3 ± 5 cm), SBP (from 126 ± 3.3 to 120 ± 2.1 mmHg), and brachial-to-ankle pulse wave velocity (from 8.2 ± 1.0 to 7.4 ± 0.2 m/s). Nitrate/nitrite levels increased (from 54.5 ± 5.1 to 57.2 ± 5.2 µmol) along a reduction in CRP levels (from 0.5 ± 0.4 to 0.2 ± 0.1 mg/L). There were no significant changes in ET-1 (P = 0.22). Conclusions These findings indicate that jump rope exercise may be an effective intervention to improve these CVD risk factors in prehypertensive adolescent girls. Jumping rope is an easily accessible exercise modality that may have important health implications for CVD prevention in younger populations

Combined exercise training reduces blood pressure, arterial stiffness, and insulin resistance in obese prehypertensive adolescent girls

Childhood obesity is strongly linked to pathological processes for cardiovascular diseases in later adulthood. Obese adolescent girls with high blood pressure (BP) are reported to have increased arterial stiffness, which is associated with the development of hypertension and atherosclerosis. The present study sought to examine the impact of combined resistance and aerobic exercise (CRAE) training on BP, brachial-ankle pulse wave velocity (baPWV), insulin resistance (IR), and body composition in obese prehypertensive girls. Forty girls (age, 15 ± 1 years; systolic BP, 132 ± 2 mmHg, diastolic BP, 80 ± 5 mmHg) were randomly assigned to either a combined exercise (EX, n = 20) or no exercise group (CON, n = 20). The EX group performed CRAE for 12 weeks, 3 times per week. BP, baPWV, blood nitrite/nitrate, endothelin-1 (ET-1), homeostasis model assessment for insulin resistance (HOMA-IR), and body composition were measured before and after the exercise intervention. BP (∆-7.3 ± 2.67 mmHg), baPWV (∆-1.23 ± 0.49 m/s), ET-1 (∆-14.35 ± 1.76 μmol/mL), nitrite/nitrate (∆0.5 ± 0.09 μM), HOMA-IR (∆-1.4 ± 0.07), percent body fat (∆-1.35 ± 0.9%), and waist circumference were significantly improved (P \u3c 0.05) in the EX group after 12 weeks of training versus the CON group. These findings indicate that 12 weeks of CRAE improves BP, HOMA-IR, and arterial stiffness and reduces central adiposity in obese adolescent girls with prehypertension. Thus, this study provides evidence that CRAE can be a useful therapeutic treatment for high BP, IR, and central adiposity, thereby reducing the likelihood of pathological development for cardiovascular diseases in later adulthood