Guidance Approach Research Articles

A priority-driven optimal guidance approach to moving target tracking for safe navigation in a narrow space

This paper presents an ‘optimally designed’ anti-collision trajectory plan suitable for moving target tracking in narrow spaces like corridors, aisles, etc. Narrow spaces constitute of highly constrained reachable states in the context of dynamic motion. Tracking is the default mode, while the safe trajectory is triggered on a priority-basis. The optimal switching point plays a key role in preventing a possible collision due to a ‘mis-timed’ change of manoeuvre, in case the obstacle shows unanticipated motion. Moreover, it also ensures that tracking is resumed at a point which minimises tracking error under the said deviation from the desired path. A smoothening filter has been proposed to make seamless transitions at the switching points.

Career development learning in childhood: a collaborative guidance approach in Spanish low-income contexts

ABSTRACT This research analyses childhood career development learning through a qualitative career assessment. To help children to make meaning of the career influences, culturally sensitive procedures were used. A case-study design has been carried out, using techniques such as mapping, family portrait, role-playing and self-portrait to unveil the process of 5-year old children's career development learning. The findings illustrate the process of meaning making of the children's system of influences in low-income contexts. They show the life themes that shape the construction of identities. The conclusion highlights the usefulness of qualitative career assessment in enhancing career development learning. The use of culturally sensitive procedures allows children to raise critical awareness about the factors that influence their career construction.

The practical relevance of ideal theory as part of the ideal guidance approach

ABSTRACT Contrary to comparativist critics of ideal theory, I argue that ideal institutions become relevant for issues of nonideal theory through their role as part of the ideal guidance approach (IGA). So far, the most important argument against the IGA has been the second-best argument. However, this argument is only damaging for the IGA under certain conditions: Firstly, when the ideal is not realizable, and, secondly, when the path to the ideal does not contain the second-best world. Since it is an empirical question whether this is the case, the article discusses the empirical relevance of the second-best argument. By employing causal mechanisms identified in the institutionalist literature – path dependence and institutional complementarity – I argue that the IGA actually offers better prospects for the evaluation of nonideal alternatives than the comparative approach. This is, because the latter systematically excludes the information of how an ideal institutional design looks like from consideration. I also discuss and reject the objection that a more comprehensive version of the comparative approach could take these issues into consideration: Such an approach is either epistemically infeasible or very similar to the IGA.

Hallway exploration-inspired guidance: applications in autonomous material transportation in construction sites

Continued attempts have been conducted to improve construction productivity with automatic material transportation robots, yet neither of them has been popularized. The reason is that navigating in highly unstructured and dynamic indoor environments remains a great challenge. Therefore, we present a hallway exploration-inspired guidance approach (HEIGA), which guides an agent to its destination based on a series of directional guidance without the need for self-localization in a global frame. A series of experiments were conducted which prove that fully autonomous material transportation can be realized without being influenced by the complexity or dynamics of real construction sites. We expect this new approach to effectively: (i)free workers from heavy and repetitive material transportation tasks; and (ii) improve construction productivity. In the future, the presented approach will be applied in construction sites considering multi-robot collaboration, aiming at a higher material transportation efficiency.

C-MET Receptor-Targeted Fluorescence on the Road to Image-Guided Surgery in Penile Squamous Cell Carcinoma Patients.

In penile squamous cell carcinoma (pSCC), primary surgery aims to obtain oncologically safe margins while minimizing mutilation. Surgical guidance provided by receptor-specific tracers could potentially improve margin detection and reduce unnecessary excision of healthy tissue. Here, we present the first results of a prospective feasibility study for real-time intraoperative visualization of pSCC using a fluorescent mesenchymal-epithelial transition factor (c-MET) receptor targeting tracer (EMI-137). Methods: EMI-137 tracer performance was initially assessed ex vivo (n = 10) via incubation of freshly excised pSCC in a solution containing EMI-137 (500 nM). The invivo potential of c-MET targeting and intraoperative tumor visualization was assessed after intravenous administration of EMI-137 to 5 pSCC patients scheduled for surgical resection using a cyanine-5 fluorescence camera. Fluorescence imaging results were related to standard pathologic tumor evaluation and c-MET immunohistochemistry. Three of the 5 invivo patients also underwent a sentinel node resection after local administration of the hybrid tracer indocyanine green- 99mTc-nanocolloid, which could be imaged using a near-infrared fluorescence camera. Results: No tracer-related adverse events were encountered. Both ex vivo and invivo, EMI-137 enabled c-MET-based tumor visualization in all patients. Histopathologic analyses showed that all pSCCs expressed c-MET, with expression levels of at least 70% in 14 of 15 patients. Moreover, the highest c-MET expression levels were seen on the outside rim of the tumors, and a visual correlation was found between c-MET expression and fluorescence signal intensity. No complications were encountered when combining primary tumor targeting with lymphatic mapping. As such, simultaneous use of cyanine-5 and indocyanine green in the same patient proved to be feasible. Conclusion: Fluorescence imaging of c-MET receptor- expressing pSCC tumors after intravenous injection of EMI-137 was shown to be feasible and can be combined with fluorescence-based lymphatic mapping. This combination is unique and paves the way toward further development of this surgical guidance approach.

Autonomous closed-loop guidance using reinforcement learning in a low-thrust, multi-body dynamical environment

Onboard autonomy is an essential component in enabling increasingly complex missions into deep space. In nonlinear dynamical environments, computationally efficient guidance strategies are challenging. Many traditional approaches rely on either simplifying assumptions in the dynamical model or on abundant computational resources. This research effort employs reinforcement learning, a subset of machine learning, to produce a ‘lightweight’ closed-loop controller that is potentially suitable for onboard low-thrust guidance in challenging dynamical regions of space. The results demonstrate the controller’s ability to directly guide a spacecraft despite large initial deviations and to augment a traditional targeting guidance approach. The proposed controller functions without direct knowledge of the dynamical model; direct interaction with the nonlinear equations of motion creates a flexible learning scheme that is not limited to a single force model, mission scenario, or spacecraft. The learning process leverages high-performance computing to train a closed-loop neural network controller. This controller may be employed onboard to autonomously generate low-thrust control profiles in real-time without imposing a heavy workload on a flight computer. Control feasibility is demonstrated through sample transfers between Lyapunov orbits in the Earth–Moon system. The sample low-thrust controller exhibits remarkable robustness to perturbations and generalizes effectively to nearby motion. Finally, the flexibility of the learning framework is demonstrated across a range of mission scenarios and low-thrust engine types.

Three-dimensional guidance and control for ground moving target tracking by a quadrotor

Abstract This paper develops a three-dimensional guidance and control algorithm to ensure that a manoeuverable target is preserved by a quadrotor in a long-term tracking scenario. The proposed guidance approach determines the desired altitude of the quadrotor to adjust the field of view (FOV) to the union of two desired trusted and critical regions. The dimensions of the desired trusted region depend on the controller performance that is evaluated by the distance of the target from the center of the FOV. The critical region is a predefined margin around the trusted region that is defined by the operator based on the upper bounds of the quadrotor and target localisation errors. It also depends on the duration and magnitude of the temporal increase in the target velocity compared to the quadrotor velocity. A sufficient condition is provided for the minimum desired altitude of the quadrotor to ensure that the target is maintained in the FOV. Furthermore, a model predictive control (MPC) is employed to preserve the target at the center of the aerial image and the desired altitude determined by the guidance law. Also, the integrals of the position errors are used to achieve null steady-state errors in the presence of wind disturbances. The simulation results show the effectiveness of the proposed approach in preserving the manoeuverable target in the FOV in the presence of the wind, the uncertainty of the target and quadrotor localisation, accelerations estimation errors, and terrain altitude variation.

Factors Affecting Youths Towards Crime: A Case Study from Kathmandu, Nepal

Youths are taken as change agent for the society and development. So, it is necessary to groom them and motivate them towards sustainable development by understanding their problems and issues. The importance and values of youths to the nation should be understood. The literature has shown that the public’s view for increased youth crime is a relatively less researched area, however media has played a good role in this. Based on the data collected, this study highlights and ranks the variables that affect youths towards crime and how the issues can be solved. In Nepal, some steps been taken by the Nepal Government to prevent young offenders from re-offending the crime through various measures. Few of the development partners are also investing money in this sector too. The current approach to control the situation, the programs implemented are personalized approach based on the needs of the youths, training approach, education approach and support and guidance approach. Some level of improvements and quality must be developed to save the youths population for future. In Nepal, there is negative attitudes and perception of public, professionals’ people, community members towards youth. They are lacking direct and positive thinking to them. Perception is generated from the online news, televisions etc. This is the possible bias collected through that needs to re-address the issues on how the society deal with the problems play an important role.

Tracheostomy- a complete guide for pediatric post tracheostomy care

Introduction: Tracheostomy tube care in a pediatric age group is challenging. The systematic approach for tracheostomy care and guidance to the care giver and parents will reduce complications related to tracheostomy. The purpose of this article is to ensure the safety of the infants and children who have tracheostomy tube placed in the neck. Materials and Methods: The acronym (tracheostomy) was created to teach and train the care giver and nursing staff for better post tracheostomy care. All the aspects of tracheostomy care have been included in this as mentioned below Tube change-when to change? Regular cleaning-how to perform? Airway protection-what is required? Complication awareness-how to prevent? Home kit requirement-things to keep ready bedside. Emergency situations-when to call your doctor? Oral hygiene- why it is important? Stoma/skin care-what to look for? Ties care-too tight or too loose? Outer & inner tube cleaning-how to perform? Mucous problems-suctioning tips Your safety-what all you must know. Results: The acronym is easy to remember and easy to follow. Conclusion: A systematic tracheostomy care approach can give better outcomes and reduced complication rate in pediatric age group. It will be benefitted for all the health care professionals, nursing staff and the care givers involved with the children who need tracheostomy care. Keywords: tracheostomy post tracheostomy care.

Rainfall Threshold for Flash Flood Warning Based on Model Output of Soil Moisture: Case Study Wernersbach, Germany

Convective rainfall can cause dangerous flash floods within less than six hours. Thus, simple approaches are required for issuing quick warnings. The flash flood guidance (FFG) approach pre-calculates rainfall levels (thresholds) potentially causing critical water levels for a specific catchment. Afterwards, only rainfall and soil moisture information are required to issue warnings. This study applied the principle of FFG to the Wernersbach Catchment (Germany) with excellent data coverage using the BROOK90 water budget model. The rainfall thresholds were determined for durations of 1 to 24 h, by running BROOK90 in “inverse” mode, identifying rainfall values for each duration that led to exceedance of critical discharge (fixed value). After calibrating the model based on its runoff, we ran it in hourly mode with four precipitation types and various levels of initial soil moisture for the period 1996–2010. The rainfall threshold curves showed a very high probability of detection (POD) of 91% for the 40 extracted flash flood events in the study period, however, the false alarm rate (FAR) of 56% and the critical success index (CSI) of 42% should be improved in further studies. The proposed adjusted FFG approach has the potential to provide reliable support in flash flood forecasting.

An Approach for Integrating and Analyzing Sustainability in Food-Based Dietary Guidelines

International organizations, governments, researchers, and activists have proposed the need for deeper integration of sustainability considerations in national food-based dietary guidelines (FBDGs). Yet, as recent scholarship advances the conversation, questions remain around how to effectively frame and address the interconnectedness of multiple sustainability domains. Little systematic analysis has evaluated how current FBDGs have integrated complex messages about socially, environmentally, and economically sustainable consumption practices with nutrition and health messages. This study had two nested objectives: (i) to examine the validity of an existing sustainable diets framework by assessing how sustainability concepts have been framed and included in national FBDGs available from 2011 to 2019 and (ii) to describe a novel analysis approach that augments an existing framework which integrates sustainability domains and can be adapted for use by future FBDGs. A qualitative content analysis was used to examine sustainability concepts found in 12 FBDGs and supporting documents available in English that were developed for use in 16 countries across Europe, North and South America, and Asia as of 2019—from a global review of those published prior to 2016 and gray literature review of publications between 2016 and 2019. Health domains were the primary frame found across the FBDGs examined, but documents also commonly incorporated agricultural, sociocultural, and economic sustainability principles. Analyzed documents were used to adapt an existing policy analysis framework into a “Sustainability in FBDGs Framework.” This proposed framework contributes a novel analysis approach and has five core domains that are interconnected: health and nutrition, food security and agriculture, markets and value chains, sociocultural and political, and environment and ecosystems. This study adds to the growing body of literature related to sustainable food systems and dietary guidelines by presenting how sustainability framing in FBDGs can be used to further develop a comprehensive framework for integrating sustainability domains. While this project helps to validate previous work, further analyses of FBDGs which have emerged since this study and those not available in English are needed to improve the guidance approach described here and for assessing the incorporation of sustainability domains in future FBDGs. This work is useful in informing processes for policy developers to integrate sustainability considerations into their national FBDGs.

Reciprocal guidance approach for suspicious collision point identification in a multi-agent unmanned aerial vehicle scenario

In a multi-agent unmanned aerial vehicle scenario, identification of the suspicious collision point is a crucial part of the collusion avoidance algorithm. This paper presents a novel suspicious collision identification approach, which is based on the assumption that the scenario participants intentionally guide themselves towards mutual interception. This reciprocal guidance approach enables the development of a closed-form solution for the expected miss distance between the agents, thus enabling the implementation of the approach in real-time systems. The algorithm incorporates agents' maneuvering capability restrictions, thus basing its decision on feasible maneuvers. Simulations demonstrated the ability of the reciprocal guidance approach to identify collisions in advance and exemplified its robustness to circular-path engagements and variable-speed agents.

State Estimation for a Class of Distributed Parameter Systems with Time-Varying Delay over Mobile Sensor–Actuator Networks with Missing Measurements

This work proposes a state estimation strategy over mobile sensor–actuator networks with missing measurements for a class of distributed parameter systems (DPSs) with time-varying delay. Initially, taking advantage of the abstract development equation theory and operator semigroup method, this kind of delayed DPSs described by partial differential equations (PDEs) is derived for evolution equations. Subsequently, the distributed state estimators including consistency component and gain component are designed; the purpose is to estimate the original state distribution of the delayed DPSs with missing measurements. Then, a delay-dependent guidance approach is presented in the form of mobile control forces by constructing an appropriate Lyapunov function candidate. Furthermore, by applying Lyapunov stability theorem, operator semigroup theory, and a stochastic analysis approach, the estimation error systems have been proved asymptotically stable in the mean square sense, which indicates the estimators can approximate the original system states effectively when this kind of DPS has time-delay and the mobile sensors occur missing measurements. Finally, the correctness of control strategy is illustrated by numerical simulation results.

Ground- and ship-based guidance approaches for autonomous landing of UAV

Ground- and ship-based guidance approaches for autonomous landing of UAV

A Preclinical System Prototype for Focused Microwave Breast Hyperthermia Guided by Compressive Thermoacoustic Tomography

As a newly developed technique, focused microwave breast hyperthermia (FMBH) can provide accurate and cost-effective treatment of breast tumors with low side effect. A clinically feasible FMBH system requires a guidance technique to monitor the microwave power distribution in the breast. Compressive thermoacoustic tomography (CTT) is a suitable guidance approach for FMBH, which is more cost-effective than MRI. However, no experimental validation based on a realized FMBH-CTT system has been reported, which greatly hinders the further advancement of this novel approach. We developed a preclinical system prototype for the FMBH-CTT technique, containing a microwave phased antenna array, a microwave source, an ultrasound transducer array and associated data acquisition module. Experimental results employing homogeneous and inhomogeneous breast-mimicking phantoms demonstrate that the CTT technique can offer reliable guidance for the entire process of the FMBH. In addition, small phase noises do not deteriorate the overall performance of the system prototype. The realized preclinical FMBH-CTT system prototype is capable for noninvasive, accurate and low-side-effect breast tumor treatment with effective guidance. The experimentally validated FMBH-CTT system prototype provides a feasible paradigm for CTT guided FMBH, establishes a practical platform for future improvement of this technique, and paves the way for potential clinical translation.

Defender-Aware Attacking Guidance Policy for the Target–Attacker–Defender Differential Game

Deep reinforcement learning was used to train an agent within the framework of a Markov decision process (MDP) to pursue a target, while avoiding a defender, for the target–attacker–defender (TAD) differential game of pursuit and evasion. The aim of this work was to explore the games where the previous attacking guidance methods found in literature failed to capture the target. The reward function of the MDP presented by this work allowed for an attacking agent to learn a policy that expanded the number of cases where the target is captured beyond the former limit of success through the application of the twin delayed deep deterministic policy gradient algorithm. The strategy developed using artificial intelligence expands the target capture guidance approach to enable the attacker to avoid the defender in states where the two agents are in close proximity. Initial target positions within a limited set were considered with fixed values for agent velocities and attacker and defender initial positions to evaluate the attacker’s learned behavior in comparison with the optimal point capture guidance laws for target capture in the TAD game.

Finite-time output feedback path following control of underactuated MSV based on FTESO

The paper designs a finite-time output feedback path following control strategy of underactuated marine surface vehicle (MSV) with the unavailable velocity, the unknown dynamic and unknown external environment disturbances. Firstly, a new finite time extended state observer (FTESO) is devised to accurately observe the unknown velocity and unknown lumped disturbances within finite time. Secondly, depending on the output of FTESO, the velocity observation-based finite-time LOS guidance approach is raised to acquire the reference yaw angle. Thirdly, the finite-time output feedback path following controllers are constructed through the backstepping method to track the desired path with precise tracking performance. It has been demonstrated that the observation error of FTESO is capable of converging to zero and the path following error is able to converge to an arbitrarily small domain near zero in finite time according to the homogeneous theory and the Lyapunov theory. Simulation comparison researches are performed to demonstrate the availability of the designed finite-time output feedback path following strategy.

Concept description and accuracy evaluation of a moldable surgical targeting system

.Purpose: We explain our concept for customization of a guidance instrument, present a prototype, and describe a set of experiments to evaluate its positioning and drilling accuracy.Methods: Our concept is characterized by the use of bone cement, which enables fixation of a specific configuration for each individual surgical template. This well-established medical product was selected to ensure future intraoperative fabrication of the template under sterile conditions. For customization, a manually operated alignment device is proposed that temporary defines the planned trajectory until the bone cement is hardened. Experiments () with half-skull phantoms were performed. Analysis of accuracy comprises targeting validations and experiments including drilling in bone substitutes.Results: The resulting mean positioning error was found to be at the level of the target point whereas drilling was possible with a mean accuracy of .Conclusion: We proposed a cost-effective, easy-to-use approach for accurate instrument guidance that enables template fabrication under sterile conditions. The utilization of bone cement was proven to fulfill the demands of an easy, quick, and prospectively intraoperatively doable customization. We could demonstrate sufficient accuracy for many surgical applications, e.g., in neurosurgery. The system in this early development stage already outperforms conventional stereotactic frames and image-guided surgery systems in terms of targeting accuracy.

Percutaneous Spine Biopsy: A Review of the Current Literature.

Spine lesions are often the result of pathologic processes elsewhere in the body; prompt and accurate diagnosis are crucial to optimize treatment. Despite modern advances in imaging modalities, definitive diagnosis ultimately requires biopsy and histologic analysis. Although open surgical biopsy has traditionally been considered the benchmark, percutaneous image-guided needle biopsy of the spine has proven to be a safe and highly effective method in making a diagnosis. Choosing the optimal biopsy approach, instrumentation and modality of image guidance may depend on a number of factors including lesion type, location, and level within the spine. Knowledge of relevant anatomy, indications, contraindications, and potential complications are critical to a successful biopsy procedure.

PENGARUH ANAK ADHD TERHADAP INTERAKSI SOSIAL DAN PEMBELAJARAN DI SDS SEJAHTERA WAY KANDIS BANDAR LAMPUNG

The purpose of this study was to determine the problems of guidance and counseling at SDS Sejahtera Bandar Lampung and to determine the concentration of learning ADHD children given by parents and class teachers. The method used is qualitative. The counseling guidance approach applied at SDS Sejahtera is like a special approach such as sitting next to the teacher, emotional guidance and giving advice. The techniques used by teachers and researchers are test techniques and non-test techniques (observation, interviews, and documentation). The case subjects in the study were children with ADHD aged 10 years, grade 4 years ago, and now they are 11 years old in grade 5. Participant subjects were teachers and parents. The concentration of learning is shown by the behavior of not listening to the teacher’s orders, teasing his friends and teachers, disturbing friends, even committing acts of violence such as hitting, pinching, injuring, throwing tantrums and screaming, scribbling on the blackboard, not being able to study in groups and interacting with surrounding environment. Handling guidance provided by teachers and parents is such as occupational therapy (doing activities or daily activities independently, physical exercise, and brain balance), talking, and nerve massage.