Search

Economic and social progress in the Republic of Korea resulted in an increased standard of living, which subsequently produced more waste. The Korean government implemented a volume-based trash disposal system that may modify waste disposal characteristics to handle vast volumes of waste efficiently. However, the inconvenience of having to purchase standard garbage bags on one's own led to passive participation by citizens and instances of illegally dumping waste in non-standard plastic bags. As a result, there is a need for the development of automatic detection and reporting of illegal acts of garbage dumping. To achieve this, we suggest a system for tracking unlawful rubbish disposal that is based on deep neural networks. The proposed monitoring approach obtains the articulation points (joints) of a dumper through OpenPose and identifies the type of garbage bag through the object detection model, You Only Look Once (YOLO), to determine the distance of the dumper's wrist to the garbage bag and decide whether it is illegal dumping. Additionally, we introduced a method of tracking the IDs issued to the waste bags using the multi-object tracking (MOT) model to reduce the false detection of illegal dumping. To evaluate the efficacy of the proposed illegal dumping monitoring system, we compared it with the other systems based on behavior recognition. As a result, it was validated that the suggested approach had a higher degree of accuracy and a lower percentage of false alarms, making it useful for a variety of upcoming applications. [ABSTRACT FROM AUTHOR]

Recently, the rapid development of convolutional neural networks (CNN) has consistently improved object detection performance using CNN and has naturally been implemented in autonomous driving due to its operational potential in real-time. Detecting moving targets to realize autonomous driving is an essential task for the safety of drivers and pedestrians, and CNN-based moving target detectors have shown stable performance in fair weather. However, there is a considerable drop in detection performance during poor weather conditions like hazy or foggy situations due to particles in the atmosphere. To ensure stable moving object detection, an image restoration process with haze removal must be accompanied. Therefore, this paper proposes an image dehazing network that estimates the current weather conditions and removes haze using the haze level to improve the detection performance under poor weather conditions due to haze and low visibility. Combined with the thermal image, the restored image is assigned to the two You Only Look Once (YOLO) object detectors, respectively, which detect moving targets independently and improve object detection performance using late fusion. The proposed model showed improved dehazing performance compared with the existing image dehazing models and has proved that images taken under foggy conditions, the poorest weather for autonomous driving, can be restored to normal images. Through the fusion of the RGB image restored by the proposed image dehazing network with thermal images, the proposed model improved the detection accuracy by up to 22% or above in a dense haze environment like fog compared with models using existing image dehazing techniques. [ABSTRACT FROM AUTHOR]

A standard receiver autonomous integrity monitoring (RAIM) technique for the global positioning system (GPS) has been dedicated to provide an integrity monitoring capability for safety-critical GPS applications, such as in civil aviation for the en-route (ER) through non-precision approach (NPA) or lateral navigation (LNAV). The performance of the existing RAIM method, however, may not meet more stringent aviation requirements for availability and integrity during the precision approach and landing phases of flight due to insufficient observables and/or untimely warning to the user beyond a specified time-to-alert in the event of a significant GPS failure. This has led to an enhanced RAIM architecture ensuring stricter integrity requirement by greatly decreasing the detection time when a satellite failure or a measurement error has occurred. We thus attempted to devise a user integrity monitor which is capable of identifying the GPS failure more rapidly than a standard RAIM scheme by incorporating the RAIM with the relative entropy, which is a likelihood ratio approach to assess the inconsistence between two data streams, quite different from a Euclidean distance. In addition, the delay-coordinate embedding technique needs to be considered and preprocessed to associate the discriminant measure obtained from the RAIM with the relative entropy in the new RAIM design. In simulation results, we demonstrate that the proposed user integrity monitor outperforms the standard RAIM with a higher level of detection rate of anomalies which could be hazardous to the users in the approach or landing phase and is a very promising alternative for the detection of deviations in GPS signal. The comparison also shows that it enables to catch even small anomalous gradients more rapidly than a typical user integrity monitor. [ABSTRACT FROM AUTHOR]

A significant anomaly of great importance for ground-based augmentation systems (GBAS) is the steep gradient in ionospheric delays caused by rare ionospheric storms. To avoid such hazardous errors, code-carrier divergence (CCD) monitors have been applied to support the use of GBAS in Category I (CAT I) operation. However, to meet the stricter requirements for CAT II/III operation, it may be necessary to greatly improve the speed with which existing CCD monitors detect ionospheric gradients or develop an innovative divergence monitor. One way of obtaining stricter integrity is to detect anomalous divergence behavior more rapidly than the CCD monitor does. Therefore, we attempted to devise a divergence monitor in which the detection time is reduced by using the Kullback-Leibler information. In simulations and experimental results, we demonstrate that the proposed divergence measure is quite capable of detecting ionospheric anomalies that are hazardous to GBAS and is a very promising alternative for the detection of deviations. A comparison with existing CCD monitors shows its increased fault detectability, which enables it to sense even small ionospheric gradients more rapidly than typical monitors. [ABSTRACT FROM AUTHOR]

Ground-based augmentation system (GBAS) reference stations provide pseudo-range corrections (PRCs) and range rate corrections (RRCs) for visible GPS satellites along with the standard deviations of the PRC errors (\sigma_prgnd) and B-values for the reference receivers. When generating PRCs, a GBAS should adjust the reference receiver clock bias to limit the PRC values within a certain range specified by international standards. Since \sigma_prgnd should reflect the PRC errors accurately for system integrity, it must consider the effect of the clock adjustment procedure. Nevertheless, this has hardly been researched, since it is well known that the clock adjustment does not impact on the user position solution. This paper notices that \sigma_prgnd is also used for GBAS integrity monitoring functions which are implemented in range domain, not position domain. Thus, the work presented here investigates continuity and integrity performance risk in range domain in case a GBAS estimates \sigma_prgnd ignoring the clock adjustment procedure and uses it for integrity monitors. The work presented here analyzes the risk by a simulation and proposes strategies for \sigma_prgnd establishment considering the clock adjustment effects to prevent system performance risk. [ABSTRACT FROM AUTHOR]

Owing to the continuous increase in the damage to farms due to wild animals' destruction of crops in South Korea, various methods have been proposed to resolve these issues, such as installing electric fences and using warning lamps or ultrasonic waves. Recently, new methods have been attempted by applying deep learning-based object-detection techniques to a robot. However, for effective training of a deep learning-based object-detection model, overfitting or biased training should be avoided; furthermore, a huge number of datasets are required. In particular, establishing a training dataset for specific wild animals requires considerable time and labor. Therefore, this study proposes an Extract–Append data augmentation method where specific objects are extracted from a limited number of images via semantic segmentation and corresponding objects are appended to numerous arbitrary background images. Thus, the study aimed to improve the model's detection performance by generating a rich dataset on wild animals with various background images, particularly images of water deer and wild boar, which are currently causing the most problematic social issues. The comparison between the object detector trained using the proposed Extract–Append technique and that trained using the existing data augmentation techniques showed that the mean Average Precision (mAP) improved by ≥2.2%. Moreover, further improvement in detection performance of the deep learning-based object-detection model can be expected as the proposed technique can solve the issue of the lack of specific data that are difficult to obtain. [ABSTRACT FROM AUTHOR]

Recently, as the demand for technological advancement in the field of autonomous driving and smart video surveillance is gradually increasing, considerable progress in multi-object tracking using deep neural networks has been achieved, and its application field is also expanding. However, various problems have not been fully addressed owing to the inherent limitations in video cameras, such as the tracking of objects in an occluded environment. Therefore, in this study, we propose a density-based object tracking technique redesigned based on DBSCAN, which has high robustness against noise and is excellent for nonlinear clustering. Moreover, it improves the noise vulnerability inherent to multi-object tracking, reduces the difficulty of trajectory separation, and facilitates real-time processing through simple structural expansion. Through performance test evaluation, it was confirmed that by using the proposed technique, several performance indices were improved compared to the existing tracking technique. In particular, when added as a post processor to the existing tracker, the tracking performance owing to noise suppression was considerably improved by more than 10%. Thus, the proposed method can be applied in industrial environments, such as real pedestrian analysis and surveillance security systems. [ABSTRACT FROM AUTHOR]

Abstract: Wireless Brain Machine Interface (BMI) communication protocols are faced with the challenge of transmitting the activity of hundreds of neurons which requires large bandwidth. Previously a data compression scheme for neural activity was introduced based on Self Organizing Maps (SOM). In this paper we propose a dynamic learning rule for improved training of the SOM on signals with sparse events which allows for more representative prototype vectors to be found, and consequently better signal reconstruction. This work was developed with BMI applications in mind and therefore our examples are geared towards this type of signals. The simulation results show that the proposed strategy outperforms conventional vector quantization methods for spike reconstruction. [Copyright &y& Elsevier]

Abstract: In this paper, a multiple discrete quasi-sliding mode (QSM) control scheme is proposed for a general class of nonlinear discrete time systems with unknown dynamical equations, provided that input–output data is available for system identification. The self-organizing map (SOM) is employed to divide the state space into local regions such that it associates the operating region where a local linear model is the winner with a local quasi-sliding mode controller (QSMC). Switching of the controllers is done synchronously with the active local linear model that tracks the different operating conditions. The simulation results show that the proposed controller outperforms tracking the desired trajectory in noisy environments either with a global controller or simpler controllers based on multiple models. [Copyright &y& Elsevier]

An essential component for the autonomous flight or air-to-ground surveillance of a UAV is an object detection device. It must possess a high detection accuracy and requires real-time data processing to be employed for various tasks such as search and rescue, object tracking and disaster analysis. With the recent advancements in multimodal data-based object detection architectures, autonomous driving technology has significantly improved, and the latest algorithm has achieved an average precision of up to 96%. However, these remarkable advances may be unsuitable for the image processing of UAV aerial data directly onboard for object detection because of the following major problems: (1) Objects in aerial views generally have a smaller size than in an image and they are uneven and sparsely distributed throughout an image; (2) Objects are exposed to various environmental changes, such as occlusion and background interference; and (3) The payload weight of a UAV is limited. Thus, we propose employing a new real-time onboard object detection architecture, an RGB aerial image and a point cloud data (PCD) depth map image network (RGDiNet). A faster region-based convolutional neural network was used as the baseline detection network and an RGD, an integration of the RGB aerial image and the depth map reconstructed by the light detection and ranging PCD, was utilized as an input for computational efficiency. Performance tests and evaluation of the proposed RGDiNet were conducted under various operating conditions using hand-labeled aerial datasets. Consequently, it was shown that the proposed method has a superior performance for the detection of vehicles and pedestrians than conventional vision-based methods. [ABSTRACT FROM AUTHOR]

We report direct measurement of the electrochemical potential at organic semiconductor/gate dielectric interfaces in printed polymer transistors employing a gel electrolyte as the gate insulator. An oxidized silver wire reference electrode was embedded into the gel electrolyte, and its potential relative to the grounded source contact was measured simultaneously with the transistor transfer characteristics. The referenced turn-on voltages of transistors based on three common polymer semiconductors [(poly-3-hexylthiophene, poly(3,3‴-didodecylquaterthiophene), and poly(9,9′-dioctylfluorene-co-bithiophene)] were found to correlate with the reported highest occupied molecular orbital levels (ionization potentials) for these materials. Further, analysis of the transfer characteristics revealed a negative differential transconductance regime at high gate-induced carrier densities (∼1015 cm-2), which we attribute to a combination of band filling and a mobility lowering effect. [ABSTRACT FROM AUTHOR]

In spatial data with complexity, different clusters can be very contiguous, and the density of each cluster can be arbitrary and uneven. In addition, background noise that does not belong to any clusters in the data, or chain noise that connects multiple clusters may be included. This makes it difficult to separate clusters in contact with adjacent clusters, so a new approach is required to solve the nonlinear shape, irregular density, and touching problems of adjacent clusters that are common in complex spatial data clustering, as well as to improve robustness against various types of noise in spatial clusters. Accordingly, we proposed an efficient graph-based spatial clustering technique that employs Delaunay triangulation and the mechanism of DBSCAN (density-based spatial clustering of applications with noise). In the performance evaluation using simulated synthetic data as well as real 3D point clouds, the proposed method maintained better clustering and separability of neighboring clusters compared to other clustering techniques, and is expected to be of practical use in the field of spatial data mining. [ABSTRACT FROM AUTHOR]

Due to various accidents and crime threats to an unspecified number of people, many surveillance technologies have been studied as an interest in individual security continues to increase throughout society. In particular, intelligent video surveillance technology is one of the most active research areas in the field of surveillance; this popularity has been spurred by recent advances in computer vision/image processing and machine learning. The main goal is to automatically detect, recognize, and analyze objects of interest from collected sensor information and then efficiently extract/utilize this useful information, such as by detecting abnormal events or intruders and recognizing objects. Anomalous event detection is a key component of security, and many existing anomaly detection algorithms rely on a foreground subtraction process to detect changes in the foreground scene. By comparing input image frames with a reference image, changed areas of the image can be efficiently detected. However, this technique can be insensitive to static changes and has difficulties in noisy environments since it depends on a reference image. We propose a new strategy for improved dynamic/static change detection that complements the weak points of existing detection methods, which have low robustness in noisy environments. To achieve this goal, we employed a self-organizing map (SOM) for data clustering and regarded the cluster distribution of neurons, represented by the weight of the optimized SOM, as a directed graph problem. We then applied the shortest path algorithm to recognize anomalous events. The real-time monitoring capability of the proposed change detection system was verified by applying it to self-produced test data and the CDnet-2014 dataset. This system showed robustness against noise that was superior to other surveillance systems in various environments. [ABSTRACT FROM AUTHOR]

The reliability of a navigation system is crucial for navigation purposes, especially in areas where stringent performance is required, such as civil aviation or intelligent transportation systems (ITSs). Therefore, integrity monitoring is an inseparable part of safety-critical navigation applications. The receiver autonomous integrity monitor (RAIM) has been used with the global navigation satellite system (GNSS) to provide integrity monitoring within avionics itself, such as in civil aviation for lateral navigation (LNAV) or the non-precision approach (NPA). However, standard RAIM may not meet the stricter aviation availability and integrity requirements for certain operations, e.g., precision approach flight phases, and also is not sufficient for on-ground vehicle integrity monitoring of several specific ITS applications. One possible way to more clearly distinguish anomalies in observed GNSS signals is to take advantage of time-delayed neural networks (TDNNs) to estimate useful information about the faulty characteristics, rather than simply using RAIM alone. Based on the performance evaluation, it was determined that this method can reliably detect flaws in navigation satellites significantly faster than RAIM alone, and it was confirmed that TDNN-based integrity monitoring using RAIM is an encouraging alternative to improve the integrity assurance level of RAIM in terms of GNSS anomaly detection. [ABSTRACT FROM AUTHOR]

A novel method of designing a group delay equalizer consisting of a typical 3‐dB hybrid coupler combined with one of newly proposed 4 types of resonator is presented. It is designed by applying the phase obtained from the reflection coefficient between the 3‐dB coupler and the proposed resonator to the group delay formula. Once the resonance frequency with the group delay as the peak is set to form a desired band by setting the parallel and series resonance frequencies, each component value of the proposed equalizer is obtained. In order to improve the group delay bandwidth, the proposed equalizers with different target frequencies are connected as cascaded. One of the proposed 4 types of equalizers was implemented using open and short stubs due to the fabrication limitation of lumped components, and its measurement results showed that the insertion loss is under −1 dB, and the group delay is 4.5 ns with ±1.5 fabrication error. This implies that the measurement results were well matched with the design method of the proposed equalizer. [ABSTRACT FROM AUTHOR]

In this paper, we propose a newly enhanced Doherty combiner by adding a 180° transmission line to the stage of the peaking amplifier of a typical Doherty combiner such that the designer can easily construct a combiner having a phase deviation to be turned on within the intended bandwidth. Given such characteristics, the proposed structure provides wider phase bandwidth and better performance with respect to power combining rate than the conventional structure does. We introduce formulas for the design variables of the added transmission line and also demonstrate its validity through circuit design and experiment. [ABSTRACT FROM AUTHOR]

Abstract: A wireless type of chip-to-chip communication (WCC) technology is proposed as the next generation of 3D semiconductor technology. To demonstrate the feasibility of this technology, we designed a coil, transmitter and receiver for wireless chip-to-chip communication using a 50-nm digital CMOS process. The coil is designed using inductive coupling with design parameters that include the number of turns, the metal width, and the space between adjacent metal lines. A differential transceiver structure is proposed for the WCC technology. The transmitter of the transceiver acts as a termination and bias circuit for the receiver while the transceiver is operating as a receiver. The receiver is designed with a typical differential amplifier and a latch to recover the transmitted original digital signal. The proposed transceiver and coil for the proposed WCC technology is implemented using commercial 50-nm digital CMOS technology. Experimental results successfully demonstrate the feasibility of the WCC technology. [Copyright &y& Elsevier]