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This paper explores the effectiveness of MOOS-IvP middleware for Unmanned Surface Vehicles(USV). As unmanned technology evolves, various functions are required to carry out some missions. Also, as the USVs have more sensors, the complexity of data sharing is increasing. A good solution to deal with this is middleware. The MOOS-IvP is a C++ based open source publish-subscribe middleware. It consists...
For the underwater search task, imaging sonar is very useful equipment to obtain the visual data of the underwater environment. Generally, the search range of imaging sonar depends on the frequency of the sound. High-frequency imaging sonar is suitable to search near area within 5m and low-frequency is able to search the area between 5m to 100m. In this paper, we presents experimental results of landmarks...
Underwater harbor structures should be inspected regularly for safety problem. Conventional inspection methods which are performed by divers have several limitations including safety and health problem of divers. This paper presents development of a ROV and experimental results for visual inspection of harbor structures. The ROV is equipped with visual systems for inspection tasks, navigation system...
Development of localization method is crucial for underwater vehicles to navigate in underwater environments. This paper presents a method of localization for underwater vehicles using acoustic signal. Artificial underwater acoustic sources are used as landmarks in underwater environment and underwater vehicle performs localization by acquiring acoustic signals transmitted from the sources. TDOA based...
Recently, a number of unmanned surface vehicles (USVs) have been developed and researched for various fields such as military, environment and robotics. These vehicles are used as an application platform of diverse algorithms. This paper introduces a development of a multi-purpose USV “eVe-1”. Also, several path tracking methods are compared by using simulation. The hardware of “eVe-1” is designed...
This paper proposes a practical object shape reconstruction method using an underwater forward-looking sonar. In order to achieve the object shape reconstruction, three practical methods are adopted. The forward-looking sonar has a vertical field of view, which affect the re-projection; thus, the vertical field of view is modified to a narrow angle to reduce the uncertainty in elevation angle. Simple...
This paper presents a method of topological modeling for marine environment. The proposed method detects landmarks from underwater and above-water environment. The topological model is acquired by applying Delaunay triangulation to the detected landmarks. Nodes are defined as triangulated region of Delaunay triangulation and edges represent adjacency between two nodes. The proposed method constructs...
For SSD-based RAID systems, the Diff-RAID technique has been proposed to reduce the probability of correlated multiple failures among SSDs by differentiating the amount of written data to each SSD. Although Diff-RAID works well for workloads with many small random writes (which require frequent parity updates), it does not perform well with recent data center workloads (e.g., key-value stores) which...
TDR is used to detect and locate the water leakages at pipe joint. A wire attached on the pipe surface is soaked by water when the leakage occurs and it affects the characteristic impedance of the wet part, leading to the change of the reflected signal. To infer the leakage from the TDR signal, we used the finite difference time domain based forward model which provides output of the TDR signal given...
This paper concerns about thermal management issues of Li-ion battery for optimal and safe operation of the battery. For the thermal management, it is important to estimate implicit thermal states such as internal temperature and heat generation rate of the battery. This research presents an online thermal state estimation technique for a pouch-type Li-ion polymer battery. The thermal states are represented...
The 2014 IEEE PHM data challenge problem deals with the state-of-health (SOH) of proton exchange membrane fuel cell (PEMFC) given two degradation data sets: (i) a reference data set (FC1) operated under constant current is fully given until 991 h and (ii) a test data set (FC2) operated under rippled current is partially given until 550h. The proposed research aims at predicting the SOH (or EIS spectra)...
IEEE 802.15 task group 8 (IEEE 802.15.8) has been recently chartered to define PHY and MAC mechanism for wireless personal area networks (WPAN) peer aware communications (PAC) optimized for peer to peer and infrastructureless communications with fully distributed coordination. The most promising services created by IEEE 802.15.8 would be multicast communication with simultaneous membership in multiple...
Demand side management (DSM) is an important technique for demand response (DR) system in smart grid networks. The DSM techniques traditionally have focused on minimizing electricity bill or peak load. More recent work reveals that users wish to reduce their electricity bills without sacrificing user convenience. Hence, waiting time has been introduced to reflect the user comfort for the DSM. Residents...
An all-digital, wide-range phase inversion delay-locked loop (PIDLL) with a high-resolution duty-cycle corrector (DCC) is presented. The proposed PIDLL utilizes a new phase inversion scheme to reduce the total number of delay elements (DEs) in the digitally controlled delay line (DCDL) by approximately one-half, enabling shorter locking times, lower power consumption, reduced jitter performance, and...
In OpenFlow system, there are Switches and a Controller which are communicated by OpenFlow protocol. In the beginning, a Controller receives the information from all Switches in the network and based on the received information, a Controller can build the network topology. Afterwards, Switches receive FlowTable from the Controller to operate properly based on the FlowTable. Once receiving the packets,...
Traditional data-driven prognostics often requires a large amount of failure data for the offline training in order to achieve good accuracy for the online prediction. However, in many engineered systems, failure data are fairly expensive and time-consuming to obtain while suspension data are readily available. In such cases, it becomes essentially critical to utilize suspension data, which may carry...
In this paper, a novel topology is proposed that can significantly increase the efficiency of photovoltaic (PV) system. The multi-level topology consists of several H-bridge cells connected in series, each one connected to a string of PV modules. The proposed topology offers advantages such as the operation at lower switching frequency or lower current ripple compared to conventional two level topologies...
In this paper, a novel topology is proposed that can significantly increase the efficiency of photovoltaic (PV) system. The multi level topology consists of several H-bridge cells connected in series, each one connected to a string of PV modules. The proposed topology offers advantages such as the operation at lower switching frequency or lower current ripple compared to conventional two level topologies...
This paper presents an efficient design of a processor-based PDP timing controller that supports multiple high frequency control signal channels in multi-clock domain. We implemented a prototype system using the proposed design on FPGA attached to 42-inch and 50-inch PDP panels with HD resolution.
Nowadays, the advanced digital display technology makes display devices support extreme high quality video like full HD. In order to support the quality, a communication interface of the display devices must provide a high bandwidth in video transmission. The DisplayPort, as one of the solutions, was proposed as an industry standard to transmit high color depths, refresh rates and display resolution...
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