scispace - formally typeset
Search or ask a question
Author

Dov Kruger

Bio: Dov Kruger is an academic researcher from Stevens Institute of Technology. The author has contributed to research in topics: Underwater & Sound transmission class. The author has an hindex of 3, co-authored 8 publications receiving 25 citations.

Papers
More filters
Proceedings ArticleDOI
01 Oct 2007
TL;DR: In this article, the authors study the behavior of estuary water conditions and attempt to characterize the acoustic sensor coverage in an estuary using environmental data extracted from the NYHOPS forecast model.
Abstract: Monitoring underwater environments is challenging. Terrestrial and aerial surveillance technology cannot be adopted directly since optical and electromagnetic waves have extremely high attenuation in water. Most existing underwater detection technologies rely upon sound waves as sound can travel a relatively long distance in water. However underwater sound propagation is highly susceptible to interference depending on the water conditions. Sharp gradients in salinity and temperature cause sound to refract and reflect. Thus the listening range, or coverage, of a sound detector is largely influenced by the underwater environment. This effect is particularly prominent in an estuary where fresh water mixes with sea water, and tidal action causes significant current changes. We study the behavior of estuary water conditions and attempt to characterize the acoustic sensor coverage in an estuary. We use environmental data extracted from the NYHOPS forecast model. Acoustic conditions in water are evaluated based on sound speed variation. Based on scans over a ten-month period, we characterize the impacts from major environmental factors on underwater sound propagation. We further calculate sound transmission loss for typical water conditions and analyze the variation of sensing range for underwater sound detectors.

20 citations

Patent
28 Sep 2017
TL;DR: In this article, the authors propose a web protocol that can be embedded within a custom browser to communicate directly, eliminating translation and layers of programming, and skip the intermediate representation of HTML, CSS, and JavaScript.
Abstract: A protocol, server and client producing high performance web service with security and lower power requirements. A web protocol retrofits web browsers with a translating program on the client to relay the messages to the server with less bandwidth. Optionally, the protocol is embedded within a custom browser to communicate directly, eliminating translation and layers of programming. By storing web pages in a binary format and skipping the intermediate representation of HTML, CSS, and JavaScript the size of the web page, and the time it takes to display it can be reduced. The elimination of JavaScript also increases security because JavaScript is a known, common source of attacks. Communication of static data is minimized. A key repository and automated client use thereof may eliminate manual entry and transmission of access credentials making phishing attacks impossible.

4 citations

Proceedings ArticleDOI
01 Aug 2019
TL;DR: A new protocol of pre-authorization in which all parties agree and sign, and the blockchain ratifies the resulting agreement is defined, to prevent losses in cryptocurrency transactions.
Abstract: This paper describes a new way to create a pre-authorized transaction on the blockchain so that the transaction is less likely to have errors. Currently, cryptocurrency transactions do not allow a sender to modify or cancel a transaction that has been sent to a wrong address or person. There is no way for the user to retrieve the funds, and the receiver may not return any coins or data. Thus, if a user sends a coin or data to a wrong or non-existent party the coin or data is permanently lost once the transaction is accepted in the blockchain. Current blockchain frameworks such as Bitcoin and Ethereum share this unidirectional technical standard. It is also possible to make it appear that a recipient is taking a bribe by sending them cryptocurrency without their permission. We define a new protocol of pre-authorization in which all parties agree and sign, and the blockchain ratifies the resulting agreement. While nothing will eliminate all risk of error and fraud, this proposal will prevent these kinds of losses.

3 citations

Proceedings ArticleDOI
17 Sep 2009
TL;DR: A high efficiency algorithm, Multiple Analytical Distribution Filter (MADF), to estimate location for underwater navigation using small grid sampling around candidate areas of high probability, which computes probabilities directly from the known analytical distributions of each beacon.
Abstract: This paper presents a high efficiency algorithm, Multiple Analytical Distribution Filter (MADF), to estimate location for underwater navigation. Using small grid sampling around candidate areas of high probability, MADF computes probabilities directly from the known analytical distributions of each beacon. The algorithm is deterministic and achieves similar results to particle filters, but at a lower computational cost in our tests. MADF and particle filters represent improvements over Kalman Filters for environments characterized by non-Gaussian noise distribution.

1 citations

Proceedings ArticleDOI
23 May 2007
TL;DR: The result shows that careful planning is required for sensor placement in an estuary area, and the design of remote sensing and detecting systems for the underwater environment around estuary areas is reviewed.
Abstract: The paper focuses on the design of remote sensing and detecting systems for the underwater environment around estuary areas. The behavior of estuary water conditions is studied and the environmental impacts on the performance of underwater sensing and detecting systems are investigated. Sensor coverage variations are determined in particular. Environmental data is extracted from the NYHOPS ocean model with periodic calibration from fixed CTD stations in the Hudson River. The result shows that careful planning is required for sensor placement in an estuary area.

1 citations


Cited by
More filters
Proceedings ArticleDOI
19 Apr 2009
TL;DR: This paper constructs the spatial-temporal conflict graph (ST-CG) to describe the conflict delays among transmission links explicitly, and proposes a novel heuristic, called the traffic-based one-step trial approach (TOTA), to solve the coloring problem.
Abstract: Underwater sensor networks (UWSNs) have attracted a lot of attention recently. Since data in UWSNs are transmitted by acoustic signals, the characteristics of a UWSN are different from those of a terrestrial sensor network. In other words, the high propagation delay of acoustic signals in UWSNs causes spatial-temporal uncertainty, and makes transmission scheduling in UWSNs a challenging problem. Hence, in this paper, we propose a spatial-temporal MAC scheduling protocol, called ST-MAC, which is designed to overcome spatial-temporal uncertainty based on TDMA-based MAC scheduling for energy saving and throughput improvement. We construct the spatial-temporal conflict graph (ST-CG) to describe the conflict delays among transmission links explicitly, and model ST-MAC as a new vertex coloring problem of ST-CG. We then propose a novel heuristic, called the traffic-based one-step trial approach (TOTA), to solve the coloring problem. In order to obtain the optimal solution of the scheduling problem, we also derive a mixed integer linear programming (MILP) model. Finally, we present a comprehensive performance study via simulations. The results show that ST-MAC can perform better than existing MAC schemes (such as S-MAC, ECDiG, and T-Lohi) in terms of the network throughput and energy cost.

151 citations

Journal ArticleDOI
TL;DR: This work translates the TDMA-based scheduling problem in UWSNs into a special vertex-coloring problem in the context of a spatial-temporal conflict graph (ST-CG) that describes explicitly the conflict delays among transmission links.
Abstract: Since data in underwater sensor networks (UWSNs) is transmitted by acoustic signals, the characteristics of a UWSN are different from those of a terrestrial sensor network. Specifically, due to the high propagation delay of acoustic signals in UWSNs, referred as spatial-temporal uncertainty, current terrestrial MAC schemes do not work well in UWSNs. Hence, we consider spatial-temporal uncertainty in the design of an energy-efficient TDMA-based MAC protocol for UWSNs. We first translate the TDMA-based scheduling problem in UWSNs into a special vertex-coloring problem in the context of a spatial-temporal conflict graph (ST-CG) that describes explicitly the conflict delays among transmission links. With the help of the ST-CG, we propose two novel heuristic approaches: 1) the traffic-based one-step trial approach (TOTA) to solve the coloring problem in a centralized fashion; and for scalability, 2) the distributed traffic-based one-step trial approach (DTOTA) to assign the data schedule for tree-based routing structures in a distributed manner. In addition, a mixed integer linear programming (MILP) model is derived to obtain a theoretical bound for the TDMA-based scheduling problem in UWSNs. Finally, a comprehensive performance study is presented, showing that both TOTA and DTOTA guarantee collision-free transmission. They thus outperform existing MAC schemes such as S-MAC, ECDiG, and T-Lohi in terms of network throughput and energy consumption.

36 citations

Proceedings ArticleDOI
15 Dec 2009
TL;DR: An adaptive topology reorganization scheme has been proposed that is able to maintain connectivity in multi-hop three-dimensional UWSNs affected by shadow zones and improves communication quality.
Abstract: Shadow zones in Underwater Wireless Sensor Networks (UWSNs) dramatically impact communication system performance. In this paper an adaptive topology reorganization scheme has been proposed that is able to maintain connectivity in multi-hop three-dimensional UWSNs affected by shadow zones. The optimal placement for the sensor nodes to minimize the transmission loss and to maintain the network connectivity has been found using our proposed mathematical model. The theoretical analysis and the numerical evaluations reveal that our proposed scheme reduces the transmission loss under all propagation phenomena for all water depths in UWSNs and improves communication quality.

21 citations

Proceedings ArticleDOI
12 May 2009
TL;DR: In this article, a distributed control law and coordination algorithm is proposed for coverage control of a network of mobile sensors. But the coverage is not guaranteed to converge, since the global sensing performance function is not known a priori.
Abstract: This paper addresses the problem of coverage control of a network of mobile sensors. In the current literature, this is commonly formulated as a locational optimization problem under the assumption that sensing performance is independent of the locations of sensors. We extend this work to a more general framework where the sensor model is location-dependent. We propose a distributed control law and coordination algorithm. If the global sensing performance function is known a priori, we prove that the algorithm is guaranteed to converge. To validate this algorithm, we conduct experiments with indoor and outdoor deployments of Cyclops cameras and model its sensing performance. This model is used to simulate deployments on 1D pathways and study the coverage obtained. We also examine the coverage in the case when the global sensing function is not known and is estimated in an online fashion.

18 citations

Journal ArticleDOI
TL;DR: The framework is tested in numerical experiments with real-life data for circular and elliptic hydrophone placements and is shown to be superior to a deterministic energy-based approach.
Abstract: A comprehensive framework for diver detection by a hydrophone network in an urban harbor is presented. It includes a signal processing algorithm and a diver detection test and formulates optimal hydrophone placement as a two-stage stochastic optimization problem with respect to different scenarios of underwater noise. The signal processing algorithm identifies sound intensity peaks associated with diver breathing and outputs a diver number measuring the likelihood of diver presence, whereas the diver detection test aggregates the diver numbers obtained from the hydrophones in a linear statistic and optimizes the statistic's coefficients and a detection threshold for each noise scenario. The serial dependence of the diver numbers on a short time scale (several detection periods) is modeled by a hidden Markov chain, and finding the worst-case diver's trajectory for each hydrophone placement and noise scenario is reduced to a linear programming problem. The framework is tested in numerical experiments with real-life data for circular and elliptic hydrophone placements and is shown to be superior to a deterministic energy-based approach.

16 citations