RDOA based Emitter Localization using Constrained Least Square Algorithm under NLOS Environment

In this paper, we apply Kalman filter and constrained least square (CLS) algorithm for compensating these noises. With the proposed two algorithms, we can confirm high accuracy for localization. A simulation demonstrates the performance of our proposed algorithm. 

Computational Analysis for Estimation of Mooring Force Acting on Various Ships in Busan New Port

Recently, smart port systems connected to autonomous ships have attracted increasing interest. Thus, an intelligent port system can automatically berth to create an intelligent port system. To ensure the safety of large ships moored in open coastal terminals, which are often subjected to bad weather such as strong winds, it is necessary to calculate and evaluate their mooring security on a case-by-case basis. In this study, the mooring capacities of the large ships were estimated according to the port and fishing port design criteria of the Ministry of Ocean and Fisheries. Under the wind speed of 14 m/s, the longitudinal and lateral forces acting on the JBC, KCS, and KVLCC ships are 41.2 and 340 kN, 38.7 and 837 kN, and 77.2 and 222 kN, while under the wind speed of 30 m/s, they are 43 and 1674 kN, 132.7 and 4118 kN, and 159.2 and 1091 kN, respectively, for the mooring forces

Hybrid TDOA and AOA Localization using Weighted Least Square via RSS

In this paper, we propose an estimation technique based on hybrid time differential-of-arrival (TDOA) and angle-of-arrival (AOA) that allows the application of weighted least squares (WLS). The accuracy of localization is a very significant problem since the measurement data can be affected by environmental noise

A Review of Progress and Applications of Automated Vacuum Mooring Systems

Compared with the traditional mooring system, the automated vacuum mooring system can meet the development needs of large-scale ship automation, port automation, and environmental protection. This review describes the latest research focuses, progress, applications, and future perspectives regarding the automated vacuum mooring system. First, the components, working principles, advantages, limits, and risks of the automated vacuum mooring system are discussed. Secondly, typical application cases of automated vacuum mooring systems are introduced, looking at two aspects of the ship-based system and shore-based system. Then, the routine maintenance of the automated vacuum mooring system is introduced. Finally, a discussion on the challenges and future perspectives of the automated vacuum mooring system is provided in this review. The advantages of an automated vacuum mooring system make it a potentially highly effective and economical option for a wider range of ship mooring than a traditional mooring system

Rudder gap cavitation: Fundamental understanding and its suppression devices

With the increasing size and speed of cargo ships, which results in high speed flow in propeller slipstream, cavitation is frequently observed on and around the rudder system. Among the various types of cavitation on the rudder system, the rudder gap cavitation is the most difficult one to control and suppress. For the development of rudder gap cavitation suppression devices, both experimental and numerical analyses of the physical phenomenon are warranted. In the present study, experiments of the incipient cavitation and pressure measurement were carried out for typical cargo ship rudder sections with and without the suppression devices, which were suggested by the author. The experiments were simulated using computational fluid dynamics tools and the results were compared in terms of the cavitation inception and surface pressure distribution. Fundamental understanding of the rudder gap cavitation inception was obtained along with its relevance to the surface pressure distribution. It is confirmed that the gap flow blocking devices effectively suppress the rudder gap cavitation and, at the same time, augment lift.World Class University Project (R32-2008-000-10161-0, MEST) New & Renewable Energy R&D Program (2009302170010, MKE) funded by the Korea government Korea Science and Engineering Foundation (R0A-2007-000-10028-0)

Association of the neutrophil-to-lymphocyte ratio (NLR) and prostate cancer detection rates in patients via contemporary multi-core prostate biopsy

The aim of this study was to determine whether the neutrophil-to-lymphocyte ratio (NLR), a measure of the systemic inflammatory response is associated with the overall prostate cancer detection rate in men who underwent contemporary multi (≥12)-core transrectal ultrasound (TRUS) biopsy. We reviewed the records of 3913 patients with initial prostate-specific antigen (PSA) levels ranging from 4 to 10 ng ml−1 who underwent TRUS-guided prostate biopsy between April 2006 and May 2014. NLR was calculated by prebiopsy neutrophil and lymphocyte counts. We excluded patients who had evidence of acute prostatitis, a history of prostate surgery, and any systemic inflammatory disease. A multivariate logistic regression model was used to analyze prostate cancer detection. After adjusting for confounding factors, predictive values were determined according to the receiver operating characteristic-derived area under the curve, both including and excluding the NLR variable. In univariate analyses, NLR was a significant predictor of prostate cancer detection (P < 0.001). In multivariate analyses, a higher NLR was significantly associated with prostate cancer detection after adjusting for other factors (OR = 1.372, P= 0.038). The addition of NLR increased the accuracy from 0.712 to 0.725 (P = 0.005) in the multivariate model for prostate cancer detection. NLR may be a potentially useful clinical marker in the detection of prostate cancer among men with a PSA level in the 4-10 ng ml−1 range. These findings are derived from a retrospective analysis and should be validated in larger populations through prospective studies

Evaluation of Influencing Factors in Cleaning Performance for Bio-Fouling Removal Based on High-Pressure Water Jets

Regular inspections and hull cleanings are essential to prevent bio-fouling on ships. However, traditional cleaning methods such as brush cleaning and high-pressure water-jet cleaning at docks are ineffective in cleaning niche areas like bow thrusters and sea chests. Consequently, cleaning robots based on brushes and water jets have been developed to effectively remove bio-fouling. However, there are concerns that brushes may damage hull coatings, allowing bio-fouling to penetrate the damaged areas. In this study, removal experiments were conducted to identify the most dominant factor in fouling removal using water jet-based cleaning, in preparation for the development of non-contact cavitation high-pressure water jet-cleaning robots. The Taguchi method was used to identify influential factors and generate experimental conditions, and equipment systems for the removal experiments were established. Image analysis was performed to assess the bio-fouling occurrences on each specimen before and after cleaning, and numerical simulations of the nozzle were conducted to estimate stagnation pressure and wall shear stress to confirm the effect on micro-fouling removal. The results indicated that pump pressure is the most influential factor in removing large bio-fouling organisms grown in marine environments and on ship surfaces