The enforcement of shipping standards under UNCLOS

This article discusses the enforcement of shipping standards, with a particular focus on Part XII of UNCLOS. Section 6 of Part XII contains the only comprehensive set of vessel-related enforcement provisions in the Convention, but the Part’s scope is limited to “the preservation and protection of the marine environment.” Therefore, not all shipping standards fall clearly within Part XII’s ambit, including those centered on safety, security, and crewing considerations. The enforcement provisions of Section 6 are favorable to flag states and their vessels, and Section 7 contains a number of safeguards for their benefit, so it is in the interests of these parties to have coastal state enforcement governed by Part XII. However, the ability of coastal states to establish and enforce shipping standards that apply within the territorial sea extends to more than just environmental matters. The result is that different standards give rise to different enforcement powers, depending on the maritime zone in which a vessel is located, even if those standards arise from the same international agreement. It is suggested that to remedy these problems, UNCLOS would need to be amended in order to provide a comprehensive enforcement regime for the enforcement of shipping standards.     

Color image segmentation by edge linking and region grouping

A novel method toward color image segmentation is proposed based on edge linking and region grouping. Firstly, the edges extracted by the Canny detector are linked to form regions. Each of the end points of edges is connected by a direct line to the nearest pixel on another edge segment within a sub-window. A new distance is defined based on the feature that the edge tends to preserve its original direction. By sampling the lines to the image, the image is over-segmented to labeled regions. Secondly, the labeled regions are grouped both locally and globally. A decision tree is constructed to decide the importance of properties that affect the merging procedure. Finally, the result is refined by user’s selection of regions that compose the desired object. Experiments show that the method can effectively segment the object and is much faster than the state-of-the-art color image segmentation methods.     

Efficient democratic group signatures with threshold traceability

Democratic group signature (DGS) is a group-oriented primitive with great flexibilities, i.e., no group manager, anonymity, and traceability. In a DGS scheme with (t, n)-threshold traceability, any subset of not less than t members can jointly reveal the identity of the signer while preserving security even in the presence of an active adversary can corrupt up to t − 1 group members. This paper proposes an efficient DGS scheme. We use publicly verifiable secret sharing (PVSS) to distribute the trapdoor via which the real signer is revealed. The computation cost and communication overhead of our DGS signatures are greatly reduced, compared with the existing work. For example, the size of the resulting signature contains only 2n + 1 elements of Z _q , except the PVSS output.     

An analysis of the determinants of children’s weekend physical activity participation

This paper examines the out-of-home, weekend, time-use patterns of children aged 5–17 years, with a specific emphasis on their physical activity participation. The impact of several types of factors, including individual and household demographics, neighborhood demographics, built environment characteristics, and activity day variables, on physical activity participation is analyzed using a joint nested multiple discrete–continuous extreme value-binary choice model. The sample for analysis is drawn from the 2000 San Francisco Bay Area Travel Survey. The model developed in the paper can be used to assess the impacts of changing demographics and built environment characteristics on children’s physical activity levels.     

Seabed scene simulation and its realization in extending Vega

Realistic simulation of underwater scene is always difficult because of the special and complex vision effects in underwater space. Seabed is an important part of underwater environment. This paper describes the methods for seabed scene simulation based on OpenGL. It includes construction of fluetuant terrain based on the random sinusoidal algorithm, simulation of seabed flicker effect by means of circular texture mapping and generation of turbidity effect by using fog techniques. For the application based on the leading high level 3D development environment-Vega, underwater scene simulation is still a difficulty since there is no module for it. Based on the analysis of Vega software and the research on seabed scene simulation methods, a Vega extending module named “Underwater Space” was created through developing module class and extending lynx interface. The module class was designed through developing DLL written in C . The Lynx was extended through developing keyword configure file, GUI configure file and lynx plug-in DLL. The problem that Vega can‘t simulate underwater space, is elementarily resolved. The results show that this module is efficient, easy using, and the seabed scene images am vivid.     

The dynamic relationships between paper petroleum refining and physical trade of crude oil into the United States

This article examines the relationship between refinery margins traded on paper using petroleum futures (the paper refinery) and the physical trade of crude oil into the US. Computations of a 3:2:1 crack spread were constructed using daily observations of second- and third-nearby unleaded gasoline and heating oil futures contracts traded on the New York Mercantile Exchange (NY MEX) and spot Brent crude oil prices. The crack spread represents the margin between the cost of crude oil feed stock today and the value of the products produced by a refinery in the future. Unit root tests on each of the time series found crack spreads to be stationary while crude oil imports were found to be non-stationary. A s the two series were found to be integrated of different order, cointegration analysis of the two series was not deemed appropriate. Instead, linear relationships between crack spreads and imports were examined using causality tests. It was found that the 2-month 3:2:1 crack spread Granger-causes crude oil imports and that this causality is unidirectional. The significance of these findings lies in the fact that other industries like tanker shipping derive their demand from the demand for, and trade in, petroleum. Crack spreads, therefore, can provide a leading indicator for short term developments in tanker demand. For a chartering manager who has ships on the spot market, crack spreads can help him/her anticipate demand developments and influence vessel deployment and chartering decisions.