A quay crane scheduling algorithm considering the workload of yard cranes in a container yard

Quay cranes (QCs) are the most important equipment for vessel operation in container terminals. It is important to efficiently schedule the operations of QCs so that a high productivity may be achieved in terminals. Because the storage yard is shared by multiple vessels, where the congestion of yard cranes and yard trucks must be considered, the operations of QCs for multiple vessels must be simultaneously considered for QC scheduling. The objective terms include the QC make-span, the total traveling distance of QCs, the expected delay time from interference, and the uniformity of workload among blocks. This study suggests a heuristic algorithm based on a meta-heuristic search algorithm. Finally, a numerical experiment is carried out to test the performance of the algorithm.     

Individual,social, and organizational contexts for active knowledge sharing in communities of practice

Firms that have implemented knowledge management initiatives are now interested in nurturing voluntary knowledge sharing organizations, called communities of practice (CoPs). Adopting the Triandis model on attitude formation, we identified and validated a set of organizational factors that was anticipated to have effects on knowledge sharing by CoP members such as perceived consequences, affect, social factors and facilitating conditions. One hundred and seventy-nine members from 70 CoPs of a large multinational electronics firm participated in this survey. Based on the PLS analysis, perceived consequences, affect, social factors, and facilitating conditions were found to significantly affect knowledge sharing in CoPs.     

A new weighted approach to imbalanced data classification problem via support vector machine with quadratic cost function

In this paper, a new weighted approach on Lagrangian support vector machine for imbalanced data classification problem is proposed. The weight parameters are embedded in the Lagrangian SVM formulation. The training method for weighted Lagrangian SVM is presented and its convergence is proven. The weighted Lagrangian SVM classifier is tested and compared with some other SVMs using synthetic and real data to show its effectiveness and feasibility.     

Antecedents of application service continuance: A synthesis of satisfaction and trust

Although ASP (Application Service Provider) has the potential to fundamentally change the manner in which IT services are provided for user firms, current ASPs often fail to provide good results in accumulating and retaining customers. To fill the gap between the expected benefits of application service and its disappointing results in the real world, we present a conceptual model including three quality measures – System Quality, Information Quality, and Service Quality. To extend the horizons of ASP acceptance, this study sharpens the model that these quality measures regulate Satisfaction and Trust, which lead to Continuance Intention. We test the research model and hypotheses through the use of the data from 203 small and medium enterprises with application service experience. Data analysis results using LISREL reveal that Satisfaction and Trust have significant effects on a client firm’s Continuance Intention. Trust is found to be the most salient determinant while previous studies mainly focused on the role of Satisfaction. Furthermore, an empirical support is found for the direct effect of Service Quality on Continuance Intention as well as its mediating effects.     

A dispatching method for automated lifting vehicles in automated port container terminals

In automated container terminals, containers are transported from the marshalling yard to a ship and vice versa by automated vehicles. The automated vehicle type studied in this paper is an automated lifting vehicle (ALV) that is capable of lifting a container from the ground by itself. This study discusses how to dispatch ALVs by utilizing information about pickup and delivery locations and time in future delivery tasks. A mixed-integer programming model is provided for assigning optimal delivery tasks to ALVs. A procedure for converting buffer constraints into time window constraints and a heuristic algorithm for overcoming the excessive computational time required for solving the mathematical model are suggested. Numerical experiments are reported to compare the objective values and computational times by a heuristic algorithm with those by an optimizing method and to analyze the effects of dual cycle operation, number of ALVs, and buffer capacity on the performance of ALVs.     

Feature detection of triangular meshes based on tensor voting theory

This paper presents n-dimensional feature recognition of triangular meshes that can handle both geometric properties and additional attributes such as color information of a physical object. Our method is based on a tensor voting technique for classifying features and integrates a clustering and region growing methodology for segmenting a mesh into sub-patches. We classify a feature into a corner, a sharp edge and a face. Then, finally we detect features via region merging and cleaning processes. Our feature detection shows good performance with efficiency for various dimensional models.     

Finding the longest common nonsuperstring in linear time

String inclusion and non-inclusion problems have been vigorously studied in such diverse fields as molecular biology, data compression, and computer security. Among the well-known string inclusion or non-inclusion notions, we are interested in the longest common nonsuperstring. Given a set of strings, the longest common nonsuperstring problem is finding the longest string that is not a superstring of any string in the given set. It is known that the longest common nonsuperstring problem is solvable in polynomial time.In this paper, we propose an efficient algorithm for the longest common nonsuperstring problem. The running time of our algorithm is linear with respect to the sum of the lengths of the strings in the given set, using generalized suffix trees.     

Improving multikey Quicksort for sorting strings with many equal elements

Bentley and Sedgewick proposed multikey Quicksort with ‘split-end’ partitioning for sorting strings. But it can be slow in case of many equal elements because it adopted ‘split-end’ partitioning that moves equal elements to the ends and swaps back to the middle. We present ‘collect-center’ partitioning to improve multikey Quicksort in that case. It moves equal elements to the middle directly like the ‘Dutch National Flag Problem’ partitioning approach and it uses two inner loops like Bentley and McIlroy's. In case of many equal elements such as DNA sequences, HTML files, and English texts, multikey Quicksort with ‘collect-center’ partitioning is faster than multikey Quicksort with ‘split-end’ partitioning.     

Local and singularity-free G 1 triangular spline surfaces using a minimum degree scheme

We develop a scheme for constructing G ¹ triangular spline surfaces of arbitrary topological type. To assure that the scheme is local and singularity-free, we analyze the selection of scalar weight functions and the construction of the boundary curve network in detail. With the further requirements of interpolating positions, normals, and surface curvatures, we show that the minimum degree of such a triangular spline surface is 6. And we present a method for constructing boundary curves network, which consists of cubic Bézier curves. To deal with certain singular cases, the base mesh must be locally subdivided and we proposed an adaptive subdivision strategy for it. An application of our G ¹ triangular spline surfaces to the approximation of implicit surfaces is described. The visual quality of this scheme is demonstrated by some examples.     

Fully discrete potential-based finite element methods for a transient eddy current problem

Fully discrete potential-based finite element methods called methods are used to solve a transient eddy current problem in a three-dimensional convex bounded polyhedron. Using methods, fully discrete coupled and decoupled numerical schemes are developed. The existence and uniqueness of solutions for these schemes together with the energy-norm error estimates are provided. To verify the validity of both schemes, some computer simulations are performed for the model from TEAM Workshop Problem 7. This work was supported by Postech BSRI Research Fund-2009, National Basic Research Program of China (2008CB425701), NSFC under the grant 10671025 and the Key Project of Chinese Ministry of Education (No. 107018).