• Journal of the Society of Naval Architects of Korea
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• v.51 no.3
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• pp.239-245
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• 2014

This paper deal with the block storage planning problem of storing and retrieving assembly blocks in a temporary storage yard with limited capacity, which is one of the critical managerial problems in shipbuilding. The block storage planning problem is required to minimize the number of relocations of blocks while the constraints for storage and retrieval time windows are satisfied. We first show NP-hardness of the block storage planning problem. Next we propose a heuristic algorithm to generate good quality solutions for larger instances in very short computational time. The proposed heuristic algorithm was validated by comparing the results with the mathematical model presented in the previous study.

• Industrial Engineering and Management Systems
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• v.11 no.3
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• pp.276-287
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• 2012

Determining storage locations of containers is an important issue for efficient operation of container terminals. This study assumes a storage yard with a horizontal layout in which blocks are laid out in parallel to the quay and trucks enter at the side of a block to deliver (receive) a container to (from) the yard crane. Various storage rules for determining storage locations of containers are introduced. Simulation studies are conducted for evaluating various rules. The following guidelines are derived from the result of our simulation study: when designing a block, consider a block configuration in which the longest gantry and the longest trolley travel times of rail-mounted gantry cranes (RMGCs) are similar; do not restrict the types of containers that can be stored in a storage area; if different roles are to be assigned to different storage areas, one possible way is to divide a bay into two areas so that some rows in the bay are allocated to inbound containers while the other rows in the same bay are allocated to outbound containers; reserve the space in bay unit for a high productivity of RMGCs but reserve the space in stack unit when the storage space is not enough; when the storage space is not sufficient, allocate storage location in a way of starting from the end and ending at the middle of a block; for reducing the travel distance of internal trucks, provide a higher priority to a block nearer to the berthing position of the corresponding vessel.

• Journal of the Korea Society of Computer and Information
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• v.8 no.4
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• pp.159-164
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• 2003

Location of stock in a warehouse directly affects the total materials handling expense of all goods moving through the warehouse. The purpose of this paper is to develop a storage policy in order picking warehouse, the block-based storage policy to minimize the total order picking time. In block-based storage policy, the rack is divided into blocks and items are assigned to each block based on the turn-over rate of each item and the average distance between the blocks and the dock. To demonstrate the performance of the proposed policy, we compare with the existing method called class-based storage policy under various matching methods.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.3
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• pp.198-208
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• 2011

At a shipyard, the efficient handling of blocks is one of the most important factors in the shipbuilding process. We consider the problem of deployment planning of blocks from storage yards. As some information of block arrangement should be considered to handle the problem, we adopt the block arrangement based on the coordinates and sizes of each block at a storage yard. Deployment planning for a block involves deciding upon its transportation route from the storage yard and searching for blocks that would obstruct its transportation along this route. A tabu search algorithm for deploying several blocks is developed to minimize the number of obstructive blocks deployed together from the storage yards at a shipyard. The results of computational experiments show that the developed algorithm is very useful in the deployment planning of multiple blocks from the storage yards.

• The Journal of Society for e-Business Studies
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• v.19 no.2
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• pp.75-93
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• 2014

We deal with the design of the effective block logistics operating system in shipyard. The block logistics operation is one of the critical managerial problems in shipbuilding. The block logistics operation in shipyard consists of storage operation for temporary storage in the limited storage area and transfer equipment operation of blocks from the given storage area to next process according to the block production schedule. We propose a design method of block logistics operating system based on the axiomatic design and IDEF0 method. As a result of axiomatic design, system functions are determined regarding implementation sequence. We validated the proposed design by implementation of a block logistics operating system for a large scale shipyard.

• Smart Media Journal
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• v.7 no.4
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• pp.9-16
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• 2018

In order to improve the economics and flexibility of cloud computing, tendency to automate the operation and management of cloud resources has become complicated. However, while automation for cloud storage depends on the manufacturer's storage hardware, it cannot flexibly support the storage type in accordance with users' needs. In this paper, we propose an automatic configuration module that supports block/file/object storages suitable for user environment. In order to automatically install ceph, a cloud storage, we propose an automatic installation and configuration module based on the Chef configuration management tool. In addition to that, we also propose an automatic configuration module based on a shell programming in pursuit of enabling users to use ceph storage of block/file/object. The proposed method can automatically set up and manage shared file, block, and object storages in a virtual or physical user environment with no hardware dependencies.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.3
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• pp.167-173
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• 2018

In general, calcium is required for the reaction of blast furnace slag fine powder and fly ash. The by-products generated during the process of producing recycled aggregates have different calcium contents depending on the crushing stage and the possibility of using the process by-product as a concrete mixture is also different. In this study, the effect of the calcium content of the by-products on the compressive strength was investigated and the block was fabricated by using this. To utilize the by-products as an admixture, the calcium content was analyzed and the bending strength and surface temperature were measured according to the shape of the water storage block. As a result of this study, the possibility of making a block using recycled aggregate by-products was verified and arch type block was constructed to secure storage capacity and bending strength. Also, the surface temperature of the water storage block was reduced by $9^{\circ}C$ or more than that of the general permeable block.

• Journal of Korean Institute of Industrial Engineers
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• v.24 no.1
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• pp.137-144
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• 1998

Block stacking, which involves the storage of unit loads in stacks within storage rows, is typically used in traditional warehouses to achieve a high space utilization at a low investment cost. In this paper, assuming that the demand size from a customer is an i.i.d. random variable, we develop a probabilistic block stacking storage model and its algorithm for a singles product, which minimizes the time-overage floor space requirement under an (s, S) inventory policy and the violation of the FIFO lot rotation rule only in a single partially-occupied row.

• IE interfaces
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• v.22 no.2
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• pp.116-125
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• 2009

We revisit the assembly block storage location assignment problem (ABSLAP) at a shipyard, in order to compensate for the deficiency in performance verification of the heuristic ABSLAP algorithm developed by the previous study. In this paper, we formulate a mathematical programming model of the ABSLAP, refine elaborately the heuristic ABSLAP algorithm, and show the performance of the developed mathematical programming model and the revised heuristic ABSLAP algorithm. In addition, we explain simulation experiments conducted using the revised heuristic ABSLAP algorithm to investigate the influences of block stockyard layouts and production schedule instability on the block stockyard operations.

• Industrial Engineering and Management Systems
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• v.11 no.4
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• pp.331-338
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• 2012

This research proposes a Pareto-based multi-objective optimization approach to class-based storage warehouse design, considering a two-block warehouse that operates under the class-based storage policy in a low-level, picker-to-part and narrow aisle warehousing system. A mathematical model is formulated to determine the number of aisles, the length of aisle and the partial length of each pick aisle to allocate to each product class that minimizes the travel distance and maximizes the usable storage space. A solution approach based on multiple objective particle swarm optimization is proposed to find the Pareto front of the problems. Numerical examples are given to show how to apply the proposed algorithm. The results from the examples show that the proposed algorithm can provide design alternatives to conflicting warehouse design decisions.