• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.438-441
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• 2003

Construction delays are a common occurrence of most construction projects and difficult to analyze. there are some techniques to analyze delays, such as using CPM, Bar Chart but they are not enough to analyze concurrent and productivity lost delays. Productivity lost delays are different to interruption delays in computing the number of delays and analyzing concurrent delay. This paper describes the delay analysis method considering productivity including concurrent delay analysis.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.947-950
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• 2005

In this paper, we present an approach to control the locomotion of snake robot with concurrent programming model constructed using threads and semaphores. The multi-thread based concurrent programming model adds the flexibility to design and synchronize the movement of snake robots as compared with microcontroller and mechanical based approaches. We have designed a physical snake robot using LEGO sensors and actuator blocks and the wave motion of the snake robot is generated by multi-thread based concurrent programming under RT-Linux. The different robot movements in a desired direction along with different types of snake movements are achieved using angle sensors.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.3
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• pp.587-595
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• 1999

The fundamental reason why inheritance anomaly occurs is that for a concurrent object, when synchronization code is not properly separated from the method code, the extension of code to produce a derived class may force the change of both the synchronization code and the method code in the super class, and inheritance is integrated inheritance in a simple and satisfactory way within a concurrent object-oriented language. The main emphasis on how to avoid or minimize inheritance anomaly. Therefore, in this paper we propose a new model, object model, and will minimizes the problem of inheritance anomaly found in concurrent object-oriented programming languages using Behavior Equation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.632-635
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• 2008

Concurrent engineering concept is used in factory automation recently. In this paper, described instance that apply concurrent engineering production concept in sheet metal cutting process. Automation system to produce metal parts designed by Client/server structure, and designed NC postprocessor on inside. Also, in this paper, when handled all justices of part production by breakup design of concurrent engineering, proved can shorten tine required in product manufacture than system past.

• Korean Journal of Construction Engineering and Management
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• v.10 no.3
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• pp.102-110
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• 2009

Although several research efforts have been directed to fast-tracking to reduce the total delivery time, few researches have been studied on concurrent engineering in construction projects. The focus of fast-tracking is primarily on overlapping independent activity pairs. In comparison, the focus of concurrent engineering is on overlapping dependent activity pairs. Dependent activities are much harder to overlap successfully. This paper presents a simulation-based Concurrent Engineering methodology to optimize the overall duration of a set of design activities in a project by modelling key factors that determine the duration of individual activities and overlap between dependent activities. This methodology involves determining how much to overlap activities, how to decide which activities to overlap and the corresponding cost and time tradeoffs using a discrete event model solution. This simulation model, therefore, can be used as a reference on decision-making to define optimum point between time and cost.

• Journal of information and communication convergence engineering
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• v.12 no.2
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• pp.109-115
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• 2014

This paper presents a concurrent channel time allocation scheme used in the reservation period for concurrent transmissions in 60-GHz wireless personal area networks (WPANs). To this end, the proposed resource allocation scheme includes an efficient method for creating a concurrent transmission group by using a table that indicates whether individual streams experience interference from other streams or not. The coordinator device calculates the number of streams that can be concurrently transmitted with each stream and groups them together on the basis of the calculation result. Then, the coordinator device allocates resources to each group such that the streams belonging to the same group can transmit data concurrently. Therefore, when the piconet coordinator (PNC) allocates the channel time to the individual groups, it should allow for maximizing the overall capacity. The performance evaluation result demonstrates that the proposed scheme outperforms the random grouping scheme in terms of the overall capacity when the beamwidth is $30^{\circ}C$ and the radiation efficiency is 0.9.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.41-48
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• 2006

Nowadays major shipbuilding companies are trying to expand their business not only to shipbuilding but to offshore projects as well. DSME is one of them. DSME is trying to set up a flexible design and construction environment for shipbuilding and offshore construction in a single shipyard. The shipbuilding and offshore projects, however, have their unique technology but they need to be designed and constructed in one site. To support this new requirement, DSME has developed an integrated CAD system for ship and offshore projects. In this integrated design environment, the designers can design commercial ships and offshore projects in a flexible manner. Concurrent design is very important for ship and offshore design. As compared to the complexity of the product, the design period is quite short. In effect, the design system for the ship and offshore project has to support concurrent design. One essential point of concurrent design environment is a product model based design system. DSME has developed and implemented the 3D product model concurrent design environment based on Tribon M3. Tribon is a widely used CAD system in shipbuilding area that is developed by Tribon Solutions. DSME has both customized the Tribon system and developed in-house application systems to support its own design and production procedures. All the design objects are modeled in one common database to support concurrent design and accurate production. The major in-house development focused on the modeling automation and automatic drawing generation. During the drawing generation process many of the additional production information are also extracted from the 3D product model. In addition, several applications and functionalities have been developed to apply the shipbuilding based Tribon M3 system to offshore projects. The development of shape nesting, tubular connection, isometric drawing, grating nesting systems are the typical.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1540-1547
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• 2009

Steel frame factories were surveyed in this study in order to explore the possibility of shortening the construction time and save on construction cost through overlapping at the stages of design or construction. In the survey, construction professionals were interviewed in order to collect quantitative data. Hypotheses were then formulated, and the data was thereby analyzed using the simulation technique in order to analyze the effects of the concurrent engineering method on shorter construction time and cost saving. In addition, actual cases were analyzed to determine the overlapping rates of major processes in terms of shorter construction time and cost saving and to analyze the relationship between time and cost due to overlapping.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.423-429
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• 2004

The concurrent engineering technologies have been broadly used in the field of the design, testing, manufacturing and maintenance works to reduce development time and costs. For this purpose, many design environments with the product data management system, the virtual engineering system and web database system are developed. In this research, we developed the driving simulator of the KTX(Korea Train Express) as a basic study for building the concurrent engineering design environment of rolling stock. The virtual track was developed from the Seoul to the Busan and the Daejeon to Mockpo to generate immersible driving environment. Also. fault generation systems were developed to educate drivers of the KTX. We expect to reduce the time and costs of newly developed rolling stock using the design environment developed in the research.

• Journal of Ocean Engineering and Technology
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• v.18 no.6 s.61
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• pp.37-43
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• 2004

Under the concept of the global economy, the enterprises are assigning design and production environments around the world in various areas. In shipbuilding companies, a serious problem of information exchange has emerged as companies use traditional hardware and very distinct softwares that is tailored to their field of expertise. To overcome the decreased productivity resulting from the interruption of information, the concepts of simultaneous engineering and concurrent design become very significant. In this article, the concept of collaborative design based on Internet environments is described. Specifically, the core technologies necessary to achieve collaborative design environments among shipbuilding companies, ship owners, ship classification societies, model basin, and consulting companies are adopted.