• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.564-570
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• 2006

This paper presents a new real-time system design methodology for embedded system as well as event-driven real time application. It is required to implement a deadline handling mechanism in order to satisfy a large-scale distributed real time application. When we design real time system, it has handled a deadline and is important to measure / control a timing issue. These timing constraints usually associated with an interface between model and system. There are many case tools that supporting a real time application, for example, UML, graphic language for designing real time system, but they cannot provide efficient way to handle deadline miss. Therefore, users have to design deadline handler manually when they need to use it. This paper contributes solving the problems of user-level deadline handling for an embedded system. Also, it also discusses an efficient deadline handler design mechanism using on RoseRT, which is a graphical CASE tool supporting from UML.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.11a
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• pp.296-303
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• 2002

The main subject to become a hub port is automation. The automated container terminal has already operated in advanced ports and it has been planned for the basic planning and operation design in domestic case. The key of automated container terminal is effective operation of both ATC(automated transfer crane) and AGV(automated guided vehicle) which is automated handling equipments. This is essential to productivity of automated container terminal. This study suggests the most optimal method of equipment operation in order to minimize loading time using each three types or effective ATC operation methods and AGV dispatching rules in automated container terminals. As the automated equipment operation causes unexpected deadlocks or interferences, it should be proceeded on event-based real time. Therefore we propose the most effective ATC operation methods and AGV dispatching rules in this paper. The various states occurred in real automated container terminals are simulated to evaluate these methods. This experiment will show the most robust automated equipment operation method on various parameters(the degree of yard re-marshaling, the number of containers and the number of AGVs)

• The Journal of Society for e-Business Studies
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• v.18 no.2
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• pp.191-203
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• 2013

Today, information technologies have been applied to operations in container terminals, and it is possible to collect operational log data due to development of equipment and operations technology. Terminal operators are collecting event log data and try to figure out the way of resolving operations problems. Operators want to analyze event logs to determine the causes of the operation problems, but it can hardly be done manually. In this paper, we suggest a formal framework to evaluate performance measures using the collected log data of operations in container terminals. The proposed formal framework supports different container terminal layout, operational processes, and equipment. Our formal framework is composed of specification of terminal layout, log data, workflow, statistics, and report, based on the concept of container handling objects. For validation of our framework, we have implemented a terminal performance analysis system based on the proposed framework.

• Computers and Concrete
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• v.3 no.4
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• pp.213-233
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• 2006

Over the past years techniques for non-linear analysis have been enhanced significantly via improved solution procedures, extended finite element techniques and increased robustness of constitutive models. Nevertheless, problems remain, especially for real world structures of softening materials like concrete. The softening gives negative stiffness and risk of bifurcations due to multiple cracks that compete to survive. Incremental-iterative techniques have difficulties in selecting and handling the local peaks and snap-backs. In this contribution, an alternative method is proposed. The softening diagram of negative slope is replaced by a saw-tooth diagram of positive slopes. The incremental-iterative Newton method is replaced by a series of linear analyses using a special scaling technique with subsequent stiffness/strength reduction per critical element. It is shown that this event-by-event strategy is robust and reliable. First, the model is shown to be objective with respect to mesh refinement. Next, the example of a large-scale dog-bone specimen in direct tension is analyzed using an isotropic version of the saw-tooth model. The model is capable of automatically providing the snap-back response. Subsequently, the saw-tooth model is extended to include anisotropy for fixed crack directions to accommodate both tensile cracking and compression strut action for reinforced concrete. Three different reinforced concrete structures are analyzed, a tension-pull specimen, a slender beam and a slab. In all cases, the model naturally provides the local peaks and snap-backs associated with the subsequent development of primary cracks starting from the rebar. The secant saw-tooth stiffness is always positive and the analysis always 'converges'. Bifurcations are prevented due to the scaling technique.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.224-227
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• 2015

Data transmission via the car driver's tethered smart phone may have a volume-dependent billing in case car driver' phone transmits data in real-time to the remote data center. The on-board diagnosis data generated are temporary stored locally to mobile remote diagnosis application on the car driver's phone, and then transmit to the data center later when car driver connects to the Internet. To increase the easiest of using the remote vehicle application without blocking other tasks to be executing on the cloud, node.js stands as a suitable candidate for handling tasks of data storage on the cloud via mobile network. We demonstrate the effectiveness of the proposed architecture by simulating a preliminary case study of an android application responsible of real time analysis by using a vehicle-to- smart phones applications interface approach that considers the smart phones to act as a remote user which passes driver inputs and delivers output from external applications. In this paper, we propose a study on development of Remote Vehicle fault diagnostic system features web server architecture based event loop approach using node.js platform, and wireless communication to handle vehicle diagnostics data to a data center.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.59-69
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• 2018

This study deals with the case study on the pallet quantity determination problem for the flexible manufacturing system producing 32 different types of aircraft wing ribs which are major structures of an aircraft wings. A Korean company has constructed the WFMS (wing rib flexible manufacturing system) that is composed of several automated equipments such as the 5-axis machining centers, the RGV (rail guided vehicles)s, the AS/RS (automated storage and retrieval system), the loading/unloading stations, and so on. Pallets play a critical role in the WFMS to maintain high system utilization and continuous work flow between 5-axis machining machines and automated material handling devices. The discrete event simulation method is used to evaluate the performance of the WFMS under various pallet mix alternatives for wing rib manufacturing processes. Four performance measures including system utilization, throughput, lead-time and work in process inventory level are investigated to determine the best pallet mix alternative. The best pallet mix identified by the simulation study is adopted in setting up and operating a real Korean aircraft parts manufacturing shop. By comparing the real WFMS's performances with those of the simulation study, we discussed the cause of performance difference observed and the necessity of developing the CPS (cyber physical system).

• Journal of Energy Engineering
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• v.11 no.3
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• pp.194-202
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• 2002

In this paper, we simulate the power system transient stability of Kwang Yang steel works using object-oriented programming (OOP). OOP is a more flexible method than procedural programming. There are several advantages in dynamic system simulation using OOP, The maintenance and repair of program are easy because it is sufficient to modify necessary parts which correspond to the change of system without overall change of program. We have implemented a graphical man-machine interface (MMI) that can be used draw one-line system diagram and analyze power flow and dynamic stability. The implemented MMI also provide a graphical viewer that display dynamic stability analysis results by mouse event handling. The proposed method have been applied to Kwang Yang steel works network for on-line dynamic stability analysis. The dynamic behaviour of 17 synchronous generators and 25 synchronous motors has been studied in the Kwang Yang network.

• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.729-734
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• 2011

In this paper, e-Meters middleware and applications using standardized middleware in the EPCglobal is suggested. An standardized middleware of the EPCglobal is designed to manage as a form of SCM and other logistics. In order to support a variety of services using RFID-based, the system must be able to support each protocol. The main features of e-Meters middleware is consist of information status and delivery, distributed database processing, event data analysis, and handling. To operate real time e-Meters system information, The realized middleware is configured to process the results of data collection.

• International Commerce and Information Review
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• v.8 no.4
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• pp.147-156
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• 2006

In all cargo cases one of the first things the person handling the claim must do is decide who is potentially liable as a carrier of the goods. This issue arises because bills of lading often do not identify the carrier. The "carrier" could be the shipowner or the charterer or both. The issue of the identity of the "carrier" is a question of fact. The question to ask in each case is who undertook or agreed to carry and deliver the goods. The answer to this question will largely depend on the facts. The shipowner is almost always liable as a carrier under Common law provided there is no demise charter of the ship. The more recent case law, however, suggests that in the usual situation both the charterer and shipowner will be liable. Accordingly, both the owner and charterer should be put on notice of any claim and, in the event an extension of suit time is required, the extension should be obtained from both. An alternative method by which the charterer can avoid liability is to insert and 'Identity of Carrier' clause in the bill of lading.

• Journal of Radiation Protection and Research
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• v.19 no.2
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• pp.147-156
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• 1994

On-line gamma monitoring system around KAERI-site was set up to monitor the radiation fluctuations in environment. Data on gamma exposure rates measured by the ionication chamber in the monitoring posts are transmitted to a computer of central control station with. radio telemetry transmission modem and monitored in real time. Radio telemetry transmission system is economical and reliable on handling and storing of data. This monitroing system can triger an early warning system in the event of abnormal radiation levels.