• IE interfaces
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• v.23 no.2
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• pp.182-192
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• 2010

Customer needs for final products are very unpredictable because product specifications and technologies are being improved very quickly thereby their requirement level is also elevated correspondingly. In order to survive and to enhance competitiveness in the global market, many manufacturing companies are trying to find a breakthrough from collaborization. Even though they want to collaborate with others, however, they do not exactly know what kind of system they have to develop or which technology they have to use. In this paper, therefore, we first investigate status and trend of information systems and infrastructure that are essential for collaboration. We then clearly describe definition and classification of collaboration with various point of views considering collaboration pattern, timing condition of collaborative activities, organizational structure, etc. With web-based collaboration systems already developed by i-Manufacturing (Korean-style Manufacturing Innovation) project, led by Korean government from 2004, we introduce main functions and analyze collaboration types of each system. Strategically important technologies for supporting collaboration will also be illustrated by reorganizing collaborization technologies after evaluating them with respect to emergency and importance of each technology. We hope this research will provide a guideline on collaboration especially for small and medium sized manufacturing companies.

• Journal of Biosystems Engineering
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• v.31 no.1 s.114
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• pp.39-45
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• 2006

Fundamental informations on performance of sets of solenoid valve and nozzle were necessary to develop a target selectable spraying system. The experiments were performed for the sets of solenoid valves and flat spraying nozzles at 3 levels of the operating pressures, and the obtained results are as follows; Rise time of the system pressure to reach up to 90% of the operating pressure after the valve turned was affected by nozzle size and operating pressure. Maximum overshoot of the system pressure was about 170% not affected by the sets of valve and nozzle and operating pressure. The system pressure after its settle down within 5% of the set pressure showed good uniformity in any condition of the experiment as less as 2.3% of its coefficient of variation. Time requirement to lower the system pressure down to 50% after the valve power turned off was affected by valve and nozzle set and operating pressure.

• ETRI Journal
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• v.36 no.1
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• pp.141-150
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• 2014

A fully integrated CMOS security-enhanced passive (SEP) tag that compensates the security weakness of ISO/IEC 18000-6C is presented in this paper. For this purpose, we propose a security-enhanced protocol that provides mutual authentication between tag and reader. We show that the proposed protocol meets the security demands of the ongoing international standard for RFID secure systems, ISO/IEC 29167-6. This paper fabricates the SEP tag with a 0.18-${\mu}m$ CMOS technology and suggests the optimal operating frequency of the CMOS SEP tag to comply with ISO/IEC 18000-6C. Furthermore, we measure the SEP tag under a wireless environment. The measured results show that communications between the SEP tag and reader are successfully executed in both conventional passive and SEP modes, which follow ISO/IEC 18000-6C and the proposed security enhanced protocol, respectively. In particular, this paper shows that the SEP tag satisfies the timing link requirement specified in ISO/IEC 18000-6C.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.3
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• pp.1337-1362
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• 2020

Advances in localization-based technologies and the increase in ubiquitous computing have led to a growing interest in location-based applications and services. High accuracy of the position of a wireless device is still a crucial requirement to be satisfied. Firstly, the rapid development of wireless communication technologies has affected the location accuracy of radio monitoring systems employed locally and globally. Secondly, the location is determined using standard complex computing methods and needs a relatively long execution time. In this paper, two geolocalization techniques, based on trigonometric and CORDIC computing processes, are proposed and implemented for Bluetooth-based indoor monitoring applications. Theoretical analysis and simulation results are investigated in terms of accuracy, scalability, and responsiveness. They show that the proposed techniques can locate a target wireless device accurately and are well suited for timing estimation.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2002.05a
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• pp.429-434
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• 2002

For companies assembling end products from sub assemblies or components, MRP (Material Requirement Planning) logic is frequently used to synchronize and pace the production activities for the required parts. However, in MRP, the planning of operational-level activities is left to short term scheduling. So, we need a good scheduling algorithm to generate feasible schedules taking into account shop floor characteristics and multi-level job structures used in MRP. In this paper, we present a GA (Genetic Algorithm) solution for this complex scheduling problem based on a new gene to reflect the machine assignment, operation sequences and the levels of the operations relative to final operation. The relative operation level is the control parameter that paces the completion timing of the components belonging to the same branch in the multi-level job hierarchy. In order to revise the fixed relative level which solutions are confined to, we apply large step transition in the first step and GA in the second step. We compare the genetic algorithm and 2-phase optimization with several dispatching rules in terms of tardiness for about forty modified standard job-shop problem instances.

• Journal of Positioning, Navigation, and Timing
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• v.3 no.4
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• pp.131-141
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• 2014

Over the last decade, the Global Navigation Satellite System (GNSS) has been increasingly utilized as a meteorological research tool. The Korea Astronomy and Space Science Institute (KASI) has also been developing a near real-time GNSS precipitable water vapor (PWV) information management system that can produce a precise PWV for the Korean Peninsula region using GNSS data processing and meteorological measurements. The goal of this paper is to evaluate whether the precise point positioning (PPP) strategy will be used as the new data processing strategy of the GNSS-PWV information management system. For this purpose, quality assessment has been performed by means of a comparative analysis of the troposphere zenith total delay (ZTD) estimates from KASI PPP solutions (KPS), KASI network solutions (KNS), and International GNSS Service (IGS) final troposphere products (IFTP) for ten permanent GNSS stations in the Korean Peninsula. The assessment consists largely of two steps: First, the troposphere ZTD of the KNS are compared to those of the IFTP for only DAEJ and SUWN, in which the IFTP are used as the reference. Second, the KPS are compared to the KNS for all ten GNSS stations. In this step, the KNS are used as a new reference rather than the IFTP, because it was proved in the previous step that the KNS can be a suitable reference. As a result, it was found that the ZTD values from both the KPS and the KNS followed the same overall pattern, with an RMS of 5.36 mm. When the average RMS was converted into an error of GNSS-PWV by considering the typical ratio of zenith wet delay and PWV, the GNSS-PWV error met the requirement for PWV accuracy in this application. Therefore, the PPP strategy can be used as a new data processing strategy in the near real-time GNSS-PWV information management system.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.1
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• pp.61-67
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• 2014

Conventional synchronous circuits in low power required systems such as sensor systems cannot only satisfy the timing requirement of the low voltage digital systems, but also they may generate wrong outputs under the influence of PVT variations and aging effects. Therefore, in the reliable ultra-low power design, asynchronous circuits have recently been reconsidered as a solution for scaling issues. However, it is not easy to totally replace synchronous circuits with asynchronous circuits in the digital systems, so the interfacing between the synchronous and asynchronous circuits is indispensable for the digital systems. This paper presents a new design for interfacing between asynchronous circuits and synchronous circuits, and the interface circuits are applied to a $4{\times}4$ multiplier logic designed using 0.11um technology.

• Journal of the military operations research society of Korea
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• v.36 no.2
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• pp.53-69
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• 2010

The long-term purpose of Military Acquisition Program Management (MAPM) is to fulfill requested performance, budget, and timing of military capability building. The Defense Acquisition Program Administration was established in 2006 and it adopted Integrated Control System. Moreover, there have no much studies done to examine the condition of Defense Capability Improvement Project in Korea through an empirical research although there are sixty one organizations are operating currently under Defense Capability Improvement Project. The objective of this study is to recognize Military Acquisition Program Management as a single project and to critically review relationship between Critical Success Factors (CSF) and Military Acquisition Program Management. Accordingly, three determinants to lead to successful Military Acquisition Program Management are "Communication" "User Participation" and "User Requirement." This study also demonstrates that Critical Success Factors have distinctive influences on successful Military Acquisition Program Management based on characteristic, size and phase of project. In retrospect, it is meaningful that Integrated Project Team (IPT) could classify priority of management according to characteristic, size and phase of project in the course of implementation.

• The Journal of Information Systems
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• v.12 no.2
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• pp.129-149
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• 2003

One of the important applications in Enterprise Resource Planning(ERP) systems is the Manufacturing Resource Planning(MRPII) system using Bill of Material(BOM). The manufacturing resource planning determines the quantity and timing of the production or purchase of subassemblies and raw materials needed to support the Master Production Scheduling(MPS). The bill of material is the recipe, a list of the materials needed to make a product. This paper intends to suggest a component-based materials management system using Unified Modeling Language(UML), as an application system for automobile part industry. Applying component based materials management systems designed with UML methodology, we analyzed the workflow and the document on materials management process from production planning to inventory management, and implemented a prototype of efficient materials management system, as a surrogate of existing material requirement planning(MRPI) system. To produce many other assemblies for a automobile part firm, component parts are assembled into subassemblies that are joined to assemble the finished product. Through the system suggested in this study, the level of inventory has cut down and the cost of inventory management has decreased. Also, the development method using UML makes the analysis and design phase to shorten in implementation period of MRPII system. The implementation of materials management system using CBD shows the ease of use in software reuse and the interoperability with corporate Internal information system. The result of applying object-oriented CBD technique is to minimize the risk of life cycle and facilitate the reuse of software as mentioned to limitation of information engineering methodology.

• Journal of KIISE:Databases
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• v.27 no.1
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• pp.42-52
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• 2000

In many real time applications that the system maintains sensitive information to be shared by multiple users with different security levels, security is another important requirement. A secure real time database system must satisfy not only logical data consistency but also timing constrains and security requirements associated with transactions. Even though an optimistic concurrency control method outperforms locking based method in firm real time database systems, where late transactions are immediately discarded, most existing secure real time concurrency control methods are based on locking. In this paper, we propose a new optimistic concurrency control protocol for secure real time database systems, and compare the performance characteristics of our protocol with locking based method while varying workloads. The result shoes that our proposed O.C.C protocol has good performance in case of many data conflict.