• Nuclear Engineering and Technology
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• v.53 no.1
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• pp.178-187
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• 2021

Dual-cooled annular fuel allows a significant increase in power density while maintaining or improving safety margins. However, the dual-cooled design brings much higher Zircaloy charge in reactor core, which could cause a great threaten of hydrogen explosion during severe accidents. Hence, an innovative fuel combined dual-cooled annular geometry and SiC cladding was proposed for the first time in this study. Capabilities of fuel design and behavior simulation were developed for this new fuel by the upgrade of FROBA-ANNULAR code. Considering characteristics of both SiC cladding and dual-cooled annular geometry, the basic fuel design was proposed and preliminary proved to be feasible. After that, a design optimization study was conducted, and the optimal values of as-fabricated plenum pressure and gas gap sizes were obtained. Finally, the performance simulation of the new fuel was carried out with the full consideration of realistic operation conditions. Results indicate that in addition to possessing advantages of both dual-cooled annular fuel and accident tolerant cladding at the same time, this innovative fuel could overcome the brittle failure issue of SiC induced by pellet-cladding interaction.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.498-509
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• 2021

The wake turbulence at the wingtip of preceding aircraft may affect the normal operation of following aircraft. Aircraft are classified into four categories according to their maximum take-off weight, and horizontal separation is applied with this category matrix. The FAA and EUROCONTROL revealed that the magnitude and effect of preceding aircraft wake turbulence were smaller than the current distance separation minima suggest. This new information presents the opportunity for revising wake turbulence minima into seven categories (RECAT). This paper confirms the feasibility of implementing RECAT at major airports in South Korea using the draft of ICAO Doc. 10122. The paper also calculates the ultimate runway capacity of Incheon International Airport in South Korea using the Harris Model and comparatively analyzes the amount of runway capacity. As a result of the analysis, it was confirmed that the implementation of RECAT could increase the ultimate runway capacity of Incheon International Airport. This paper's calculation methods and results can be used as primary data for implementing RECAT in other airports.

• Knowledge Management Research
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• v.24 no.3
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• pp.127-148
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• 2023

Traditional Business Intelligence environment is limited to support the rapidly changing businesses and the exponential growth of data in both volume and complexity of data. Companies should shift their business intelligence environment into Self-Service Business Intelligence (SSBI) environment in order to make smarter and faster decisions. However, firms seem to face various challenges in implementing and leveraging the effective business intelligence system, and academics do not provide sufficient studies related including the success factors of SSBI. This study analyzes the three cases of Korean companies in depth, their development process and the assessment of business intelligence, based on the theoretical model on the key success factors of business intelligence systems. The comparative analysis of the three cases including project managers' interviews and performance evaluations provide rich implications for the successful adoption and the use of business intelligence systems of firms. The study is expected to provide useful references for firms to fully leverage the effects of business intelligence systems and upgrade towards self-service business intelligence systems.

• Journal of Environmental Science International
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• v.33 no.9
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• pp.645-665
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• 2024

For volatile organic compounds (VOCs) emanating from workplaces within the Noksan national industrial complex, the emission characteristics of pollutants were identified through zone-based measurements using vehicles equipped with selective ion flow tube mass spectrometry(SIFT-MS). The average concentration of total VOCs was higher in zones 2, 4, and 5 than in zones 1, 3, and 6, and was 2.1 to 4.2 times higher than background concentrations. The average concentrations of pollutants investigated were (from highest to lowest) methyl ethyl ketone, formaldehyde, methanol, and n-hexane. However, the pollutants that should be prioritized for reduction to decrease ozone generation were (from highest to lowest) methyl ethyl ketone, n-hexane, for maldehyde, and ethylbenzene+xylene. Benzene, a substance governed by atmospheric environmental standards, exhibited a frequency distribution exceeding the stipulated limits, and concentrations exceeding 100 ppb were identified for methyl ethyl ketone, methanol, toluene, and n-hexane. In certain class 4 and 5 workplace facilities, VOC emissions and emission prevention installations were inadequately managed, necessitating the formulation of management measures for small enterprises. Also, workplaces that emit large amounts of VOCs need to upgrade to VOC-prevention installations with higher processing efficiencies. To efficiently monitor VOCs in a wide range of areas, such as the Noksan national industrial complex, it is considered appropriate to monitor workplaces that emit high concentrations of VOCs using mobile SIFT-MS in real time rather than relying on fixed monitoring methods. A specialized method targeting approximately 10 VOCs is necessary to quickly track emission sources.Furthermore, it is essential to phase in a system for the intensive management of suspected workplaces based on accumulated data from SIFT-MS in areas where high VOC concentrations are measured and to establish a cooperative system for sharing data between relevant institutions.

• Archives of design research
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• v.12 no.4
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• pp.61-68
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• 1999

Most of the time, developers spend their energy to analyze the main function of the system or make source codes. As a result, they can not consider user interface on their own system and this is true in most programmer's world. But we want to consider the design concept in developing mechanism. In this case we have to upgrade the legacy system which maintaining the transmission system using the copper cables, and add the transmission system using the optical fiber cables. Therefore we design the user interface make easy for end users who are using the maintaining system on copper cables not to confuse the new system which include optical fibers. Especially, we are consider the developing model of design policy and real user to make easy to use new system. In this paper we will describe the instance to adapt the design concept on Broadband Access Network Operation Support System.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.5_6
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• pp.299-306
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• 2003

This paper formulates a problem of embedded real-time system re-engineering, and presents its solution approach. Embedded system re-engineering is defined as a development task of meeting performance requirements newly imposed on a system after its hardware and software have been fully implemented. The performance requirements nay include a real-time throughput and an input-to-output latency. The proposed solution approach is based on a bottleneck analysis and nonlinear optimization. The inputs to the approach include a system design specified with a process network and a set of task graphs, task allocation and scheduling, and a new real-time throughput requirement specified as a system's period constraint. The solution approach works in two steps. In the first step, it determines bottleneck precesses in the process network via estimation of process latencies. In the second step, it derives a system of constraints with performance scaling factors of processing elements being variables. It then solves the constraints for the performance staling factors with an objective of minimizing the total hardware cost of the resultant system. These scaling factors suggest the minimal cost hardware upgrade to meet the new performance requirement. Since this approach does not modify carefully designed software structures, it helps reduce the re-engineering cycle.

• Journal of Intelligence and Information Systems
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• v.14 no.2
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• pp.83-102
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• 2008

Ubiquitous computing requires timely supply of contextual information in order to upgrade decision quality. In this sense, this study is aimed at proposing a multi-dynamic decision support system for highly ill-structured problems. Especially, it is very important for decision makers in the ubiquitous computing to coordinate conflicts among local goals and global goal harmoniously. The proposed Multi-Dynamic Decision Support System (MDDSS) is basically composed of both central structure and distributed structure, in which central structure supports multi objects decision making and distributed structure supports individual decision making. Its hybrid architecture consists of decision processor, multi-agent controller and intelligent knowledge management processor. Decision processor provides decision support using contexts which come from individual agents. Multi-agent controller coordinates tension among multi agents to resolve conflicts among them. Meanwhile, intelligent knowledge management processor manages knowledge to support decision making such as rules, knowledge, cases and so on. To prove the validity of the proposed MDDSS, we applied it to an u-fulfillment problem system in which many kinds of decision makers exist trying to satisfy their own objectives, and timely adjustment of action strategy is required. Therefore, the u-fulfillment problem is a highly ill-structured problem. We proved its effectiveness with the aid of multi-agent simulation comprising 60 customers and 10 vehicles under three experimental modes.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.1
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• pp.89-100
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• 2006

Recently the dramatical development of domestic spatial information technology and the successful construction of Korea NGIS(Nation Geographic Information System) have been the foundation of the scientific national territory utilization and management. However, there still exists the original problems to construct the thematic maps for supporting the various administrative services because administrative officials tend to depend on paper maps and inventories to generate spatial information, process, upgrade and manage. In this situation, there is a greater need to develop GIS system for the effective construction of various thematic maps. In this study, the satellite image based high accurate e-thematic construction and management system was developed to support the forest administrative service such as generating user based forest thematic maps, modifying them, analyzing and outputting through GIS, GPS and satellite images. For the case study, the previous forest paper map of Jeju Island was converted in format of raster and vector data using satellite images to maintain more exact location information so that this system helps to manage domestic spatial information scientifically and effectively within shorter time then support the standard for domestic spatial information. Moreover, this system plays the role of DSS(Decision Supporting System) for forest administrative affairs by integrating the attribute data, managing the GPS data and linking the multimedia data. For this, the additional main objective of this study was acquired powerful GIS component, which is called as e-mapping component, so that it could be regarded as enabling interoperability and reusability within this application. For the future works, the essential element idea and technology in this study could be applied very usefully to other official works such as constructing thematic maps and supporting the desired affairs.

• Progress in Medical Physics
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• v.26 no.4
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• pp.250-257
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• 2015

Multi-leaf collimator (MLC) systems are frequently used to deliver photon-based radiation, and allow conformal shaping of treatment beams. Many proton beam centers currently make use of aperture and snout systems, which involve use of a snout to shape and focus the proton beam, a brass aperture to modify field shape, and an acrylic compensator to modulate depth. However, it needs a lot of time and cost of preparing treatment, therefore, we developed the manual MLC for solving this problem. This study was carried out with the intent of designing an MLC system as an alternative to an aperture block system. Radio-activation and dose due to primary proton beam leakage and the presence of secondary neutrons were taken into account during these iterations. Analytical calculations were used to study the effects of leaf material on activation. We have fabricated tray model for adoption with a wobbling snout ($30{\times}40cm^2$) system which used uniform scanning beam. We designed the manual MLC and tray and can reduce the cost and time for treatment. After leakage test of new tray, we upgrade the tray with brass and made the safety tool. First, we have tested the radio-activation with usually brass and new brass for new manual MLC. It shows similar behavior and decay trend. In addition, we have measured the leakage test of a gantry with new tray and MLC tray, while we exposed the high energy with full modulation process on film dosimetry. The radiation leakage is less than 1%. From these results, we have developed the design of the tray and upgrade for safety. Through the radio-activation behavior, we figure out the proton beam leakage level of safety, where there detects the secondary particle, including neutron. After developing new design of the tray, it will be able to reduce the time and cost of proton treatment. Finally, we have applied in clinic test with original brass aperture and manual MLC and calculated the gamma index, 99.74% between them.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.12
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• pp.1166-1176
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• 2011

The prospect in opening the arctic trade transportation route on a year-round basis offers vast opportunity of exploring untapped resources and shortened navigational routes. In addition, the environment's remoteness and lack of technical experiences remains a big challenge for the maritime industry. With this, engine designers and makers are continually investigating, specifically optimizing propulsion shafting system design, to meet the environmental and technical challenges of the region. The International Association of Classification Society, specifically machinery requirements for polar class ships(IACS UR13), embodies the propulsion shafting design requirements for ice class vessels. However, the necessity to upgrade the various features of the unified rules in meeting current polar requirements is acknowledged by IACS and other classification societies. For the polar class propulsion shafting system, it is perceived that the main source of excitation will be the propeller - ice load interaction. The milling - and the impact load, in addition to the load cases interpreted by IACS, contribute greatly to the overall characteristic of the system and due considerations are given during the propulsion design stage. This paper will expound on the excitation load estimation factors affecting the dynamic response of the different propulsion shafting system design. It is anticipated that detailed understanding of these factors will have a significant role during propulsion shafting design in the future.