• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.12
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• pp.3118-3126
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• 1994

This paper describes the use of the concept of (relative) entropy for effective characterization of the amplitude and the frequency distributions of the surface profile formed in machining operation. For this purpose, a theoretical model for surface texture formation in turning operation is developed first. Then, the concept of (relative) entropy is reviewed and its effectiveness is examined based on the simulation and experimental results. The results also suggest that under random tool vibration the effect of the geometrical factors on the surface texture formation can be successfully decomposed and therefore, identified by applying the concept of (relative) entropy.

• Journal of Navigation and Port Research
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• v.41 no.5
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• pp.277-286
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• 2017

IMO introduced e-Navigation concept to improve the efficiency of ship operation, port operation, and ship navigation technology. IMO proposed sixteen MSPs (Maritime Service Portfolio) applicable to the ships and onshore in case of e-Navigation implementation. In order to meet the demands of the international society, the system implementation work for the Korean e-Navigation has been specified. The Korean e-Navigation system has five service categories: the S2 service category, which is a ship anomaly monitoring service, is a service that classifies emergency levels according to the degree of abnormal condition when a ship has an abnormality in ship operation, and provides guidance for emergency situations. The navigation safety module is a sub-module of the S2 service that determines the emergency level in case of navigation equipment malfunctioning, engine or steering gear failure during navigation. It provides emergency response guidance based on emergency level to the abnormal ship. If an abnormal condition occurs during the ship operation, first, the ship shall determine the emergency level, according to the degree of abnormality of the ship. Second, an emergency response guidance is generated based on the determined emergency level, and the guidance is transmitted to the ship, which helps the navigators prevent accidents and not to spread. In this study, the operational concept for the implementation of the Korean e-Navigation system is designed and the concept is focused on the navigation safety module of S2 service.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.4
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• pp.132-144
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• 2022

In response to the recent surge in aviation demand, major airport and aviation authorities continue to make efforts to formulate arrival procedures that take into account efficient aircraft separation, noise and environmental issues related to carbon (CO₂) emissions. In order to ensure efficient traffic control and environmental issues, as a result, a new concept Trombone, Point Merge, etc. have been introduced and widely used. However, these new concept incisions are becoming a factor that hinders operational efficiency and stability due to the restricted domestic airspace such as military airspace and excessive constraints of altitude, speed, etc. which do not reflect the concept of continuous descent operation and eventually needs to be modified to make continuous descent operation as feasible as possible. We herewith analyze and propose the way of improving flight safety and efficiency in the arrival operation procedure by supplementary modification which consequently contribute to the aviation industry international competitiveness.

• Nuclear Engineering and Technology
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• v.56 no.3
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• pp.900-906
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• 2024

The Passively-Cooled Molten Salt Fast Reactor (PMFR) is one of the advanced design concepts of the Molten Salt Fast Reactor (MSFR) which utilizes a natural circulation for the primary loop and aims to attain a long-life operation without any means of fuel reprocessing. For an extended operation period, it is necessary to have enough fissile material, i.e., high excess reactivity, at the onset of operation. Since the PMFR is based on a fast neutron spectrum, direct implementation of a burnable absorber concept for the control of excess reactivity would be ineffective. Therefore, a localized moderator concept that encircles the active core has been envisioned for the PMFR which enables the effective utilization of a burnable absorber to achieve low reactivity swing and long-life operation. The modified PMFR design that incorporates a moderator and burnable absorber is presented, where depletion calculation is performed to estimate the reactor lifetime and reactivity swing to assess the feasibility of the proposed design. All the presented neutronic analysis has been conducted based on the Monte Carlo Serpent2 code with ENDF/B-VII.1 library.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.821-826
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• 2002

The KOMPSAT-2 DCSU(the data compression & storage unit) performs the acquisition of image data from cameras, the compression with requested compression rate, the storage with specified file ID on the mission command and the distribution to the assigned DLS(Data Link System) channels per the mission and operation requirements. The worldwide observation using the MSC is able to be achieved by this DCSU's behavior. This paper presents the features of KOMPSAT-2 DCSU and provides proper ground operation concept after launch.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1008-1012
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• 1987

This paper describes the general approach to ISDN operation & maintenance. First we focused on the CCITT SG XVIII activities on the ISDN. As a general principles for operating and maintaining an ISDN they propose TMN(Telecommunication Management Network) concept which specifies several OM function modules and standard interfaces. Based on the concept we studied proper methodology to set up an efficient OM structure under the ISDN environments.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.5
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• pp.529-544
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• 2018

Ship owners now demand a new design approach for the rudder that considers detailed design information such as maneuverability and environmental loads etc. on a quantified basis. In this paper, we developed the concept of a safe operation capability chart for the design of a rudder area. The chart can be used as the basis of design considering the maneuverability and environmental loads. To confirm the applicability of the safe operation capability chart for use as the basis of design, four different rudders are assumed in this work. First, it is determined whether or not it is appropriate to design a rudder by applying a conventional design approach based on IMO maneuvering tests. The proposed concept is reviewed for use as the basis of the design by investigating the effect of rudder area on capability charts that are plotted according to the rudder under various environmental conditions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.10
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• pp.1451-1457
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• 2013

Recently, new concept of energy systems such as microgrid, smart grid, supergrid, and energy network has been introducing. In this paper, the concept of the centralized micro-energy network, which is an energy community of a building group without district heating system, is introduced. In addition, a mathematical model for optimal operation of the micro-energy network as a main function of an energy management system (EMS) for the micro-energy network is proposed. In order to show the validation, the proposed model is tested through the simulation and analyzed.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2000.05a
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• pp.5-8
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• 2000

Using the concept of a piecewise linear function, we present new operations for fuzzy arithmetic and then compare the operation based by the extension principle with the new operation.

• Strategy21
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• s.32
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• pp.5-35
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• 2013

The purpose of this thesis is to suggest how to plan ROK(Republic of Korea) Navy's strategy concerning to JOAC(Joint Operation Access Concept) and ASB(Air-Sea Battle) concept of US(United States) armed forces. Since 2006, US armed forces has been developing CONOPS(Concepts of Operations), JOAC & ASB. These concepts will not only affect security environment for Korea Peninsula and West Pacific Area, but also will be affected to ROK Navy's Strategy. Therefore, Korea Navy has to consider and review those concepts and should discuss the way to secure peace of Korea Peninsula. JOAC & ASB have been developed for securing operational access ability of US armed forces against enemy forces. A2/AD(Anti-Access, Area-Denial) is the strategy of possible enemy forces against US forces' approaching into the operation area and impede operations within area. US forces had to overcome enemy's A2/AD strategy in coming century to protect national interest and sustain global leadership. The main concept of JOAC & ASB is "Cross-domain Synergy", which means 'to eliminate duplicate and improve joint operability containing space and cyber operation area.' Korea Navy's acceptance of JOAC & ASB without any revising is not a rational choice. Without the amendment some problems can be occurred by the Korea navy's acceptance for the original version of JOAC & ASB. Those are "Missing differences of operation environment between Korea and US", "Impediment from neighbor nations, especially PRC (People's Republic of China)", and "Impediment inside from Korea armed forces". Therefore, Korea Navy has to evaluate and find out the way to solve for JOAC & ASB to apply for their strategy and minimise those possible problems above. This thesis is expected to be the solution.