• Earthquakes and Structures
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• v.13 no.3
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• pp.221-230
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• 2017

One of the important phases of probabilistic performance-based methodology is establishing appropriate probabilistic seismic demand models (PSDMs). These demand models relate ground motion intensity measures (IMs) to demand measures (DMs). The objective of this paper is selection of the optimal IMs in probabilistic seismic demand analysis (PSDA) of the RC high-rise buildings. In selection process features such as: efficiency, practically, proficiency and sufficiency are considered. RC high-rise buildings with core wall structural system are selected as a case study building class with the three characteristic heights: 20-storey, 30-storey and 40-storey. In order to determine the most optimal IMs, 720 nonlinear time-history analyses are conducted for 60 ground motion records with a wide range of magnitudes and distances to source, and for various soil types, thus taking into account uncertainties during ground motion selection. The non-linear 3D models of the case study buildings are constructed. A detailed regression analysis and statistical processing of results are performed and appropriate PSDMs for the RC high-rise building are derived. Analyzing a large number of results it are adopted conclusions on the optimality of individual ground motion IMs for the RC high-rise building.

• The KIPS Transactions:PartC
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• v.16C no.1
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• pp.117-124
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• 2009

Recently, the application of network technology extends to all areas because of development of digital information technology. Thus, networks are being evolved towards a next-generation communication environments where all information devices, home appliances, and object are connected and interoperated. In order to provide adequate convergence services in IMS-based networks that are the core technology of the next-generation communication environments, seamless service should be possible although the underlying network and the device in use may change in the networks. In this paper, we propose an efficient architecture, algorithm, and protocol of service session control for seamless service in such networks.

• The KIPS Transactions:PartC
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• v.13C no.5 s.108
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• pp.659-668
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• 2006

Various schemes for mobility support are currently proposed in NGN. However the performance comparison of all existing schemes is not relatively examined as yet. Therefore, in this paper, we investigate the location registration and handover procedure of MIPv6, IP2, Q.MMF, IMS, compare and analyze the location registration time and cost and handover latency time using various performance parameters and simulation for the performance analysis. As a result of analysis, when Location Manager locates in the center of core network, IP2 showed better performance than other schemes.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.325-326
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• 2008

The telecom world is steadily converging with the IP world, the benefits of converged services are required by many traditional telecom users. The aim of this thesis is to study the functional architecture of NGN based converged service. This thesis also shows how the converged service could be implemented on NGN with IMS core architecture.

• Steel and Composite Structures
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• v.45 no.3
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• pp.349-367
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• 2022

In this research, an approach combining a semi-analytical method and an analytical method is presented to investigate the static and dynamic post-buckling behavior of the sandwich functionally graded (FG) porous cylindrical shells exposed to external pressure. The sandwich cylindrical shell considered is composed of a viscoelastic core and two FG porous (FGP) face layers. The viscoelastic core is made of Kelvin-Voigt-type material. The material properties of the FG porous face layer are considered continuous through each face thickness according to a porosity coefficient and a volume fraction index. Two types of sandwich FG porous viscoelastic cylindrical shells named Type A and Type B are considered in the research. Type A shell has the porosity evenly distributed across the thickness direction, and Type B has the porosity unevenly distributes across the thickness direction. The FG face layers are considered in two cases: outside metal surface, inside ceramic surface (OMS-ICS), and inside metal surface, outside ceramic surface (IMS-OCS). According to Donnell shell theory, von-Karman equation, and Galerkin's method, a discretized nonlinear governing equation is derived for analyzing the behavior of the shells. The explicit expressions for static and dynamic critical buckling loading are thus developed. To study the dynamic buckling of the shells, the governing equation is examined via a numerical approach implementing the fourth-order Runge-Kutta method. With a procedure presented by Budiansky-Roth, the critical load for dynamic post-buckling is obtained. The effects of various parameters, such as material and geometrical parameters, on the post-buckling behaviors are investigated.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.118-120
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• 2017

모바일 이동통신망의 Core 노드들은 2G CDMA, 3G WCDMA, 4G LTE 교환기를 비롯하여 IMS 및 다양한 부가장비들로 이루어져 있다. 최근 5G로 진화하는 과정에는 NFV(Network Function Virtualization)가 그 중심에 서 있다. NFV 환경에서는 기존 통신 노드와 다르게 범용서버 및 범용 운영체제가 주축이 되어, 일반 IT 툴로도 통신망 내부 노드의 로그분석이 용이해 졌다. 또한 다양하고 복잡한 Core 네트워크에서 빅데이터로 발생하는 로그 또한 머신러닝으로 분석이 가능하며, 운용에 활용할 수 있다. 따라서 본 연구에서는 vDPI, vMMSGW OS 로그를 대상으로 분석하였으며, 잠재되어 있는 문제점들을 확인할 수 있었다. 또한 어플리케이션의 비정형화 된 로그에서도 비정상적인 패턴들을 발견하여 대용량 트래픽이 발생하며 SLA가 유난히 높은 통신환경에서도 비지도 머신러닝 분석이 유용함을 확인하였다.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.4
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• pp.419-426
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• 2020

Understanding the pore structure including pore shape and connectivity in unconventional reservoirs is essential to increase the recovery rate of unconventional energy resources such as shale gas and oil. In this study, we found analysis condition to probe the nanoscale pore structure in shale reservoirs using Focused Ion Beam (FIB) and Ion Milling System (IMS). A-068 core samples from Liard Basin are used to probe the pore structure in shale reservoirs. The pore structure is analyzed with different pretreatment methods and analysis condition because each sample has different characteristics. The results show that surface milling by FIB is effective to obtain pore images of several micrometers local area while milling a large-area by IMS is efficient to observe various pore structure in a short time. Especially, it was confirmed that the pore structure of rocks with high content of carbonate minerals and high strength can be observed with milling by IMS. In this study, the analysis condition and process for observing the pore structure in the shale reservoirs is established. Further studies are needed to perform for probing the effect of pore size and shape on the enhancement of shale gas recovery.

• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.4
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• pp.218-228
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• 2008

The convergence of broadcasting and telecommunication services is being accelerated by broadband networks, digital broadcasting and Web2.0. This paper describes the definition and service characteristics of IPTV as a representative of broadcasting and telecommunication convergence services. Especially, the changes of infrastructure and technology for IPTV2.0 are addressed in terms of the service features of mobility, intelligence and participation. IPTV2.0 shall be characterized by the open IPTV service based on Web2.0 and the mobile IPTV service over the heterogeneous networks employing various wireless/wired access technologies. The IP Multimedia Subsystem (IMS) and Service Delivery Platform (SDP) technologies are increasingly considered to support the personalization and openness. The mobility management technology is being evolved to provide QoS-guaranteed mobile communication services to users at anytime and anywhere. IPTV2.0 services and platforms are also anticipated to be core components to achieve knowledge-based ubiquitous society. IPTV2.0 contents are required to be integrated with the enhanced metadata to efficiently support search, selection, convergence and delivery of the contents. Moreover, those contents shall be enhanced to provide the scalable services which is adaptable to the network status and user preferences. Therefore, the networking technologies for IPTV2.0 should tightly cooperate with application services and adaptive contents. Those technologies will be developed to construct the ubiquitous content service platform considering the evolution of networks and various converged services.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.4
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• pp.133-141
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• 2001

Rapid development in computer and network technology these days has created in environment in which decisions for manufacturing companies can be made in a much broader perspective. Especially, better decisions on production and distribution planning(PDP) problems can be made laking advantage of real time information from all the parties concerned. However, since the PDP problem-a core part of the supply chain management- is known to be the so-called NP-hard problem, so heuristic methods are dominantly used to find out solutions in a reasonable time. As one of those heuristic techniques, many previous studios considered genetic a1gorithms. A standard genetic a1gorithm applies rules of reproduction, gene crossover, and mutation to the pseudo-organisms so the organisms can pass along beneficial and survival-enhancing trails to a new generation. When it comes to representing a chromosome on the problem, it is hard to guarantee an evolution of solutions through classic a1gorithm operations alone, for there exists a strong epitasis among genes. To resolve this problem, we propose a hybrid genetic a1gorithm based on Silver-Meal heuristic. Using IMS-TB(Intelligent Manufacturing System Test-bed) problem sets. the good performance of the proposed a1gorithm is demonstrated.

• Journal of the Korean Society of Industry Convergence
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• v.8 no.2
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• pp.69-76
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• 2005

This study for Customer Satisfaction(Customer Focus) by Profit security' in the field Process improvement activity and man-power upgrade by DAS(DATA Acquisition System) in the Plant that is fusion Off Line and On Line(IT), Especially the basic of the most foundation in the beginning Step of Toyota system is 3-jeong(a standard instrument; right volume, right box, right position), 5S(Seiri, Seiton, Seisoh, Seiketsu, Sitsuke ; KAISEN, KANBNA System(for Logistic), Further more KPC has established the digital environment such as CIM ; Computer Integrated Manufacturing), IMS ; Intelligent Manufacturing System ERP ; Enterprise Resource Planning, DAS; Data Acquisition System, Autonomous QC & SPC etc,.) in order to realize the intelligent informatization, which is core base for obtaining the competitive power and for responding to the various 21C management environment in flexibility. In this digital management environment, continuously and powerfully they would advance for becoming the best of the world. For strategic changes to take place in industry 3 key important factors need to be included ; Integration of tasks function and process, Decentralization of information, Responsibility, Finally simplification of products and product structures.