• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.200-201
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• 2016

Recently, according to era of Internet of Things was opened, various mobile devices connected to the internet using wireless communication. Many IoT devices have limited communication performance. Thus, these devices efficiently forward data using an abbreviated ID method. However, movement of devices causes abbreviated ID confliction, and These conflict degraded network performance. Therefore it is important management of ID conflict. In this paper, we proposed an abbreviated ID conflict management method to improve the efficiency of communication in the dynamic IoT network.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.35-42
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• 2019

Risk assessment and analysis for a medium-to-small sized chemical plant that manufactures a polyester resin by the process of batch-type condensation reaction was conducted using K-PSR technique which is one of the risk assessment methods used to implement the Process Safety Management System (PSM). K-PSR is a risk assessment technique developed by KOSHA to compensate for difficulties caused by the lack of infrastructure of medium-to-small sized chemical plants in the re-evaluation. To apply the K-PSR technique, the entire process of a selected chemical palnt was classified in two review sections, i.e., the condensation reaction process and the dilution/filtration process, and the potential risks of the process about these review sections were identified and classified based on the four guide-words (release, fire.explosion, process trouble, and injury). As the results of the research, refer to recommend of risk rating has been confirmed that non-destructive testing of old facilities and the preparation of LOTO procedures for the electrical equipments are necessary as specific measures to prevent the risk of release and fire.explosion. It was also shown that pressure gauges and thermometers should be installed on the hot-oil supply piping to minimize the process trouble, and exhausting hood should be installed to prevent potential injury.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06c
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• pp.31-36
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• 2010

최근 대두되고 있는 웹2.0의 특징은 일반 사용자들이 능동적으로 정보를 생산해내고 공유하는데 있다. 웹 2.0의 참여형 아키텍쳐를 구성하는 핵심요소로 인식되고 있는 폭소노미(Folksonomy)는 과거 택소노미(Taxonomy)와 같이 전문가에 의하여 구축되는 분류 체계가 아닌 사용자들이 협동적으로 태그(Tag)들을 만들고 관리하는 소셜 태깅(Social Tagging)에 의한 분류 시스템이다. 최근 이러한 폭소노미를 활용하여 이미지를 공유하고 검색하고자 하는 다양한 시도들이 진행되고 있다. 그러나 Flickr와 같은 태그 기반 이미지 공유 시스템에서는 태그의 문법적, 의미적 모호성과 이미지에 대한 태그들의 중요성 또는 상관관계를 고려하지 않아 태그 기반 검색 시 정확성 및 신뢰성을 보장할 수 없다. 이러한 문제를 해결하기 위해 폭소노미에 기반한 이미지 공유 데이터베이스에서 적합한 태그들을 태그 전달(Tag Propagation)하거나 확률 및 출현빈도에 기반하여 태그 랭킹을 수행하기 위한 연구들이 활발히 진행되고 있지만 여전히 만족할만한 성능을 보이지 못하고 있다. 본 논문에서는 이미지 공유 데이터베이스에서 유사한 이미지들로부터 이미지에 보다 적합한 태그들을 부여하기 위해서, WordNet을 활용하여 태그들 간의 의미관계에 기반한 효율적인 태그 랭킹 기법을 제안한다. 또한, 신뢰성 있는 태그 기반 검색을 위하여 제안한 태그 랭킹 기법이 현재 이미지 공유 시스템의 랭킹 결과보다 정확성을 높일 수 있음을 실험 예제를 통하여 확인하였다.

• Journal of KIISE
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• v.42 no.12
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• pp.1623-1628
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• 2015

As the performance of mobile devices has increased, high-end multicore CPUs have become the norm in smartphones. However, such high performance devices are exposed to the problem of battery depletion due to the energy consumption caused by software performance, and despite increases in battery capacity. The required resources are dynamic and varied, and further user interaction is highly random; thus, Linux-based power management such as DVFS is needed to fulfill requirements. In order to reduce power consumption, we propose a method to restrict the CPU frequency of data download while maintaining user reactivity. This can supplement the weakness of existing Linux-based power management techniques like DVFS in relation to webpage loading. Through the implementation of our method at the application level, we confirm that energy consumption from webpage loading is reduced.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.850-857
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• 2013

The objective of this paper is to provide service continuity based on an efficient subchannel allocation in OFDMA systems. The resource management for handover are necessary to maintain the QoS requirements of different multimedia applications because the service continuity may be defected by some delay and information loss. Therefore we propose two subchannel management schemes applied to OFDMA systems. Firstly, a superposition allocation of interference subchannels is achieved by modifying a frequency reuse scheme, using co-subchannel interference principle. Secondly for handover applications, we suggest a novel subchannel reservation scheme to adjust the number of allocated channels, depending on the different characteristics and diverse quality of mobile multimedia applications. Simulation results show that the total throughput for the proposed method is increased up to 20% at average and peak arrivals and the handover failure rate is decreased to about 25%, as compared to the conventional method.

• The KIPS Transactions:PartD
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• v.10D no.2
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• pp.187-194
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• 2003

Main Memory storage system can increase the performance of the system by assigning enough slack time to real-time transactions. Due to its high response time of main memory devices, main memory resident data management systems have been used for location management of personal mobile clients to cope with urgent location related operations. In this paper we have developed a multi-threaded main memory storage system as a core component of real-time retrieval system to handle a huge amount of readers and writers of main memory resident data. The storage system is implemented as an embedded component which is working with the help of a disk resident database system. It uses multi-threaded executions and utilizes latches for its concurrency control rather than complex locking method. It only saves most recent data on main memory and data synchronization is done only when disk resident database asks for update transactions. The system controls the number of read threads and update threads to guarantee the minimum requirements of real-time retrievals.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.241-246
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• 2004

Medical images are being managed more by PACS in general medical institutions. It is important to protect patients from being invaded their privacy related to the images. It is also necessary to confirm the ownership, the right of properity of the medical images and notice whether the data are modified. In this paper, we propose a robust watermarking against RST attacks in medical images on the PACS. The proposed scheme modifies and improves Log-Polar Mapping and Fourier Mellin Transform in order to realize and recover serious image degradation and watermark data loss caused by the conversion between cartesian coordinate and log-polar coordinate. We used the radius and theta Look Up Table to solve the realization of the Fourier Mellin Transform, and inserted a watermark into 2D-DFT magnitudes using Spread Spectrum. Experimental results shows that this method are robust to several attack.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.301-301
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• 2020

물은 보다 나은 삶을 살아가는데 있어 매우 중요한 자원이며, 안전하고 깨끗한 물을 공급받는 것은 국민 생활 영위에 반드시 필요한 부분이다. 국내 주요 수자원은 하천수를 통해 확보하고 있으며, 안전한 수자원 공급을 위해서는 하천관리를 통한 수질오염사고에 대비한 대책 수립이 필요하다. 국내에서는 페놀, 황산 등 독성오염물질 유출로 인한 수질오염사고가 발생한 바 있고, 그 피해액이 수백억에 달한다. 이러한 수질오염사고로 인한 피해액을 감소시키고 안전한 수자원 공급을 유지하기 위해서는 오염물질의 거동을 이해하고 예측하는 것이 매우 중요하다. 국내하천의 경우, 대부분 하폭 대비 수심비가 크기 때문에 오염물질이 2차원 혼합특성을 나타낸다. 따라서 본 연구에서는 하천 내 오염물질의 2차원적 혼합거동을 해석할 수 있는 수치모형을 개발하고자 하며, 현장에 적합한 해석기법을 검토하고 모형 개발 방향을 결정하고자 한다. 본 연구에서는 하천 내 수질오염사고 발생 시 신속하고 정확한 수질 분석 및 예측을 목표로 오염물질 혼합해석에 주로 활용되는 격자기반 모형과 입자추적 기반 모형의 프로토타입을 개발했다. 용존성 오염물질을 대상으로 격자 기반 및 입자 기반 혼합해석 모형을 개발했으며, 오염물질의 주입형태와 하천 내 유속 분포를 가정해 혼합해석을 수행했다. 격자 기반 모형의 경우, 경계조건과 분산계수의 결정이 필요하고 수렴/발산 문제로 인해 모형의 안정적 실행을 위한 조건 수립이 필요하다. 입자 기반 모형의 경우에도 입자 수에 따른 계산시간 개선이 필요하지만, 입력조건 결정이 간편하고 분산계수 입력이 필요 없어 신속한 모의조건 설정이 가능하다. 오염물질 혼합해석 모형 개발을 위한 해석기법 검토 결과, 신속한 수질 분석 및 예측 결과를 제공하기 위해서는 계산시간 개선을 전제로 모의조건 설정이 용이한 입자 기반 모형이 가장 적합한 것으로 판단된다.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.95-102
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• 2007

This paper presents the core technology of Construction Business Process Automation to model and automate construction business processes. Business Process Reengineering (BPR) and Automation (BPA) have been recognized as one of the important aspects in construction business management. However, BPR requires a lot of efforts to identify, document, implement, execute, maintain, and keep track thousands of business processes to deliver a project. Moreover, existing BPA technologies used in existing Enterprise Resource Planning (ERP) systems do not lend themselves to effective scalability for construction business process management. Application of Workflow and Object Technologies would be quite effective in implementing a scalable enterprise application for construction business processes by addressing how: 1) Automated construction management tasks are developed as software components, 2) The process modeling is facilitated by dragging-and dropping task components in a network, 3) Raising business requests and instantiating corresponding process instances are delivered, and 4) Business process instances are executed by using workflow technology based on real-time simulation engine. This paper presents how the construction business process automation is achieved by using equipment reservation and cancellation processes simplified intentionally.

• Korean Journal of Construction Engineering and Management
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• v.20 no.1
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• pp.114-123
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• 2019

Tracking ICT applications on construction business processes is critical to the success of ICT-applied construction projects. Existing IDEF0 is a representative modeling method for visualizing and analyzing business processes. It defines a construction production process into a visual information model, hence, encouraging the project participant to understand the activities, their deliverable, and control flow of the process. However, IDEF0 dose not lend itself to ICT-applied construction processes, because it does not provide a mean to define how, in what order, by which each and every activity that ICT applied implements. This paper presents a new business modeling method that improves the traceability of ICT application (IAMB: ICT Application tracking Model for Business process) for construction management. The IAMB contributes to handle the sophisticated features of construction management processes to which ICT are applied. The method categorizes the process into three types: management, construction, and information exchange. The validity of IAMB was confirmed by analyzing the performance when it is used for tracking each modeling step of lift reservation process which making use of ICT. The test case provides an admissible evidence that the method encourage to define who, what, how, which order, and by which ICT tools the construction process exchanges production information.