• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.461-461
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• 2011

강수, 수위 및 유량자료 등의 수문자료는 안정된 물 관리 계획, 홍수조절 및 공급계획, 전력공급 등을 위한 댐의 역할을 원활하게 하기위한 운영의사결정을 위한 매우 중요한 기초자료가 된다. 댐 운영을 위한 다양한 기능을 가진 모델을 가지고 있다고 하더라도 매년 변하고 있는 댐 유역의 수문현상에 대한 관측자료를 이용하여 지속적으로 모델을 보정하여 정확성을 확인하고 향상시키는 노력을 기울여야 하므로 수문자료는 댐 운영에 있어서 필수적인 요소일 수밖에 없다. 본 연구에서는 한국수력원자력(주)의 9개 댐 유역에서 기존 활용 가능한 관측소 현황 및 현장조사를 통해 운영상 목적에 맞는 최적의 수위관측망을 설계하여 제시하였다. 설계 방법으로는 댐 유입량 파악과 개략적인 도달시간 파악을 위해 주요 유입지천인 국가하천과 지류 중 지방하천이라도 유역면적이 $150\;km^2$ 이상인 경우에는 유입량 파악을 위한 수위관측소를 두도록 설계하였다. 관측소 밀도는 각 댐 유역의 수문학적 유역 특성인 유역면적, 유입하천의 지형적 특성, 하천크기 등을 고려하여 결정하였다. 설계된 수위관측소들은 현장의 수위관측 및 유량관측에 대한 적정성을 검토하여 댐 저류지 배수영향 등으로 인해 관측이 부적정할 경우 이설을 통해 적정한 위치에서 수문조사가 이루어지도록 제안하였다. 본 연구에서 제안된 한국수력원자력(주) 관할 댐 유역의 수위관측망은 자체 관할 수위관측소 뿐 아니라 자료의 공동 활용이 가능한 국토해양부 등의 관측소까지 포함하고 있다. 따라서 댐 운영 의사결정을 위한 중요한 기초자료로서의 수위 및 유량자료를 경제적이고 효율적으로 제공할 수 있을 것으로 기대된다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.9
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• pp.1257-1263
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• 2018

Secure authentication technology is a fundamental building block for secure services for Internet of Things devices. Particularly, the multiplication operation is a core operation of public key cryptography, such as RSA, ECC, and SIDH. However, modern low-power processor, namely ARM Cortex-M3 processor, is not secure enough for practical usages, since it executes the multiplication operation in variable-time depending on the input length. When the execution is performed in variable-time, the attacker can extract the password from the measured timing. In order to resolve this issue, recent work presented constant-time solution for multiplication operation. However, the implementation still missed various speed-optimization techniques. In this paper, we analyze previous multiplication methods over ARM Cortex-M3 and provide optimized implementations to accelerate the speed-performance further. The proposed method successfully accelerates the execution-time by up-to 25.7% than previous works.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.9
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• pp.1159-1164
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• 2018

Recently, Internet use is increasing in various fields. Especially in the sudden disaster area, the role of Internet of things that can continuously monitor is getting bigger. In this study, the characteristics of the confined space and the environmental hazards are examined, and the Internet of the object which is being commercialized will be reviewed. Accidents in confined spaces are very high compared to other places, and it is very difficult to predict accidents. Recently, various attempts have been made to prevent accidents in confined spaces using the Internet of things. Especially, it detects the various gases that can occur in the closed space using sensors and sends them to the workers in real time, so that the risk can be detected in advance to minimize the risk. In this paper, we propose an effective disaster prevention plan using the Internet of things through the case study of the Internet for the prevention of accidents in a confined space.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.543-547
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• 2006

Recently domestic companies have been needed to securing competitive techniques due to increasing orders of plant industries in the oversea construction market. Although domestic engineering companies have been assessed competitive in the field of detail design, their high value-added basic design have evaluated uncompetitive. To manage efficiently various contents which occurred in works of design steps, the management method must be built. In this study, we have found the contents which required to management through the definition of main works and analysis of characteristics in the step of basic design. Then, we have suggested to Contents Classification System which reflected of work flows and relations among stakeholders. Proposed Contents Classification System will help us when requiring the proper documents, drawings, sheets and other information.

• Korean Journal of Construction Engineering and Management
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• v.17 no.1
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• pp.66-75
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• 2016

As the demands for traditional Korean housing has been increased in recent years, modernized Korean traditional housing (Hanok) was developed as a way of providing Hanok for the public. Modernized Hanok attempts to remedy the shortcomings of the traditional hanok (i.e., high unit cost of building and low energy performance). In the previous researches, standardization and productivity improvement for modernized Hanok dissemination have been intensely developed. Above all, cost estimating for modernized Hanok is also an important factor. In an effort to provide effective system for Hanok construction, this paper developed 'standard cost data' for modernized Hanok. Distinct characteristic of modernized Hanok construction were analyzed first. Then, basic structure was identified, and major items were selected for Hanok standard cost data. However, this set of cost data was developed based on two mock-up Hanok projects actually constructed. Accordingly, this standard cost data will be further updated and modified by continuously accumulating real-world Hanok projects

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.1B
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• pp.7-16
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• 2005

Resource Reservation Protocol(RSVP) can provide Quality-of-Service(QoS) guarantees for real-time services in wired networks. However, RSVP suffers from mobility problem in the mobile Internet. Therefore, to provide seamless QoS services, it is needed that a mobile node makes a reservation everywhere it visits. Recently, many protocols have been proposed to provide QoS guarantees through advance resource reservation. But, these proposals have problems with a waste of bandwidth and the signaling overhead due to advance resource reservation. In this paper, we propose new advance resevation protocol, Proportional Aggregate RSVP(PA-RSVP) to minimize the resource reservation bandwidth and the signaling overhead in the mobile Intemet while providing QoS guarantees. Based on the performance evaluation, we show that the proposed protocol provides an improved performance over existing protocols under various system conditions.

• Journal of KIISE:Software and Applications
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• v.28 no.11
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• pp.864-873
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• 2001

In this paper, a new approach to building a registration authority for issuing PKI-based certificates is presented to make the process of identifying an individual more secure and reliable by utilizing human iris recognition technology. The tasks of the proposed system associated with the manipulation of irises except for the general functions of registration authorities can be categorized into three modules, the acquisition of iris images, the registration of iris information, and the verification of users by means of iris patterns. The information among the three modules is safely exchanged through encryption and decryption with a symmetric cryptographic method. As a feature extraction method for a given iris image, a wavelet transform is applied to represent a feature vector with a small dimension of information obtained by subsampling an image corresponding to lower frequency bands successively without loss of information. Through the experiments on human iris recognition technology we proposed and applied to the registration authority, the potential of biometric technology in various applications is confirmed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4296-4301
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• 2011

Gantry loader which is also called as gantry robot is a kind of cartesian coordinate robot with two or more linear motions. A conventional gantry system has cableveyor for protecting power and signal cables, but the use of cableveyor makes a delay of work due to frequent repairing for its aging. This study reports that a wireless gantry loader is able to be operated without a power line for power transmission or a signal cable for motion control. The wireless gantry loader enables a convenient maintenance and a stable productivity by the reduction of wire broken from fatigue. The developed loader system is controlled by PC-based motion controller and is communicated by wireless LAN devices. The line from a power source to the loader system was substituted by attaching trolley bar on the traveling beam. The loader system was designed to be moved with high speed and high repeatability, and the motion was observed continuously by monitoring system in the PC-based controller. The maximum speed and the repeatability for the transferring and loading axes are 200 m/min, 60 mm and 100 m/min, 40 mm respectively.

• Journal of KIISE:Databases
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• v.30 no.2
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• pp.176-183
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• 2003

Various techniques including histograms, sampling and parametric techniques have been proposed to estimate query result sizes for the query optimization. Histogram-based techniques are the most widely used form for the selectivity estimation in relational database systems. However, in the spatio-temporal databases for the moving objects, the continual changes of the data distribution suffer the direct utilization of the state of the art histogram techniques. Specifically for the future queries, we need another methodology that considers the updated information and keeps the accuracy of the result. In this paper we propose a novel approach based upon the duality and the marginal distribution to construct a histogram with very little time since the spatio-temporal histogram requires the data distribution defined by query predicates. We use data synopsis method in the dual space to construct spatio-temporal histograms. Our method is robust to changing data distributions during a certain period of time while the objects keep the linear movements. An additional feature of our approach supports the dynamic update incrementally and maintains the accuracy of the estimated result.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.1-7
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• 2012

It is necessary to construct the process automation system to improve the design efficiency and procure the higher design quality on the field of ship building. To construct this system, the shipbuilding companies should improve the 3D CAD/CAM system customized to the ship design and the software about design information management which could solve the conflict problem between the several related design division at the same time. The typical example is the Hole-plan process in the ship-building design. For the request of additional holes from outfitting division, the hull design division checks the compatibility conditions and reflects these holes to the hull panels if acceptable. if not, the requests are rejected and sent back to the outfitting division. These serial processes are not simple and require the tedious communication, discussion, and the complicated drawings. This article gives a basic introduction to the process of hole-plan system and proposes a strategy to automate its process.