• Smart Structures and Systems
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• v.18 no.2
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• pp.317-334
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• 2016

Structural Health Monitoring System (SHMS) works as an efficient platform for monitoring the health status and performance deterioration of engineering structures during long-term service periods. The objective of its installation is to provide reasonable suggestions for structural maintenance and management, and therefore ensure the structural safety based on the information extracted from the real-time measured data. In this paper, the SHMS implemented on a world-famous kilometer-level cable-stayed bridge, named as Sutong Cable-stayed Bridge (SCB), is introduced in detail. The composition and core functions of the SHMS on SCB are elaborately presented. The system consists of four main subsystems including sensory subsystem, data acquisition and transmission subsystem, data management and control subsystem and structural health evaluation subsystem. All of the four parts are decomposed to separately describe their own constitutions and connected to illustrate the systematic functions. Accordingly, the main techniques and strategies adopted in the SHMS establishment are presented and some extension researches based on structural health monitoring are discussed. The introduction of the SHMS on SCB is expected to provide references for the establishment of SHMSs on long-span bridges with similar features as well as the implementation of potential researches based on structural health monitoring.

• Earthquakes and Structures
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• v.13 no.1
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• pp.51-58
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• 2017

Passive dynamic vibration absorbers (DVAs) are often used to suppress the excessive vibration of a large structure due to their simple construction and low maintenance cost compared to other vibration control techniques. A new type of passive DVA consists of two pendulums connected with spring and dashpot element is investigated. This research evaluated the performance of the DVA in reducing the vibration response of a two degree of freedom shear structure. A model for the two DOF vibration system with the absorber is developed. The nominal absorber parameters are calculated using a Genetic Algorithm(GA) procedure. A parametric study is performed to evaluate the effect of each absorber parameter on performance. The simulation results show that the optimum condition for the absorber frequencies and damping ratios is mainly affected by pendulum length, mass, and the damping coefficient of the pendulum's hinge joint. An experimental model validates the theoretical results. The simulation and experimental results show that the proposed technique is able be used as an effective alternative solution for reducing the vibration response of a multi degree of freedom vibration system.

• Journal of the Korean Institute of Gas
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• v.11 no.3
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• pp.56-63
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• 2007

These days, needs and wants of the customers are getting diversified and the market is also changing rapidely. Many organizations are now attempting change and innovation activities to improve products and service quality. This study was performed to apply 6 sigma tools for the efficient repair management of city gas supply equipment. Vital few factors, RISK factors, sigma values, root causes. and solutions were derived by 6 sigma tools. We are performing statistical process control for the new process. Six sigma for city gas supply equipment safety management enabled to improve the business management for efficiency by reducing variation and eliminating cost for quality.

• Journal of Korean Neurosurgical Society
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• v.30 no.sup1
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• pp.159-164
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• 2001

Reduction cranioplasty is one of the treatment modality among many treatment options for macrocephaly with hydrocephalus. The most previous techniques of reduction cranioplasty have some disadvantages such as difficult airway maintenance, pressure sore due to modified prone position, severe venous infarct due to obstruction of venous blood flow and large amount of bleeding from the dissection of superior sagittal sinus to obtain bone fragment needed. A 28-month-old girl had extreme macrocephaly. She couldn't control head rotation and keep sitting position. The operation was performed at supine position with adequate exposure of entire calvarium and the hinge was made in occipital bone fragment that covered posterior part of superior sagittal sinus. Bleeding volume and the other complications were decreased and acceptable reduction was achieved with this method.

• Journal of Korean Society on Water Environment
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• v.39 no.1
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• pp.87-101
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• 2023

The constituents of a watershed control a wide range of ecosystem processes, such as, carbon sequestration, nutrient retention, and biodiversity preservation. Maintenance of a healthy watershed is advantageous to humans in many direct and indirect ways. Dissolved organic matter fluorescence analysis is one of the most commonly utilized parameters for water quality measurement, pollution source tracking, and determination of the ecological state of a watershed. Throughout the recent decades, the advancement in data processing, instrumentation, and methods has resulted in many improvements in the area of watershed study with fluorescence analysis. The current trend of coupling advanced instrumentations and new comparative parameters, such as, microplastics of different types, antibiotics, and specific bacterial contaminants have been reported in watershed studies. However, conventional methodologies for obtaining fluorescence excitation emission matrices and for calculating the fluorescence and spectral indices are preferred to advanced methods, due to their easiness and simple data collection. This review aims to gain a general understanding of the use of dissolved organic matter fluorescence analysis for diagnosis and source identification of watershed pollutions, by focusing on how the studies have utilized fluorescence analysis to improve existing knowledge and techniques in recent years.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.1
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• pp.137-142
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• 2014

Industrial control system (ICS) is a computer based system which are typically used in nation-wide critical infra-structure facilities such as electrical, gas, water, wastewater, oil and transportation. In addition, ICS is essentially used in industrial application domain to effectively monitor and control the remotely scattered systems. The highly developed information technology (IT) and related network techniques are continually adapted into domains of industrial control system. However, industrial control system is confronted significant side-effects, which ICS is exposed to prevalent cyber threats typically found in IT environments. Therefore, cyber security vulnerabilities and possibilities of cyber incidents are dramatically increased in industrial control system. The vulnerabilities that may be found in typical ICS are grouped into Policy and Procedure, Platform, and Network categories to assist in determining optimal mitigation strategies. The order of these vulnerabilities does not necessarily reflect any priority in terms of likelihood of occurrence or severity of impact. Firstly, corporate security policy can reduce vulnerabilities by mandating conduct such as password usage and maintenance or requirements for connecting modems to ICS. Secondly, platfom vulnerabilities can be mitigated through various security controls, such as OS and application patching, physical access control, and security software. Thirdly, network vulnerabilities can be eliminated or mitigated through various security controls, such as defense-in-depth network design, encrypting network communication, restricting network traffic flows, and providing physical access control for network components.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.4 no.1
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• pp.80-89
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• 2001

The objective of this study was to introduce the current status and development strategy for the environmental restoration of stream side in Japan, and to consider the methodology which could be effectively applied to the environmental restoration of stream side in Korea. 1. We should establish a new paradigm of forest conservation and erosion control which can emphasize the restoration of the stream side ecosystem and reduce soil movement in the areas. Also, in the past, the objective of forest conservation and erosion control was to fix soil by constructing permanent structures. The direction of future forest conservation and erosion control needs to be new forest conservation and erosion control technology to prevent large scale soil movement but allow small scale soil movement to conserve sound ecosystem and biotic habitats. 2. In the past, the goal of forest conservation and erosion control planning was to fix the amount of soil movement by constructing permanent facilities. Forest conservation and erosion control planning in the future needs to change the techniques which could prevent soil movement from large scale of soil disasters, but allow soil movement effectively to a small and middle scale's soil movement. Also, it is considered to change erosion control dams from non passing type to passing type. 3. In the point of ecological conservation aspects, we should evaluate the effects of new forest conservation and erosion control methods which are emphasized on the restoration of the stream side ecosystem. Also, forest conservation and erosion control construction projects for restoring stream and river ecosystem should be planned for perfectly restorating their ecosystems by the way of sustainable maintenance and management. 4. The restoration direction of stream and river ecosystems needs to be restoring the diversity of small geographies such as waterway, shoal and puddles rather than flattening stream bed. And the restoration of the stream side ecosystem should provide continuity of the stream side environment which allows desirable biological habitats, and environmentally sound facilities to harmonize with the environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.1
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• pp.1-5
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• 2010

Recently emphasizing the importance of security such as national major institutions' facilities or major industrial facilities for the maintenance of security/crime prevention due to specialization of the Green Information Technology(G-IT) and Green Ubiquitous Technology(G-UT) industry fields, The Security System Building linked high technology within the government-related organization, enterprise and army the military is urgently required. This paper is about the green USN intelligent an unmanned guard MUX system that receive the signals, from alarm device within surveillance area, with various ways of communication techniques and then transmit to local control center and remote control server trough TCP/IP network. This study enables the mutual senergy effect by realizing a total solution of an unmanned guard system and also significantly contributes to the global/domestic market expansion. That can be applied to the crime prevention/security fields in the Green Ubiquitous Environment Implemented Business(survalance-Home, Gu-City, Gu-Health, etc.), and will contribute to expand companies with international competitiveness that can provide the Green Ubiquitous Vision(Gu-Vision).

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.99-99
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• 2011

Fuel cell systems are a completely different form of electricity source that has been used so far and is an aggregation of multiple technologies with multidisciplinary features that can be operated safely only when gas and electrical safety are being considered. Since fuel cells generate through electrochemical reactions there are difficulties in ensuring electricity safety, power quality assessment, effective control and reliability standards for system faults using conventional inspection techniques and even though they are necessary as a primary means for reduction of CO2 owing to the Climate Convention, electrical safety assessment and measures are required for the prevention of faults in residential facilities. Although small-scaled distributed power supplies can be utilized as important means of peak control and energy management measures, research is required for observing the effects on the system and the development of inspection technology to ensure stable operation, and the electrical safety of residential fuel cell systems need to be assessed and the problems derived for establishing electrical safety standards. From the year 2002, Japan has established laws on technical safety standards and development and rules on the product specifications and standards for the industrialization of hydrogen fuel cells. Also, a lot of effort have been made for the commercialization of fuel cells by building one-stop certification services. Internationally, the IEC TC 105 has established international standards based on fuel cells. In order to protect the national interest, the country should be able to respond accordingly meet global standards. In fact, in Korea, to comply with the international trend, Korea Energy Management Corporation is establishing a certified agenda for fuel cells and Korean Agency for Technology and Standards is enacting technical standards for fuel cells. The current terms of fuel cells are that research has been focused more on the quality and performance of manufactured products rather than stable power operation and maintenance over time. In this paper, by considering the household fuel cell as a power device, the safety standards of the fuel cell system for a reliable operation with the existing power system is being proposed.

• Journal of Digital Convergence
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• v.14 no.8
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• pp.305-311
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• 2016

If the automated image calibration system is performed in the position of non-experts, an expert will be required in every case inefficiently. But this requires an expert only when absolutely necessary. As well as the rapid system operation and efficient workforce can be managed. Image correction to perform projector inspection and management skills and to filter SW plug-in correction is that special theater system maintenance is not only managed efficiently, but also combined image analysis techniques can improve the technical perfection. This paper is to minimize the economic loss by developing a 10-bit High-depth and high-resolution $360^{\circ}$ projection image analysis technique and is to development of the special theater calibration system to effectively support quality.