• International Journal of Ocean System Engineering
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• v.2 no.2
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• pp.71-81
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• 2012

Several methods have been proposed to control the sedimentation process. These include catchment management, flushing, sluicing, density current venting, and dredging. Flushing is used to erode previously deposited sediments. In pressurized flushing, the sediment in the vicinity of the outlet openings is scoured and a funnel shaped crater is created. In this study, the effect of localized vibrations in the sediment layers on the dimensions of the flushing cone was investigated experimentally. For this purpose, experiments were carried out with two bottom outlet diameters, five discharge releases for each desired water depth, and one water depth above the center of the bottom outlets. The results indicate that the volume and dimensions of the flushing cone are strongly affected by localized vibrations.

• Tunnel and Underground Space
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• v.19 no.2
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• pp.77-85
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• 2009

Flexible and lined segment air-tight tunnelling technology for Compressed Air Energy Storage-Gas Turbine(CAES-G/T) power generation was introduced. The distinguished characteristics of the air-tight tunnel system can be summarized by two facts. One is that the high inner pressure due to compressed air is sustained by surrounding rock mass with allowing sufficient displacement of lining segment. The other is that the air-tightness of storage tunnel was enhanced by adopting a specially designed rubber sheet. The flexible lined air-tight underground tunnel can be constructed at a comparatively shallow depth and near urban area so that the locally distributed CAES-G/T power generation can be accomplished. In addition, this air-tight tunnelling technology can be applied to a variety of energy underground storage tunnels such as Compressed Natural Gas(CNG), Liquifed Petroleum Gas(LPG), DeMethyl Ether(DME) etc.

• Journal of the Korean Institute of Gas
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• v.21 no.3
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• pp.39-45
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• 2017

The LNG storage tank as core facility of LNG industry is mainly composed of the inner tank of nikel 9% steel and the outer tank of prestressed concrete. To respond proactively increased risk of structure performance deterioration due to fatigue of the inner tank and durability reduction of the outer tank, life evaluation program for LNG storage tank is needed. In this study, life evaluation program for LNG storage tank was developed to assess fatigue of the inner tank and durability(carbonation and chloride attack) of the outer tank. By defining the main three scenarios in the inner tank, the fatigue life analysis is conducted from structural analysis and Miner's damage rule. Carbonation progress of the outer tank is predicted according to thickness of cover concrete by using carbon dioxide contents and data of penetration depth. To consider a variety of input conditions and a reliability in results of chloride attack, the evaluation of choride attack for the outer tank is constructed through Life-365 program of open source.

• Journal of Navigation and Port Research
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• v.43 no.2
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• pp.79-85
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• 2019

Climate change is a very vital issue that can be no longer avoided. Korea has been a top-level country Iin dealing with carbon dioxide emissions since 1960. Many studies have been conducted to suppress or eliminate carbon dioxide emissions, which account for a large portion of greenhouse gases. Carbon Capture and Storage (CCS), the most practical method of them, plays a significant role. However, these methods have the disadvantage of the limits of geographical distribution and high possibility of re-emission into the atmosphere. Recently, ocean storage has been studied using Accelerated Weathering of Limestone (AWL), a technique for storing carbon dioxide in the ocean as an alternative to CCS, an underground storage. AWL is a method of converting carbon dioxide into concentrated water in the form of bicarbonate ion and discharging it to the ocean to dilute and store it. It does not cause re-emission to the atmosphere, and the discharged concentrated water increases the alkalinity of the ocean to prevent marine acidification. The objective of this study was to understand the behavior of DIC (Dissolved Inorganic Carbon) including carbon dioxide during the ocean discharge of bicarbonate ion concentrated water in AWL method. This study area was set near Ulleung-do where sufficient water depth and operational efficiency were secured. CORMIX model was used to calculate the material diffusion by submerged discharge using ship.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.157-166
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• 2021

With the rising of the middle-class in China, the garage reserve has become an important element considered by the high-end community in improving user's experience. Taking Oak Bay, China as an example, this study aims to present a new system of storage service that can help companies achieve sustainable development of storage services. In order to achieve this goal, a customized service process is made by investigating user's need with sample visits and in-depth interviews, and finding user's key points with journey maps. The final analysis shows that this storage service system helps to expand the space and improve user's satisfaction. Therefore, this paper provides theoretical support and practical basis of garage services for other construction companies, and greatly improves the service system of community.

• Journal of Electrical Engineering and Technology
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• v.1 no.3
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• pp.396-405
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• 2006

The visual analysis of buried channel (Be) devices such as buried channel MOSFETs and CCDs (Charge Coupled Devices) is investigated to give better understanding and insight for their electrical behaviours using a 3-dimensional (3-D) numerical simulation. This paper clearly demonstrates the capability of the numerical simulation of 'EVEREST' for characterising the analysis of a depletion mode MOSFET and BC CCD, which is a simulation software package of the semiconductor device. The inverse threshold and punch-through voltages obtained from the simulations showed an excellent agreement with those from the measurement involving errors of within approximately 1.8% and 6%, respectively, leading to the channel implanted doping profile of only approximately $4{\sim}5%$ error. For simulation of a buried channel CCD an advanced adaptive discretising technique was used to provide more accurate analysis for the potential barrier height between two channels and depletion depth of a deep depletion CCD, thereby reducing the CPU running time and computer storage requirements. The simulated result for the depletion depth also showed good agreement with the measurement. Thus, the results obtained from this simulation can be employed as the input data of a circuit simulator.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.375-378
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• 2005

The multi-view video is a collection of multiple videos capturing the same scene at different viewpoints. The multi-view video can be used in various applications, including free viewpoint TV and three-dimensional TV. Since the data size of the multi-view video linearly increases as the number of cameras, it is necessary to compress multi-view video data for efficient storage and transmission. The multi-view video can be coded using the concept of the layered depth image (LDI). In this paper, we describe a procedure to generate LDI from the natural multi-view video and present a method to encode multi-view video using the concept of LDI.

• Journal of architectural history
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• v.18 no.6
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• pp.47-64
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• 2009

This research was to analyze the inland signal-fire which is the main facility of military protective duty for safety of land in chosun dynasty. The results of this research were described separately as follows. 1. Five types of site plan of signal-fire were observed, which is circle, oval, rectangular, indeterminate form. The majorities were oval type. 2. Plan configuration of brazier which is separated with circle, rectangular type roughly was constructed with circle type generally. The height of brazier was about 3~4.5m. The diameter of brazier was 1.5~2.5m. Building base that protect ground moisture and infilteration of rainfall was found in 5 inland singal-fire, the height of it was about 0.3m~2.5m. 3. The heigh to protective wall remained until present was about 1m, the depth was about average 1.2m. 4. Entrance was mainly stairs or open type and average width was 1.0~1.2m. However the depth was almost observed as 1m, originally, it was estimated it has more depth. 5. The storage of inland signal-fire has rectangular dimension, several types of $1.8{\times}1.2m{\sim}5.7{\times}4.4m$, square(間) of $1{\times}1{\sim}2{\times}1$. The building material was stone and located below or near the brazier.

• Nuclear Engineering and Technology
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• v.52 no.8
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• pp.1669-1676
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• 2020

The IAEA held the IAEA Robotics Challenge 2017 (IRC2017) to protect workers during inspections of spent nuclear fuel and to improve work efficiency and accuracy rates. To this end, we developed an unmanned surface vehicle (USV) system called the spent fuel check vehicle (SCV). The SCV extracts and tracks the target through image processing, and it is necessary to find suitable parameters for the SNF storage environment in advance. This preliminary work takes time. It is also difficult to prepare the environment in which the work will proceed. In addition, if the preliminary work does not proceed as planned, the system will not move at the proper speed and will become unstable, with yawing and overshoot. To solve this problem, we developed a controller with a camera that can extract the depth at which the target is stored and allow distance-adaptive control. This controller is able to attenuate system instability factors such as yawing and overshoot better than existing controllers by continuously changing system operation parameters according to the depth. In addition, the time required for preliminary work during inspections can be shortened.

• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.1025-1042
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• 2002

The goal of this study is to generate a structured document which improves the performance of an information retrieval system by using thesaurus, information on relations between words (terms), and to study on the technique for searching this structured document. In order to accomplish this goal, we propose a DODI (Depth -Oriented Decomposition Index) technique for the structured document and an algorithm to search for related information efficient]y through this index technique that uses a thesaurus. We establish a storage system by which the structured document generated by this index technique is saved in a database through OpenXML and XML documents are generated through ForXML methods.