• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.10a
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• pp.105-114
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• 2006

Together with the trend of enhancement in domestic industrial development and economic progress due to import and export, the demand for construction of the roads, bridges, especially port facilities, and several coastal protection and ocean structures is increasing rapidly. MOMAF of Korean Government is driving construction of 9 new ports and renovation of the existing fishery ports. Among these structures most of bridge base, wharves, dolphins, quays, and jetties are being newly built of steel or concrete pile. As the base, supporting bulkheads, and piles are underwater after construction, it is difficult to figure out the status of structures and not enough to get maintenance and strengthen the structures. Every year, moreover, these works suck the government budget due to higher incomplete maintenance expense for protection from corrosions of structures and increased underwater construction period. for the purpose of cutting down the government budget, it is necessary to extend the life cycle of the existing structures. We developed a new method for maintenance of submerged structures near the waterline by allowing dry work environment with the floating caisson. The method shows easy to move around the working area and handle. It also showed not only a significant reduction of maintenance expenses and time for anti-corrosion work but also better protection. This will be a milestone to reduce the maintenance and construction expenses for the shore and water structures.

• The KIPS Transactions:PartD
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• v.14D no.7
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• pp.763-772
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• 2007

Due to increased software development cost, interest about the method and automated tool for reusing legacy system have been running high. Therefore, In this study, it proves the definition, concept and also background of legacy system by showing real market and technology trend. Automation tool is designed and developed to handle the concrete development methodology, procedure and reference. Also, we implemented the process that analyze the legacy system and extract, refine, store and reuse the candidate components by using LM(Legacy to Modern System) supporting tool presented in this paper. If LM supporting tool is applied to legacy system migration, we can expect cutting costs, shortening the developing period and succeeding the intellectual property by software re-engineering.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.2
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• pp.139-165
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• 2019

The current status and prospect of decommissioning technology development at KAERI are reviewed here. Specifically, this review focuses on four key technologies: decontamination, remote dismantling, decommissioning waste treatments, and site remediation. The decontamination technologies described are component decontamination and system decontamination. A cutting method and a remote handling method together with a decommissioning simulation are described as remote dismantling technologies. Although there are various types of radioactive waste generated by decommissioning activities, this review focuses on the major types of waste, such as metal waste, concrete waste, and soil waste together with certain special types, such as high-level and high-salt liquid waste, organic mixed waste, and uranium complex waste, which are known to be difficult to treat. Finally, in a site remediation technology review, a measurement and safety evaluation related to site reuse and a site remediation technique are described.

• Advances in concrete construction
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• v.13 no.5
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• pp.385-394
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• 2022

Recently, an increasing number of cutting-edged studies have shown that designing a smart active control for real-time implementation requires piles of hard-work criteria in the design process, including performance controllers to reduce the tracking errors and tolerance to external interference and measure system disturbed perturbations. This article proposes an effective artificial-intelligence method using these rigorous criteria, which can be translated into general control plants for the management of civil engineering installations. To facilitate the calculation, an efficient solution process based on linear matrix (LMI) inequality has been introduced to verify the relevance of the proposed method, and extensive simulators have been carried out for the numerical constructive model in the seismic stimulation of the active rigidity. Additionally, a fuzzy model of the neural network based system (NN) is developed using an interconnected method for LDI (linear differential) representation determined for arbitrary dynamics. This expression is constructed with a nonlinear sector which converts the nonlinear model into a multiple linear deformation of the linear model and a new state sufficient to guarantee the asymptomatic stability of the Lyapunov function of the linear matrix inequality. In the control design, we incorporated H Infinity optimized development algorithm and performance analysis stability. Finally, there is a numerical practical example with simulations to show the results. The implication results in the RMS response with as well as without tuned mass damper (TMD) of the benchmark building under the external excitation, the El-Centro Earthquake, in which it also showed the simulation using evolved bat algorithmic LMI fuzzy controllers in term of RMS in acceleration and displacement of the building.

• Convergence Security Journal
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• v.23 no.3
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• pp.65-71
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• 2023

The importance of combat drones has been highlighted through the recent outbreak of the Russia-Ukraine war. The combat drones play a significant role as a a game changer that alters the conventional wisdom of traditional warfare. Many pundits expect the role of combat swarm drones would be more crucial in the future warfare. In this regard, this paper aims to analyze the development of artificial intelligence-enabled combat swarm drones. To transform the human-operated swarm drones into fully autonomous weaponry system our suggestions are as follows. Developments of (1) AI algorithms for optimized swarm drone operations, (2) decentralized command and control system, (3) inter-drones' mission analysis and allocation technology, (4) enhanced drone communication security and (5) set up of ethical guideline for the autonomous system. Specifically, we suggest the development of AI algorithms for drone collision avoidance and moving target attacks. Also, in order to adjust rapidly changing military environment, decentralized command and control system and mission analysis allocation technology are necessary. Lastly, cutting-edging secure communication technology and concrete ethical guidelines are essential for future AI-enabled combat swarm drones.

• Steel and Composite Structures
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• v.50 no.3
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• pp.347-362
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• 2024

Controlling vibrations and noise in steel box girders is important for reducing noise pollution and avoiding discomfort to residents of dwellings along bridges. The fundamental approach to solving this problem involves first identifying the main path of transmission of the vibration energy and then cutting it off by using targeted measures. However, this requires an investigation of the characteristics of flow of vibration energy in the steel box girder, whereas most studies in the area have focused on analyzing its single-point frequency response and overall vibrations. To solve this problem, this study examines the transmission of vibrations through the segments of a steel box girder when it is subjected to harmonic loads through structural intensity analysis based on standard finite element software and a post-processing code created by the authors. We identified several frequencies that dominated the vibrations of the steel box girder as well as the factors that influenced their emergence. We also assessed the contributions of a variety of vibrational waves to power flow, and the results showed that bending waves were dominant in the top plate and in-plane waves in the vertical plate of the girder. Finally, we analyzed the effects of commonly used stiffened structures and steel-concrete composite structures on the flow of vibration energy in the girder, and verified their positive impacts on energy regionalization. In addition to providing an efficient tool for the relevant analyses, the work here informs research on optimizing steel box girders to reduce vibrations and noise in them.

• Journal of Korean Society of Forest Science
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• v.4 no.1
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• pp.1-8
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• 1965

In this study, the present institution of reserved forests in Korea has been criticized through the analysis of the present situation of reserved forests in Korea, and mainly, on designation and cancellation of them because of this important institution thought as restriction of forest ownership. Reserved forest land in Korea as of the end of 1962 is 996,915 chungbo in area, or about 14.8% of the total forest land area, 6,750,324 chungbo in Korea, and we can find that the area of reserved forest land has increased remarkably since the Liberation in 1945, in comparison with about 180,000 chungbo-a little over 1% of the total forest land area, 16,000,000 chungbo, through Southern and Northern Korea till the Liberation in 1945. This fact clearly proves that Korean forests are extremely devastated since the Liberation in 1945, and in Korea we can find that reserved forest policy is very important in forest policy, consequently, reserved forest institution must be dealt with care. Moreover, the area of reserved forest land, 996,915 chungbo, which is divided into 43,820 chungbo of national forest land, 59,302 chungbo of public forest land, 893,793 chungbo of private forest land, and private forest land is excellently large, or about 89.7% of the total area of reserved forest land. In this number, we may understand the fact that reserved forests have the most influences on private forests, therefore, we may recognize that it is necessary for reserved forest constitution which is infringement of private right to be carried out carefully. From the first beginning, the institution of reserved forests is serious restriction to the forest ownership. Consequently, when the area of reserved forest land grows, it interferes seriously with the free forest management and the desire for forest own ership is decreased, at the same time, forest enterprise results in obstruction. Especially, Korean forests are destroyed extremely at present, so, intensification of reserved forest institution is unavoidable for completion of the national aim which forests have, but the author thinks that reserved forest institution must be as avoidable as possible, and we have to obtain good results by supervision of forest management which is regulated in the Forest Law. Consequently, designation of reserved forests must be minimized, and although forests were already designated as reserved forests they must be cancellated as fast as fast as possible and put them free in the owner's hands when they are in cancellation conditions. According to the provision of Article 18 of the Forest Law concrete cases designated as a reserved forest are enumerated for the purpose of maintaining the forest ownership and avoiding to give the forest authorities a free hand in order to protect forest owners from one-sided damage. Therefore, the forest authorities must not abuse the institution of reserved forests, and it is not good tendency to give only the authorities a free hand in eesignation and cancellation of reserved forests, and especially, when the forest owners object to that, establishing some legal organization like the reserved forest council in each province in order to hear about impartial opinions, and it is more suitable than administrative disposal by the same organization. The compensation of damages for reserved forests by the provision of Article 25 of the Forest Law is a different problem by forest policy, but the results of compensation of damages regulated in the Forest Law are wholly lacking up to now, the author thinks that this is caused to poor forest cover, the forest owner's unconcern and insincerity of administrative authorities. Therefore, the government must enlarge the range of compensation and minimize the forest owner's economic sacrifice, also, the government must mollify the conditions of the legal restrictions to reserved forests, and harmonize with functions of national conservation and economy. This means that it is necessary to modify the restrictive conditions for the effective utilization of forest resources within the range in which can be attained the purpose of designation, from permanent prohibition of cutting. Except the reserved forests of fish habitat, public sanitation, maintaining scenery and navigational mark ect., most of reserved forests are prohibited from cutting, and the present situation of forests in Korea are extremely devastated and those forests are not so expected in cancellation possibility in near future. Therefore, when the forest owners apply for national purchase of those reserved forests, the government had better nationalize them, protect and manage to reduce the forest owner's economic sacrifice.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.9 no.2
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• pp.59-71
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• 2006

Due to the rapid process of industrialization the cities of Korea confront changes of climate, destructions of the habitate and decrease of the green. Recently Seoul and other local governments have implemented policies and projects to improve the environmental surroundings. In reality, however, those policies and projects face difficulties in the course of implementation. The fact that there are no concrete regulations and specific legal procedures turns out to be one of the main difficulties. The aim of this study is to present specific plans and methods of wall-planting and to provide basic guidelines for the future direction of wall-planting and offer ideas of facilitating wall-planting. This study is based on questionnaires from specialists of landscape architecture through individual interviews and/or e-mails. The questionnaire is consisted of following 4 sections. 1. Show the experts current regulations and/or legal procedures and ask them improvements and suggestions. 2. Ask them choose matters of the highest priority by using Ricardo's diagram method. 3. Ask them to make a graded list in terms of the location and method of wall-planting. 4. Study the maketability of the wall-planting products currently in circulation. The city of Seoul and the Ministry of Environment recommend that trellis and/or planting inducement structures be installed on the building wall by regulation. The specialists responded to the questionnaire advocate that green wall without trellis should be allowed as green zone. Therefore regulations concerning the wall-planting should be determined specifically according to the characteristics of individual plants and walls. It has been urged that legal aid and social support must be reinforced to establish rules dealing with wall-planting. The respondents also point out that significant cutting down of the tax is far more effective in accelerating the wall-green instead of administrative support. The highest priority in terms of planting has been given to sound-proof wall, retaining wall and building wall. Concerning the maketability of the wall-planting products, panel products are recommended for early-planting and building planting. It has been suggested that the research and study of new materials and species be done in advance.

• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.447-455
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• 2006

Together with the trend of enhancement in domestic industrial development and economic progress due to import and export, the demand for construction of the roads, bridges, especially port facilities, and several coastal protection and ocean structures is increasing rapidly. MOMAF of Korean Government is driving construction cf 9 new ports and renovation cf the existing fishery ports. Among these structures most of bridge base, wharves, dolphins, quays, and jetties are being newly built cf steel or concrete pile. As the base, supporting bulkheads, and piles are underwater after construction, it is difficult to figure out the status of structures and not enough to get maintenance and strengthen the structures. Every year, moreover, these works suck the government budget due to higher incomplete maintenance expense for protection from corrosions cf structures and increased underwater construction period. For the purpose cf cutting down the expense cf government budget, it is necessary to extend the life cycle of the existing structures. Therefore, we developed a new method for maintenance of submerged structures near the waterline by allowing dry work environment with the floating caisson. The method shows easy to move around the working area and handle. It also showed not only a significant reduction of maintenance expenses and time for anti-corrosion work but also better protection This will be a milestone to reduce the maintenance and construction expenses for the shore and water structures.

• Korean Journal of Plant Resources
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• v.16 no.2
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• pp.99-108
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• 2003

This study was carried out to make a standard criteria for protection and maintenance of the big and old trees in Ansung city, Kyonggi Prvince. There have been found 6 vegetative species cultivated in this area, which are Zelkova serrata, Gingko biloba, Kalopanax pictus, Pyrus ussuriensis var. macrostipes, Pyrus ussuriensis var. acidula, Pinus densiflora, etc. The Zelkova serrata tree is the major species among them and about 73.5％ in the population of the big and old trees in this area. The DBH (diameter at brest height) of them is 1.5-1.9m in 29.4% of whole population and the tree height is 10-l4m in 47.1%. The estimate age of 7 trees is more than 500 years old and they were 20.6％ of the whole population. Interesting point is that about 64.7％ of these trees in this area have own succeed story in terms of folk religion, object of worship, taboo, legend or secret. This study has also revealed that many fowls, small animals and epiphyte inhabited with the big and old trees have been found. However, 97.1％ of them are in danger from the plant disease and noxious insects or cutting damage of branches, but no management has been taken. More over, 85.3％ of the whole investigated big and old trees have been in the poor condition for percolation or aeration because the area around them has been payed with asphalt or concrete.