• Journal of Digital Convergence
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• v.17 no.10
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• pp.223-232
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• 2019

With the development of the information communication industry, the size of the communication device has been reduced to a system that generates a large amount of heat. Therefore, since the amount of heat generated by the wireless equipment is large in the wireless base station, the energy consumption is continuously consumed and the failure of the wireless base station may occur. Therefore, in this study, The study was analyzed. As a research method, we performed base station with a lot of calorific value and electric charge. We selected 25 base stations and obtained data for two weeks. To ensure reliability, the room temperature was kept constant at $27^{\circ}C$, and the control system was installed and equiped for two weeks to obtain the date analysis. In order to calculate the test results in the study method, the instrument was used with a computer, a digital thermometer, and dust measurement. For the date analysis, we conducted a research study on 25 wireless basestations before and after the installation of Control Sysetm.

• Architectural research
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• v.25 no.4
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• pp.61-72
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• 2023

The main factors that made Seoul's rapid population accommodation and urbanization possible in the mid-to-late 20th century were the ex-pansion of urban infrastructure, completion of the transportation system, and housing supply. The development of transportation and resi-dential development occurred simultaneously, and in particular, apartment complexes, a representative residential area in Seoul, were most influenced by Perry's neighborhood unit theory. The purpose of this study is to analyze the process of the physical environment of apartment complexes in the metropolitan area in response to development of transportation in the mid-to-late 20th century. The analysis sites are Jamsil Apartment Complex(1974), Dunchon Apartment Complex(1979), Mok-dong New Town(1983), Sanggye New Town(1985), Bundang New-town(1990) and Ilsan Newtown(1990), which were planned at the turning point of development of transportation and actively reflect the neigh-borhood unit theory. The analysis was conducted in three stages. Analyzing the status of transportation when the plan was established, deriv-ing the planning elements, and classifying the planning elements into walking, bus, car, and subway which is the representative transportation. The conclusions from the analysis are as follows. Firstly, completing the legal system and expanding the related infrastructure are essential. Secondly, in contrast to the increase in traffic volume, the pedestrian environment has been continuously improved. Thirdly, despite the emergence of new mode of transportation, there was a tendency to activate the linkage between transportation.

• Journal of Soil and Groundwater Environment
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• v.28 no.5
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• pp.1-11
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• 2023

The phenomenon of sediment resuspension in rivers and lakes causes contaminants (heavy metals and nutrients) accumulated in the sediment to leach into the overlying water. As a result, it can lead to changes in toxic effects and eutrophication in the aquatic ecosystem. In this regard, it is important to quantitatively determine the amount of contaminants leached during sediment resuspension. In this study, methods for assessing the amount of released contaminants and the types of contaminants potentially released due to sediment resuspension were studied and summarized. Methods for assessing leaching can be divided into three groups based on the principle of causing resuspension: (i) the oscillating grid chamber method, (ii) the mechanical stirrer method, and (iii) the shaker method. It was confirmed that the types of contaminants that can potentially be released include heavy metals bound to sulfides, as well as exchangeable and labile forms of heavy metals and nutrients. To effectively manage stable aquatic ecosystems in the future, a simplified leaching test method is needed to assess in advance the risks (i.e., changes in toxic effects and eutrophication) that sediment resuspension may pose to aquatic ecosystems.

• Journal of the Korea Institute of Building Construction
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• v.23 no.5
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• pp.571-581
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• 2023

The contemporary domestic construction landscape has witnessed a contraction, primarily attributed to the operational challenges faced by construction entities and a downtrend in the initiation of new projects. In light of this, domestic construction enterprises are ardently seeking avenues to economize whilst simultaneously amplifying the quality across diverse construction genres. Value engineering (VE), heralded for its prowess in not only cost mitigation but also in accelerating project timelines and bolstering construction quality, has been extensively adopted in refining finishing tasks. However, its application to framework enhancements remains conspicuously limited. Particularly in factory edification, framing emerges as a pivotal process exerting significant influence over the entire construction continuum. Thus, it becomes imperative to integrate VE techniques at the inception phase of framing. This would facilitate a meticulous examination of design schematics and on-site conditions, paving the way for alternative strategies that condense construction durations, economize on costs, and augment work efficiency, all the while upholding paramount standards of quality and safety. Such a venture stands to be foundational in expediting construction timelines, fostering economic efficiency, and buttressing construction safety protocols.

• Earthquakes and Structures
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• v.26 no.1
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• pp.49-58
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• 2024

The purpose of this study was to develop a system capable of restoring the seismic performance of a precast concrete (PC) connection damaged by an earthquake. The developed PC connection consists of a top-and-seat angle, post-tensioning (PT) tendons, and U-shaped steel. The PC beam can be replaced by cutting the PT tendons in the event of damage. In addition, the seismic performance of the developed PC beam-column connection was evaluated experimentally. A PC beam-column connection specimen was fabricated, and a quasistatic cyclic loading test was conducted to a maximum drift ratio of 2.3%. Subsequently, the PC beam was replaced by a new PC beam, and the repaired PC connection was loaded to a maximum drift ratio of 5.1%. The structural performance of the repaired PC connection was then compared with that of the original PC connection. The difference in the load at the drift ratio of 2.3% between the original and the repaired PC specimens was only 0.2%. The residual drift ratio in the repaired PC specimen did not exceed 1.0% at the 2.0 % drift ratio cycles, which satisfies the life safety performance level specified in ACI 374.2R-13. When the developed PC connection system is used, structural performance can be restored by rapidly replacing the damaged elements.

• Journal of Korea Water Resources Association
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• v.55 no.6
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• pp.471-480
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• 2022

In this study, a integrated platform applied with various analysis and evaluation models and data collection modules was developed for urban river management. Modules applied to the integrated platform are data collection and provision module, flood analysis module, river evaluation module, and levee breach simulation module, which were selected and applied for efficient urban river management. The integrated platform collects data for application to analysis and evaluation modules from various institutions. The collected data is refined through pre-processing and stored. The stored data is used as input data for each module and is also provided as an Open API through the platform. The flood analysis module is provided to analyze and prepare for floods occurring in cities and rivers. The river evaluation module is used for river planning and management by evaluating rivers in various ways. Finally, the levee breach simulation module can be used to establish countermeasures by deriving a possible damage area due to levee breach through analysis of a virtual breach situation.

• The Journal of Korean Institute of Next Generation Computing
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• v.13 no.2
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• pp.35-48
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• 2017

There are many and various devices like sensors, displays, smart phone, etc. in smart environment. And contents can be provided by using these devices. Vast amounts of contents are provided to users, but in most environments, there are no regard for user or some simple elements like location and time are regarded. So there's a limit to provide meaningful contents to users. In this paper, I suggest the contents recommendation system that can recommend contents to users by reasoning context of users, devices and contents. The contents recommendation system suggested in this paper recommend the contents by calculating the user preferences using the situation reasoned with the contextual data acquired from various devices and the user profile received from the user directly. To organize this process, the method on how to model ontology with domain knowledge and how to design and develop the contents recommendation system are discussed in this paper. And an application of the contents recommendation system in Centum City, Busan is introduced. Then, the evaluation methods how the contents recommendation system is evaluated are explained. The evaluation result shows that the mean absolute error is 0.8730, which shows the excellent performance of the proposed contents recommendation system.

• Korean Journal of Hazardous Materials
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• v.2 no.1
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• pp.12-17
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• 2014

With a rapid growth of domestic industry in korea, now about 25,000 kinds of chemicals are being distributed, and it has been known that just about 15% of them has toxic substances. Recently, South Koreans have an anxiety about the stability and accidents of chemicals because chemical accidents like Gumi hydrofluoric acid accident have occurred. The U.S. has adopted the systems like EPCRA (Emergency Planning and Community Right-to-Know Act), TRI (Toxic Release Inventory) and TSCA (Toxic Substances Control Act), and is also managing the hazardous chemicals by providing the information about them to its people and site workers. Japan's Ministry of Health, Labor and Welfare also has adopted J-CHECK system and is implementing it to let Japanese people know the information of safety of chemicals about REACH. However, the Korean government has a difficult situation to mediate the different idea with the Korean industry to make lower statute of Pre-legislation registration & evaluation of chemicals that will be implemented and Chemical Material Control Association that is being implemented. Especially city and country areas located in the industrial areas need political improvement focusing on vulnerable area through the check about current situation of hazardous chemicals of jurisdiction and management method, but the information about the management situation of small scale work places is insufficient. Therefore this study set up the urgent management area in Ansan Smart Hub through NFPA code according to the types of accident and dander characteristics of each chemical being used in the companies that have less than 50 workers and deal with chemicals located in Ansan Smart Hub in Gyeonggi-do.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.51-60
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• 2021

Modern society is becoming more informed and intelligent with the development of digital technology, in which humans, objects, and networks relate with each other. In accordance with the changing times, a garden system has emerged that makes it easy to supply the ideal temperature, humidity, sunlight, and moisture conditions to grow plants. Therefore, this study attempted to grasp the concept, perception, and trends of smart gardens, a recent concept. To achieve the purpose of this study, previous studies and text mining were used, and the results are as follows. First, the core characteristics of smart gardens are new gardens in which IoT technology and gardening techniques are fused in indoor and outdoor spaces due to technological developments and changes in people's lifestyles. As technology advances and the importance of the environment increases, smart gardens are becoming a reality due to the need for living spaces where humans and nature can co-exist. With the advent of smart gardens, it will be possible to contribute to gardens' vitalization to deal with changes in garden-related industries and people's lifestyles. Second, in current research related to smart gardens and users' experiences, the technical aspects of smart gardens are the most interesting. People value smart garden functions and technical aspects that enable a safe, comfortable, and convenient life, and subjective uses are emerging depending on individual tastes and the comfort with digital devices. Third, looking at the usage behavior of smart gardens, they are mainly used in indoor spaces, with edible plants are being grown. Due to the growing importance of the environment and concerns about climate change and a possible food crisis, the tendency is to prefer the cultivation of plants related to food, but the expansion of garden functions can satisfying users' needs with various technologies that allow for the growing of flowers. In addition, as users feel the shapes of smart gardens are new and sophisticated, it can be seen that design is an essential factor that helps to satisfy users. Currently, smart gardens are developing in terms of technology. However, the main components of the smart garden are the combination of humans, nature, and technology rather than focusing on growing plants conveniently by simply connecting potted plants and smart devices. It strengthens connectivity with various city services and smart homes. Smart gardens interact with the landscape of the architect's ideas rather than reproducing nature through science and technology. Therefore, it is necessary to have a design that considers the functions of the garden and the needs of users. In addition, by providing citizens indoor and urban parks and public facilities, it is possible to share the functions of communication and gardening among generations targeting those who do not enjoy 'smart' services due to age and bridge the digital device and information gap. Smart gardens have potential as a new landscaping space.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.601-613
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• 2018

This study aims to find out the types of convergence types between devices/technology and artifact in smart city space. The main contents of the research are in-depth analysis on the convergence change of ET, IT, and ET+IT in a smart city. First, the devices/technology and artifacts through 31 cases study are found out below. There are 92 artifacts and 134 devices/technologies (ET:83, IT:51). Second, the convergence change between devices/technology and artifacts is evolved by 7 types. Type 1, the Evolutionary ET type of ET-centric, is Period 1 (Separation fusion between ET and IT), Period 2 (ET-centric fusion), and Period 3 (Growth IT and ET+IT fusion of ET-centric). Type 2, the Advanced ET type of ET+IT-centric, is Period 1 (ET+IT fusion), Period 2 (Advanced ET of ET+IT-centric), and Period 3 (Hyper-advanced ET of ET+IT-centric). Type 3, the All-in-One type of ET+IT, is Period 1 (Separation fusion between ET and IT), Period 2 (Mixed fusion between ET and IT), and Period 3 (All-in-One fusion of ET and IT). Type 4, the Advanced type of IT-centric, is Period 1 (Development of IT-centric), Period 2 (Advanced IT-centric), and Period 3 (Hyper-advanced IT-centric). Types 5 and 6, the Advanced together type of ET+IT, is Period 1 (Developed IT of ET+IT-centric), Period 2 (Advanced IT of ET+IT-centric), and Period 3 (Hyper-advanced IT of ET+IT-centric). Type 7, the Advanced IT type of ET+IT-centric, is Period 1 (ET+IT fusion), Period 2 (Sub-fusion of ET, Advanced IT), and Period 3 (Sub-fusion of ET, Hyper-advanced IT). This study results are going to expect making new types of convergence through further study.