• Economic and Environmental Geology
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• v.55 no.6
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• pp.701-716
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• 2022

This study investigated the distribution behaviors of PM2.5 and PM10 at two air quality monitoring sites, Go-eup (GO) and Backseokeup (BS), located in Yangju City, South Korea. The amounts of emissions sources of pollutants were analyzed based on the Clean Air Policy Support System (CAPSS), and the contribution rates of neighboring cities were enumerated in Yangju. Yangju has a geological basin structure, and it is a city with mixed urban and rural characteristics. The emission concentration of particulate matter was affected by geological and seasonal factors for all sites observed in this study. Therefore, these factors should be considered when establishing policies related to particulate matter. Because the official GO and BS station sites in Yangju are both situated in the southern part of the city, the representativeness of both stations was checked using correlation analysis for the measurement of PM2.5 and PM10 by considering two more sites-those of Bongyang-dong (BY) and the Gumjun (GJ) industrial complex. The data included discharge amounts for business types 4 and 5, which were not sufficiently considered in the CAPSS estimates. Because the 4 and 5 types of businesses represent over 92.6% of businesses in this city, they are workplaces in Yangju that have a significant effect on the total air pollutant emission. These types of businesses should be re-inspected as the main discharge sources in industry, and basic data accumulation should be carried out. Moreover, to manage the emission of particulate matter, attainable countermeasures for the main sources of these emissions should be prepared in a prioritized fashion; such countermeasures include prohibition of backyard burning, supervision of charcoal kilns, and management of livestock excretions and fugitive dust in construction sites and on roads. The contribution rates by neighboring cities was enumerated between 6.3% and 10.9% for PM2.5. Cooperation policies are thought to be required with neighboring cites to reduce particulate matter.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.2
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• pp.149-159
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• 2020

Cured-in-place-pipe(CIPP) is the most adopted trenchless application for sewer rehabilitation to extend the life of the existing sewer without compromising both direct construction and indirect social costs especially applied in the congested urban area. This technology is globally and domestically known to be the most suitable for partial and full deteriorated pipe structure rehabilitation in a sewer system. The typical design of CIPP requires a significant thickness of lining to support loading causing sewage flow interruption and increasing material cost. This paper presents development of a high strength glass fiber composite lining material for the CIPP application and structural test results. The test results exhibit that the new glass fiber composite lining material has 12 times of flexural strength, 6.2 times of flexural modulus, and 0.5 Creep Retention Factor. These test results can reduce lining design thickness 35% at minimum. Even though taking into consideration extra materials such as outer and inner films for actual field applications, the structural capacity of the composite material significantly increases and it reduces 20 percent or more line thickness as compared to the conventional CIPP. We expect that the newly developed CIPP lining material lowers material costs and minimizes flow capacity reduction, and fully replaceable to the conventional CIPP lining materials.

• Journal of People, Plants, and Environment
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• v.22 no.6
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• pp.665-676
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• 2019

The Korean society is currently showing a decrease in the child population and a rapid increase in the elderly population due to low birth rates and aging, but the current park system does not reflect the changing population structure. This study aimed to find ways to plan and promote use of senior-friendly parks for the aging society. The results are as follows. First, the elderly mostly gathered in Tapgol Park and Jongmyo Park which were accessible to subways and close to amenities and traditional markets. The elders usually gathered around buffer zones or green spaces set up to protect cultural heritages. Second, many elderly users were observed in Osolgil Silver Park and Sinteuri Park which were renovated with senior-friendly concept. These parks were recognized as places that the elderly people could visit without minding users of other generations because the elderly users were ensured by words such as 'seniors only' or 'senior-friendly'. Third, the importance of the locational conditions for the senior-friendly parks should be mentioned. A senior-friendly park must be located in an urban center to have convenient access to transportation, secure large green spaces, and make elderly users feel at ease with social connectivity when they use the amenities there. Fourth, the survey results showed that elderly people visited parks to exerciseand take a walk (track),by age, older age groups visited the park to socialize with other elders around their age. Fifth, the most desired facilities for constructing senior-friendly parks were fitness equipment, and sports facilities like a trail, track, and gateball field, and in some cases, vegetable gardens and indoor rest area to avoid wind in cold weather.

• Journal of the Korean Society of Food Culture
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• v.26 no.6
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• pp.539-553
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• 2011

This study was intended to examine the continuance and transformation of food culture during the enlightenment and Japanese ruling era by analyzing the novel of "Toji". In the novel "Toji", the chaotic political and economic situation is reflected, along with the peoples' hard lives in the latter era of the Choson Dynasty. After the full-fledged invasion of China by the Japanese, the shift to a wartime posture was accompanied by an increased need for food. This led to a rationing and delivery system for rice in the late 1930s. While it was hard for people to obtain even brewer's grains and bean-curd dregs, food distribution officers were well off. Another distinctive feature of the food culture during the enlightenment and Japanese ruling era was that foreign food and recipes were introduced naturally to Korea through the influx of various foreigners. The industry of Choson was held by Japanese monopolistic capital, as a result, Choson had equal to the role as a spending site and was only gradually left destitute. In the Japanese ruling era, there were new type of business including such as patisserie of the types of civilization in the town, and those tempted Korean people. However, the Japanese and pro-Japan collaborators dominated commercial business. Being urbanization through the modernization, it was became patronized fast food in the populous downtown, and the change of industry structure and life style greatly influenced into our food culture. Acceptance the convenient Japanese style fast food such as Udong, pickled radish made was actively accepted with a longing for the advancement civilization. After the enlightenment, many Japanese exchange students went to Tokyo to get advanced civilization and provided urban mood according to their consumption of bread, coffee, Western food, which were considered a part of the elite culture.

• Wind and Structures
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• v.36 no.6
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• pp.405-421
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• 2023

Strong wind is the main factors of wind-damage of high-rise buildings, which often creates largely economical losses and casualties. Wind pressure plays a critical role in wind effects on buildings. To obtain the high-resolution wind pressure field, it often requires massive pressure taps. In this study, two traditional methods, including bilinear and bicubic interpolation, and two deep learning techniques including Residual Networks (ResNet) and Generative Adversarial Networks (GANs), are employed to reconstruct wind pressure filed from limited pressure taps on the surface of an ideal building from TPU database. It was found that the GANs model exhibits the best performance in reconstructing the wind pressure field. Meanwhile, it was confirmed that k-means clustering based retained pressure taps as model input can significantly improve the reconstruction ability of GANs model. Finally, the generalization ability of k-means clustering based GANs model in reconstructing wind pressure field is verified by an actual engineering structure. Importantly, the k-means clustering based GANs model can achieve satisfactory reconstruction in wind pressure field under the inputs processing by k-means clustering, even the 20% of pressure taps. Therefore, it is expected to save a huge number of pressure taps under the field reconstruction and achieve timely and accurately reconstruction of wind pressure field under k-means clustering based GANs model.

• International Journal of High-Rise Buildings
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• v.4 no.1
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• pp.9-25
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• 2015

Field measurements of various structures have been conducted for many purposes. Measurement data obtained by field measurement is very useful to determine vibration characteristics including dynamic characteristics such as the damping ratio, natural frequency, and mode shape of a structure. In addition, results of field measurements and modal identification can be used for modal updating of FEM analysis, for checking the efficiency of damping devices and so on. This paper shows some examples of field measurements and modal identification for structural health monitoring. As the first example, changes of dynamic characteristics of a 15-story office building in four construction stages from the foundation stage to completion are described. The dynamic characteristics of each construction stage were modeled as accurately as possible by FEM, and the stiffness of the main structural frame was evaluated and the FEM results were compared with measurements performed on non-load-bearing elements. Simple FEM modal updating was also applied. As the next example, full-scale measurements were also carried out on a high-rise chimney, and the efficiency of the tuned mass damper was investigated by using two kinds of modal identification techniques. Good correspondence was shown with vibration characteristics obtained by the 2DOF-RD technique and the Frequency Domain Decomposition method. As the last example, the wind-induced response using RTK-GPS and the feasibility of hybrid use of FEM analysis and RTK-GPS for confirming the integrity of structures during strong typhoons were shown. The member stresses obtained by hybrid use of FEM analysis and RTK-GPS were close to the member stresses measured by strain gauges.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.6 no.2
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• pp.27-38
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• 2003

This study aimed to provide basic data for future management of roadside trees by analyzing problems associated with plantation and management of roadside trees through categorization of functions and organizational structure, plantation and management, and management regulations and generating improvement opportunities based on the result of a survey on the awareness of government officials who are directly in charge of managing roadside trees in 31 cities & counties within Kyonggi province. The summary of key results of this study is as follows. First, "roadside tree-related function" is still not considered to be independent. About a half of government officials in charge did not majored in this field and they spent only about "2.09hours", in average, in the roadside tree-related function out of 8 working hours per day. Second, regarding problems and improvement opportunities in roadside tree-related function, lack of time was considered to be the biggest problem in overall management of roadside trees. As for improvement opportunities, "increase of dedicated manpower" and "system development" to facilitate efficient processing were suggested. Third, an annual budget for roadside tree-related affairs was merely 92 million won per city/county. A registry for management of roadside trees was kept manually. As for the roles of roadside trees, improvement of landscape and securing of green area itself were valued highly. Fourth, Ginkgo biloba, Zelkova serrata, and Prunus yedoensis were suggested to be the most appropriate species for roadside tree and Platanus occidentalis, Populus albaglandulosa, Populus euramericana, and Robinia pseudo-acacia were mentioned to be the least appropriate species.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1256-1263
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• 2022

With the advent of the Fourth Industrial Revolution, the amount of energy used in buildings has been increasing due to changes in the energy use structure caused by the massive spread of information-oriented equipment, climate change and greenhouse gas emissions. For the efficient use of energy, it is necessary to have a plan that can predict and reduce the amount of energy use according to the type of energy source and the use of buildings. To address such issues, this study presents a model embedded in a digital twin that predicts energy use in buildings. The digital twin is a system that can support a solution of urban problems through the process of simulations and analyses based on the data collected via sensors in real-time. To develop the energy use prediction model, energy-related data such as actual room use, power use and gas use were collected. Factors that significantly affect energy use were identified through a correlation analysis and multiple regression analysis based on the collected data. The proof-of-concept prototype was developed with an exhibition facility for performance evaluation and validation. The test results confirm that the error rate of the energy consumption prediction model decreases, and the prediction performance improves as the data is accumulated by comparing the error rates of the model. The energy use prediction model thus predicts future energy use and supports formulating a systematic energy management plan in consideration of characteristics of building spaces such as the purpose and the occupancy time of each room. It is suggested to collect and analyze data from other facilities in the future to develop a general-purpose energy use prediction model.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.5
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• pp.56-67
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• 2005

Rapid and reckless economical development is causing nationwide deforestation; more and more forest is being developed to be used as a base for economic advancement. While benefiting the national economy, this destruction of forest is creating a serious problem in the National Land Plan. To solve this problem, it is imperative to understand the current condition of damaged forest and make an environment-friendly plan. This paper explains the principles of spatial plan and sets the criteria for the plan, such as patch size, connectivity, and edge of the Landscape Ecology. The paper assesses the conservational value of area that are currently being developed or planned to be developed to figure out the current environmental situation. This conservational value was verified by the field survey. The result of assessment appears that the patch size of the major mountains in site is over 1,000ha and edge is located widely beside roads. The area of the high connectivity is located agriculture area in valley or narrow roads. The research shows that the patch size is related to biodiversity the larger the patch size, the more populated the species are. The research also reveals the conservational value indicated by degree of connection to forest, difference in the structure of vegetation between core area and edge area, and effects of surrounding environment. In further study, we will assess other criteria of conservation value, such as patch shape and fragmentation to the Landscape Ecology, and apply those criteria in biological aspects of the spatial plan.

• International Journal of High-Rise Buildings
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• v.7 no.4
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• pp.375-387
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• 2018

This paper presents a review on progressive collapse mechanism of steel framed buildings exposed to fire. The influence of load ratios, strength of structural members (beam, column, slab, connection), fire scenarios, bracing systems, fire protections on the collapse mode and collapse time of structures is comprehensively reviewed. It is found that the key influencing factors include load ratio, fire scenario, bracing layout and fire protection. The application of strong beams, high load ratios, multi-compartment fires will lead to global downward collapse which is undesirable. The catenary action in beams and tensile membrane action in slabs contribute to the enhancement of structural collapse resistance, leading to a ductile collapse mechanism. It is recommended to increase the reinforcement ratio in the sagging and hogging region of slabs to not only enhance the tensile membrane action in the slab, but to prevent the failure of beam-to-column connections. It is also found that a frame may collapse in the cooling phase of compartment fires or under travelling fires. This is because that the steel members may experience maximum temperatures and maximum displacements under these two fire scenarios. An edge bay fire is more prone to induce the collapse of structures than a central bay fire. The progressive collapse of buildings can be effectively prevented by using bracing systems and fire protections. A combination of horizontal and vertical bracing systems as well as increasing the strength and stiffness of bracing members is recommended to enhance the collapse resistance. A protected frame dose not collapse immediately after the local failure but experiences a relatively long withstanding period of at least 60 mins. It is suggested to use three-dimensional models for accurate predictions of whether, when and how a structure collapses under various fire scenarios.