• Journal of the Korean Geosynthetics Society
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• v.22 no.2
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• pp.35-45
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• 2023

In accordance with the urban development project, cases of constructing temporary wall structures for ground excavation in the vicinity of railway structures are increasing. In addition, the complaints about train vibration are also increasing from people living in large buildings newly built after installing the temporary wall structures. In order to solve this problem, a method for reducing train vibration is considered from the design stage of the building, and a vibration reduction system is installed on the structure when the building is newly constructed. However, the vibration reduction method established at the structure design stage can be determined through the results of field measurements or dynamic numerical analysis for a specific area, and there is a limit to evaluating whether the established vibration reduction method is appropriate due to the lack of objective research data. Therefore, in order to provide objective basic data when establishing a vibration reduction method, this study performed the dynamic numerical analysis for a operating train with a speed 80km/h by applying differently the depths of railway structures, the distances between railways and temporary wall structures, and ground conditions. It was found that the range of influence of a train operating at 80 km/h was within 4.5D of the lateral distance from the railway structure in the case of the condition where the temporary wall was installed.

• Journal of the Korean Geotechnical Society
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• v.26 no.11
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• pp.47-61
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• 2010

To predict the settlement rate of a ground area that incorporates vertical drains, it is desirable to conduct various kinds of advanced field and laboratory tests for hydraulic properties. However, it is urgently needed to appropriately evaluate the hydraulic properties using the results of conventional soil tests which are extensively used for local practice. To achieve this purpose, a number of CPT dissipation test, laboratory permeability and consolidation tests were performed at five sites in the floodplain of the Nakdong River delta, and the test data were comprehensively analyzed. As a result, it is found that the coefficients of horizontal consolidation ($C_{h,NC}$) and permeability ($k_{h,OC}$) of the clay agreed well with those of the CPT-based methods proposed by Baligh and Levadoux (1986). The values of $C_{h,NC}$ and $k_{h,OC}$ were in the range of $0.4{\sim}3.0\;cm^2/sec$ and $0.40{\sim}2.50\;cm^2/sec$, each of which slightly increases or decreases with depth, respectively. It was also inferred that these trends seem to reflect the depositional environments of the clay.

• Journal of the Korean Geotechnical Society
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• v.26 no.3
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• pp.59-68
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• 2010

Systematic risk management is necessary in grand scaled urban construction because of the existence of complicated and various risk factors. Problems of obstructions, adjacent structures, safety, environment, traffic and geotechnical properties need to be solved because urban construction is progressed in limited space not as general earthwork. Therefore the establishment of special risk management system is necessary to manage not only geotechnical properties but also social and cultural uncertainties. This research presents the technique analysis by the current state of risk management technique. Risk factors were noticed and the importance of each factor was estimated through survey. The systemically categorized database was established. Risk extraction module, matrix and score module were developed based on the database. Expected construction budget and time distribution can be computed by Monte Carlo analysis of probabilities and influences. Construction budgets and time distributions of before and after response can be compared and analyzed 80 the risks are manageable for entire whole construction time. This system will be the foundation of standardization and integration. Procurement, efficiency improvement, effective time and resource management are available through integrated management technique development and application. Conclusively decrease in cost and time is expected by systemization of project management.

• Journal of the Korean Geotechnical Society
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• v.23 no.7
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• pp.37-46
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• 2007

In the practice of preloading method for soft ground improvement, field engineers need information of ground properties, construction works and field monitoring on ground behaviors of the site. So, integrating all these informations into one database can provide more efficient way for managing and utilizing the data for construction management. In this study, integrated system for construction management of ground improvement sites under preloading is developed. The developed system consists of database (DB) and application program. The database contains all collected data in a construction site and processed data in the system with their geographic information. All informations in the database are standardized from the result of data characterization. Application program performs various functions on managing and utilizing information in the database; pre- and post- data processing with graphic visualization of output, spatial data interpolation, and prediction of ground behavior using field measuring data. And by providing integrating informations and predictions over entire project area with comprehensible visual displays, the applicability and effectiveness of the developed system for construction management were confirmed.

• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.307-315
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• 2022

In terms of habitat conservation, it is essential to develop a habitat assessment system that can evaluate not only the suitability of the current habitat, but also the health and stability of the habitat. This study aimed to develop a methodology of habitat quality assessment for endangered species by analyzing various existing habitat assessment methods. The habitat quality assessment consisted of selecting targeted species, planning of assessment, selecting targeted sites, assessing performance, calculating grade, and expert verification. Target sites were selected separately from core and potential habitats using a species distribution model or habitat suitability index. Habitat assessment factors were classified into ecological characteristic, landscape characteristic, and species-habitat characteristic. Ecological characteristic consisted of thirteen factors related to health of tree, vegetation, and soil. Landscape characteristic consisted of five factors related to fragment and connectivity of habitat. Species-habitat characteristic consisted of factors for evaluating habitat suitability depending on target species. Since meanings are different depending on characteristics, habitat quality assessment of this study could be used by classifying results for each characteristic according to various assessment purposes, such as designation of alternative habitats, assessment of restoration project, and protected area valuation for endangered species. Forest habitat quality assessment is expected to play an important role in conservation acts of endangered species in the future through continuous supplementation of this system in regard to quantitative assessment criteria and weighting for each factor with an influence.

• Design Convergence Study
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• v.16 no.4
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• pp.1-16
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• 2017

As the local manufacturing industry has entered a phase of stagnation, service and product design based on user experience has been highlighted as an alternative for the innovation. However, SMEs(Small and Medium-sized Enterprises) are still struggling to overcome the current crisis. One of the reasons is that SMEs do not have enough contact points with the validated UX firms and experts. Thus, SMEs has a high barrier to invest in new opportunity area, user experience. In this study, we aim to figure out UX experts' competence to perform the UX method to solve the UX problems based on the KSA framework(Knowledge, Skill, Attitude). Based on the literature review and expert workshop, we grouped the UX method according to the similarity of the competence required to conduct the method. With cluster analysis, 5 different groups of UX method were defined based on the competence, Panoramic Analysis, Meticulous Observation and Analysis, Intuitive Interpretation, Agile Visualization, and Logical Inspection. The results would be applied to compose a portfolio of UX experts and to implement a mechanism that could recommend the professional experts to the company.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.2
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• pp.247-264
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• 2023

Objectives: The study was to examine the features of three-dimensional(3D) face dimensions and to develop fit test panels for the labor population using respirators in South Korea. Methods: This study was part of the first-year work of a two-year-project conducted at Occupational Safety and Health Research Institute in 2021. After 3D head dimensions data were collected from Size Korea Center managing Sixth Size Korea databases, 3D face dimensions DB for the South Korean labor population was established for 21 items of face dimensions in line with the ISO/TS 16976-2 and KS A ISO 15535. With the South Korean labor population 3D face dimensions DB, in accordance with the ISO/TS 16976-2, the descriptive statistics of 3D face dimensions were calculated and two fit test panels were developed. Results: A total of 2,752 subjects were finally determined and they were 52.9% for male, 41.2% for the highest age-group of 15-29, and residents in the capital area. Mean and standard deviation were obtained for each of the 21 3D face dimensions items for the South Korean labor population. Among the items, male and female face widths were 137.6±5.7 mm, 133.2±5.0 mm, respectively. Male and female face lengths were 116.6±7.0 mm, 107.8±6.8 mm, respectively. Two new South Korean fit test panels, a bivariate test panel and a principal component analysis test panel, were developed using the 3D face dimensions DB as well. Conclusions: Using the 3D face dimensions DB, the mean and standard deviation were featured for each of the 21 items and also the two fit test panels were newly developed in the study. It is suggested that the study outputs should be utilized practically and effectively in selection, use, and management of respirators at work, expecting that respiratory protection can be furthermore improved for respirator users including labor population across the country.

• 지역과문화
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• v.4 no.2
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• pp.1-23
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• 2017

The regional development plan by the city of Andong in establishing the foundation for cultural eco-tourism in the cultural area of confucianism(2010-2020) consists of 2 leading projects (the World Confucian Scholar Culture Park, the Korean Culture Theme Park) and 2 strategic projects (the Confucian Scholars' Literature Park, the Sunsunghyun Culture Complex, the Traditional Bittarae Weaving Village). By inter-regional input-output analysis, their multiplier effects of output, value-added, income and employment are estimated respectively 990.2 billion won(multiplier 2.23), 318.2 billion won(multiplier 0.72), 187.7 billion won(multiplier 0.42), and 4,791 workers(multiplier 10.6 workers/billion won). The ongoing project has been, however, delayed due to various issues and has hit a ceiling towards achieving the original objectives of the familiarization, industrialization and globalization of Confucian culture. To overcome these problems, the associated plans of constructing the Korean SMART LINK LINE, of developing contents blending traditional culture and ICT, of establishing tourist complexes and infrastructure around Lake Andong, and of constructing interactive attractions of traditional culture were proposed as new growth-leading plans.

• Journal of The Geomorphological Association of Korea
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• v.18 no.4
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• pp.59-78
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• 2011

In this study, the tidal flat research history of South Korea was organized by type and period. South Korea's tidal flat research history was largely divided into four fields: sediment research of tidal flat, research using satellite imagery, research on the Quaternary environment change and tidal flats, and ecological research on tidal flats. The comprehensive review of the South Korean tidal flat research history showed that tidal flats had been researched on since the period of Japanese colonial period, but most of the past studies were related to fisheries. Then, in the 1960s, the studies started to focus on the reclaimed land created through reclamation projects. The research on tidal flats from a geomorphological perspective fundamentally started in the 1970s, and the importance of tidal flats became more widely known in the 1980s. Most of the studies then were about the sedimentary environment and the form of landform, the ecosystem, and morphological changes. Since the 2000s, research has been carried out on satellite imagery data together with field survey, to continuously monitor the changes in the sedimentary facies of tidal flats, and in the sedimentary environment. There have been many academic studies on the geographic field of tidal flats, but the research performance on tidal flats in terms of geomorphology is still a blue ocean that has been touched by only a few. Therefore, it is hoped that various studies on Korean tidal flats will be conducted by geomorphologists in the future, and that such area will be established as an important field of study in geomorphology.

• Journal of the Korean earth science society
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• v.44 no.6
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• pp.629-642
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• 2023

Currently, low and intermediate level radioactive waste is being disposed of at the Gyeongju disposal site for permanent isolation. Since 2006, the Korea Radioactive Waste Agency has been conducting site characteristics surveys continuously verifying changes in the site based on the site monitoring and investigation plan. The hydrogeochemical environment of the disposal site is considered for the evaluation of natural barriers. However, the seawater must be considered because of the regional characteristics of Gyeongju, which is near the East Sea. Therefore, this study, collected 30 samples for deriving the groundwater quality data from seven wells and compared with two seawater samples collected from October 2017 to June 2022. Additionally, the study explores the groundwater monitoring method using statistical tools such as clustering and background concentration analysis. The groundwater samples in the study area were classified into two to four clusters depending on their chemical constituents-especially, EC, HCO₃, Na, and Cl-using statistical analysis, molar ratio, and K-means clustering.