• Smart Structures and Systems
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• v.7 no.4
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• pp.275-287
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• 2011

The behaviors of saturated soils such as compressibility and permeability are distinguished by preconsolidation stress. Preconsolidation stress becomes an important design parameter in geotechnical structures. The goal of this study is to introduce a new method for the evaluation of preconsolidation stress based on the shear wave velocity at small strain, using Busan, Incheon, and Gwangyang clays in Korea. Standard consolidation tests are conducted by using an oedometer cell equipped with bender elements. The preconsolidation stresses estimated by shear wave velocity are compared with those evaluated by the Casagrande, constrained modulus, work, and logarithmic methods. The preconsolidation stresses estimated by the shear wave velocity produce very similar values to those evaluated by the Onitsuka method (one of the logarithmic methods), which yields an almost real preconsolidation stress. This study shows that the shear wave velocity method provides a reliable method for evaluating preconsolidation stress and can be used as a complementary method.

• Journal of the Korean GEO-environmental Society
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• v.24 no.10
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• pp.5-13
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• 2023

With the recent increase in development projects centered on urban areas, the construction of building structures is increasing in areas adjacent to the urban railway operation section. In this case, since ground vibration is generated by the train in operation and affects the adjacent structure, the building structure needs appropriate vibration reduction against train vibration generated at the adjacent location from the desing phase. However, the vibration levels calculated vary depending on the train vibration evaluation method, which means that the implementation of vibration reduction may vary depending on the train vibration evaluation method. Therefore, this study calculated the vibration level according to ground conditions, tunnel depth and separation distance between vibration sources and adjacent structures using numerical analysis and train vibration evaluation methods, and compared them to designning phase. And the appropriate separation distance between the tunnel and the adjacent structure was evaluated by comparing the vibration level with the allowable standards. As a result of the study, the Ungar and Bender evaluation method is evaluated as the most appropriate among the train vibration evaluation methods, and the appropriate separation distance between the tunnel and the adjacent structure is evaluated to be more than 4.5D.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.2
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• pp.114-123
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• 2010

The Environmental Conservation Value Assessment Map (ECVAM) is a five grade assessment map created with nationally integrated environmental information and environmental values. The map is made through the evaluation of 67 items, including greenbelt area and bio-diversity. The ECVAM assesses the stability of the community using forest maps. However, the existing assessment method is problematic because the assessment grades are evaluated using higher than practical values; in part because it uses even-valued overlay and minimal indicator methods. This study was performed in order to suggest an integrated assessment method that could complement the stability evaluation based on existing methods. Accordingly, this study added forest type information, including whether the forest was natural or artificial, to the overlay method using forest diameter maps and forest density maps. As a result, the proposed ECVAM indicated a drastic grade change. After applying the method in South Korea, Grade I areas decreased 12.1%, from 52.6% to 40.6%, Grade II areas increased 11.9%, from 17.4% to 29.2%, and Grade III areas increased 0.2%, from 17.1% to 17.4%, respectively. From the results of the field survey, we found differences between natural forest and planted forest with regard to the number of mortality, species of shrubs, and vine cover. This means that natural forests are more stable than planted forests. This study suggests an improved assessment methodology to complement the existing EVCAM method. The results are expected to be used in environmental evaluations and forest conservation value assessments in ecology and environmental fields.

• Journal of Wellbeing Management and Applied Psychology
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• v.6 no.2
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• pp.39-46
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• 2023

Purpose: The small-scale environmental impact assessment system in Korea was introduced and implemented in August 2000, but it has a problem that it cannot guarantee implementation due to the large proportion of qualitative reduction measures for each evaluation item. Therefore, when preparing a small-scale environmental impact assessment, research was conducted on how to improve the existing simple listing-type reduction measures and qualitative evaluation standards to quantitative reduction measures and evaluation standards reflecting regional characteristics. Research design, data and methodology: The small-scale environmental impact assessment system in Korea was introduced and implemented in August 2000, but it has a problem that it cannot guarantee implementation due to the large proportion of qualitative reduction measures for each evaluation item. Therefore, when preparing a small-scale environmental impact assessment, research was conducted on how to improve the existing simple listing-type reduction measures and qualitative evaluation standards to quantitative reduction measures and evaluation standards reflecting regional characteristics. Results: As a result of the analysis of qualitative and quantitative factors, the arithmetic sum of the qualitative factors of the total six projects is 160, accounting for 80% of the total number of reduction measures, and the quantitative factors are 40, accounting for 20%. Among them, the number of qualitative reduction measures reached 97.4% for animal and plant items, and more than 90% for air quality, noise and vibration, and eco-friendly resource circulation items. Conclusions: Therefore, it is necessary to avoid establishing qualitative reduction measures and set quantitative measures as the basis, but to specify the specifications, size, and installation location related to the reduction measures, and to calculate the numerical reduction efficiency.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.4
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• pp.209-219
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• 2000

A method is developed to evaluate machining process and to determine the optimal machining conditions considering the environmental effects. The method Is based on the evaluation attributes from the general LCA programs and the analysis technique of AHP from HHS. To assist the analysis. the mass models of cutting energy, tools, and fluids are developed. The models may be used for both quantitative prediction of the uses and disposed masses of materials and optimization of the machining conditions. The algorithm with the mass models is applied to the milling process planning. The process to survey the environmental data, calculate the used mass, and evaluate the alternatives is demonstrated. This demonstration illustrates the of the change of process conditions of the decision making.

• Proceedings of the Korean Society for Quality Management Conference
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• 2007.04a
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• pp.362-369
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• 2007

This study set the hypothesis to develop the method that was analysis and application of a reliability evaluation method of environmental material for the Computer, Color TV, Monitor, Microwave oven, Electric Refrigerator, Automobile parts, other goods. RoHS management and product reliability ensure method for the conservation of environment. Especially, this study emphasis on regulate export of the EU and North America that it's a environmental material problem. Therefore, this study emphasis on the application of a reliability ensure method of environmental material and the use of other parameter by environmental reliability test data. The result of this study is as follows. 1) There is relationship between regulate material and technical protecting system. 2) Characteristics of hazard material is operating a healthcare damage factor as well as regulate environmental factors.

• Korean Journal of Organic Agriculture
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• v.10 no.2
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• pp.51-66
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• 2002

It is almost impossible to aggregate environment-related information, simply because it is vast. Therefore, Recently, the development of an environmental index is attracting the attention in Korea and other nations, since it is taken to be useful for legislating environmental policies. When it comes to the development of an environmental index, the first necessary step is to organize environmental information by using an accounting framework that manifests outstanding consistency and inclusiveness. And then, this organized environmental information should be appropriately used, whenever required. Compared to these movements, it is necessary to point out that the environmental accounts in the agricultural section still suffer from numerous problems that need to be solved. According1y, this dissertation suggests and considers at least the following three matters. First of all, an integrated index evaluation method should be developed, taking domestic and foreign movements into consideration at the time of conducting the environmental evaluation. Secondly, a master plan for the environmental accounts should be developed for the agricultural sector. And thirdly and finally, problems and solutions incurred during the process of performing the aforementioned tasks need to be examined in detail.

• Structural Engineering and Mechanics
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• v.73 no.2
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• pp.167-179
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• 2020

This study provides a simplified method for the evaluation of shear lag stress in rectangular box T-joints. The occurrence of shear lag phenomenon in the box T-joint generates stress concentration localized at both web-flange junctions of the beam, which leads to cracking or failure in the weld region of the joint. To prevent such critical circumstance, peak stress at the weld region is required to be checked during a preliminary design stage. In this paper, the shear lag stresses in the T-joints were evaluated using least-work solution in which the longitudinal displacements of the beam flange and web were presumed. The evaluation process considered particularly the effect of column flange flexibility, which was represented by an axial spring model, on the shear lag stress distribution. A simplified method for stress evaluation was provided to avoid solving complex mathematical problems using a stress modification factor β_s from a parametric study. The results showed that the proposed method was valid for predicting the shear lag stress in the box T-joints manually, as well compared with finite element results. The results are further summarized, discussed, and clarified that more flexible column flange caused higher stress concentration.

• Journal of Engineering Education Research
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• v.7 no.1
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• pp.64-73
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• 2004

Universities have to offer efficient education through measuring and evaluating courses precisely. Course evaluation gives instructors a chance of understanding quality and issues arisen in courses, and students a chance of the effective learning. This study investigates general characteristics and administration method of course evaluation in engineering education. The investigation includes elements of course evaluation, various evaluation methods, effective administration methods, and validation of the evaluation. A survey was undertaken to the students at Myongji University regarding course evaluation. The study summarized the results of the survey.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.11a
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• pp.65-79
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• 2005