• Journal of International Area Studies (JIAS)
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• v.18 no.3
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• pp.145-168
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• 2014

Given the distance from Mt. Baekdu, volcanic ash will have the direct impact on South Korea in case Mt. Baekdu erupts. Ash fall deposits or particulate matters(PM10) in the air will cause damages in various sectors. In particular, the PM10 impact on the manufacturing sector when the ash disperses in Korea is needed to be assessed since South Korea's manufacturing sector accounts for more than 30% of GDP. Meanwhile the economic impacts of PM10, including Asian dust, have been researched in Korea as the events become frequent, and losses in the manufacturing have been also reported. This study is to identify vulnerable sectors to volcanic ash in the korean industry, and to assess economic losses in case of a Mt. Baekdu eruption scenario, based on the historical loss experience with particulate matters. Study results show that airline, precision such as electronics and semiconductors, distribution, shipbuilding, car, leisure, glass, dairy farming are vulnerable to volcanic ash, or PM10. The economic losses in both car and shipbuilding industry is estimated to 46.49 billion Korean won due to shutdown for 6 hours in case of a Mt. Baekdu eruption scenario.

• Korean Journal of Social Welfare Studies
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• v.40 no.1
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• pp.323-351
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• 2009

The purpose of this study is to investigate which factors affect working women's intention of second childbirth and what paths that determine this intention exist. Especially, this study focused on the influence of 'values regarding children' on intention of second childbirth of working women, and divided 'values regarding children' into 'individualistic value regarding children'and 'group-oriented value regarding children'. Findings from this study are as follows. First, the research model of this study was appropriate to explain the intention of second childbirth in working women with a child by measurement model analysis and structural model analysis. Second, it appeared that the factor which directly determined the intention of second childbirth in working women with a child was 'values regarding children', and the impact of 'individualistic values regarding children' was stronger than that of 'group-oriented values regarding children'between the two. Third, 'Economic resource'factor and 'service'factor affected 'intention of second childbirth' indirectly through other factors. Fourth, the level of public and private service resources for reconciling work and family life is affected by the level of economic resources. Finally, it appeared that 'values regarding children' could be formed or changed by working women's environmental condition like public and private service resources to support reconciling work and family life. Based on these findings, this study proposed that it should be important to form values regarding children positively by improving environmental condition for reconciling work and family life to increase childbirth intention of working women.

• Journal of Korean Tunnelling and Underground Space Association
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• v.25 no.2
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• pp.157-173
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• 2023

Although this site is designed with a non-vibration excavation method for a section of 265 m, there are concerns about decline of constructability and economic feasibility. For this reason, the low-vibration electronic detonator blasting method was suggested. To evaluate the applicability of the low-vibration electronic detonator blasting method, the damage range of blasting vibration of low-vibration electronic detonator blasting applied just before the site (suggestion I) and low-vibration electronic detonator blasting constructed close range the subway like this site (suggestion II) was analyzed. As a result of comparing the blasting vibration damage ranges of the two suggestions, the damage range of suggestion II was calculated more conservatively. Considering the specificity of the close range of this site, suggestion II was selected for design change for safer construction. As a result, it is predicted that there will be no damage to the structure even if the 72 m section out of the non-vibration excavation 265 m section is changed to the Low-vibration electronic detonator blasting. And it is evaluated that high economic benefits can be obtained because the total expected excavation period can be reduced by 144 days from 662.5 days.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.141-152
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• 2023

The scale of the authenticity perceived by the athletes of the domestic business team was developed. Through this, it is intended to accumulate information and authenticity research on human resource management of unemployment teams. The authenticity scale was developed through a total of 6 steps by referring to previous studies on the scale development process at domestic and international. In the first stage, the basic composition was confirmed through the review of previous studies.In the second stage, preliminary questions were drawn through in-depth interviews with 13 players belonging to the business team. In the third stage, the authenticity attribute and structure were confirmed through an expert meeting. In the fourth stage, the appropriateness of the items was verified through exploratory factor analysis and reliability analysis of 248 people. In the 5th stage, 288 subjects were tested for construct validity, convergent validity, and discriminant validity through confirmatory factor analysis, correlation analysis, and reliability analysis. The sixth step was to verify the relationship through regression analysis with the performance variables to examine the applicability and predictability of the developed scale. Through the above procedures, 4 dimensions of organizational authenticity and 18 measurement items were developed, and 3 dimensions of leader authenticity and 18 measurement items were developed.

• Journal of the Korean Geotechnical Society
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• v.22 no.9
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• pp.45-59
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• 2006

The successful performance of any numerical geotechnical simulation depends on the accuracy and efficiency of the numerical implementation of constitutive model used to simulate the stress-strain (constitutive) response of the soil. The corner stone of the numerical implementation of constitutive models is the numerical integration of the incremental form of soil-plasticity constitutive equations over a discrete sequence of time steps. In this paper a well known two-surface soil plasticity model is implemented using a generalized implicit return mapping algorithm to arbitrary convex yield surfaces referred to as the Closest-Point-Projection method (CPPM). The two-surface model describes the nonlinear behavior of coarse-grained materials by incorporating a bounding surface concept together with isotropic and kinematic hardening as well as fabric formulation to account for the effect of fabric formation on the unloading response. In the course of investigating the performance of the CPPM integration method, it is proven that the algorithm is an accurate, robust, and efficient integration technique useful in finite element contexts. It is also shown that the algorithm produces a consistent tangent operator $\frac{d\sigma}{d\varepsilon}$ during the iterative process with quadratic convergence rate of the global iteration process.

• Journal of the Korean Geotechnical Society
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• v.25 no.7
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• pp.35-46
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• 2009

Pressure grouting is a common technique in geotechnical engineering to increase the stiffness and strength of the ground mass and to fill boreholes or void space in a tunnel lining and so on. Recently, the pressure grouting has been applied to a soil-nailing system which is widely used to improve slope stability. The soil-nailing design has been empirically performed in most geotechnical applications because the interaction between pressurized grouting paste and the adjacent ground mass is complicated and difficult to analyze. The purpose of this study is to analyze the increase of pullout resistance induced by pressurized grouting with the aid of performing laboratory model tests and field tests. In this paper, two main causes of pullout resistance increases induced by pressurized grouting were verified: the increase of mean normal stress and the increase of coefficient of pullout friction. From laboratory tests, it was found that dilatancy angle could be estimated by modified cavity expansion theory using the measured wall displacements. The radial displacement increases with dilatancy angle decrease and the dilatancy angle increases with injection pressure increase. The measured pullout resistance obtained from field tests is in good agreement with the estimated one from the modified cavity expansion theory.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.57-67
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• 2009

Along with the advanced construction technologies, the maximum size of coarse aggregate used for dam construction ranges from several cm to 1m. Testing the original gradation samples is not only expensive but also causes many technical difficulties. Generally, indoor tests are performed on the samples with the parallel grading method after which the results are applied to the design and interpretation of the actual geotechnical structure. In order to anticipate the exact behavior characteristics for the geotechnical structure, it is necessary to understand the changes in the shear behavior. In this study, the Large Triaxial Test was performed on the parallel grading method samples that were restructured with river bed sand-gravel, with a different maximum size, which is the material that was used to construct Dam B in Korea. And the Stress - Strain characteristics of the parallel grading method samples and the characteristics of the shear strength were compared and analyzed. In the test results, the coarse-grained showed strain softening and expansion behavior of the volume, which became more obvious as the maximum size increased. The internal angle of friction and the shear strength appeared to increase as the maximum size of the parallel grading method sample increased.

• Geophysics and Geophysical Exploration
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• v.26 no.2
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• pp.62-76
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• 2023

Recently, machine learning (ML) techniques have been actively applied for seismic trace interpolation. However, because most research is based on training-inference strategies that treat missing trace gather data as a 2D image with a blank area, a sufficient number of fully sampled data are required for training. This study proposes trace interpolation using ML, which uses only irregularly sampled field data, both in training and inference, by modifying the training-inference strategies of trace-based interpolation techniques. In this study, we describe a method for constructing networks that vary depending on the maximum number of consecutive gaps in seismic field data and the training method. To verify the applicability of the proposed method to field data, we applied our method to time-migrated seismic data acquired from the Vincent oilfield in the Exmouth Sub-basin area of Western Australia and compared the results with those of the conventional trace interpolation method. Both methods showed high interpolation performance, as confirmed by quantitative indicators, and the interpolation performance was uniformly good at all frequencies.

• Geophysics and Geophysical Exploration
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• v.25 no.4
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• pp.227-241
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• 2022

Full waveform inversion (FWI) in the field of seismic data processing is an inversion technique that is used to estimate the velocity model of the subsurface for oil and gas exploration. Recently, deep learning (DL) technology has been increasingly used for seismic data processing, and its combination with FWI has attracted remarkable research efforts. For example, DL-based data processing techniques have been utilized for preprocessing input data for FWI, enabling the direct implementation of FWI through DL technology. DL-based FWI can be divided into the following methods: pure data-based, physics-based neural network, encoder-decoder, reparameterized FWI, and physics-informed neural network. In this review, we describe the theory and characteristics of the methods by systematizing them in the order of advancements. In the early days of DL-based FWI, the DL model predicted the velocity model by preparing a large training data set to adopt faithfully the basic principles of data science and apply a pure data-based prediction model. The current research trend is to supplement the shortcomings of the pure data-based approach using the loss function consisting of seismic data or physical information from the wave equation itself in deep neural networks. Based on these developments, DL-based FWI has evolved to not require a large amount of learning data, alleviating the cycle-skipping problem, which is an intrinsic limitation of FWI, and reducing computation times dramatically. The value of DL-based FWI is expected to increase continually in the processing of seismic data.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.368-368
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• 2020

최근 초대형화 되어 나타나고 있는 이상홍수와 지진 등에 의한 저수지 붕괴와 같은 대규모 비상상황 발생으로 하류지역 주민의 생명과 재산의 피해가 발생하고 있다. 국내의 경우 1996년 이후로 지속적으로 발생하고 있는 이상홍수로 인해 1998년에는 40개,1999년에는 5개의 소규모 저수지가 붕괴되었으며 최근 2013년과 2014년에도 저수지가 붕괴되는 상황이 발생했다. 댐붕괴의 원인은 구조물의 자연적 노화, 극심한 강우나 홍수, 지진, 제체전도, 파이핑, 침윤발생, 월류 및 파랑 등에 의한 자연적 상황 등이 요인이 될 수 있으며, 시공결함, 사고 또는 전쟁과 같은 인위적인 요인으로 발생할 수도 있다. 과거에 설계 및 시공기술이 부족하였거나 경제적인 이유로 부실하게 건설되어 있는 댐이 세계적으로 산재되어 있어 잠재적인 위험을 상당수 내재하고 있는 실정이다. 본연구는 댐의 점진적인 파괴에 의해 발생하는 유출수문곡선을 구하고 파괴의 성질을 예측 및 홍수파를 수리학적으로 추적하기위해 BREACH 모형과 DAMBRK 모형을 사용했으며 극한홍수(PMF)조건과와 최대지진발생(MCE)조건을 적용하여 원주시 관내 저수지 붕괴 모의 시나리오를 구축했다. 저수지 붕괴에 따른 유출수문곡선을 유도하기 위해서 본 연구에서는 기존의 EAP보고서 자료를 참고하여 붕괴지속시간, 붕괴부 평균폭, 붕괴부 측벽면 경사의 변화에 따라 다양한 모의를 수행함으로써 발생되는 붕괴부 유량 수문곡선을 도출하여 각각의 조건들이 붕괴파 형성에 미치는 영향에 대한 분석을 실시하였다. 그 결과 저수지의 붕괴시 첨두유출량에 민감한 영향을 주는 인자는 붕괴지속시간과, 붕괴부 평균폭으로서 이들 값이 붕괴유출량 변화에 많은 영향을 주는 것으로 나타났다. 최대지진발생(MCE)조건 해석결과 홍수류의 범람으로 인해 홍수파가 하류측으로 진행할수록 완만히 감소하며, 하천 중·상류부 인근 제내지로 홍수류의 범람이 발생하는 것으로 검토되었으며, 극한홍수(PMF)조건 해석결과 최대지진발생(MCE)조건과 같이 홍수파가 하류측으로 진행할수록 완만히 감소하는 특성을 보이며, 하천 전체 구간에서 인근제내지로 홍수류의 범람이 발생하는 것으로 검토되었다. 본 연구는 침수구역 피해규모 산정 및 비상대처계획도를 작성시 기초데이터가 되어 상황별 피해예상지역에 대해 응급행동요령, 주민대피계획비상대처계획을 수립하여 지역 주민생활에 안정을 기여하고자 한다.