• Journal of Korean Society of Disaster and Security
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• v.8 no.2
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• pp.21-26
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• 2015

This study analyzes the failure predict of model slope due to changes in ground condition followed by heavy rainfall with a simulated rainfall system. the movement of a slope from the rainfall penetrating the unsaturated soil is investigated with respect to various conditions of pore-water pressure, earth pressure and moisture content, considering rainfall duration and permeability.

• Computers and Concrete
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• v.4 no.6
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• pp.437-456
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• 2007

The shrinkage of large reinforced concrete floors often gives rise to cracking problems. To identify the problematic areas, shrinkage movement analysis is often carried out by finite element method with proper creep and shrinkage models using step-by-step time integration. However as the full stress history prior to the time interval considered is necessary, with the increase in the number of time intervals used, the amount of computations increases dramatically. Therefore a new method using the shrinkage-adjusted elasticity modulus (SAEM) is introduced so that analysis can be carried out using one single step. Examples are presented to demonstrate its usefulness.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1400-1407
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• 2005

There are a number of approaches to in situ remediation that are used at contaminated sites for removing contaminants from the contaminated zone without excavating the soil. These include soil flushing, dual phase extraction, and soil vapor extraction. Of these techniques, soil flushing is the focus of the investigation in this paper. The concept of using prefabricated vertical drains(PVDs) for remediation of contaminated sites with fine-grained soils is examined. The PVD system is used to shorten the drainage path or the groundwater flow and promote subsurface liquid movement expediting the soil flushing process. The use of PVDs in the current state of practice has been limited to soil improvement. The use of PVDs under vacuum conditions is investigated using sample soil consisting of silty sand.

• Korean Journal of Hydrosciences
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• v.10
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• pp.1-15
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• 1999

A relaxed similarity theory which can be applied to river madels with movable beds is established by modifying existing theory by Einstein and Chien(1954). Experimental data collected from river models with movable beds were used to evaluate the applicability of the proposed theory. Effects of similarity of flow. $\Delta$F$\Delta$M, and similarity of sediment movement, $\Delta$$F_s$, were examined by analyzing the behavior of total river-bed change. The results show that the smaller $\Delta$F$\Delta$M or $\Delta$$F_s$ is, respectively, the larger total sedimentation is. The modified similarity theory established in this study would be useful and practical whenever it is impossible or very difficult to satisfy strict theoretical requirments concerning the river model experiments with movable beds.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1614-1622
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• 2008

A series of three-dimensional numerical modelling have been conducted to clarify the behaviour of multi-pressurised soil nails with high strength steel pipes. In this study, the soil non-linearity, the soil-nail interaction and staged construction are considered. It has been found that pressurised soil nails can reduce lateral ground movement by 14-21% compared to general soil nails with very low pressure. In addition, ground settlement was reduced when using multi-pressurised soil nails. The pressurised soil nail may result in an increase in the surcharge loading on the ground surface.

• The Korean Journal of Archival Studies
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• no.3
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• pp.65-89
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• 2001

We, at The Korea Democracy Movement Archives opened temporarily at SungKongHoe University(SKHU), have currently collected about 100,000 recorded materials of democratization movement related with labor, farmer, civilian, human rights, peace, unification, young people, student and women's movements by investigating, collecting and receiving donations from civil organizations and individuals, and about 70,000 data out of this 100,000 data were converted into computer files. The Korea Democracy Movement Archives(temp) at SKHU has a significance in that it is the first archive opened by an organization. Furthermore, the opening of this Archive means the expansion of awareness on recording culture and accumulation of the achievements of the democratization movement in Korea. However, many obstacles still remain in the establishment of this Archive in a full-scale. This article examined many theoretical and realistic obstacles posed to the archivists, who are the professionals responsible for record management, in process of establishing the Archive, and the role and future perspectives of the archivists at The Korea Democracy Movement Archives(temp). The first obstacles in the process of organizing and separating the recorded materials at the Archive is a difficulty in the description of classifying the different movement organizations. The second obstacle is a difficulty in specifically applying the international standard, ISAD(G), of record description in the process of establishing the description items. Through many trials and errors, we need to try to confirm the description befitting. The Korea Democracy Movement Archives through continuous adjustment and complementary measures. The third obstacle is a difficulty in estimating the range and physical and quantitative amount of the recorded materials since the collection of recorded materials is complete. Thus, the answers to these problems lie in continuous efforts to establish a creative classification system befitting the democratization movement in Korea in the process of many trials and errors and endeavor. The evaluation classification done by archivists is a creative act forming record heritage, and archivists need to form record heritage reflecting the evaluation system of a certain period. Moreover, they transmit the shape of the current era in a maximum scale to the future by using the minimum amount of records. An archivist is responsible for two tasks, i.e., preserving a record and making other people to utilize the record by working with record. However, We, at The Korea Democracy Movement Archives(temp), have an additional task of contributing to the democratization movement in korea that has not ended by collecting, preserving and making people to utilize the fragments of memory in the recent history of Korea by establishing the Archives.

• Wind and Structures
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• v.27 no.1
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• pp.29-40
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• 2018

To investigate the characteristics of the combined wind field produced by the natural wind field and the train-induced wind field on the bridge, the aerodynamic models of train and bridge are established and the overset mesh technology is applied to simulate the movement of high-speed train. Based on ten study cases with various crosswind velocities of 0~20 m/s and train speeds of 200~350 km/h, the distributions of combined wind velocities at monitoring points around the train and the pressure on the car-body surface are analyzed. Meanwhile, the difference between the train-induced wind fields calculated by static train model and moving train model is compared. The results show that under non-crosswind condition, the train-induced wind velocity increases with the train speed while decreases with the distance to the train. Under the crosswind, the combined wind velocity is mainly controlled by the crosswind, and slightly increases with the train speed. In the combined wind field, the peak pressure zone on the headstock surface moves from the nose area to the windward side with the increase of wind velocity. The moving train model ismore applicable in analyzing the train induced wind field.

• Earthquakes and Structures
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• v.15 no.4
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• pp.411-417
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• 2018

To solve the seismic response problem of a vertical floating roof tank with base isolation, the floating roof is assumed to experience homogeneous rigid circular plate vibration, where the wave height of the vibration is linearly distributed along the radius, starting from the theory of fluid velocity potential; the potential function of the liquid movement and the corresponding theoretical expression of the base shear, overturning the moment, are then established. According to the equivalent principle of the shear and moment, a simplified mechanical model of a base isolation tank with a swinging effect is established, along with a motion equation of a vertical storage tank isolation system that considers the swinging effect based on the energy principle. At the same time, taking a 150,000 m 3 large-scale storage tank as an example, a numerical analysis of the dampening effect was conducted using a vibration mode decomposition response spectrum method, and a comparative analysis with a simplified mechanical model with no swinging effect was applied.

• Korean Journal of Labor Studies
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• v.23 no.2
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• pp.109-139
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• 2017

In light that solidarity movements become significant under the situation of 'labor and labor movement' crisis, our study pays attention to the fact that the Hope Bus campaigns made remarkable achievements, and aims to figure out how those campaigns were successful, by focusing on their solidarity networking. The successful operating conditions of solidarity networking in the Hope Bus campaigns are examined in three aspects - the conditions of triggering, forming, and activating. The solidarity networking of Hope Bus campaigns were mainly triggered by the injustice of layoffs by Hanjin Heavy Industry, aerial protest by Jin-sook Kim, and the tragic symbol of the protest site (Crane no. 85). The solidarity movement of Hope Bus could be formed by the mutual trust and cohesive team-building of key network brokers, their utilization and expansion of social movement networks, and massive ripple effect of SNS-mediated communication. The solidarity networking of Hope Bus was effectively activated by open and de-hierarchical operations of the central planning group, active solidarity activities of participant groups, and the provision of 'heuristic experience' for developing the sensibility to labor solidarity. The virtuous combination of those three operating conditions leads to the building of unified forces among social movements, massive civil participation, and meaningful movement outcomes, through the solidarity networking of Hope Bus campaigns.

• Wind and Structures
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• v.18 no.2
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• pp.155-180
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• 2014

The safety of road vehicles on the ground in crosswind has been investigated for many years. One of the most important fundamentals in the safety analysis is aerodynamic characteristics of a vehicle in crosswind. The most common way to study the aerodynamic characteristics of a vehicle in crosswind is wind tunnel tests to measure the aerodynamic coefficients and/or pressure coefficients of the vehicle. Due to the complexity of wind tunnel test equipment and procedure, the features of flow field around the vehicle are seldom explored in a wind tunnel, particularly for the vehicle moving on the ground. As a complementary to wind tunnel tests, the numerical method using computational fluid dynamics (CFD) can be employed as an effective tool to explore the aerodynamic characteristics of as well as flow features around the vehicle. This study explores crosswind effects on a high-sided lorry on the ground with and without movement through CFD simulations together with wind tunnel tests. Firstly, the aerodynamic forces on a stationary lorry model are measured in a wind tunnel, and the results are compared with the previous measurement results. The CFD with unsteady RANS method is then employed to simulate wind flow around and wind pressures on the stationary lorry. The numerical aerodynamic forces are compared with the wind tunnel test results. Furthermore, the same CFD method is extended to investigate the moving vehicle on the ground in crosswind. The results show that the CFD results match with wind tunnel test results and the current way using aerodynamic coefficients from a stationary vehicle in crosswind is acceptable. The CFD simulation can provide more insights on flow field and pressure distribution which are difficult to be obtained by wind tunnel tests.