• Journal of the Korean Geotechnical Society
• /
• v.29 no.3
• /
• pp.51-60
• /
• 2013

The slime, deposited in the bored pile due to falling soil particle, reduces the bearing capacity of bored pile and thus the stability of construction also decreases. The weight pendulum and iron have been used for estimating the slime thickness based on the subjective judgment and thus the previous method has a limitation of reliability. The objective of this paper is to suggest the method for estimating the slime thickness by using characteristics of electrical resistivity as scientific method. The temperature-compensation resistivity probe (TRP), which has a conical shape and the diameter of 35.7mm, is applied to the measurement of the electrical resistivity in the borehole during penetration. The field tests are carried out for estimating the slime thickness in the application site of bored pile. The slime thickness is calculated through the difference between excavation depth of borehole and measured data. Furthermore, the laboratory tests are also conducted for investigating effects of casing, time elapsing and relative density by using the specimen of slime. The laboratory test supporting the suggested method is reasonable for determining the slime depth. The paper suggests that the electrical resistivity method may be a useful method for detecting slime thickness and the method is expected to be applicable to various sites of bored piles.

• The Korean Journal of Air & Space Law and Policy
• /
• no.spc
• /
• pp.59-86
• /
• 2007

The purpose of this paper is to suggest to tackle the problem of poor cooperation in space activities, by re-examining the nature of the competitive political environment, and by building up a normative overarching framework, One of the most acute problems that hampers regional cooperation is the U.S. influence as represented in the MTCR, a supplier's cartel, as was evidenced in the ill-fate of the 2001 launch contract between China and Korea the next year. Notably China, the third space power in the world, has not been allowed to join the MTCR despite her application in June 2004. A possible reconciliation between China and the MTCR over her application for a partnership would set a cornerstone in building up a cooperative environment in the Northeast Asia. Just as the Helsinki process was an overarching norm building framework, comprising human rights, security and environmental issues, it would be desirable that a future peace framework in Northeast Asia dealing with the pending issues of Korean peninsula should also comprise of such broad issues as one relating to cooperation in space activities in the region. South Korea could tap expertise from her neighbor China. When South Korea become an independent space power either with her own technology or otherwise, she would be in a better position to play a role as a balancer in coordinating between the two neighboring space giants. It is remarkable that the Japanese led APRSAT has contributed much in establishing Sentinel Asia as a part of the Disaster Management Scheme, in that each participant, whether it be a state agency, or a private entity like a university or a research institute, can tap the common data to contribute to the common good of safety.

• The Journal of Art Theory & Practice
• /
• no.14
• /
• pp.7-32
• /
• 2012

The exhibition was started in 2010 in the New Acropolis Museum of Athens and embarked a journey since 2011 as a travelling exhibition inside Greece and abroad. The main purpose of the exhibition was to draw attention of the general public to the value of the 'rescue excavation' and of cultural heritage of Greece, by presenting the reconstruction bust of a girl whose skull was found in Kerameikos cemetery of ancient Athens. The new Kerameikos excavation was initiated by the construction of Metropolitan Railway lines in the center of Athens between 1992 to 1998. It revealed a pit of a mass burial where about 150 people were inhumed in a very hasty way without proper funeral rites or offerings. These bodies are identified as the victims of the infamous plague of Athens in the first years of the Peloponnesian War(430-426 BC). The epidemic disease killed almost one third of the city population including Pericles, and brought extreme fear and panic to the Athens society. The traditional funerary rites were totally disrupted, and the social decorum and the morality among the citizens became enfeebled. The plague and the civil war were the decisive factors to end the Golden Age of Democratic Athens. However, the exhibition organizers did not focus on the tragic aspect of this disaster and its casualties. Their main concern was to simplify the scholarly works of archaeological excavation and microchemistry analysis so that the exhibition viewers will easily understand and empathize the living value of the scholarly works of ancient Greek civilization. The centripetal element of the exhibition was the vivid face of an 11 years old ancient girl 'Myrtis', which was carefully reconstructed based on both the scientific data and artistic imagination. Also the set up of the exhibition was structured in order to stimuli cognitive and emotional experience of the visitors who witnessed the rebirth of a vibrant human being from an ancient debris. The museologists' continuous efforts to promote projects of contemporary artists, publications, and school programs related to the exhibition indicate that the ulterior motive of this exhibition is the cultural education of the present and future generation through the intimate experiences of ancient Greek life. Also this is the reason why the various museums that held the travelling exhibition try to make the presentation as a gesture of memorial service for an anonymous Athenian girl who deceased circa 2400 years ago. The pragmatic efforts of Greek scholars and museologists through exhibition show us a way to find a solution to the continuous threat of cultural resources by massive construction projects and land development, and to overcome public indifference to the history and cultural heritage.

• Journal of Korea Water Resources Association
• /
• v.41 no.9
• /
• pp.929-941
• /
• 2008

The objectives of this study are to propose a system for combined use of a hydrologic and a hydraulic model for urban flood forecast model and to evaluate the system on the $300km^2$ Jungrang urban watershed area, which is relatively large area as an urban watershed and consequently composed of very complex drainage pipes and streams with different land uses. In this study, SWMM for hydrologic model and HEC-RAS for hydraulic model are used and the study area is divided into 25 subbasins. The SWMM model is used for sewer drainage analysis within each subbasin, while HEC-RAS for unstready flow analysis in the channel streams. Also, this study develops a GUI system composed of mean areal precipitation input component, hydrologic runoff analysis component, stream channel routing component, and graphical representation of model output. The proposed system was calibrated for the model parameters and verified for the model applicability by using the observation data. The correlation coefficients between simulated and observed flows at the 2 important locations were ranged on 0.83-0.98, while the coefficients of model efficiency on 0.60-0.92 for the verification periods. This study also provided the possibilities of manhole overflows and channel bank inundation through the calculated water profile of longitudinal and channel sections, respectively. It can be concluded that the proposed system can be used as a surface runoff and channel routing models for urban flood forecast over the large watershed area.

• Journal of Wetlands Research
• /
• v.13 no.1
• /
• pp.1-11
• /
• 2011

A chronic drought stress has been imposed during non-rainy season(from winter to spring) since 1990s. We faced the most significant water crisis in 2001, and the drought was characterized by sultry weather and severe drought on a national scale. It has been widely acknowledged that the drought related damage is 2-3 times serious than floods. In the list of the world's largest natural disaster compiled by NOAA, 4 of the top 5 disasters are droughts. And according to the analysis from the NDMC report, the drought has the highest annual average damage among all the disasters. There was a very serious impact on the economic such as rising consumer price during the 2001 spring drought in Korea. There has been flood prevention measures implemented at national-level but for mitigation of droughts, there are only plans aimed at emergency (short-term) restoration rather than the comprehensive preventive measures. In addition, there is a lack of a clear set of indicators to express drought situation objectively, and therefore it is important and urgent to begin a systematic study. In this study, a nonstationary downscaling model using RCM based climate change scenario was first applied to simulate precipitation, and the simulated precipitation data was used to derive Standardized Precipitation Index (SPI). The SPI under climate change was used to evaluate the spatio-temporal variability of drought through principal component analysis at three different time scales which are 2015, 2045 and 2075. It was found that spatio-temporal variability is likely to modulate with climate change.

• Journal of Wetlands Research
• /
• v.19 no.1
• /
• pp.45-51
• /
• 2017

Nepal is a landlocked mountainous country in South Asia, located between China to the north and India to the south, east, and west. As such, wastewater management has become one of the most significant problems in urban area of Nepal. In Nepal, the centralized wastewater treatment systems were dysfunctional due to high cost of operation, discontinuous power supply, lack of proper maintenance and proper technical workforce to address the issues. As such, constructed wetlands (CW) were applied to treat various secondary wastewater as alternative to wastewater treatment facilities. Generally, efficiency and sustainability of CW technology depends on proper operation and maintenance and active community involvement. This study summarizes information about 26 CW in Nepal. Specifically, factors including data banking, removal efficiency, quality of discharged water, compliance to water quality standard of Nepal and operation and maintenance were investigated. Considering removal efficiency per pollutant, Ka-1 achieved the greatest reduction for most pollutant followed by B-1, L-3, Ka-5 and K-1. Nepal has practiced CW technology for more than 2 decades but currently, development of technology was interrupted by the inefficient performance of existing facilities. Public awareness about the technology, natural disaster, unavailability of specified substrate materials, lack of fund for further research and experiments has hindered the expansion of technology. In spite of these concerns, CW was still proven as an alternative solution to the present wastewater problems in urban areas of Nepal.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.12
• /
• pp.17-25
• /
• 2017

Owing to recent climate change, the scale of rainfall tends to increase gradually and the risk of flooding has increased. Therefore, the importance of improving the levee management and disaster response is increasing. Levee management in Korea is carried out at the level of damage recovery after the occurrence of damage. Therefore, it is necessary to develop a technology for predicting and managing the levee safety with proactive river management. In this study, a method to estimate the safety against erosion and overflow was suggested. A map of levee safety that can be used as basic data is presented by displaying the levee safety on the map. The levee erosion safety was calculated as the ratio of the internal and external force for each shore type. The levee overflow safety was calculated as the ratio of the maximum conveyance and design flood. The maximum conveyance was a discharge when the level of the river was equal to the level of the levee crown. The levee safety was classified into 5 grades: very safe, safe, normal, dangerous, and very dangerous. As a research area from downstream of Nam River Dam to Nakdong River Junction, the levee safety against erosion and overflow was estimated for all levees and all cross-sections of the river. The levee safety was displayed on a map using GIS. Through the levee safety map as a result of this study, the levee safety can be observed intuitively. Using the levee safety map, a maintenance plan for a river can be easy to build. This levee safety map can be used to help determine the priority of investment for efficient budget used.

• Journal of the Institute of Convergence Signal Processing
• /
• v.4 no.1
• /
• pp.15-26
• /
• 2003

Ultrasonic inspection methods are widely used for detecting flaws in materials. The signal analysis step plays a crucial part in the data interpretation process. A number of signal processing methods have been proposed to classify ultrasonic flaw signals. One of the more popular methods involves the extraction of an appropriate set of features followed by the use of a neural network for the classification of the signals in the feature space. This paper describes an alternative approach which uses the least mean square (LMS) method and expectation maximization (EM) algorithm with the model based deconvolution which is employed for classifying nondestructive evaluation (NDE) signals from steam generator tubes in a nuclear power plant. The signals due to cracks and deposits are not significantly different. These signals must be discriminated to prevent from happening a huge disaster such as contamination of water or explosion. A model based deconvolution has been described to facilitate comparison of classification results. The method uses the space alternating generalized expectation maximization (SAGE) algorithm In conjunction with the Newton-Raphson method which uses the Hessian parameter resulting in fast convergence to estimate the time of flight and the distance between the tube wall and the ultrasonic sensor Results using these schemes for the classification of ultrasonic signals from cracks and deposits within steam generator tubes are presented and showed a reasonable performances.

• Journal of Conservation Science
• /
• v.33 no.4
• /
• pp.267-274
• /
• 2017

The Silleuksa temple in Yeoju city is adjacent to the South Han River and often has high humidity and fog days. In addition, its proximity to forests renders it prone to damage by insects and microorganisms. In order to obtain the basic data necessary for the establishment of a cultural property preservation management plan, the biological distribution of the wooden buildings and the termite distribution in the surrounding forests were monitored for three years. The wood-boring bee, an insect known to inflict damage to heritage structures, was confirmed, and the distribution of insects varied annually and seasonally, presumably due to the location characteristics of the site and the climate change during the year. In the forest behind, termite colonies were identified as a whole and their distribution pattern was different every year. As per the results of the microorganism survey, the species distribution and pollution degree were different at the entrance of the building. Therefore, it needs continuous biological distribution and conservation environment monitoring to mitigate the effects of wood-damaging organisms.were different according to the entrance of the building.

• Journal of Korean Society of societal Security
• /
• v.2 no.3
• /
• pp.47-53
• /
• 2009

This study performed the construction of test bed for the combination of the health monitoring system In Yongjong grand bridge with the safety management network system in order to explore the feasibility of combining the existing monitoring system with the safety management network system. For this purpose, connection program which consists of DAQ sender server program and DAQ receiver server program has been developed. DAQ sender server program installed in the connection server, which is located on the DMZ zone of the existing monitoring system, plays the role of communicating with the monitoring system. On the other hand, DAQ receiver server program installed in the connection server, which is located on the integrated operation center of the safety management network system, plays the part of gathering real time and tim history data of the existing monitoring system and storing them in the integrated operation server through the communication with the DAQ sender. Test bed demonstrated the feasibility of combining the existing monitoring system with the safety management network system.