• Geomechanics and Engineering
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• v.31 no.5
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• pp.453-460
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• 2022

It is essential for geotechnical engineers to conduct studies and make predictions about the stability of slopes, since collapse of a slope may result in catastrophic events. The Gaussian process regression (GPR) approach was carried out for the purpose of predicting the factor of safety (FOS) of the slopes in the study that was presented here. The model makes use of a total of 327 slope cases from Iran, each of which has a unique combination of geometric and shear strength parameters that were analyzed by PLAXIS software in order to determine their FOS. The K-fold (K = 5) technique of cross-validation (CV) was used in order to conduct an analysis of the accuracy of the models' predictions. In conclusion, the GPR model showed excellent ability in the prediction of FOS of slope stability, with an R² value of 0.8355, RMSE value of 0.1372, and MAPE value of 6.6389%, respectively. According to the results of the sensitivity analysis, the characteristics (friction angle) and (unit weight) are, in descending order, the most effective, the next most effective, and the least effective parameters for determining slope stability.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.1 s.343
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• pp.59-64
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• 2006

The slope of the ramp generator in a single slope ADC(analog-to-digital converter) suffers from process and frequency variation. This variation in ramp slope causes ADC gain variation and eventually limits the performance of the ISP(image signal processing) in a CIS(CMOS image sensor) that uses the single slope ADC. This paper proposes a ramp slope BISC(built-in-self-calibration) scheme for CIS. The CIS with proposed BISC was fabricated with a $0.35{\mu}m$ process. The measurement results show that the proposed architecture effectively calibrate the ramp slope against process and clock frequency variation. The silicon area overhead is less than $0.7\%$ of the full chip area.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.6 s.113
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• pp.127-139
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• 2006

Mt. Yokmang landscape design awarded first in [North container terminal site furtherance construction in Busan new port], design competition sponsoring in the Korea Container Terminal Authority in 2005. Design guideline was to propose the symbol of new port and to establish landscape plan in consideration of view and geological location. Because landscape plan required establishment of restoration plan for cutting slope, Mt. Yokmang became the major object. The purpose of planning are as follows. The first purpose is to minimize existent natural environment damage, and the second, to connect with ambit and create new image. The third is to provide place of rest and interchange for local resident. Reflecting stratum structure and landscape characteristics, cutting slope consisted of [utilization slope], [presentation slope], [landscape slope], and [ecological slope]. Vegetation design applied ecological restoration method through restoration of stratum, and eve environment-friendly afforestation, planned program that can connect area with existing ecosystem. In process that decides form of the cutting slope, analyze view structure and visual exposure in various access routes, sensitivity etc. was accomplished. Also, symbolic tower(Ocean Polaris) that presents in architecture and landscaping features, night landscape planning could gain synergy effect by keeping consistence with landscape and ecological planning. Passing through final design and construction process, I expect that the Mt. Yokmang will be a new landmark in Busan new port.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.1130-1137
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• 2022

The Industry Foundation Classes (IFC) provides standardized product models for the building construction domain. However, the current IFC schema has limited representation for infrastructure. Several studies have examined the data schema for road and highway modeling, but not in a sufficiently comprehensive and robust manner to facilitate the overall integrated project delivery of road projects. Several discussions have focused on slope engineering for road projects, but no solution has been provided regarding the formalized parametric modeling up to now. Iterative design, analysis, and modification are observed during the process of slope design for road projects. The practitioners need to carry out the stability analysis to consider different road design alternatives, including horizontal, vertical, and cross-section designs. The procedure is neither formalized nor automated. Thus, there is a need to develop the formal representation of the product and process of slope analysis for road design. The objective of this research is to develop a formal representation (i.e., an IFC extension data schema) for slope analysis. It consists of comprehensive information required for slope analysis in a structured manner. The deliverable of this study contributes to both the formal representation of infrastructure development and, further, the automated process of slope design for road projects.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1-13
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• 2010

Numerous landslides had occurred in Kangwondo in July 2006 and several restoration works had been done. A-day-accumulative rainfalls from July 12 to July 13 and July 15 to July 16 were 176mm and 202mm respectively. Disaster sites at which slope failures were studied to main causes of slope failures by investigating characteristics of rainfall, geological formation, topography and ground surface exploration around the boundary of landslides. In this study, a series of slope restoration work process is presented for reference which about the landsliding area in Han-Gye-Ryeong to O-Saek in Kwangwon-do where one of the most severe damaged area in 2006. The slope restoration work process includes site investigation, analysis on affected factor, restoration or reinforcing method design, construction procedure and recent status of that area. Also several considering points are suggested while design and construction for the reference at the other restoration works.

• Journal of Sensor Science and Technology
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• v.24 no.4
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• pp.252-257
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• 2015

This paper proposes a single slope A/D converter (SSADC) that is possible to process the signal of the ultraviolet, visible and infrared rays with a single chip. And the proposed SSADC is a type of single channel ADC. In the conventional SSADC, it is possible to process the only one signal with a kind of the sensor because the speed of the operating frequency and the slope of ramp signal generated by the ramp generator are fixed. In order to improve the disadvantages, a ramp generator which has variable slope in ramp function is designed and $3{\times}1$ MUX(multiplexer) is adopted so that we can change the speed of the operating frequency and the slope of ramp signal. Therefore, the multiple signal processing of the wanted sensors can be possible. The designed circuit is layout by the $0.35-{\mu}m$ CMOS 2-poly 4-metal technology process and is checked through DRC and LVS tools.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.06a
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• pp.33-42
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• 2003

Since the cut slope has been big concern due to frequent failures, the government decided to include cut slopes in the“Act for Safety Control of Public Structures”. Based on the Act, the cut slope whose height is over 50m and length is over 200m should be inspected on the regular basis. According to the Act, KISTEC developed the objective evaluation method for the condition of cut slope. The evaluation method is divided into two categories: evaluation for damaged condition and evaluation for failure affecting factor. Based on the evaluation results, the cut slope is graded from A to E. In this study, the process to evaluate the cut slope condition and the evaluation criteria to divide the grade of cut slope are introduced.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.507-512
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• 2002

Generally gneiss regions catagolized as metamorphic ground are very complicated and difficult for geotenical engineer to establish stability, this slopes include falt zone and many folding structures. therefore the slope in this study is very complicated and highly wheathered and framentation conditions are irregular by this study, we hope that geotechical engineers who are confronted with the same complicated slope as this slope are doing his job easily and they know which system are adequate to establish the slope stability in large-scale slope with complicated geological structure, and besides through our work flow and modeling process, we hope that our study can be useful for geotenical engineer who may work slope design and construct in complicated ground.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.34-34
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• 2012

Heavy storms rainfall has caused many landslides and slope failures especially in the mountainous area of the world. Landslides and slope failures are common geologic hazards and posed serious threats and globally cause billions in monetary losses and thousands of casualies each year so that studies on slope stability and its failure mechanism under rainfall are being increasing attention of these days. Rainfall-induced slope failures are generally caused by the rise in ground water level, and increase in pore water pressures and seepage forces during periods of intense rainfall. The effective stress in the soil will be decreased due to the increased pore pressure, which thus reduces the soil shear strength, eventually resulting in slope failure. During the rainfall, a wetting front goes downward into the slope, resulting in a gradual increase of the water content and a decrease of the negative pore-water pressure. This negative pore-water pressure is referred to as matric suction when referenced to the pore air pressure that contributes to the stability of unsaturated soil slopes. Therefore, the importance is the study of saturated unsaturated soil behaviors in evaluation of slope stability under heavy rainfall condition. In an actual field, a series of failures may occur in a slope due to a rainfall event. So, this study attempts to develop a numerical model to investigate this failure mechanism. A two-dimensional seepage flow model coupled with a one-dimensional surface flow and erosion/deposition model is used for seepage analysis. It is necessary to identify either there is surface runoff produced or not in a soil slope during a rainfall event, while analyzing the seepage and stability of such slopes. Runoff produced by rainfall may result erosion/deposition process on the surface of the slope. The depth of runoff has vital role in the seepage process within the soil domain so that surface flow and erosion/deposition model computes the surface water head of the runoff produced by the rainfall, and erosion/deposition on the surface of the model slope. Pore water pressure and moisture content data obtained by the seepage flow model are then used to analyze the stability of the slope. Spencer method of slope stability analysis is incorporated into dynamic programming to locate the critical slip surface of a general slope.

• The Journal of Engineering Geology
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• v.16 no.2 s.48
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• pp.135-143
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• 2006

This study presents the results of a series of laboratory scale slope failure experiments aimed at clarifying the process and the condition leading to the initiation of rainfall-induced slope failures. For the evaluation of hydrologic response of the model slopes in relation the process of failure initiation, measurements were focused on the changes in volumetric water content during the initiation process. The process leading to failure initiation commences by the development of a seepage face. It appears reasonable to conclude that slope failures are a consequence of the instability of seepage area formed at the slope surface during rainfall period. Therefore, this demonstrates the importance of monitoring the development seepage area for useful prediction about the timing of a particular failure event. The hydrologic response of soil slopes leading to failure initiation is characterized by three phases (phase I, II and III) of significant increase in volumetric water content in association with the ingress of wetting front and the rise of groundwater level within the slope. The period of phase III increase in volumetric water content can be used to initiate advance warning towards a failure initiation event. Therefore, for the concept outlined above, direct and continuous monitoring of the change in volumetric water content is likely to provide the possibility for the development of a reliable and effective means of predicting the occurrence of rainfall-induced slope failures.