• Journal of the Korean Society of Industry Convergence
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• v.24 no.6_2
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• pp.841-848
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• 2021

This study investigated the acceleration characteristics of rock slopes when earthquakes, which have not been studied much in Korea, occur. The rock slope was modeled with a similar raw of 1/20 in consideration of the height(10m), roughness, strength, and the joint dips(20°). After the completion of the model, a shaking table tests was conducted according to the magnitude of the acceleration and the type of seismic wave. The maximum acceleration was greater in the short-period seismic wave than in the long-period seismic wave, and the maximum acceleration was larger in the small acceleration. The rock slope was close to a rigid block and a structure more vulnerable to the long period wave than to the short period wave. In the event of an earthquake smaller than the domestic earthquake-resistant maximum design acceleration(0.154g), safety management of the rock slope was required.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1304-1312
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• 2008

In this study, the analysis to the preference level on slope measuring instrument of weight values on effect factors find out the reasonable monitoring on slope was performed, in which used AHP(Analytic Hierarchy Process) techniques. The results on professional group, such as the industry, academic, institute and government, analyzed that the very important effect factors, which were indicator of various collapse type, convenience of instrument management, The evaluation of preference level on the slope measuring instrument analyzed the invar wire extensometer which was high level at convenience of install, economical efficiency of install and convenience of instrument management.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1990.04a
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• pp.151-162
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• 1990

Occupational disease among typists such as Carpal Tunnel Syndrome(CTS) and tendonitis has increased along with rapid expansion of office automation. During typing, the posture can be defined as forearm pronation, ulnar abduction, wrist extension and finger flexion. The CTS results from awkward posture between forearm-wrist-hand and the keyboard arrangement. Therefore, ergonomic principles should be emphasized in keyboard design. The objective of the study is to improve keyboard design by analyzing anatomical posture of forearm and hand during typing. An experimental study was performed to investigate relationships between a keyboard and typing performance. Results showed that typing performance is dependent to angles and slopes of a keyboard. Statistical analysis indicated that the suggested ergonomic keyboard improved typing speed significantly(17%).

• Journal of the Society of Disaster Information
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• v.16 no.1
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• pp.111-122
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• 2020

Purpose: In order to manage the steep slopes effectively, this study diagnose problems in the procedure of steep slopes management and propose Improved frame work is intended to mitigate human and property damage Method: Problems in the system are drawn through review of procedures for designation of collapse risk zones and fied investigation, interviews with local governments, and expert advice. Result: The selection stage, the subject of the management, the management method, and the factors that need to be improved by the management stage before the evaluation are derived. Conclusion: This paper identified the problems raised and drew improvements and presented the research direction for the development of the new system (plan) and the steep slope site.

• Journal of Climate Change Research
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• v.9 no.3
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• pp.293-302
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• 2018

This study was carried out to provide basic information on efficient preservation and management of an Abies koreana forest through analyzing the ecological characteristics by slope in Seseok, Mt. Jirisan. Soil moisture content at southern and northern slopes was 29.9% and 21.7%, respectively, and there was no significant difference among soil properties between southern and northern slopes. The importance value of A. koreana in the southern and northern slopes was high for tree and subtree layers, respectively. It is noteworthy that many seedling and saplings of A. koreana were present on the southern slope. The species diversity was 0.413 for the tree layer, 0.632 for the subtree layer, and 0.609 for the shrub layer on the southern slope and 0.396 for the tree layer, 0.783 for the subtree layer, and 1.215 for the shrub layer on the northern slope. Evenness and dominance ranged from 0.371 to 0.609 and 0.629 to 0.391 on the southern slope and from 0.380 to 0.968 and 0.620 to 0.032 on the northern slope, respectively. The mortality of A. koreana was 9.6% on the southern slope and 24.4% on the northern slope, a distinct difference between the slopes. The mortality type at two slopes was the highest proportion of standing dead. Annual mean tree ring growth of A. koreana on the southern slope (1.76 mm/yr) was higher than that on the northern slope (1.64 mm/yr).

• The Journal of Engineering Geology
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• v.27 no.3
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• pp.275-292
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• 2017

Large landslides have occurred more than 100 times each year by the influence of cyclones and torrential rain each year in Vietnam. Nevertheless, they $don^{\circ}$Øt have a scientific management system to prevent the landslide disaster in advance. In this study, we acquisited the risk factor and damage factor about each slope throughout basic survey at Hoang Sa Costal Road, Danang and at Ho Chi Minh Road, Quangnam. The priority of investigation technique considering of the exposure characteristics of the road slope in Vietnam developed by the empirical analysis with the acquired data. As a result, we can set the foundation of scientific management for the road slope management system in Vietnam.

• The Journal of Engineering Geology
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• v.22 no.4
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• pp.417-425
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• 2012

CCTV cameras are used for surveillance and purposes of security, and can also be applied for monitoring infrastructure and equipment. In the Cut Slope Management System managed by KICT (Korea Institute of Construction Technology), cut slopes are continuously monitored using a real-time system, with CCTV cameras installed at 119 sites to detect slope activity. Here we compare CCTV images with displacement at three sites and perform a quantitative analysis. Methods for improving CCTV camera management and systems are also discussed with regard to communication, obstacles, and nighttime management.

• The Journal of Engineering Geology
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• v.31 no.1
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• pp.31-42
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• 2021

Database of Cut-slope management system (CSMS) has been constructed based on investigations of all slopes on the roads of the whole country. The investigation data is documented by human, so it is inevitable to avoid human-error such as missing-data and incorrect entering data into computer. The goal of this paper is constructing a prediction model based on several machine-learning algorithms to solve those imperfection problems of the CSMS data. First of all, the character-type data in CSMS data must be transformed to numeric data. After then, two algorithms, i.g., multinomial logistic regression and deep-neural-network (DNN), are performed, and those prediction models from two algorithms are compared. Finally, it is identified that the accuracy of DNN-model is better than logistic model, and the DNN-model will be utilized to improve data-quality.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1358-1365
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• 2010

Estimating condition of slope is difficult because of nonlinear time dependency and seasonal effects, which affect the displacements. Displacements and displacement patterns of landslides are highly variable in time and space, and a unique approach cannot be defined to model landslide movements. Characteristics of movements are obtained by using a statistical method called Principal Component Analysis(PCA). The PCA is a non-parametric method to separate unknown, statistically uncorrelated source processes from observed mixed processes. In the non-parametric approaches, no physical assumptions of target systems are required. Instead, since the "best" mathematical relationship is estimated for given data sets of the input and output measured from target systems. As a consequence, non-parametric approaches are advantageous in modeling systems whose geomechanical properties are unknown or difficult to be measured. Non-parametric approaches are consequently more flexible in modeling than parametric approaches. This method is expected to be a useful tool for the slope management of and alarm systems.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.728-735
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• 2022

Roofers get exposed to increased risk of knee musculoskeletal disorders (MSDs) at different phases of a sloped shingle installation task. As different phases are associated with different risk levels, this study explored the application of machine learning for automated classification of seven phases in a shingle installation task using knee kinematics and roof slope information. An optical motion capture system was used to collect knee kinematics data from nine subjects who mimicked shingle installation on a slope-adjustable wooden platform. Four features were used in building a phase classification model. They were three knee joint rotation angles (i.e., flexion, abduction-adduction, and internal-external rotation) of the subjects, and the roof slope at which they operated. Three ensemble machine learning algorithms (i.e., random forests, decision trees, and k-nearest neighbors) were used for training and prediction. The simulations indicate that the k-nearest neighbor classifier provided the best performance, with an overall accuracy of 92.62%, demonstrating the considerable potential of machine learning methods in detecting shingle installation phases from workers knee joint rotation and roof slope information. This knowledge, with further investigation, may facilitate knee MSD risk identification among roofers and intervention development.