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

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.9
• /
• pp.5829-5835
• /
• 2015

This paper investigates the impact of corporate governance structure on the firm's debt costs under different governance environments. We find that after the 2008 banking crisis, family firms with controlling shareholders benefit from lower debt cost through the strong control rights of dominating large shareholders, compared with the firms with diversified minority-shareholders. Foreign investors are related statistically to the higher cost of debt. Before the 2008 banking crisis, cash flows and growth potentials are positively associated with the firm's cost of debt.

• Journal of Convergence for Information Technology
• /
• v.9 no.12
• /
• pp.227-235
• /
• 2019

This study was conducted on 1,865 drunk elderly people who had teeth that were over 65 years old. As a result of analysis of factors related to tooth extraction, the higher the income, the lower the income, the higher the risk of having to remove teeth from smokers, poorer oral health status, and no oral hygiene products. The difference was statistically significant. In order to identify the risk factors of tooth extraction for the elderly and prevent tooth loss early and to extend the life of residual teeth as much as possible, it is necessary to improve the drinking culture and seek oral health care strategies in the previous life cycle, not the present, Oral health policy should be pursued.

• Journal of the Korea Society of Computer and Information
• /
• v.13 no.5
• /
• pp.279-289
• /
• 2008

This study has the primary purpose to understanding the present situation through research on the actual condition about human resource outsourcing in the stocks and KOSDAQ enterprises, and would give the basic and useful data to develop human resource outsourcing. Data were collected from 1,500 charge of human resource management in the stocks and KOSDAQ enterprises which introduced or will be introduced human resource outsourcing. Frequencies, cross-tabs and independent-samples t-test were used to understanding the actual condition. Research findings are summarized as follows. First, as the introduction area of human resource outsourcing following training and development on the list were personnel information system, recruitment and selection. Second, tasks that transfer outsourcing supply firms owing to human resource outsourcing were common and typical operation function than complex and specific planning function.

• Journal of the Korean Society for Computer Game
• /
• v.31 no.4
• /
• pp.145-155
• /
• 2018

This study aims to extract additional elements to the existing game value evaluation using Delphi technique to 23 game experts. As a result of reviewing the characteristics of the development model using the evaluation model of the existing game contents, it was found that the evaluation factor was selected when selecting the content. The Delphi analysis was conducted two times, the first was the expert FGI and the second was the Delphi questionnaire. More detailed elements were presented in the related items such as results, technology transfer and dissemination, and details for promoting commercialization. Through focus group interviews, we extracted additional factors and predicted market size, growth potential, regulatory and market appeal and risk through market analysis of content success in the game industry. This will allow the industry to understand market size, growth potential, regulation, market appeal and risk through a market analysis of its success targets. This study suggests that the proposed evaluation factors can be applied to the entire game and cultural contents industry and will also help to construct market factors such as market value evaluation of contents, goal and goal setting, selection of entry method, and strategic factors.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.25 no.7
• /
• pp.962-970
• /
• 2021

The cause of the majority of vehicle accidents is a safety issue due to the driver's inattention, such as drowsy driving. A forward collision warning system (FCWS) can significantly reduce the number and severity of accidents by detecting the risk of collision with vehicles in front and providing an advanced warning signal to the driver. This paper describes a low power embedded system based FCWS for safety. The algorithm computes time to collision (TTC) through detection, tracking, distance calculation for the vehicle ahead and current vehicle speed information with a single camera. Additionally, in order to operate in real time even in a low-performance embedded system, an optimization technique in the program with high and low levels will be introduced. The system has been tested through the driving video of the vehicle in the embedded system. As a result of using the optimization technique, the execution time was about 170 times faster than that when using the previous non-optimized process.

• Journal of the Korea Society for Simulation
• /
• v.29 no.4
• /
• pp.73-84
• /
• 2020

As the Internet began to become popular, there have been hacking and attacks on networks including systems, and as the techniques evolved day by day, it put risks and burdens on companies and society. In order to alleviate that risk and burden, it is necessary to detect hacking and attacks early and respond appropriately. Prior to that, it is necessary to increase the reliability in detecting network intrusion. This study was conducted on applying weight initialization and weight optimization to the KDD'99 dataset to improve the accuracy of detecting network intrusion. As for the weight initialization, it was found through experiments that the initialization method related to the weight learning structure, like Xavier and He method, affects the accuracy. In addition, the weight optimization was confirmed through the experiment of the network intrusion detection dataset that the Adam algorithm, which combines the advantages of the Momentum reflecting the previous change and RMSProp, which allows the current weight to be reflected in the learning rate, stands out in terms of accuracy.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.450-450
• /
• 2021

기후변화 보고서에 따르면 집중 호우의 강도 및 빈도 증가가 향후 몇 년동안 지속될 것이라 제시하였다. 이러한 집중호우가 빈번히 발생하게 된다면 강우 침식성이 증가하여 표토 침식에 더 취약하게 발생된다. Universal Soil Loss Equation (USLE) 입력 매개 변수 중 하나인 강우침식능인자는 토양 유실을 예측할때 강우 강도의 미치는 영향을 제시하는 인자이다. 선행 연구에서 USLE 방법을 사용하여 강우침식능인자를 산정하였지만, 60분 단위 강우자료를 이용하였기 때문에 정확한 30분 최대 강우강도 산정을 고려하지 못하는 한계점이 있다. 본 연구의 목적은 강우침식능인자를 이전의 진행된 방법보다 더 빠르고 정확하게 예측하는 머신러닝 모델을 개발하며, 총 월별 강우량, 최대 일 강우량 및 최대 시간별 강우량 데이터만 있어도 산정이 가능하도록 하였다. 이를 위해 본 연구에서는 강우침식능인자의 산정 값의 정확도를 높이기 위해 1분 간격 강우 데이터를 사용하며, 최근 강우 패턴을 반영하기 위해서 2013-2019년 자료로 이용했다. 우선, 월별 특성을 파악하기 위해 USLE 계산 방법을 사용하여 월별 강우침식능인자를 산정하였고, 국내 50개 지점을 대상으로 계산된 월별 강우침식능인자를 실측 값으로 정하여, 머신러닝 모델을 통하여 강우침식능인자 예측하도록 학습시켜 분석하였다. 이 연구에 사용된 머신러닝 모델들은 Decision Tree, Random Forest, K-Nearest Neighbors, Gradient Boosting, eXtreme Gradient Boost 및 Deep Neural Network을 이용하였다. 또한, 교차 검증을 통해서 모델 중 Deep Neural Network이 강우침식능인자 예측 정확도가 가장 높게 산정하였다. Deep Neural Network은 Nash-Sutcliffe Efficiency (NSE) 와 Coefficient of determination (R²)의 결과값이 0.87로서 모델의 예측성을 입증하였으며, 검증 모델을 테스트 하기 위해 국내 6개 지점을 무작위로 선별하여 강우침식능인자를 분석하였다. 본 연구 결과에서 나온 Deep Neural Network을 이용하면, 훨씬 적은 노력과 시간으로 원하는 지점에서 월별 강우침식능인자를 예측할 수 있으며, 한국 강우 패턴을 효율적으로 분석 할 수 있을 것이라 판단된다. 이를 통해 향후 토양 침식 위험을 지표화하는 것뿐만 아니라 토양 보전 계획을 수립할 수 있으며, 위험 지역을 우선적으로 선별하고 제시하는데 유용하게 사용 될 것이라 사료된다.

• Information Systems Review
• /
• v.19 no.4
• /
• pp.171-182
• /
• 2017

Although economic growth has been retarded since the global economic crisis over recent decades, a large number of firms consider mergers and acquisitions (M and A) as a strategy to survive in a highly competitive market. In particular, an increasing number of firms pursue M and A with IT firms in recent years. In this study, we analyze the post-merger risks measured as ROA volatility for acquiring firms when they seek to acquire an IT firm. Our analysis suggests that a firm with prior experience in M and A acquires IT firms aggressively. Moreover, a substantial number of IT firms are relatively small and unlisted when they are acquired. We also show that an acquiring firm's post-merger risk (i.e., ROA volatility) increases after its acquisition of IT firms. However, an increase in post-merger risk is alleviated when relatedness exists between an acquiring firm and target.

• Geophysics and Geophysical Exploration
• /
• v.9 no.1
• /
• pp.50-59
• /
• 2006

The risk of fault reactivation in the Gippsland Basin was calculated using the FAST (Fault Analysis Seal Technology) technique, which determines fault reactivation risk by estimating the increase in pore pressure required to cause reactivation within the present-day stress field. The stress regime in the Gippsland Basin is on the boundary between strike-slip and reverse faulting: maximum horizontal stress $({\sim}\;40.5\;Mpa/km)$ > vertical stress (21 Mpa/km) ${\sim}$ minimum horizontal stress (20 MPa/km). Pore pressure is hydrostatic above the Campanian Volcanics of the Golden Beach Subgroup. The NW-SE maximum horizontal stress orientation $(139^{\circ}N)$ determined herein is broadly consistent with previous estimates, and verifies a NW-SE maximum horizontal stress orientation in the Gippsland Basin. Fault reactivation risk in the Gippsland Basin was calculated using two fault strength scenarios; cohesionless faults $(C=0;{\mu}=0.65)$ and healed faults $(C=5.4;\;{\mu}=0.78)$. The orientations of faults with relatively high and relatively low reactivation potential are almost identical for healed and cohesionless fault strength scenarios. High-angle faults striking NE-SW are unlikely to reactivate in the current stress regime. High-angle faults oriented SSE-NNW and ENE-WSW have the highest fault reactivation risk. Additionally, low-angle faults (thrust faults) striking NE-SW have a relatively high risk of reactivation. The highest reactivation risk for optimally oriented faults corresponds to an estimated pore pressure increase (Delta-P) of 3.8 MPa $({\sim}548\;psi)$ for cohesionless faults and 15.6 MPa $({\sim}2262\;psi)$ for healed faults. The absolute values of pore pressure increase obtained from fault reactivation analysis presented in this paper are subject to large errors because of uncertainties in the geomechanical model (in situ stress and rock strength data). In particular, the maximum horizontal stress magnitude and fault strength data are poorly constrained. Therefore, fault reactivation analysis cannot be used to directly measure the maximum allowable pore pressure increase within a reservoir. We argue that fault reactivation analysis of this type can only be used for assessing the relative risk of fault reactivation and not to determine the maximum allowable pore pressure increase a fault can withstand prior to reactivation.