• Wind and Structures
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• v.29 no.5
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• pp.313-321
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• 2019

The wind blowing at high velocity in an open storage yard leads to wind erosion and loss of material. Fence structures can be constructed around the periphery of the storage yard to reduce the erosion. The fence will cause turbulence and recirculation behind it which can be utilized to reduce the wind erosion and loss of material. A properly designed fence system will produce lesser turbulence and longer shelter effect. This paper aims to show the applicability of Support Vector Machine (SVM) to predict the recirculation length. A SVM model was built, trained and tested using the experimental data gathered from the literature. The newly developed model is compared with numerical turbulence model, in particular, modified $k-{\varepsilon}$ model along with the experimental results. From the results, it was observed that the SVM model has a better capability in predicting the recirculation length. The SVM model was able to predict the recirculation length at a lesser time as compared to modified $k-{\varepsilon}$ model. All the results are analyzed in terms of statistical measures, such as root mean square error, correlation coefficient, and scatter index. These examinations demonstrate that SVM has a strong potential as a feasible tool for predicting recirculation length.

• Korean Journal of Artificial Intelligence
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• v.8 no.2
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• pp.1-5
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• 2020

Children's home accidents are less common than in the past. However, safety accidents continue to occur due to carelessness of the parents. To solve the problem, there are fall prevention screens that can withstand the weight of children, and safety railings that can be adjusted directly to solve the problem. However, these have disadvantages such as stability, convenience, and damage to the landscape. In this paper, we developed an automatic safety accident prevention fence system that can be installed on a window using Arduino, eliminating the disadvantages of previous safety accident prevention products. This system measures the height of a person standing in front of the fence and the distance between the person and the fence with two infrared sensors and moves automatically using a motor. In addition, in accordance with the U-Healthcare society, users can check the temperature, humidity, and fine dust concentration of the external environment through mobile. Each information can be obtained through DHT 11 sensor, fine dust concentration sensor, and Bluetooth connected toArduino. These can help the user's health care.

• Journal of the Korean School Mathematics Society
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• v.20 no.3
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• pp.325-344
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• 2017

Since PISA2006, the computer based assessment in mathematics(CBAM) was introduced for the first times and at last PISA2015 used all items in CBAM for problem solving. In this study, we focused on which important properties were considered in constructing geometric 'fence items' used in PISA 2015 to find the future direction over our teacher education, especially for constructing 'computer based assessment items.' For the purpose of the study, we analyzed the fence items on three components such as dependency, invariant, and path found in dragging activities, within a computer environment using the dynamic Geometry Software, GSP. Also, for the future, we provided an open-ended problem related to the fence items, which we could use as the merit of computer-based environment.

• Journal of the Korea Furniture Society
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• v.20 no.4
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• pp.307-316
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• 2009

Seoul, the capital of Korea, is worldwide city; Seoul is 600 year-old city as a capital and more than 10 millions of population live in Seoul, Image of Seoul has began to be known to the peoples in the world through 1988 Seoul Olympic Games and 2002 World Cup. However, in the public design and trees lining street system, Seoul hasn't been escaped from the image of a city which lacks of the characterization in the culture and identity aspects. This paper applied a protective fence designing simulation for Cultural Street in Seoul to develop much more the identity of Seoul and characterization of local culture. Also, It's examined and analyzed R&D data, and applied traditional patterns to design to set developmental capacity of design and a direction of fence design in the past, present and future. It's analyzed the present condition of domestic manufacturers and examples for installation, selected randomly 7 places of domestic cultural places as an alternative to compare the previous design to the present design with 3D design and photos composing method, and developed the related situation. Also, It's visualized this method to let the citizens and all levels of society determine the design. besides that, developed the traditional patterns to apply the patterns to the design, considering the characteristic of each region and characteristic of each road. It's suggested this fence design to apply the image of advanced Korea and Seoul as a creative cultural city, and the international status of Korea and Seoul to the trees on the historical and traditional street. Also, put an importance to bring the identity of Seoul and Korea in the world into relief.

• Journal of the Society of Naval Architects of Korea
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• v.33 no.4
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• pp.22-31
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• 1996

An efficient calculation method of pressure acting on a bluff body is developed. The method is applied to assess the containment capability of an oil fence, considering skirt deformation in current. The pressure on the frontal side of the oil fence is determined by analyzing the potential flow, substituting the wake region as a rigid body which has its boundary at the closed separation streamlines. The pressure at the downstream side of the fence, the so called base pressure, is obtained from the existing experimental results. To verify the calculation method, pressure drag of some bluff bodies in an infinite-fluid medium is calculated, which shows good agreement with the experimental results. The deformed shape of the oil fence is obtained by solving, iteratively, the coupled equations governing the flow field and the deformation of the oil fence, respectively. The deformed shape and the decrease of draft of oil fences with different ballast mass in various current conditions are investigated.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.5
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• pp.297-302
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• 2020

Korea has many mountainous regions, and slope collapse that can lead to damage in road facilities and loss of lives often occurs. Rockfall-protection facilities are necessary to reduce such damages. Among these facilities, the standard Korean rockfall-protection fence is designed to resist 50 kJ of rockfall impact energy. However, the range of rockfall energy significantly varies depending on the condition of the slope, and it sometimes reaches up to 100 kJ. Thus, providing several types of standardized rockfall-protection fence is necessary to address the different rockfall impact energy for efficient response to rockfalls. This paper presents a study on standardized rockfall-protection fence for various rockfall impact energy using finite-element analysis. According to the results, standardized rockfall-protection fences against rockfall impact energy of 30 and 100 kJ were proposed and have been verified.

• Korean Journal of Construction Engineering and Management
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• v.5 no.5 s.21
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• pp.135-142
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• 2004

This paper proposes the CPM bar chart (CBC), a hybrid of the bar chart and the critical pad method (CPM). The CBC overcomes shortages of the fenced bar chart, while still keeping advantages. The fence with direction is applied instead of the broken fence, which triggers considerable problems to identify and apply in the fenced bar chart. In addition, the notorious task to find dummy activities is no longer required. Upon the benefits of simplicity in the bar chart and logical work sequence in the CPM network. the CBC provides a relatively easy way to create and understand a schedule, thus improving communication quality between project participants. With the advantages, the CBC can also be effectively applied to various scheduling techniques such as resource constrained scheduling, resource leveling, scheduling with activity split, delay impact analysis, etc.

• Journal of the Korean GEO-environmental Society
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• v.23 no.2
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• pp.5-12
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• 2022

In this study, a field test was conducted to present a test method for performance evaluation of a rock fall prevention fence, centering on the vertical drop test among the existing test methods of the rock fall prevention fence. A test to determine the support capacity of a rockfall prevention fence in Korea is usually conducted using a combination of wire mesh, poles, and wire rope, and the location of the impact of falling rocks has been conducted centered on the center of the wire mesh. However, in the case of domestic papers and test data, there is no data on direct hit of post. Therefore, the amount of displacement and weak section were analyzed when the impact on 100kJ class rock energy was hit on the post, centering on the Rockfall Protection fence (highway type No. 2).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.5
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• pp.1071-1076
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• 2015

This paper proposed an efficient algorithm for tension sensing smart fence system with wireless sensor transmission module installation and alarming services. The wired transmission system demonstrates high accuracy and low latency, but the cost is expensive and transmission error may occur. For these reasons, this paper presented to use wireless transmission communication using Zigbee module technology in order to decrease delay and latency and solve the battery issues.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.61-62
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• 2006

The suppression of fluid force acting on a square prism near plane wall was studied by attaching fences on the comers of the prism. The height of the fence was 10% of the square width and the range of Reynolds number considered was $Re=2.0{\times}10^4$. The experimental parameters were the attaching position and numbers of fences, the space ratios $G/B(G/B=0.1{\sim}1.2)$ between prism and plane wall. The average drag coefficients were increased and the average hit coefficients were decreased and increased with the space ratios foulard plane wall. The drag of the prism was reduced average 7.6% with the space ratios by attaching the normal fence at the rear and upper comer and the horizontal normal fence at the rear and lower corner on the prism.