• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.2
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• pp.115-121
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• 2022

As city environments have recently become crowded, there are many obstacles that interfere with the walking of the visually impaired on pedestrian roads. Typical examples include ballads, parking breakers and standing signs, which usually do not get in the way, but blind people may be injured by collisions. To solve such a problem, many solutions have been proposed, but they are limited in applied in practical environments due to the several restrictions such as outside use only, inaccurate obstacle sensing and requirement of special devices. In this paper, we propose a new method to automatically detect obstacles while walking on the pedestrian roads and warn the collision risk in advance by using only sensors embedded in typical mobile phones. The proposed method supports the walking of the visually impaired by notifying the type of obstacles appearing in front of them as well as the distance remaining from the obstacles. To accomplish this goal, we utilized an object recognition technology applying the latest deep learning algorithms in order to identify the obstacles appeared in real-time videos. In addition, we also calculate the distance to the obstacles using the number of steps and the pedestrian's stride. Compared to the existing walking support technologies for the visually impaired, our proposed method ensures efficient and safe walking with only simple devices regardless of the places.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.1
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• pp.1-14
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• 2022

In order to conduct rapid, accurate and safe surveying at the excavation site, In this study, the possibility of underground facility survey using drones and the expected effect of 3D visualization were obtained as follows. Phantom4Pro 20MP drones have a 30m flight altitude and a redundant 85% flight plan, securing a GSD (Ground Sampling Distance) value of 0.85mm and 4points of GCP (Groud Control Point)and 2points of check point were calculated, and 7.3mm of ground control point and 11mm of check point were obtained. The importance of GCP was confirmed when measured with low-cost drones. If there is no ground reference point, the error range of X value is derived from -81.2 cm to +90.0 cm, and the error range of Y value is +6.8 cm to 155.9 cm. This study classifies point cloud data using the Pix4D program. I'm sorting underground facility data and road pavement data, and visualized 3D data of road and underground facilities of actual model through overlapping process. Overlaid point cloud data can be used to check the location and depth of the place you want through the Open Source program CloudCompare. This study will become a new paradigm of underground facility surveying.

• Journal of Internet Computing and Services
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• v.24 no.6
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• pp.171-180
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• 2023

Hydrogen energy technology is gaining importance in the era of the Fourth Industrial Revolution, offering military advantages when applied to military vehicles due to its characteristics such as reduced greenhouse gas emissions, noise, and low vibration. Korea's military has initiated the Army Tiger 4.0 plan, focusing on hydrogen application, downsizing, and AI-based smart features. The Ministry of National Defense plans to collaborate with the Ministry of Environment to expand hydrogen charging stations nationwide, anticipating increased deployment of military hydrogen vehicles. However, considering the Jet Fire and VCE(Vapor Cloud Explosion) nature of hydrogen, ensuring safety during installation is crucial. Current military guidelines specify a minimum safety distance of 2m from adjacent buildings for charging stations. Scientific methods have been employed to quantitatively assess the accident damage range of hydrogen, proposing a minimum safety distance beyond the affected area.

• Journal of Navigation and Port Research
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• v.38 no.1
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• pp.19-27
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• 2014

When a ship operates in a shallow water and channel, the hull sinkage and asymmetrical force generated around the ship by the influence of sea bottom and bank walls are caused collision with sea bottom, other ships or the bank itself. Especially, the shipping company and pilots navigating the area of Europe and North America with many channels are deal with it as a important matter to prevent collision. In this paper, hydrodynamic force generated between the ship and bank using the numerical analysis for the safe navigation of ship, that is, sway force and yaw moment should be presumed qualitatively. It makes a program for fluid analysis of the shallow water and bank effect. Analyses are carried out for three kind of parameter, that is, ship's speed, water depth and ship-bank distance for crude oil carriers. The numerical analysis results are compared with results of the experiments and the previous published papers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2324-2329
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• 2014

The inspection of distance to go train control system conducted only when train is in main line or inspecting line, that affects low work efficiency and hazard elements to safe operation. Before or after train operation, the interface test between on-board and wayside signal system must be conducted. In this paper, onboard signal interface inspection system based on the real-time automatic analysis of onboard system status information that is transmitted to the wayside system and the operation status check of the onboard signal device operates as a virtual train information that is transmitted to the onboard system have been proposed. And after building the inspection system to the inspecting track of Daejeon Subway Line 1, Panam Depot, the verification algorithm of proposed interface test and the results was presented. therefore, it has enhanced work efficiency to do not carry train operation of a half hour in test line to test on-board system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.5525-5533
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• 2012

Because of ultra-high buildings or deeper underground space, recent buildings have the potential that people who have lack of physical strength collapse before arriving at the emergency exits when catastrophes occur. In case of fire, the way to escape is that first, people take the stairs of the adjacent areas and then use the elevator to the remaining distance by road to escape notice or be safe. For this reason, the skyscrapers guidelines of Seoul for information on the elevator for evacuation has been established. Nevertheless, when designing buildings to install a elevator for evacuation separately is not effective, so passenger elevators installation according to the criteria are encouraged to use as evacuation elevators. However, this does not include detailed design guidelines so far. Therefore, this study was to investigate design method to use the passenger elevator for evacuation according to the domestic law and international installation criteria, and to calculated number of lifts and refuge to use the elevator using by the ELVAC+ and PathFinder evacuation program.

• Journal of the Ergonomics Society of Korea
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• v.31 no.2
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• pp.397-406
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• 2012

Objective: The aim of this study is to determine legible Korean font sizes within in-vehicle information systems(IVISs) in diving conditions. Background: Font legibility within IVISs is one of important causes on its' safe operations during driving. Several researches proposed some guidelines on the legible English font sizes within IVISs. On the contrary, appropriate Korean font sizes have been hardly known in spite of the typological differences between English and Korean. Therefore, more systematic researches for improving the legibility on Korean font size within IVISs have been required. Method: In this study, an experiment was performed with the following experimental factors: the existence of vibration, the color contrasts(white on black, black on white), the font types(HDR, CubeR, Gothic), and the font sizes(6, 8, 10, 12, 14, 16, 18, 20, 22, 24pt). To fit the experimental conditions into real driving environments, the illuminance was controlled to 15lx by using LED lamp and the distance between IVIS and participants was kept to 70cm. Moreover, all participants took the shutter glasses for employing well-known occlusion techniques. Results: The experimental results showed that 'HDR' and 'Non-vibration + Black on white' group took the shortest response time, and decreasing slopes of the response time with increasing font sizes were slowing down at 14pt then flattened out at 22pt regardless of the existence of vibration and color contrasts. Conclusion: The minimum size for legible Korean font would be about 14pt(5.47mm) and the optimum size would be about 22pt(8.59mm). Application: The guideline on the Korean font sizes from this study will be applied to design an IVIS in the future.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.2 s.5
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• pp.75-83
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• 2004

July 1, 2004 Seoul Metropolitan city is operating the Median Bus Lane System on Gangnam Main Street, Seongsan-Susaek-ro (Road) and Dobong- Mia-ro (Road) as one of the systematic reorganizations in public transportation. It has been assumed that there was an improvement in the speed of bus considering that the Median Bus Lane System practiced on Cheonho-daero (Main Street) since 1996 have had 35km/h on the average. If the Median Bus Lane goes into effect, there is a problem with the left turn on the crossroad. The buses go on the existing first lane so that the left fuming cars cannot help but turn left on the second lane. In case that the Median Bus Lane is put into practice, the left turn on the crossroad should not be allowed. However, if the left turn is not permitted on the crossroads in the aforementioned main streets, neighboring residents will complain about it and there will be some difficulties in finding other detour. On the premise that the prevalent left turn on the crossroads is allowed while the Median Bus Lane is being put into practice, this study suggests the separation of a stop line between buses and other vehicles as a way of fuming left in a safe manner and a way to calculate the appropriate distance.

• Archives of Plastic Surgery
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• v.42 no.4
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• pp.446-452
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• 2015

Background Various techniques are used for performing breast reduction. Wise-pattern and vertical scar techniques are the most commonly employed approaches. However, a vertical scar in the mid-lower breast is prominent and aesthetically less pleasant. In contrast, a semicircular horizontal approach does not leave a vertical scar in the mid breast and transverse scars can be hidden in the inframammary fold. In this paper, we describe the experiences and results of semicircular horizontal breast reductions performed by a single surgeon. Methods Between September 1996 and October 2013, our senior author used this technique in 38 cases in the US and at our institution. We used a superiorly based semicircular incision, where the upper skin paddle was pulled down to the inframammary fold with the nipple-areola complex pulled through the keyhole. Results The average total reduction per breast was 584 g, ranging from 286 to 794 g. The inferior longitudinal pedicle was used in all the cases. The average reduction of the distance from the sternal notch to the nipple was 13 cm (range, 11-15 cm). The mean decrease in the bra cup size was 1.7 cup sizes (range, a decrease of 1 to 3). We obtained very satisfactory results with a less noticeable scar, no complication such as necrosis of the nipple or the skin flap, wound infection, aseptic necrosis of the breast tissue, or wound dehiscence. One patient had a small hematoma that resolved spontaneously. Conclusions This technique is straightforward and easy to learn, and offers a safe, effective, and predictable way for treating mammary hypertrophy.

• Archives of Plastic Surgery
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• v.43 no.6
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• pp.564-569
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• 2016

Background Alar retraction is a challenging condition in rhinoplasty marked by exaggerated nostril exposure and awkwardness. Although various methods for correcting alar retraction have been introduced, none is without drawbacks. Herein, we report a simple procedure that is both effective and safe for correcting alar retraction using only conchal cartilage grafting. Methods Between August 2007 and August 2009, 18 patients underwent conchal cartilage extension grafting to correct alar retraction. Conchal cartilage extension grafts were fixed to the caudal margins of the lateral crura and covered with vestibular skin advancement flaps. Preoperative and postoperative photographs were reviewed and analyzed. Patient satisfaction was surveyed and categorized into 4 groups (very satisfied, satisfied, moderate, or unsatisfied). Results According to the survey, 8 patients were very satisfied, 9 were satisfied, and 1 considered the outcome moderate, resulting in satisfaction for most patients. The average distance from the alar rim to the long axis of the nostril was reduced by 1.4 mm (3.6 to 2.2 mm). There were no complications, except in 2 cases with palpable cartilage step-off that resolved without any aesthetic problems. Conclusions Conchal cartilage alar extension graft is a simple, effective method of correcting alar retraction that can be combined with aesthetic rhinoplasty conveniently, utilizing conchal cartilage, which is the most similar cartilage to alar cartilage, and requiring a lesser volume of cartilage harvest compared to previously devised methods. However, the current procedure lacks efficacy for severe alar retraction and a longer follow-up period may be required to substantiate the enduring efficacy of the current procedure.