• Computers and Concrete
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• v.19 no.5
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• pp.509-514
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• 2017

Concrete retaining walls are the most common types of geotechnical structures for controlling instable slopes resulting from lateral pressure. In analytical stability, calculation of the concrete retaining walls is regarded as a rigid mass when its safety is required. When cracks in these structures are created, the stability may be enforced and causes to defeat. Therefore, identification, creation and propagation of cracks are among the important steps in control of lacks and stabilization. Using the numerical methods for simulation of crack propagation in concrete retaining walls bodies are among the new aspects of geotechnical analysis. Among the considered analytical methods in geotechnical appraisal, the boundary element method (BEM) for simulation of crack propagation in concrete retaining walls is very convenient. Considered concrete retaining wall of this paper is Pars Power Plant structured in south side in Assalouyeh, SW of Iran. This wall's type is RW6 with 11 m height and 440 m length and endurance of refinery construction lateral forces. To evaluate displacement and stress distributions (${\sigma}_{1,max}/{\sigma}_{3,min}$), the surrounding, especially in tip and its opening crack BEM, is considered an appropriate method. By considering the result of this study, with accurate simulation of crack propagation, it is possible to determine the final status of progressive failure in concrete retaining walls and anticipate the suitable stabilization method.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.284-292
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• 2009

The stack-effect in high-rise buildings in winter causes many problems such as difficulties in opening or closing doors, infiltration, energy loss, noise and fire protection. Stack effect is influenced by temperature difference between the interior and exterior of building and the height of building. As an attenuation method for stack effect, the architectural methods are generally used. However, as though architectural methods were fully adopted, the problems are reported as ever in tall building. In this study, a new method to reduce stack effect will be suggested. As an active control method against the stack effect, E/V shaft natural cooling method is suggested. In this paper, the concept of E/V shaft natural cooling system and its reduction performance of stack effect by simulation and field measurement will be reported.

• Geomechanics and Engineering
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• v.14 no.1
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• pp.83-90
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• 2018

A series of pullout tests were carried out on waste tire treadmats of various weave arrangements, with confining stresses ranging from 9 to 59 kPa approximately, in order to investigate the pullout behavior and to apply the results to the design of treadmat reinforced soil structures. A treadmat reinforcement can be considered as belonging to the extensible type thus progressive failure would develop in every tread. The pullout capacity of a treadmat was found to be generally equal to the sum of capacities of the longitudinal treads, with minor enhancement realized due to the presence of transverse treads. Pullout failures occurred in treadmats under light surcharge and with treadmats with higher material presence per unit area, while breakage failures occurred in treadmats under heavier surcharge and with treadmats with higher ratio of opening. The pullout capacity of a treadmat increased with increasing surcharge height and treadmat stiffness. A pullout test on a commercially available geogrid was also carried out for comparison and the pullout capacity of a treadmat was found higher than that of the comparable geogrid under identical loading conditions, indicating the merit of using the treadmat as an alternative to the chosen geogrid.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.341-345
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• 2009

We present an augmented reality (AR) application for cell phone where users put a virtual pet on their palms and play/interact with the pet by moving their hands and fingers naturally. The application is fundamentally based on hand/palm pose recognition and finger motion estimation, which is the main concern in this paper. We propose a fast and efficient hand/palm pose recognition method which uses natural features (e.g. direction, width, contour shape of hand region) extracted from a hand image with prior knowledge for hand shape or geometry (e.g. its approximated shape when a palm is open, length ratio between palm width and pal height). We also propose a natural interaction method which recognizes natural motion of fingers such as opening/closing palm based on fingertip tracking. Based on the proposed methods, we developed and tested the AR application on an ultra-mobile PC (UMPC).

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.519-527
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• 1996

Most operation related to the application granular agrochemicals in korea are manual and labour consuming. As a multipurpose granular applicator, a pneumatic granular applicator that can be attached to conventional ride -on machines for paddy field was designed in this study. Experiments and simulations were carried out for determine in the design factors with one fertilizer (DongBu 21-17-17) and one pesticide (SamKong Ivi). The maximum terminal velocity of granular chemicals was estimated as 14.2m/s. A better distribution pattern was obtained at the diffuser having only deflectors without dividing guides. The diffuser spacing 1.0m for the fertilizer and the diffuser spacing 0.8m for the pesticide at the boom height over 0.80m were acceptable for the uniform distribution. In the case that the forward speed of ride-on machines was 0.7m/s, the groove opening and the roller speed of the selected metering device were13mm -15mm at 2 rps for the fertilizer, and 9 mm-11mm at 0.25rps or the pesticide. This study suggested a method of developing a pneumatic applicator for granular agrochemicals.

• Journal of Korean Association for Spatial Structures
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• v.18 no.3
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• pp.125-132
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• 2018

The biggest impact on the cladding design of buildings is wind loads. Wind tunnel tests were conducted to examine the applicability of current wind load standards about membrane retractable roof spatial structure. A dome model with a circular shape that is retractable to the center of the dome was made (Opening ratio = 0, 10, 30, 50). In addition, height adjustable turntables were made and tested with five patterns with H/D = 0.1, 0.2, 0.3, 0.4 and 0.5. The maximum wind pressure coefficient and the minimum wind pressure coefficient for the cladding were analyzed and the experimental wind pressure coefficient were compared with the current wind load standards, KBC2016 and AIJ-RLB(2015). The experimental value and the reference value of the enclosed roof were very similar and showed possibility of application, but opened roof case was found that the reference value was underestimated.

• Journal of the Korean housing association
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• v.18 no.5
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• pp.45-52
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• 2007

The demographic profile of the households will shift towards the 'older elderly'. There are need upgrading existing housing and new housing in aspect of floor plan, accessories, facilities and so on. The government should prepare the policy and standards of housing design for the aged and disabled in order to improving the residents' housing conditions. The purpose of this study is to compare Korean to foreign guidelines related to residential design for the elderly and disabled and find out the characteristics of our standards. It was accomplished by literature research. The results were as follows. There is disagreements between domestic standards over the clear door opening, the clear hallways and handrails at entrance. And the foreign standards are based on their wheelchair size, ours are founded on it's size which specified only maximum overall dimensions. So ours are seem to be lack of accuracy. Our standard of stairs is in details in comparison with other space components. But ours don't go into details than foreign ones over length of hand-rails, riser etc. And for recommendations denoting minimum and maximum height of various component, it should be preceded the specific survey on limits of reaching ability for the elderly and disabled.

• Journal of the Korean Home Economics Association
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• v.39 no.11
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• pp.1-14
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• 2001

In order to develop a manual of residential alterations for the physically disabled, this case study was accomplished to analyze and evaluate residential environments and residential alterations for physically disabled women. Twenty-nine physically disabled women in Seoul and Kyunggi areas were the subjects of this study. With the evaluation checklist on physical environments of their housing, data on general characteristics of wall, floor, and all features and equipments and spaces of bedroom, kitchen, bathroom, living mom, entrance and balcony were gathered. Also, data on residential alterations were gathered through personal interviews. The data were collected from July 18th to July 25th in 2000. Frequency, percentage, and mean were used to analyze the data. In kitchen, small space, hee space under the sink and heights of the lower cabinets were not properly provided. In bathroom, door width, direction of opening door, adjustable height of shower, level difference, clear space for wheelchair user, and storage place were not appropriate to the disabled. Kitchen and bathroom showed high frequencies of alteration. But most of the subjects were not satisfied with the alterations of their housing. They also wanted to alter these two spaces in the future. In order to after their housing effectively appropriate information of the residential alterations was needed. If a guide or manual book for residential alterations was provided, the physically disabled people will more easily after their housing for safe and independent life.

• Smart Media Journal
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• v.5 no.3
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• pp.93-98
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• 2016

The literal meaning of loitering is "to lingering aimlessly or as if aimless in or about a place". And most criminals show this kind of act before they actually commit crime. Therefore, detecting this kind of loitering can effectively prevent a variety of crime. In this paper, we propose a loitering-detection algorithm using the Raspberry Pi. Proposed algorithm uses an adaptive difference image to detect moving objects and morphology opening operation to enhance the accuracy of detection. The loitering- behavior is being detected by using the center of gravity of the object to see the changes of angle; and pixel movement distance to determine the height of the object. When the loitering-behavior is detected, it outputs the alarm to tell the users by using the Raspberry Pi.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.323-327
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• 2004

The bubble flow from the wafer surface during plating process was studied in this paper. The plating shape in the opening of photoresist becomes gradated shape in the fountain plating system, because bubbles from the wafer surface are difficult to escape from the deep openings, vias. So, we designed the tilted electrode ring contact to get uniform bump height on all over the wafer and evaluated the film uniformity by SEM and ${\alpha}-step$. In ${\alpha}-step$ measurement, film uniformities in the fountain plating system and the tilted electrode ring contact system were ${\pm}16.6%,\;{\pm}4%$ respectively.