• Title/Summary/Keyword: Post structures

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Measurement Accuracy for 3D Structure Shape Change using UAV Images Matching (UAV 영상정합을 통한 구조물 형상변화 측정 정확도 연구)

  • Kim, Min Chul;Yoon, Hyuk Jin;Chang, Hwi Jeong;Yoo, Jong Soo
    • Journal of Korean Society for Geospatial Information Science
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    • v.25 no.1
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    • pp.47-54
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    • 2017
  • Recently, there are many studies related aerial mapping project and 3 dimensional shape and model reconstruction using UAV(unmanned aerial vehicle) system and images. In this study, we create 3D reconstruction point data using image matching technology of the UAV overlap images, detect shape change of structure and perform accuracy assessment of area($m^2$) and volume($m^3$) value. First, we build the test structure model data and capturing its images of shape change Before and After. Second, for post-processing the Before dataset is convert the form of raster format image to ensure the compare with all 3D point clouds of the After dataset. The result shows high accuracy in the shape change of more than 30 centimeters, but less is still it becomes difficult to apply because of image matching technology has its own limits. But proposed methodology seems very useful to detect illegal any structures and the quantitative analysis of the structure's a certain amount of damage and management.

Investigation of Properties of Structural Foam with Different Conformation and via Thermal Aging Condition (구조용 폼의 조성 및 열 노화에 따른 변형특성 관찰)

  • Choe, Jin-Yeong;Kwon, Il-Jun;Park, Sung-Min;Kwon, Dong-Jun
    • Composites Research
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    • v.31 no.4
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    • pp.122-127
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    • 2018
  • Sandwich composites of carbon fiber reinforced plastic(CFRP) and polymer foam will be used to automobile and aerospace industry according to increasing importance of light weight. In this study, mechanical and heat resistance properties of sandwich composites were compared with type of polymer foam (polyethylene terephthalate(PET), polyvinylchloride(PVC), epoxy and polyurethane). All types of polymer foams were degraded to 30, 60, 120, 180 minutes in $180^{\circ}C$. After heat degradation, the polymer foams were observed using optical microscope and compressive test was performed using universal testing machine(UTM). Epoxy foam had the highest compressive property to 2.6 MPa and after thermal degradation, the mechanical property and structure of foam were less changed than others. Epoxy foam had better mechanical properties than other polymer foams under high temperature. Because the epoxy foam was post cured under high temperature. As the results, Epoxy foam was optimal materials to apply to structures that thermal energy was loaded constantly.

Clinical Applications of Neuroimaging with Susceptibility Weighted Imaging: Review Article (SWI의 신경영상분야의 임상적 이용)

  • Roh, Keuntak;Kang, Hyunkoo;Kim, Injoong
    • Investigative Magnetic Resonance Imaging
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    • v.18 no.4
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    • pp.290-302
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    • 2014
  • Purpose : Susceptibility-weighted magnetic resonance (MR) sequence is three-dimensional (3D), spoiled gradient-echo pulse sequences that provide a high sensitivity for the detection of blood degradation products, calcifications, and iron deposits. This pictorial review is aimed at illustrating and discussing its main clinical applications. Materials and Methods: SWI is based on high-resolution, 3D, fully velocity-compensated gradient-echo sequences using both magnitude and phase images. To enhance the visibility of the venous structures, the magnitude images are multiplied with a phase mask generated from the filtered phase data, which are displayed at best after post-processing of the 3D dataset with the minimal intensity projection algorithm. A total of 200 patients underwent MR examinations that included SWI on a 3 tesla MR imager were enrolled. Results: SWI is very useful in detecting multiple brain disorders. Among the 200 patients, 80 showed developmental venous anomaly, 22 showed cavernous malformation, 12 showed calcifications in various conditions, 21 showed cerebrovascular accident with susceptibility vessel sign or microbleeds, 52 showed brain tumors, 2 showed diffuse axonal injury, 3 showed arteriovenous malformation, 5 showed dural arteriovenous fistula, 1 showed moyamoya disease, and 2 showed Parkinson's disease. Conclusion: SWI is useful in detecting occult low flow vascular lesions, calcification and microbleed and characterising diverse brain disorders.

An Observation on Characteristic of Architectural Paradigm in Twentieth Century Fashion Design (20세기 패션디자인의 건축적 패러다임 특성 고찰)

  • Park, Shin-Mi;Lee, Jae-Jung
    • Journal of the Korean Society of Costume
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    • v.58 no.2
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    • pp.78-92
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    • 2008
  • The mutual relationship between fashion and architecture and the similarities in their form and structure have been continuously debated over the decades, considering that both spheres are objects used in human life. Both spheres bring about the creation of three-dimensional space structures that are completed by the human body and material, based on a design targeted for people. The similarities between fashion and architecture in terms of form and structure have been debated by western architecture scholars focusing on the support that holds the garment's shape, the tailoring of a men's suit and also the material. The debate originates from the discussion of F. Th. Vischer, Kritische Gnge, and Gottfried Semper during the nineteenth century on the similarities between crinoline and the form of architecture and also the similarities between sewing and architecture. However, architects always regarded fashion as the inferior creative process that follows architecture in viewing the relationship between fashion and architecture. During the mid to end of the twentieth century, contrary to previous decades, the sense of fashion in architecture stood out, as an issue and a different approach was taken in discussing architecture that incorporates fashion. Accordingly, in the mid 1990's, architecture scholars such as Deborah Fausch and Mark Wigley began to conduct close observation of the mutual relationship between fashion and architecture from a more equal point of view. Notwithstanding, their point of view was still biased towards architectural standards. Commencing the Millennium, fashion has become the primary work of creation which leads style in all spheres, and under these circumstances this point of view has transferred from architecture to fashion when thinking about relationships between these spheres. The discussion on fashion and architecture form fashion's point of view is currently concentrated on the post 1990's phenomenon and illustrates the environment that is related to architecture. In general, the discussion is limited to determining a work of an individual designer as 'being architectural' when explaining the sculptural form of fashion. Therefore, this research aims to renew the discussion on twentieth century fashion design, which was neglected in any studies on observing architecture and fashion. The aim of this research is to classify the architectural paradigm of twentieth century fashion design and to observe the architectural forms of the respective eras. It is necessary to have a close observation of the architectural paradigm in twentieth century fashion design where support tools such as the crinoline was avoided and the form and functionality of the garment itself was emphasized. I will conduct this research by considering the architectural form shown in fashion as a practical three-dimensional creation that exists in space.

Fine Structure on the Epidermis of the Scalp of the Head-Irradiated Rats (방사선 조사를 받은 흰쥐 머리피부 표피층의 미세구조)

  • Ko, Jeong-Sik;Kim, Jae-Ho;Yang, Nam-Gil;Ahn, E-Tay;Park, Kyung-Ho;Kim, Jin-Gook
    • Applied Microscopy
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    • v.24 no.2
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    • pp.63-77
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    • 1994
  • This experiment was performed to study the morphological responses of the epidermis of the rat scalp, following X-ray irradiation. Male rats were divided into normal and experimental groups. Rats anesthetized with sodium thiopental, were exposed only on their head areas with a single dose of 3,000rads or 6,000rads, respectively. Radiation was produced by Mitsubishi Linea Accelerator ML-4MV at the speed of 200rads/min. The target distance was 80cm. Animals were sacrificed on six hours, two days and six days following irradiation. By the perfusion fixation through the heart, rats were fixed with 1% glutaraldehyde-1% paraformaldehyde solution. Pieces of the tissue taken from the scalp were refixed in 2.5% glutaraldehyde-1.5% paraformaldehyde solution, followed by post-fixation with 1% osmium tetroxide, and embedded within araldite mixture. The sections were cut on a LKB-V ultratome, stained with uranyl acetate and lead citrate, and were observed with JEM 100CX-II electron microscope. The results were as follow; 1. Six hours after exposure to 3,000rads of X-ray. Disrupted intercellular spaces, within which some amorphous materials were filled, disrupted mitochondria, and vacuoles in the keratinocytes were frequently observed, but six days after exposure to 3,000rads of X-ray, Morphology of the keratinocytes was generally restored. 2. Many of the morphological changes were seen on the six days after exposure to 6,000rads of X-ray. 3. Widened intercellular spaces and thickened dense plaques of the desmosomes were frequently observed after exposure to 6,000rads of X-ray. 4. In the experimental groups, the Langerhans and the Merkel cells were damaged, similarly to the keratinocyte. Above results suggest that head irradiation with the dose of 3,000rads temporarily damaged the epidermis of the scalp, though most of the structures recover within six days, whereas with the dose of 6,000rads it severely damaged the epidermis without showing any recovering tendency.

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Properties of Pb(Zr, Ti)$\textrm{O}_3$ Ferroelectric Thin Films on MgO/Si Substrate by RF Sputtering (RF 스퍼터링에 의해 MgO/Si 기판위에 증착된 Pb(Zr, Ti)$\textrm{O}_3$ 강유전체 박막의 특성연구)

  • Jang, Ho-Jeong;Seo, Gwang-Jong;Jang, Ji-Geun
    • Korean Journal of Materials Research
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    • v.8 no.12
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    • pp.1170-1175
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    • 1998
  • PZT films without lower electrode were deposited on the highly doped Si(100) substrate with MgO buffer layer (Mgo/si) by RF magnetron sputtering method followed by the rapid thermal annealing at $650^{\circ}C$ . We investigated the dependences of the crystalline and electrical properties on the MgO thickness and the RTA post annealing. The PZT films on bare Si (without MgO) showed pyrochlore crystal structure while those on MgO(50 )/Si substrates showed the typical perovskite crystal structures. From SEM and AES analysis, the thickness of PZT films was about 7000 showing relatively smooth interface. The depth profiles indicated that atomic species were distributed homogeneously in the PZT/MgO/Si substrate. The dielectric constant($\varepsilon_{r}$ ) and remanent polarization(2Pr) were about 300 and $14\mu$C/$\textrm{cm}^2$;, respectively. The leakage current was about $3.2\mu$/A$\textrm{cm}^2$.

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Experimental investigation on flexural behaviour of HSS stud connected steel-concrete composite girders

  • Prakash, Amar;Anandavalli, N.;Madheswaran, C.K.;Lakshmanan, N.
    • Steel and Composite Structures
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    • v.13 no.3
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    • pp.239-258
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    • 2012
  • In this paper, experimental investigations on high strength steel (HSS) stud connected steel-concrete composite (SCC) girders to understand the effect of shear connector density on their flexural behaviour is presented. SCC girder specimens were designed for three different shear capacities (100%, 85%, and 70%), by varying the number of stud connectors in the shear span. Three SCC girder specimens were tested under monotonic/quasi-static loading, while three similar girder specimens were subjected to non-reversal cyclic loading under simply supported end conditions. Details of casting the specimens, experimental set-up, and method of testing, instrumentation for the measurement of deflection, interface-slip and strain are discussed. It is found that SCC girder specimen designed for full shear capacity exhibits interface slip for loads beyond 25% of the ultimate load capacity. Specimens with lesser degree of shear connection show lower values of load at initiation of slip. Very good ductility is exhibited by all the HSS stud connected SCC girder specimens. It is observed that the ultimate moment of resistance as well as ductility gets reduced for HSS stud connected SCC girder with reduction in stud shear connector density. Efficiency factor indicating the effectiveness of high strength stud connectors in resisting interface forces is estimated to be 0.8 from the analysis. Failure mode is primarily flexure with fracturing of stud connectors and characterised by flexural cracking and crushing of concrete at top in the pure bending region. Local buckling in the top flange of steel beam was also observed at the loads near to failure, which is influenced by spacing of studs and top flange thickness of rolled steel section. One of the recommendations is that the ultimate load capacity can be limited to 1.5 times the plastic moment capacity of the section such that the post peak load reduction is kept within limits. Load-deflection behaviour for monotonic tests compared well with the envelope of load-deflection curves for cyclic tests. It is concluded from the experimental investigations that use of HSS studs will reduce their numbers for given loading, which is advantageous in case of long spans. Buckling of top flange of rolled section is observed at failure stage. Provision of lips in the top flange is suggested to avoid this buckling. This is possible in case of longer spans, where normally built-up sections are used.

A Study on Coupling Coefficient and Resonant Frquency tunable Multi-band Internal Antenna (결합계수 및 주파수 튜너블 다중대역 내장형 안테나에 관한 연구)

  • Lee, Moon-Woo;Lee, Sang-Hyun
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.8
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    • pp.59-66
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    • 2010
  • In this paper, the internal antenna for mobile communication handset which is able to control both coupling coefficient and resonant frequency without any major modification of radiator and ground plane of antenna. Novel internal antenna with its controllable resonant frequency is presented for triple-band or over mobile handsets. The operating range can include GSM(880~960 MHz), GPS($1,575{\pm}10MHz$), DCS(1,710~1,880MHz), US-PCS(1,850~1,990 MHz), and W-CDMA(1,920~2,170 MHz). The proposed antenna is realized by combination of a half wavelength loaded line antenna and PIFA(Planner Inverted F Antenna). A single shorting and feeding points are used and they are common to both antenna structures. One of two inductors which is placed at each shorting post, one inductor is for adjusts amount of coupling, and the other controlling the resonant frequency in DCS/US-PCS/WCDMA bands. The inductance range for control of input impedance is between 0nH and 6.8nH, and each of gain variation in GSM, GPS and DCS/US-PCS/WCDMA band is under 0.15dBi, 0.73dBi and 0.29dBi. The inductance range for control of the resonant frequency is between 1640MHz and 2500MHz, and each of gain variation in GSM, GPS and DCS/US-PCS/WCDMA band is under 0.46dBi, 0.53dBi and 0.8dBi.

The Need for Weight Optimization by Design of Rolling Stock Vehicles

  • Ainoussa, Amar
    • International Journal of Railway
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    • v.2 no.3
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    • pp.124-126
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    • 2009
  • Energy savings can be achieved with optimum energy consumptions, brake energy regeneration, efficient energy storage (onboard, line side), and primarily with light weight vehicles. Over the last few years, the rolling stock industry has experienced a marked increase in eco-awareness and needs for lower life cycle energy consumption costs. For rolling stock vehicle designers and engineers, weight has always been a critical design parameter. It is often specified directly or indirectly as contractual requirements. These requirements are usually expressed in terms of specified axle load limits, braking deceleration levels and/or demands for optimum energy consumptions. The contractual requirements for lower weights are becoming increasingly more stringent. Light weight vehicles with optimized strength to weight ratios are achievable through proven design processes. The primary driving processes consist of: $\bullet$ material selection to best contribute to the intended functionality and performance $\bullet$ design and design optimization to secure the intended functionality and performance $\bullet$ weight control processes to deliver the intended functionality and performance Aluminium has become the material of choice for modern light weight bodyshells. Steel sub-structures and in particular high strength steels are also used where high strength - high elongation characteristics out way the use of aluminium. With the improved characteristics and responses of composites against tire and smoke, small and large composite materials made components are also found in greater quantities in today's railway vehicles. Full scale hybrid composite rolling stock vehicles are being developed and tested. While an "overdesigned" bodyshell may be deemed as acceptable from a structural point of view, it can, in reality, be a weight saving missed opportunity. The conventional pass/fail structural criteria and existing passenger payload definitions promote conservative designs but they do not necessarily imply optimum lightweight designs. The weight to strength design optimization should be a fundamental design driving factor rather than a feeble post design activity. It should be more than a belated attempt to mitigate against contractual weight penalties. The weight control process must be rigorous, responsible, with achievable goals and above all must be integral to the design process. It should not be a mere tabulation of weights for the sole-purpose of predicting the axle loads and wheel balances compliance. The present paper explores and discusses the topics quoted above with a view to strengthen the recommendations and needs for the weight optimization by design approach as a pro-active design activity for the rolling stock industry at large.

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Ridge and field tile aerodynamics for a low-rise building: a full-scale study

  • Tecle, Amanuel;Bitsuamlak, Girma T.;Suskawang, Nakin;Chowdury, Arindam Gan;Fuez, Serge
    • Wind and Structures
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    • v.16 no.4
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    • pp.301-322
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    • 2013
  • Recent major post-hurricane damage assessments in the United States have reported that the most common damages result from the loss of building roof coverings and subsequent wind driven rain intrusion. In an effort to look further into this problem, this paper presents a full-scale (Wall of Wind --WoW--) investigation of external and underneath wind pressures on roof tiles installed on a low-rise building model with various gable roofs. The optimal dimensions for the low-rise building that was tested with the WOW are 2.74 m (9 ft) long, 2.13 m (7 ft) wide, and 2.13 m (7 ft) high. The building is tested with interchangeable gable roofs at three different slopes (2:12; 5:12 and 7:12). The field tiles of these gable roofs are considered with three different tile profiles namely high (HP), medium (MP), and low profiles (LP) in accordance with Florida practice. For the ridge, two different types namely rounded and three-sided tiles were considered. The effect of weather block on the "underneath" pressure that develops between the tiles and the roof deck was also examined. These tests revealed the following: high pressure coefficients for the ridge tile compared to the field tiles, including those located at the corners; considerably higher pressure on the gable end ridge tiles compared to ridge tiles at the middle of the ridge line; and marginally higher pressure on barrel type tiles compared to the three-sided ridge tiles. The weather blocking of clay tiles, while useful in preventing water intrusion, it doesn't have significant effect on the wind loads of the field tiles. The case with weather blocking produces positive mean underneath pressure on the field tiles on the windward side thus reducing the net pressures on the windward surface of the roof. On the leeward side, reductions in net pressure to a non-significant level were observed due to the opposite direction of the internal and external pressures. The effect of the weather blocking on the external pressure on the ridge tile was negligible.