• Title/Summary/Keyword: The Blind

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A component method model for blind-bolts with headed anchors in tension

  • Pitrakkos, Theodoros;Tizani, Walid
    • Steel and Composite Structures
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    • v.18 no.5
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    • pp.1305-1330
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    • 2015
  • The successful application of the component-based approach - widely used to model structural joints - requires knowledge of the mechanical properties of the constitutive joint components, including an appropriate assembly procedure to derive the joint properties. This paper presents a component-method model for a structural joint component that is located in the tension zone of blind-bolted connections to concrete-filled tubular steel profiles. The model relates to the response of blind-bolts with headed anchors under monotonic loading, and the blind-bolt is termed the "Extended Hollo-bolt". Experimental data is used to develop the model, with the data being collected in a manner such that constitutive models were characterised for the principal elements which contribute to the global deformability of the connector. The model, based on a system of spring elements, incorporates pre-load and deformation from various parts of the blind-bolt: (i) the internal bolt elongation; (ii) the connector's expanding sleeves element; and (iii) the connector's mechanical anchorage element. The characteristics of these elements are determined on the basis of piecewise functions, accounting for basic geometrical and mechanical properties such as the strength of the concrete applied to the tube, the connection clamping length, and the size and class of the blind-bolt's internal bolt. An assembly process is then detailed to establish the model for the elastic and inelastic behaviour of the component. Comparisons of model predictions with experimental data show that the proposed model can predict with sufficient accuracy the response of the component. The model furthers the development of a full and detailed design method for an original connection technology.

Design Optimization of M8 Blind Rivet Nut Geometry using Finite Element Analysis (유한요소해석을 이용한 M8 블라인드 리벳 너트 형상 최적 설계)

  • Gu, B.;Choi, J.M.;Hong, S.
    • Transactions of Materials Processing
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    • v.29 no.3
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    • pp.157-162
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    • 2020
  • Blind rivet nuts are increasingly used in automotive for the joining of sheets. Their application, however, requires appropriate design guides to prevent catastrophic events arising from the failure of joints. In this study, the shaft shape of a frequently used M8 blind rivet nut is optimized based on 3D numerical analysis of the blind rivet nut considering the characteristics of thread. The thread needs to be modeled to suitably consider the fastening of the M8 bolt after the crimping process. FE analysis showed that while the friction in the contact between crimp flange and plate has no significant effect on the crimp geometry, shaft thickness (t) and shaft height (h) are the most significant design variables. The parameter study including various combinations of t and h reveals that they affect the gap (the distance between the crimped flange and the plate that develops through riveting) and the load acting on the plate. The gap is an indicator of the tightening force. It is found that t is inversely proportional to the gap, and proportional to the load, whereas h is proportional to the gap and inversely proportional to the load. Based on our FE analysis results, we propose the range 0.062 < t/h < 0.1 to ensure sufficient fastening (high clamping load, small gap) of the M8 blind rivet nut. The design guide for determining the t/h ratio proposed in this study can be used for general quantitative analysis of the size and the t/h ratio of blind rivet nuts.

Product Analysis and Development of Amblyopia Eye Patch for Children

  • Lim, Hosun;Sung, Juyoung
    • Fashion, Industry and Education
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    • v.14 no.2
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    • pp.1-10
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    • 2016
  • In the present study, the materials, sizes, and designs of blind eye patch products of skin-adhesive type and glass-attachment type currently available in the market will be analyzed and ergonomically appropriate blind eye patches will be developed. Although these skin-adhesive type eye patches were easy to use, they had shortcomings such as skin troubles due to the adhesive used on the weak and sensitive skin of children and the fact that eyebrows are pulled out and the skin is irritated when the eye patches are detached after being attached. The non-adhesive type eye patches were blind patches to be worn by putting into glasses. These products were made using diverse materials such as neoprene, non-woven fabrics, and felt and showed differences in tactile impressions and irritation to the skin depending on material characteristics. In addition, most products were efficient in blocking light with three-dimensional oval designs comprising darts. In the present study, blind eye patches were designed to reduce skin troubles by using sweat-absorbing and quick-drying functional materials with soft tactile impressions. In addition, to increase the effect to block light and the degree of tight contact with the skin when the blind eye patches are worn compared to existing eye patch designs, the sides of the wings of the blind eye patches were widened, glass frame fixing plates were added, and the darts were made to be curved thereby making an ergonomic design reflecting the shape of the face. The non-adhesive type blind eye patches developed in the present study are considered to enhance the wearing sensation with the use of the material without skin irritation but with cushioning feelings and the ergonomic design reflecting the contour of the face.

Analysis on Optimal Approach of Blind Deconvolution Algorithm in Chest CT Imaging (흉부 컴퓨터단층촬영 영상에서 블라인드 디컨볼루션 알고리즘 최적화 방법에 대한 연구)

  • Lee, Young-Jun;Min, Jung-Whan
    • Journal of radiological science and technology
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    • v.45 no.2
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    • pp.145-150
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    • 2022
  • The main purpose of this work was to restore the blurry chest CT images by applying a blind deconvolution algorithm. In general, image restoration is the procedure of improving the degraded image to get the true or original image. In this regard, we focused on a blind deblurring approach with chest CT imaging by using digital image processing in MATLAB, which the blind deconvolution technique performed without any whole knowledge or information as to the fundamental point spread function (PSF). For our approach, we acquired 30 chest CT images from the public source and applied three type's PSFs for finding the true image and the original PSF. The observed image might be convolved with an isotropic gaussian PSF or motion blurring PSF and the original image. The PSFs are assumed as a black box, hence restoring the image is called blind deconvolution. For the 30 iteration times, we analyzed diverse sizes of the PSF and tried to approximate the true PSF and the original image. For improving the ringing effect, we employed the weighted function by using the sobel filter. The results was compared with the three criteria including mean squared error (MSE), root mean squared error (RMSE) and peak signal-to-noise ratio (PSNR), which all values of the optimal-sized image outperformed those that the other reconstructed two-sized images. Therefore, we improved the blurring chest CT image by using the blind deconvolutin algorithm for optimal approach.

The cultural characteristic of American film (genre drama) in (영화 <블라인드 사이드 Blind Side>에 나타난 '드라마' 장르의 미국 문화 특성)

  • Han, Yong Taek;Woo, Jung Gueon
    • Cross-Cultural Studies
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    • v.26
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    • pp.273-296
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    • 2012
  • The purpose of this paper is to examine the characteristics of American film (genre drama) through the analysis of , which merits our attention because the proportion of domestic gross earnings to foreign gross earnings is four to one. It means that the cultural discount rate of this film is relatively higher than the films which belong to the other genres, for example adventure, action, fantasy, SF etc. And it would be correct to say that this film is typically american. What is the reason of this difference of cultural discount rate? And what allows this film to be defined as a typical American film. The analysis of shows that the difference doesn't result from the actant structure. In fact the narrative structure of this film is similar to the other films of drama genre like or : the common structure of drama genre is characterized by an encounter of sujet and adjuvant and the progress of their relationship. But the drama is a genre in which the reflection of the actualities is important as compared with other genres. In that sense the story of is based upon the American cultural characteristics. Because the process that realize the progress of relationship between two protagonists is typically American such as race problem, adoption system, concept of family, system of education and going to college etc. As a result it is possible that move less the worldwide spectators than the American spectators.

Study on the blind zone of social service in Korea (한국 사회서비스의 사각지대 실태)

  • Noh, Hyejin
    • Korean Journal of Social Welfare Studies
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    • v.47 no.1
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    • pp.179-204
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    • 2016
  • The purpose of this study is to establish the concept of the blind zone of social services and analyzing the conditions by children, the elderly, the disabled, and the poor. This study used the raw data of demand/supply of social service and sample size is 4,038. Results of the study were as follows. First, in terms of the coverage, the biggest blind zones of social service are the employment support and cultural service. These results were similar for all households. But, it is noteworthy that the size and proportion of blind zones of housing support services for children, counseling services for elderly are relatively big. Second, in terms of adequacy, the most serious blind zones of social service are health and the employment support service. Especially, the elderly, the disabled, and the poor are not the most adequate adult care services and children are community service. Based on such findings, this study suggests expansion of employment support services and health care, monitoring for the services analyzed to be over-supply, and intensive involvement of private sectors about the services provided by the government of a large blind zone.

The Watermarking Method Using by Binary Image (이진영상을 이용한 워터마킹 기법)

  • Lim Hyun-Jin;Lee Seung-Kyu;Kim Tea-Ho;Park Mu-Hun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2006.05a
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    • pp.163-166
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    • 2006
  • The field of medical images has been digitalized as the development of computer and the digitalization of the medical instruments. As a result it causes a lot of problems such as an illegal copy related to medical images and property right of the medical images. Therefore, digital watermarking is used for discrimination whether the data are modified or not. It is also used to protect both the property right of medical images and the private life of many patients. The proposed theories, the Non-blind and the Blind method, have two problems. One is needed an original image and the other is using a gaussian watermarking. This paper proposes the new Blind Watermarking using binary images in order to easily recognize the results of watermark. This algorithm is described that an watermark of a binary image is wavelet-transformed, and then a transformed watermark is inserted in medium-band of frequency domains of original image by the Circular Input method. The propose method presented the good performance of over 0.97 in NC.

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Blind Channel Estimation based on Hadamard Matrix Interstream Transmission for Multi-Cell MIMO Networks (다중 셀 MIMO 네트워크를 위한 Hadamard 행렬 Interstream 전송 기반 Blind 채널 추정)

  • Yang, Jae-Seung;Hanif, Mohammad Abu;Park, Ju-Yong;Lee, Moon-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.4
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    • pp.119-125
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    • 2015
  • In this paper, we introduce a Hadamard matrix interstream transmission based blind channel estimation for multi-cells multiple-input and multiple-output (MIMO) networks. The proposed scheme is based on a network with mobile stations (MS) which are deployed with multi cells. We assume that the MS have the signals from both cells. The signal from near cell are considered as desired signal and the signals from the other cells are interference signal. Since the channel is blind, so that we transmit Hadamard matrix pattern pilot stream to estimate the channel; that gives easier and fast channel estimation for large scale MIMO channel. The computation of Hadamard based system takes only complex additions, and thus the complexity of which is much lower than the scheme with Fourier transform since complex multiplications are not needed. The numerical analysis will give perfection of proposed channel estimation.

Effects of Postural Control Training Using a Visual Blind Board on Head Control, Trunk Control, and the Sitting Abilities of Children with Moderate to Severe Cerebral Palsy: A Pilot Study (시야 가림막을 활용한 자세 조절 훈련이 중등도-중증 뇌성마비 아동의 머리 조절, 몸통 조절, 앉기 능력에 미치는 효과: 예비연구)

  • Kim, Kun-Woo;Lee, Min-Goo;Hahm, Suk-Chan
    • Journal of the Korean Society of Physical Medicine
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    • v.17 no.3
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    • pp.31-40
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    • 2022
  • PURPOSE: This study was conducted to investigate the effects of postural control training using a visual blind board, on head control, trunk control, and the sitting abilities of children with moderate-to-severe cerebral palsy. METHODS: Ten children with moderate to severe cerebral palsy participated in this study. Postural control training with a visual blind board was given for 40 minutes per session, 3 times a week for 4 weeks (12 sessions). Before and after the intervention, head control, trunk control, and sitting abilities were quantified using the head control scale, Korean version-trunk control measurement scale, and the sitting part of the Korean version-gross motor function measure-88, respectively. RESULTS: Postural control with the visual blind board significantly improved the head control ability of children with moderate to severe cerebral palsy (p = .015). Their trunk control abilities also showed significant improvement after the intervention (p = .016). However, their sitting ability did not show a significant change. CONCLUSION: These results showed that postural control training using a visual blind board is effective in improving the head and trunk control abilities of children with cerebral palsy. Further studies with suitable sample sizes and control groups are needed to reach a conclusion about the use of postural control training with visual blind boards for improvement of postural control of children with moderate to severe cerebral palsy.

The Role of Blind Protected Specimen Brushing (PSB) in Intubated Patients (기관 삽관 중인 환자에서 Blind Protected Specimen Brushing의 역할)

  • Yoo, Hee Seung;Hong, Ji Hyun;Yoon, Jang Uk;Eom, Kwang-Seok;Lee, Jae Myung;Kim, Chul Hong;Jang, Seung Hun;Kim, Dong Gyu;Lee, Myung Goo;Hyun, In Gyu;Jung, Ki-Suck
    • Tuberculosis and Respiratory Diseases
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    • v.55 no.1
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    • pp.59-68
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    • 2003
  • Background : In intubated patients, cultures of endotracheal aspirates (EA) are apt to contamination throughout the endotracheal tube. Therefore, the identification of etiologic agents via conventional EA cultures is not always reliable. In order to differentiate a pulmonary infection from a non-infectious disease, and to identify the true etiologic agent of acute pulmonary infection, blinded protected specimen brushing (PSB) was used, and its efficacy evaluated. Methods : In 51 intubated patients, with suspected pneumonia, blind PSB were performed, and the results compared with blood and EA cultures. A protected specimen brush was introduced through the endotracheal tube, and settled at the affected large bronchus. A specimen brush was introduced to the expected region using the blind method. The tip of the brush was introduced with an aseptic technique after vigorously mixed for 1 minute in $1cm^3$ of Ringer's lactate solution. The specimens were submitted for quantitative culture within 15 minutes, with a culture being regarded as positive if the colony forming units were above $10^3/ml$. Results : Of the 51 patients, 15 (29.4%) had community-acquired pneumonia (CAP), 27 (52.9%) hospital-acquired pneumonia (HAP) and 9 (17.6%) non-infectious diseases. The sensitivity and specificity of the quantitative PSB culture for the diagnosis of pneumonia were 52.4 and 88.9%, respectively. The sensitivity and specificity of EA were 78.6 and 77.8%, respectively. The blind PSB was superior to the EA for the identification of true etiologic agents. Of 53 episodes of 27 HAP patients, MRSA (Methicillin-resistant staphylococcus aureus) (41.5%) was the most common causative agent followed by Pseudomonas aeruginosa (15.1%), Klebsiella sp. (7.5%) and Acinetobacter sp. (7.5%). Conclusions : As a simple, non-invasive diagnostic modality, the blind PSB is a useful method for the differentiation of a pulmonary infection from non-infectious diseases and to identify the etiologic agents in intubated patients. A blind PSB can be performed without bronchoscopy, so is safer, more convenient and cost-effectiveness for patients where bronchoscopy can not be performed.