• 정보보호학회논문지
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• 제9권4호
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• pp.23-36
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• 1999

은닉 서명(10)은 서명장의 신분과 메시지 내용에 대한 정보유출 방지와 함께 익명 성 보장을 위 해 전자 화폐 시스템에 사용되고 있다. 그러나 완전한 익명성은 전자 화폐에 대한 불법적 인 사용 등에 악용될수 있다. 따라서 필요로 하는 경우 특정 신뢰 센터가 전자 화폐에 대한 공정성을 검 증할 수 있어 야 한다. 본 연구에서는 Hoster가 제시한 Meta-ElGamal 기법 (12)을 분석하여 메시지 복 원 기능을 제 공하는 공정 은닉 서명 모델에 대해 고찰하고 메시지 복원 기능을 제공하는 개선된 공정 은 닉 다중서명 기법을 제시한다. 본 연구에서는 제시하는 기법은 불확정 전송 방식의 특성을 사용하여 신 뢰 센터에 의 한 공정 검증 및 확인 기능을 제공하는 다중 서명 방식으로 다양한 전자 화폐 시스템에 적 용 가능하다. As the blind signature(10) does not reveal any information about the message or its signature it has been used for preventing the information leakage and for providing the anonymity in secure electronic payment systems. Unfortunately this perfect anonymity could be misused by criminals as blind signatures prevent linking the withdrawal of money nd the payment made 표 the same customer. Therefore we should provide publicly verifiable mechanism if it is required for the judge to trace the blackmailed messages. In this paper we propose a modified blind signature scheme which additionally provides the role of message recovery after analyzing the existing meta-ELGamal scheme(12) suggested by Horster. And we suggest a new fair blind multi-signature scheme based on the oblivious transfer protocol with which a judge can publicly verify its fairness and correctness if needed. Proposed scheme can also applicable to the diverse electronic payment applications.

• 한국인터넷방송통신학회논문지
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• 제15권4호
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• pp.119-125
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• 2015

본 논문에서는 다중 셀 MIMO (multiple-input and multiple-output) 네트워크를 위한 Hadamard 행렬 인터스트림 (interstream) 전송기반 blind 채널추정을 소개한다. 제안 방법은 다중 셀로 된 이동 단말 네트워크를 기반으로 연구된다. MS (mobile station) 는 양 셀로부터 신호를 받는 것으로 가정한다. 가까운 셀로부터 받은 신호는 원하는 신호로 간주되고, 다른 셀로부터 받은 신호는 간섭신호로 간주된다. 채널은 blind이기 때문에 채널을 추정하기 위해 Hadamard 행렬 패턴의 파일럿 (pilot) 스트림 (stream) 을 전송하면, 대규모 MIMO 채널에 대해 보다 쉽고 빠른 채널 추정이 가능하게 된다. Hadamard 행렬 기반시스템의 계산은 오직 복소 가산 (complex addition) 만 필요하기 때문에, 복소 승산 (complex multiplication) 이 필요한 Fourier 변환을 이용한 방법보다 복잡도가 훨씬 줄어든다. 수치적 분석을 통해 본 결과 제안한 방법이 완벽함을 보여준다.

• 소성∙가공
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• 제29권3호
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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.

• Fashion, Industry and Education
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• 제14권2호
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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.

• Steel and Composite Structures
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• 제18권5호
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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.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2006년도 춘계종합학술대회
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• pp.163-166
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• 2006

컴퓨터의 발달과 의료기기의 디지털화로 인해 의료영상 분야도 디지털화되었다. 그 결과 디지털 의료영상의 불법복제, 소유권 및 데이터 인증 문제 또한 발생하고 있다. 이러한 환경 하에서 환자의 사생활 보호와 의료영상 자체의 소유권, 재산권의 여부 및 데이터 변형 여부의 판별을 위하여 디지털 워터마킹이 사용되고 있다. 기존에 제안된 여러 가지 워터마킹 기법들은 Non-Blind 방식에서는 원 영상이 필요하다는 점과 Blind 방식을 사용할 경우에는 육안으로는 식별이 힘든 양극 워터마크를 사용한다는 단점이 있다. 본 논문은 Blind 워터마킹에서 양극 워터마크를 삽입하는 방식을 따르지 않고, 시각적으로 인지하기 쉽도록 하기 위하여 이진 워터마크 영상을 다중 웨이블릿 변환하고, 원 영상을 이산 푸리에 변환하여 영상의 중간 주파수대에 Circular Input 방식을 이용하여 워터마크를 삽입하는 알고리즘을 제안하였고 그 방법은 상관도 0.97이라는 우수한 결과를 얻었다.

• 사회복지연구
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• 제47권1호
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• pp.179-204
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• 2016

본 연구는 가족의 삶과 매우 밀접한 영역인 사회서비스의 사각지대의 개념을 정립하고, 사회서비스의 사각지대 실태를 아동가구, 노인가구, 장애가구, 빈곤가구로 분류하여 분석하였다. 분석을 위하여 사회서비스 수요공급실태조사의 가구용 조사 원자료를 활용하였고, 분석대상은 4,038명이다. 분석의 결과 대상의 포괄성 측면에서 사각지대 규모가 가장 큰 서비스는 고용지원서비스와 문화서비스인 것으로 나타났다. 이러한 결과는 가구 유형별로 큰 차이가 없었지만, 아동가구에서 주거지원 서비스, 노인가구에서 상담서비스에 대한 욕구가 충족되지 않는다는 것도 주목할 만하다. 급여의 충분성 측면에서 사각지대 정도가 가장 큰 서비스는 보건의료와 고용지원서비스인 것으로 나타났다. 이러한 결과를 가구 유형별로 봤을 때는 노인과 장애가구, 빈곤가구 모두 성인돌봄서비스가 서비스의 양적 충분성이 가장 낮은 것으로 나타났고, 아동가구는 지역사회서비스가 불충분한 것으로 나타났다. 이러한 분석 결과를 바탕으로 본 연구는 보건의료와 고용지원 서비스에 대한 확대, 현재 과잉공급되는 것으로 분석된 서비스에 대한 점검, 정부에서 제공하는 서비스 중 사각지대가 큰 것에 대한 민간조직의 집중 개입 등을 제안하였다.

• 비교문화연구
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• 제26권
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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.

• 대한방사선기술학회지:방사선기술과학
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• 제45권2호
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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.

• 대한물리의학회지
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• 제17권3호
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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.