• 한국산업정보학회논문지
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• 제22권4호
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• pp.1-9
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• 2017

본 논문에서는 위상 천이 디지털 홀로그래피(PSDH; Phase-Shifting Digital Holography) 및 디지털 워터마킹(Digital Watermarking) 기반 디지털 홀로그램의 이중 암호화 기술을 제안한다. 이를 위해 먼저 디지털 워터마크에 사용할 로고 영상을 정하고, 이 영상에 대한 이진 위상 컴퓨터형성 홀로그램(CGH; Computer Generated Hologram)을 반복 알고리즘을 이용하여 설계한다. 그리고 랜덤하게 발생시킨 이진 위상 마스크를 워터마크로 정하고, 설계된 이진 위상 CGH와 XOR 논리연산을 통해 워터마크 정보에 대한 키 영상을 생성한다. 그리고 물체 영상을 위상 변조하여 세기가 일정한 함수로 만든 후, 워터마크인 랜덤하게 발생시킨 이진 위상 마스크를 곱하여 물체파를 생성한다. 이 물체파는 워터마크 정보가 포함된 잡음과 유사한 패턴을 가지는 1차 암호화된 영상이라고 할 수 있다. 이를 2-단계 PSDH기술을 적용하여 기준파와 간섭을 시키면 가시성이 향상된 최종 간섭무늬를 얻는다. 이 간섭패턴이 최종적으로 구하고자 하는 물체 영상의 2차 암호화된 영상이 된다. 암호화된 영상의 복호화는 2-단계 PSDH기술을 통한 암호화된 영상들을 이용하여 적절한 산술연산 처리한 후, 프레즈넬 변환 및 1차 암호화 과정의 역순으로 진행하면 된다. 제안된 방법의 암호화 및 복호화 기술은 컴퓨터 시뮬레이션을 통하여 검증된다.

• 한국의상디자인학회지
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• 제9권2호
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• pp.49-57
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• 2007

The purpose of this study was to research the efficient tool of the exclusive fabric simulation in Jacquard Textile CAD system. For performing this design study, it designed the surface design of the abstract images of flowers through EAT Designscope CAD system and simulated the interior fabric. To merchandise the fashion items and see the visual image, these fabric simulations was effected by two or three-dimension modeling through EAT designscope, YongWoo CNI, Alias and so on. The result of this study can be summarized as follows. Before the step of weaving the samples from the surface design works, jacquard fabric design can be done very efficiently to apply the design step of the fabric simulation in CAD(Computer Aided Design). As the usage of the simulation tool in CAD system, jacquard design can be easily feed-back to modify for the right fabrics and produced the various designs in the short running time very efficiently. Therefore, this jacquard design system ultimately can be saved cost and developed the higher value-added goods in more response to consumer demands.

• 한국군사과학기술학회지
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• 제11권5호
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• pp.84-91
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• 2008

The spectral radiance received by a remote sensor at a given temperature and wavelength region is consisted of the self-emitted component directly from the object surface, the reflected component of the solar irradiation at the object surface, and the scattered component by the atmosphere without ever reaching the object surface. The IR image of a ship is mainly affected by location, meteorological condition(atmosphere temperature, wind direction and velocity, humidity etc.), atmospheric transmittance, solar position and ship surface temperature etc. Computer simulations for prediction of the IR signatures of ships are very useful to examine the effects of various meteorological conditions. In this paper, we have acquired the IR signature for different meteorological conditions by using two different computer programs. The numerical results show that the IR image contrast as compared to the background sea considering the atmosphere temperature and wind velocity.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제9권3호
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• pp.166-171
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• 2009

In recent years, video detection systems have been implemented in various infrastructures such as airport, public transportation, power generation system, water dam and so on. Recognizing moving objects in video sequence is an important problem in computer vision, with applications in several fields, such as video surveillance and target tracking. Segmentation and tracking of multiple vehicles in crowded situations is made difficult by inter-object occlusion. In the system described in this paper, the mean shift algorithm is firstly used to filter and segment a color vehicle image in order to get candidate regions. These candidate regions are then analyzed and classified in order to decide whether a candidate region contains a license plate or not. And then some characters in the license plate is recognized by using the fuzzy ARTMAP neural network, which is a relatively new architecture of the neural network family and has the capability to learn incrementally unlike the conventional BP network. We finally design a license plate recognition system using the mean shift algorithm and fuzzy ARTMAP neural network and show its performance via some computer simulations.

• Journal of the Optical Society of Korea
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• 제5권3호
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• pp.99-109
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• 2001

This paper presents a phase-only modulation scheme for a three-dimensional (3-D) image matching system to improve optical efficiency of the system. The 3-D image matching system is based on the two mask heterodyne scanning. A hologram of the 3-D reference object is first created and then the phase of the hologram is extracted. The phase of the hologram is represented as one mask with the other mask being a plane wave. The superposition of each beam modulated by the two masks generated a scanning beam pattern. This beam pattern scans the 3-D target object to be recognized. The output of the scanning system gives out the correlation of the phase-only hologram of the reference object and the complex hologram of the target object. Since a hologram contains 3-D information of an object as a form of fringe pattern, the correlation of holograms matches whole 3-D aspect of the objects. Computer simulations are performed with additive gaussian noise and without noise for the complex hologram modulation scheme and the phase-only hologram modulation scheme. The computer simulation results show that the phase-only hologram modulation scheme improves the optical efficiency. Thus the system with the phase-only hologram modulation scheme is more robust than the system with the complex hologram modulation scheme.

• The Korean Journal of Pain
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• 제35권4호
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• pp.403-412
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• 2022

Background: Most pain management techniques for challenging procedures are still performed under the guidance of the C-arm fluoroscope although it is sometimes difficult for even experienced clinicians to understand the modified three-dimensional anatomy as a two-dimensional X-ray image. To overcome these difficulties, the development of a virtual simulator may be helpful. Therefore, in this study, the authors developed a virtual simulator and presented its clinical application cases. Methods: We developed a computer program to simulate the actual environment of the procedure. Computed tomography (CT) Digital Imaging and Communications in Medicine (DICOM) data were used for the simulations. Virtual needle placement was simulated at the most appropriate position for a successful block. Using a virtual C-arm, the authors searched for the position of the C-arm at which the needle was visualized as a point. The positional relationships between the anatomy of the patient and the needle were identified. Results: For the simulations, the CT DICOM data of patients who visited the outpatient clinic was used. When the patients revisited the clinic, images similar to the simulated images were obtained by manipulating the C-arm. Transforaminal epidural injection, which was difficult to perform due to severe spinal deformity, and the challenging procedures of the superior hypogastric plexus block and Gasserian ganglion block, were successfully performed with the help of the simulation. Conclusions: We created a pre-procedural virtual simulation and demonstrated its successful application in patients who are expected to undergo challenging procedures.

• 환경영향평가
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• 제3권1호
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• pp.43-52
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• 1994

This study conducted a visual impact assessment of an apartment complex project proposed in Jungkye-dong, Seoul. Three design alternatives of the project-alternatives 1, 2, and 3-which differed in form, color, scale, and arrangement of buildings were simulated with computer image processing technique. The simulations were presented to the public who were mainly residents in the project area, and visual impact resulted from the alternatives was assessed by them. Their responses were then statistically analyzed. It was found that, in terms of compatibility with the surrounding landscape, alternative 1 was the most favourable because it was more traditional, natural, and diverse than alternatives 2 and 3. At the same time, the alternative was most preferred by the public because it was more plain, natural, and diverse than other alternatives. It was suggested that the visual impact assessment with public participation conducted in this study would help both planners and the public to make more intelligent decisions.

• KIEAE Journal
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• 제8권4호
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• pp.49-54
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• 2008

Chungju city with beautiful natural environments and various cultural resources recently meets the new economic revival caused by opening of Jungbu Naeruk express way and invitation of the enterprise city. Now, the out door lightings come to the major issues to improve Chungju night image and to exploit new scenic spots. this study aims to develop the lighting plan for the jung-won bridge as a representative scenic spot in Chungju city. For the study, the field surveys and computer simulations were performed. As results, the lighting concepts such as entrance and apple images and alternative lighting plans were suggested.

• 한국광학회지
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• 제17권6호
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• pp.507-513
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• 2006

본 논문에서는 출력평면에 나타나는 원 영상을 재생시키기 위하여 위상 랩핑 방법을 이용하여 암호화 수준을 향상시키고 주파수 영역에서 위상 부호화하여 암호화함으로써 잡음에 강한 복호화 방법을 제안하였다. 암호화된 영상은 원 영상이 아닌 위상 변조된 가상 영상과 무작위 위상 영상을 곱하고 제로 패딩(ze.o-padding)하여 푸리에 변환한 후 이 변환된 복소 영상을 데이터 전송 및 매핑을 용이하게 하기 위하여 실수 값으로 변환하여 위상 부호화하여 만든다. 복호화 과정은 제안한 선형적인 영상을 비선형적인 영상으로 변환시키는 위상 랩핑 방법에 의해 각각 만들어진 암호화된 영상과 복호화 키를 곱하여 푸리에 역변환하여 공간필터를 가진 출력 평면에서 원 영상을 복원함으로써 광축 정렬 문제와 픽셀 대 픽셀 대응이 용이하여 복원영상의 해상도를 향상시킬 수 있다. 제안한 방법은 허가되지 않은 사용자가 암호화된 영상을 분석함으로써 있을 수 있는 복제 가능성을 원 영상의 어떤 정보도 포함하지 않은 가상 영상을 사용함으로써 배제할 수 있고 또한 실수 값을 위상 부호화함으로써 현재에 사용되는 공간 광 변조기로 표현이 가능하다. 컴퓨터 모의 실험을 통하여 제안한 암호화 방법의 적합성과 암호화된 영상과 복호화 키 영상에 잡음이 발생하더라도 원 영상의 복원이 가능함을 확인하였다.

• 한국의류산업학회지
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• 제7권1호
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• pp.56-62
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• 2005

Fancy Yarn has developed diverse textures in fabrics, reducing the time in yarn and fabric production or apparel making in order to develop creative goods. In this study aimed to propose the use of a 4D box system to make fancy yarn shapes with loops, knops and spirals and the like. The change in texture was analysed and simulated to produce a suitable fabric image by using the fancy yarns fabric. The results are as follows. The plain weave, 2/2 basket weave, 2/2 twill weave, 2/2 2 complete broken weaves, and 5 harness sateen weaves were woven and a fabric image formed. In the case of the loop and the knop yarns fabric image, compared to the twisted fabric image the surface was covered by loops or some parts became partially black. In the case of the spiral shape it showed pattern continuity in spiral shapes 1, 2 and 3. The more twisted spirals produced a diamond shaped pattern or a twill line and a herring bone shaped twill line. An evenly distributed black fabric image appeared in 5 harness sateen weave. For the loop shape the broken weave or 5 harness sateen weave was produced; basket weave and broken weave for the knop yarn 1 or knop yarn 2; and for the spiral shape a plain fabric or 5 harness sateen weave were produced much similar to the fabric image. The surface texture of the mapped image compared to the twisted fabric image produces fancy yarn fabric images covered with loops or irregular spots caused by the knop and the spiral. Therefore it is appropriate or suitable for the simulation of tweed or woolen wool fabrics. The fabric image which produced consistent and continuous lines is therefore more suitable for simulations of twill or herringbone fabric images.