• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.3
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• pp.8-14
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• 2012

Improving the speed of image processing is in great demand according to spread of high quality visual media or massive image applications such as 3D TV or movies, AR(Augmented reality). SIMD computer attached to a host computer can accelerate various image processing and massive data operations. MAMS is a multi-access memory system which is, along with multiple processing elements(PEs), adequate for establishing a high performance pipelined SIMD machine. MAMS supports simultaneous access to pq data elements within a horizontal, a vertical, or a block subarray with a constant interval in an arbitrary position in an $M{\times}N$ array of data elements, where the number of memory modules(MMs), m, is a prime number greater than pq. MAMS-PP4 is the first realization of the MAMS architecture, which consists of four PEs in a single chip and five MMs. This paper presents implementation of image processing algorithms and performance analysis for MAMS-PP16 which consists of 16 PEs with 17 MMs in an extension or the prior work, MAMS-PP4. The newly designed MAMS-PP16 has a 64 bit instruction format and application specific instruction set. The author develops a simulator of the MAMS-PP16 system, which implemented algorithms can be executed on. Performance analysis has done with this simulator executing implemented algorithms of processing images. The result of performance analysis verifies consistent response of MAMS-PP16 through the pyramid operation in image processing algorithms comparing with a Pentium-based serial processor. Executing the pyramid operation in MAMS-PP16 results in consistent response of processing time while randomly response time in a serial processor.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.643-648
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• 2007

유비쿼터스 컴퓨팅 기술이 문화예술 분야에 접목되면서 수동적이었던 전시 관람 형태가 능동적인 관람 형태로 바뀌고 있다. 특히, 지능형 가이드 시스템의 등장은 기존의 관람 문화를 크게 변화시켰다. 지능형 가이드 시스템이란 사용자에게 전시물에 대한 정보 및 전시장의 위치 정보를 제공해주는 시스템을 말한다. 현재 상용화되고 있는 지능형 가이드 시스템은 크게 휴대폰, PDA, 게임기 등의 휴대형 장치 기반의 가이드 시스템과 HMD와 같은 착용형 장치 기반의 가이드 시스템으로 나뉠 수 있다. 본 논문에서는 이러한 현재 상용화된 시스템들의 한계(예를 들어, 특정 장치를 직접 착용 혹은 소지해야 함)를 서술하고, 이를 보완하는 프로젝터 기반의 가이드 시스템에서 더 나아가 임의의 공간에 원하는 전시물 구성, 설치 등을 신속, 정확하게 수행하는 지능형 가이드 시스템을 제안한다. 프로젝터 기반의 지능형 가이드 시스템은 기반 기술로 지능형 프로젝션 기술을 필요로 하는데, 이는 임의의 환경에서 임의의 위치에 다수의 사용자에게 고화질, 대화면 영상 정보를 제공해 준다. 그러나, 기존의 지능형 프로젝션 기술은 성능 및 안정성을 위해 대부분 가시적인 패턴 및 마커를 사용하는데, 이는 사용자에게 제공되는 정보를 관찰하는 데 방해가 될 수 있다. 본 논문에서는 사용자의 관점에서 유용한 비간섭 지능형 프로젝션 기술을 사용한다. 즉, 본 논문에서는 마커나 패턴을 사용함으로써 정확성이나 안정성은 보장하지만, 마커나 패턴을 은닉하여 사용자의 눈에 띄지 않도록 함으로써, 사용자는 원하는 정보를 아무런 방해 없이 제공받을 수 있다. 제안된 시스템을 미술 작품 감상을 위한 가이드 시스템으로 적용해 본 결과, 사용자는 자유로운 환경에서 자신의 위치나 작품에 대한 설명을 대화면으로 제공받으면서, 편안하게 그림을 감상할 수 있었다.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.3
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• pp.65-72
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• 2011

Multi-touch display system has recently attracted world wide attention due to easy accessibility to the various interactive media without any specialized equipments. Especially, Microsoft Sphere(R) shows a considerable promise in treating non-fiat multi-touch display. The distinctive feature of the system is a stable multi-touch interaction on a spherical display. To extend the possibility of the interactions to the more various display surfaces, this paper propose a multi-touch interaction system in the circumstance of the irregular convex surface. The proposed method can be used efficiently in various tangible interface, for example, the interactive diorama system at the exhibition or the tangible arcade game.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.45-47
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• 2015

모바일 시스템의 카메라 용용 어플리케이션은 기본적인 이미지 저장 및 영상 촬영뿐만 아니라 카메라 기반의 증강현실 및 위치 기반 서비스 등 다양한 응용 분야에 활용할 수 있다. 특히, 셀프 활동에 많이 활용되는데, 이때 발생하는 문제점은 셀프 촬영이 힘들다는 것이다. 스마트폰 카메라를 자유롭게 제어하고, 나아가서는 카메라 촬영 및 다양한 이미지 프로세싱을 보조해줄 수 있는 시스템 및 장치가 필요하다. 본 논문에서는 안드로이드 스마트폰 기반의 카메라 제어 모듈과 카메라 제어 모듈을 활용한 이미지 프로세싱 보조 시스템을 구현해보도록 한다. 카메라 제어 모듈은 리모트에서 안드로이드 스마트폰의 카메라 촬영을 제어할 수 있으며, 여러 대의 안드로이드 스마트폰과 연동해서 다양한 각도에서 하나의 피사체에 대한 카메라 촬영이 가능하도록 통신 제어 시스템이다. 이를 활용하면 모바일 카메라 응용 서비스를 좀 더 폭넓게 활용할 수 있을 것이다.

• The Korean Journal of Pain
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• v.13 no.1
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• pp.93-96
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• 2000

Background: Psoas compartment block with local anesthetics and corticosteroids is one of the treatments which provides long term analgesia of the lower back and anterior thigh unilaterally, and its technical easiness and safety allows blind application without C-arm guidance in the out-patient clinic. This study aimed to evaluate the mean of the depth from the skin to the psoas compartment, and its correlation to the following attributes: age, weight, height and PI (Ponderal Index). Methods: We investigated 28 patients who underwent psoas compartment block. All blocks were performed using Chayen's method (punctured at the point of 3 cm caudally and 5 cm laterally from the 4th lumbar vertebral spinous process) with a 22 G, 8 cm Tuohy needle under C-arm guidance. We recorded the depth from skin to the psoas compartment, height, weight and PI (weight (kg)/height (cm)$\times100$ (%)). Data were analyzed using the Pearson product-moment correlation coefficients. The correlations between the depth and other attributes identified by p-value of less than 0.05 were considered statistically significant. Results: The mean depths from skin to the psoas compartment were $6.02{\pm}0.28$ cm in men, $5.44{\pm}0.22$ cm in women. There is no significant correlation between the depth and other patient's attributes. Conclusions: The mean depths from skin to the psoas compartment may be one of the guide for psoas compartment block in outpatient clinics without C-arm guidance.

• Journal of Korea Multimedia Society
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• v.9 no.4
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• pp.377-387
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• 2006

Digital documents takes place of paper (off-line) documents, because of the advantages of digital (on-line) documents: supply of information using dynamic contents and good to communize. However, users prefer paper documents to digital documents with the advantages of paper documents: inexpensive, handy to carry, and good to read. Therefore, for providing advantages of digital documents to users who prefer paper documents, many laboratories study about methods which augment digital documents to paper documents. In this paper, we propose the Hybrid Documents Authoring Tool (HDAT), which can insert, delete, and modify on-line information to the off-line. The proposed system is a unified authoring tool for reading and writing of on-line information. And we provide the most natural environment to users using computer vision technology without additional devices such as markers or patterns to retrieve documents. As shown by experimental results, we make sure that our proposed system has high usability and good efficiency on various environments through we measure the low-level of system requirement.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.461-468
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• 2008

The needs for visualizing interactive multimedia contents on portable devices with realistic three dimensional shapes are increasing as new ubiquitous services are coming into reality. Especially in digital fashion applications with virtual reality technologies for clothes of various forms on different avatars, it is required to provide very high quality visual models over mobile networks. Due to limited network bandwidths and memory spaces of portable devices, it is very difficult to transmit visual data effectively and render realistic appearance of three dimensional images. In this thesis, we propose a compression method to reduce three dimensional data for digital fashion applications. The three dimensional model includes animation of avatar which require very large amounts of data over time. Our proposed method utilizes temporal and spatial coherence of animation data, to reduce the amount. By grouping vertices from three dimensional models, the entire animation is represented by a movement path of a few representative vertices. The existing three dimensional model compression approaches can get benefits from the proposed method by reducing the compression sources through grouping. We expect that the proposed method to be applied not only to three dimensional garment animations but also to generic deformable objects.

• Journal of Korea Multimedia Society
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• v.14 no.4
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• pp.585-594
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• 2011

On live performance such as play and musical, various stage effects are utilized to attract a diverse audience. These stage effects include traditional direction techniques, striking display effects and all kinds of ways of being immersed in the scene. In this paper, we propose a novel digital visual effects(digilog) for controlling the surface texture of objects based on spatial augmented reality. For this purpose, we present a method of neutralizing the appearance of an arbitrary object using a projector-camera system. To make the object appear as if it is a transparent object by projecting a carefully determined compensation image onto the surface of objects, we use the homography method for a simple and effective off-line projector-camera calibration. The successful uses of the basic algorithm of Smart Projector for measuring radiometric parameters led us believe that this method may be used for temporal variation of plays and musicals.

• Investigative Magnetic Resonance Imaging
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• v.4 no.1
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• pp.34-41
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• 2000

Purpose: To evaluate the clinical usefulness of diffusion weighted MR imaging(DWI) in the differential diagnosis of brain tumors. Materials and methods: DWI and conventional MR images of nineteen patients with brain tumors(10 metastatic tumors, 4 high grade gliomas, 4 low grade astrocytomas, one oligodendroglioma)were obtained on 1.5T unit. DWI was obtained using single shot spin echo planar imaging with b-value near 1000. We analyzed the signal intensities of lesions including solid portion, necrotic or cystic portion and peritumoral edema of brain tumors (classified five grades comparison with the signal intensities of brain parenchyma and CSF)and calculate the SIR(signal intensity ratio)of lesions to the contralateral normal brain parenchyma. We analyzed statistically the signal intensities and SIR of tumors using independence T test. Results: In solid portions of tumors, all the metastatic tumors and high grade gliomas showed high signal intensities, but low grade astrocytomas and oligodendroglioma showed iso or slight high signal intensities to the normal brain parenchyma. The SIR of solid portion has positive correlation with malignant pot ential(metastatic tumors 1.52, high grade gliomas 1.38, low grade astrocytomas 1.16, oligodendroglioma 1.31)(p < 0.05). In peritumoral edema where seen in 14 tumors, seven of 10 metastatic tumors and two of 4 high grade gliomas showed iso signal intensities, whereas edemas in other 5 brain tumors showed hyperintense to the normal brain parenchyma. The SIRs of peritumoral edemas in metastatic tumors (1.14) was lower than high grade gliomas(1.31),but statistically insignificant. The SIR of cystic or necrotic portion of brain tumors was 0.63. In non enhancing solid portions, three of six cases showed hyperintense to the adjacent peritumoral edema. Conclusion: On DWI, the signal intensities of solid portion has positive correlation with malignant potential, and perilesional edema of brain tumors appear various signal intensities owing to "T2 shine through effect" and the extensiveness of vasogenic edema. Another merit using DWI on the evaluation of brain tumors is to improved better delineation of tumor margins from the adjacent edemas, especially at the non enhancing solid portion of the tumors.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.965-973
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• 2020

The purpose of this study was to quantitatively correlate the change of flow velocity and signal voiding in TOF-MRA. We made our phantom to control the flow velocity, and changed the flow velocity in 16 steps from 8.0 to 127.3 mc/s. The TOF-MRA test was performed using a 3.0T MRI system and the signal intensity was measured by classifying the signal voiding length and image into the In flow, Mid flow, and Out flow. The length of signal voiding was the longest when the flow velocity was 127.3 cm/s and the signal intensity decreased with increasing flow velocity(p<0.05). In flow(-.547) and Mid flow(-.643) were negatively correlated with flow velocitys(p<0.05). In conclusion, it was confirmed that the increase in flow velocity was a major factor causing signal voiding in TOF-MRA. In the future, this study will provide basic data when studying sequences and parameters to reduce signal voiding in models with a high flow velocity.