• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.3
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• pp.295-302
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• 1990

In this paper, a methodology for the automatic design of the optimal systolic arrays is proposed. Algorithm transformation is the main mathematical tool on which this methodology is based. Also, technique for partitioning algorithm into systolic arrays is presented. Algorithm partitioning is essential when the size of the computational problem is larger than the size of the array. This study results in (a) reduction of the design time of systolic arrays for given algorithms, (b) CRT display of the structures of systolic arrays, and (c) automatic designing of the optimal systolic array by the criteria such as the number of processing elements, bands, and communication paths. The procedure for these results was programmed using HP BASIC language on HP-9836 computer.

• The Journal of the Acoustical Society of Korea
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• v.12 no.1E
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• pp.39-47
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• 1993

2-Dimension IIR 디지털 필터를 시스토릭 어레이 구조로 실현하는 방법을 보였다. 시스토릭 어레이는 1-D IIR 디지털 필터로 부분 실현한 후 종속연결하여 구현하였다. 부분 실현한 시스토릭 어레이의 종속 연결은 신호 지연에 사용되는 요소를 감소 시킨다. 여기서 1-D 시스토릭 어레이는 local communication 접근에 의해 DG를 설계한후 SFG로의 사상을 통해 유도하였다. 유도된 구조는 매우 간단하며, 입력 샘플이 공급되어지면 매 샘플링 기간마다 새로운 출력을 얻는 매우 높은 데이터 처리율을 갖는다. 2-Dimension IIR 디지털 필터를 시스토릭 어레이로 실현함으로써 규칙적이고, modularity, local interconnection, 높은 농기형 다중처리의 특징을 갖기 때문에 VLSI 실현에 매우 적합하다. 또한 PE셀의 승산기 설계에서는 modified Booth's 알고리즘과 Ling's 알고리즘에 기초를 두고 고도의 병렬처리를 행할수 있도록 설계하였다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1997.11a
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• pp.221-231
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• 1997

본 논문에서는 고속 멱승을 위한 모듈라 곱셈기를 시스토릭 어레이로 설계한다. Montgomery 알고리듬 및 시스토릭 어레이 구조를 분석하고 공통 피승수 곱셈 개념을 사용한 변형된 Montgomery 알고리듬에 대해 시스토릭 어레이 곱셈기를 설계한다. 제안 곱셈기는 각 처리기 내부 연산을 병렬화 할 수 있고 연산 자체도 간단화 할 수 있어 시스토릭 어레이 하드웨어 구현에 유리하며 기존의 곱셈기를 사용하는 것보다 멱승 전체의 계산을 약 0.4배내지 0.6배로 감소시킬 수 있다.

• The Journal of the Acoustical Society of Korea
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• v.12 no.4
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• pp.32-38
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• 1993

2-D FIR 필터를 시스토릭 어레이 구조로 실현하는 방법을 제시하였다. 시스토릭 어레이는 1-D FIR 필터로 부분 실현한 후 병렬연겨랗여 구현하였다. 부분 실현한 시스토릭 어레이의 마지막 입력신호를 다음 단의 입력에 직접연결시킴으로써 입력 지연에 사용되는저장요소를 절약 시킨다. 1-D 시스ㅏ토릭 어레이는 지역통신 접근에 의해 DG를 설계한 후 SFG로으ㅟ 사상을 통해 유도하였다. 유도된 SFG는 DG의 노드가 보다 적은수의 PE에 사상됨으로써 PE의 이용률을 개선할 수 잇다. 유도된 구조는 매우 간단하며, 입력 샘플이 공급되어지면 매 샘플링 기간마다 새로운 출력을 얻는 매우 SHB은 데이터 비율(data rate)을 갖는다. 시스토릭 어레이는 규칙적이고, 모듈성이며, local interconnection, highly synchronized multiprocessing 의 특징을 갖기 때문에 VLSI 실현에 매우 적합하다. PE 셀 구조는 높은 처리율, 최소 계산시간과 최소 파이프라인 주기를 갖도록 설계하였다.

• Journal of Korean Ophthalmic Optics Society
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• v.21 no.1
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• pp.35-45
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• 2016

Purpose: The present study was aimed to investigate the effect of corneal eccentricity on the axial rotation when wearing toric soft contact lenses were worn for certain time and changing the gaze directions. Methods: Toric soft contact lenses with double thin zone design applied on 85 of with-the-rule astigmatic eyes. Then, rotational direction and amount of contact lenses were measured after 15 minutes and 6 hours of lens wear. The difference was further compared and analyzed according to corneal eccentricity. Results: The rotation of toric lens showed a tendency to rotate to temporal direction in all gaze directions except temporal-upper direction in all groups of corneal eccentricity. The amount of lens rotation in the frontal gaze direction exhibited a negative correlation since the amount was decreased with increasing corneal eccentricity after both 15 minutes and 6 hours of lens wearing. In many cases, the cornea with small eccentricity also showed the lens rotation larger than $10^{\circ}$. The difference in rotational amount after 15 minutes of toric lens wear was small according to the corneal eccentricity however, the change of rotational amount of contact lens according to corneal eccentricity was shown after 6 hours of lens wear. Conclusions: The present study revealed that the amount of axial rotation was largely varied according to the wearer's corneal eccentricity when wearing toric lens and the rotational amount after certain time of lens was also affected by corneal eccentricity. Thus, it is suggested that the selection of toric soft contact lenses based on corneal eccentricity is necessary.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.445-454
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• 2015

Purpose: The present study was aimed to investigate the effect of tear volume on a change of axial rotation according to wearing time of toric soft contact lens and gaze directions. Method: Toric soft contact lenses with double thin zone design applied on 62 eyes. Then, changes in non invasive tear film break-up time and the rotational direction/amount of lens when changing gaze direction were respectively measured after 15 minutes and 6 hours of lens wear. Results: Lens rotation to temporal direction was more found when changing gaze direction after lens wear. However, its rotation was varied according to wearing time and the subjects' tear volume. Furthermore, the frequency of lens rotation to temporal direction was higher in dry eyes compared with normal eyes at nearly all gaze directions after 15 minutes and 6 hour of lens wear. The rotational amount of lens was generally greater in dry eyes after 15 minutes of lens wear. However, its difference between normal eyes and dry eyes was not great after 6 hours of lens wear. Conclusion: The present study revealed that axial rotation of toric soft contact lens was varied according to the wearer's tear volume and lens rotational patterns at the initial, and extending periods of lens wear were different. The change in rotational pattern of toric soft contact lens from these results means the possibility of visual change after extending lens wear, and the identification of its correlation with tear volume suggests the necessity of considering factors for choosing appropriate toric soft contact lens.

• Journal of Korean Ophthalmic Optics Society
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• v.14 no.1
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• pp.39-45
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• 2009

Purpose: The purpose of this study is to compare the visual performance by contrast sensitivity (CS) and disability glare (DG) in low astigmatic eyes corrected with toric soft lenses and other optical corrections. Methods: Twenty university students with myopia (-1.00 to -6.50D Sph. with astigmatism up to 1.50 cyl) were enrolled and corrected by five different methods: 1) soft toric lenses; 2) spherical soft contact lenses; 3) RGP lenses; 4) best spectacle corrected visual acuity; 5) spherical equivalent spectacles. All subjects had corrected vision acuity of 20/20 or better. Contrast sensitivity and disability glare were measured using the OPTEC 6500 contrast sensitivity view-in tester included the EyeView Functional Vision Analysis software at photopic or mesopic conditions with glare. Results: At photopic condition, best corrected spectacle wearers had the highest monocular contrast sensitivity at all spatial frequency followed by soft toric lenses, RGP lenses, spherical equivalent spectacles, and spherical soft contact lenses. However, all of them were in normal contrast sensitivity value at photopic condition. At mesopic condition with glare, toric soft lenses were the highest and followed by RGP lenses, spherical equivalent spectacles, best spectacle corrected visual acuity and spherical soft contact lenses. It was observed that spherical soft contact lens wearers demonstrated lower range than normal contrast sensitivity value at mesopic condition with glare. Conclusion: Toric soft lenses gave better visual performance than spherical soft lenses in low astigmatic eyes. Subjects requiring the use of contact lenses under mesophic conditions could benefit from toric soft lenses.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.2
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• pp.137-144
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• 2010

Purpose: This study was to evaluate the clinical performance of 1-Day disposable toric soft contact lenses (TSCL) and to compare the visual performance with glasses and TSCL. Methods: In a two-week investigation of 'prism ballast' designed TSCL, occular refractions in 15 (30 eyes) healthy subjects were within the range of -2.75 D TO -8.00 D spherical power and -0.75 DC to -2.25 DC cylinderical power (with-the-rule). Subjects were assessed the clinical performance (orientation, centration, movement, tightness, rotation recovery, symptoms) of TSCL and compared binocular vision and contrast sensitivity with corrected glasses and TSCL at initial and two-week follow-up visits. Results: The prism-ballast design TSCL achieved better orientation, rotation recovery and symptoms over 2 week period. There was no statistically significant difference between spectacles and TSCL with respect to measuring binocular vision and contrast sensitivity. Conclusions: The clinical performance was good with prism-ballast design toric soft contact lenses. Evaluation of binocular vision and contrast sensitivity did not show the differences between spectacles and TSCL correction. This study suggests that TSCL wearers can be achieved similar visual performance for spectacles wearers.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.1
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• pp.135-146
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• 1999

Most public key cryptosystems are constructed based on a modular exponentiation, which is further decomposed into a series of modular multiplications. We design a new systolic array multiplier to speed up modular multiplication using Montgomery algorithm. This multiplier with simple circuit for each processing element will save about 14% logic gates of hardware and 20% execution time compared with previous one.

• Journal of the Korea Society of Computer and Information
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• v.3 no.2
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• pp.119-124
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• 1998

Block Matching Motion Estimation(BMME) Algorithm is demands a very large amount of computing power and have been proposed many fast algorithms. These algorithms are many problem that larger size of VLSI scale due to non-localized search block data and problem of non-reuse of input data for each processing step. In this paper, we designed systolic arry of high processing capacity, constraints input output pin size and reuse of input data for small VLSI size. The proposed systolic array is optimized memory access time because of iterative reuse of input data on search block and become independent of problem size due to increase of algorithm's parallelism and total processing elements connection is localized spatial and temporal. The designed systolic array is reduced O(N6) time complexity to O(N3) on moving vector and has O(N) input/output pin size.