• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1891-1894
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• 2003

본 논문에서는 분할 영상 좌보계 (split image coordinate: SIC)를 제안하여 3차원 영상의 주요 특징 중의 하나인 유, 무한 소실점을 그 위치의 무한성이나 카메라의 보정과 관계없이 정확하게 자동 추출하였다. 제안한 방법에서는 가우시안 구 (Gaussian sphere) 기반의 기존 방법들과는 달리 영상 공간을 누적 공간으로 활용함으로써 카메라 보정이나 영상의 사전정보가 없어도 원 영상의 정보 손실 없이 소실점을 추출할 수 있고, 영상을 무한대까지 확장한 후 분할하여 재정의 함으로써 유, 무한 소실점을 모두 추출할 수 있도록 하였다. 정확한 소실점의 검출을 위하여 직선 검출 과정에서는 방향성 마스크 (mask)를 사용하였으며, 직선들의 군집화 (clustering) 과정에서는 기울기 히스토그램 방법과 수평/수직 군집화 방법을 적응적으로 적용하였다. 제안한 방법을 합성 영상 및 건축물 (man-made environment) 영상에 적용시켜 유, 무한 소실점들을 효과적이고 정확하게 찾을 수 있음을 확인하였다.

• The Journal of the Acoustical Society of Korea
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• v.39 no.4
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• pp.237-245
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• 2020

In decades, active sonar, which transmits signals and detects incident signals reflected by underwater targets, has been significantly studied since passive sonar in Anti-Submarine Warfare (ASW) detection performance becomes lowered, as underwater threats become their radiated noise reduced. In general, active sonar using Hull-Mounted Sonar (HMS) adjusts vertical tilt (depression) and sequentially transmits multiple Linear Frequency Modulation (LFM) subpulses which have non-overlapped bands, i. e. 1 kHz ~ 2 kHz, 2 kHz ~ 3 kHz, in order to reduce shadow zones. Recently, however, Generalized SFM (GSFM), which is generalized form of SFM, is proposed, and it is confirmed that subpulses of GSFM have orthogonality among each other depending on setting of GSFM parameters. Hence, in this paper, we applied GSFM to active target detection using HMS to improve the performance by the signal processing gain obtained from enlarged bandwidths of GSFM subpulses compared to those of LFM subpulses. Through simulation, we verified that when the number of subpulses is three, the matched filter gain of GSFM is approximately 5 dB higher than that of LFM.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1723-1726
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• 2003

본 논문에서는 상세 부밴드에서의 PSNR과 웨이블릿 계수의 계층적 데이터 구조 측면에 초점을 맞추어 웨이블릿 영역에서의 신호 해석을 통한 잡음 제거를 연구하였다. 제안된 방식은 기존의 방식들과는 달리 수직 또는 수평 방향의 고주파 성분에 의한 상세 부밴드에서의 에너지 편중을 고려하여 이들의 에너지의 편중에 따른 분해 필터를 적응적으로 설계하고 부밴드의 에너지를 재분배시켜 성능을 향상 시켰으며, 웨이블릿 계수의 상호 의존성을 고려한 지역윈도우 사용해 기존의 방식을 개선하였다.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.3
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• pp.321-327
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• 2013

Purpose: To investigate a correlation between vertical fixation disparity and stereopsis by analyzing distribution of types of vertical fixation disparity. Methods: In this study, RANDOT(R) stereotest partly using random dot was used in stereopsis tests. The vertical fixation disparity in close proximity categorized fixation disparity slope into six types on the basis of the result of measurement in when two thin lines, one for one eye looks, become overlapped as a line by adding into prism with Wesson fixation disparity card while maintaining a distance of 25 cm from patients. Results: In the types of near vertical fixation disparity curve, targeting 43 people, the first type 55.82% was the most distributed, the second type is the least 23.25%, the third type of 4.65%, the fourth type of 4.65%, the fifth type of 6.98%, the sixths types of 4.65% were distributed. The result of a correlation analysis, which shows the degree of linear correlation between two variables, represented that stereopsis is not correlated with Y-intercept (r = -0.07) which show vertical fixation disparity, associated phoria (r = -0.03) and dissociated phoria (r = -0.00), but it was not statistically significant (p>0.05). Fixation disparity slope of vertical fixation disparity (r = 0.36) was shown to have a positive correlation with stereopsis. It has a low positive correlation and a meaningful statistics (p<0.05). The Y-intercept which indicates vertical fixation disparity was also not associated with stereopsis (r = -0.07) and dissociated phoria (r = -0.03), and this was not statistically significant (p>0.05), while it had a high correlation as well as a statistically significant with associated phoria (r = 0.89). There was a negative correlation between Y-intercept and fixation disparity slope of vertical fixation disparity (r = -0.33). It showed a low relationship but statistically valuable (p>0.05). As a result of regression analysis, the stereopsis was changed as 7.631" if vertical fixation disparity changes 1' and the vertical fixation disparity changed as 0.017' if stereopsis changes 1', and the change was statistically significant (p<0.05). Conclusions: The study shows that there is a low correlation between stereopsis and vertical fixation disparity, and it is difficult to determine stereopsis only using vertical fixation disparity. Therefore, it suggests other factors above vertical fixation disparity have greater influence on stereopsis.

• The Journal of Information Technology
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• v.5 no.2
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• pp.69-80
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• 2002

Conventionally, we have used an acoustic microscope at single operating frequency. The resolution and quality of the measured images are determined by transducer of the microscope. In this paper, we have studied Vertical Resolution Enhancement with Acoustic Reflection Microscope using combining bases of support for SFR(Spatial Frequency Response). Increased Vertical resolution can be obtained by taking three-dimensional images at more that one frequency and numerically combining the results. As results of the experiment, we could get enhanced images with the rate of contrast in proportion to the changing rate of depth.

• The Korean Nurse
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• v.26 no.1 s.139
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• pp.43-48
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• 1987

분만진행에 수직체위가 효과적이라는 것을 연구하는 연구자는 이러한 체위가 자궁수축력을 강화하고 분만시간을 단축하여 분만시 동통을 감소시킨다는 것을 파악했다. 분만과 출산 시 쪼그리고 앉는 방법이 역사적으로 오랜 기간 동안 적용되어 왔음에도 불구하고 연구자들은 여러가지 분만방법의 장점에 대한 연구가 부족한 실정이다. 임상 경험에 의해 쪼그리고 앉는 자세가 보다 효과적임을 알면서도 여러가지 위험을 우려하여 적용을 기피하고 있다. 그러나 연구자들은 앞으로 이러한 체위의 가치를 확인하고 특별히 다른 체위와 비교하여 쪼그리고 앉는 행위가 경관열상의 빈도, 분만 1,2기의 시간, 분만 중이나 분만 후의 뇨정체의 유무, 제대탈출의 빈도등이 어떠한지를 파악하여야 할 것이다. 쪼그리고 앉는 체위에 대한 가장 좋은 잇점을 얻기 위해 조산자는 이러한 체위를 언제 어떻게 할 것인가에 대한 지식을 가져야 한다. 또한 융통성있고 창조적인 접근방법을 시도하여 의학적수행과 분만시 사정을 용이하게 하고 산부와 의료요원이 보다 편안하도록 하여야 한다. 조산교육자나 조산자는 분만시 그들의 체위에 대한 교육을 포함하여 쪼그리고 앉은 방법의 효과적인 적용을 위해 노력해야 한다. 임부에게 안전, 편안함, 분만의 효과적인 진행, 모든 선택 가능한 체위들을 교육하고 그러한 체위 중 쪼그리고 앉는 방법을 선택하도록 격려해야 한다.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.2
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• pp.177-184
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• 2012

Purpose: In this study, the effect of the eye movement direction on visual function related to accommodation was investigated when playing computer games for a certain period of time. Methods: Total 60 subjects in 20s who had the visual acuity of 1.0 or higher without any ocular disease and accommodative dysfunction were asked to play computer games separately in horizontal and vertical directions for 40 and 90 minutes and then measured their accommodative amplitude, accommodative facility, accommodative lag and relative accommodations. Thevisual function when not doing the computer game was regarded as a control value, and further compared and analyzed. Results: The accommodative amplitude, accommodative facility, accommodative lag and relative accommodations showed the tendency of decrease after the computer game for 40 minutes, and more reduced values of the visual functions were shown when the computer game extended up to 90 minutes except positive relative accommodation. Positive relative accommodation had a tendency to increase slightly after the computer game for 90 minutes. Meanwhile, the change of the visual functions was primarily influenced by the eye movement in horizontal direction rather than by the eye movement in vertical direction during computer game when analyzed by the direction of eye movement. Conclusions: Over all accommodative functions tended to decrease with the extended VDT working time by computer game, and the frequent eye movement in horizontal direction during VDT tasks could be the main cause of eyestrain since the eye movement in horizontal direction rather than vertical direction significantly affected the change of accommodative function.

• Journal of the Korean School Mathematics Society
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• v.9 no.1
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• pp.57-76
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• 2006

In this paper, we generalized number partion problems in elementary situations to number partition models that provide some mathematical problem situations for experiencing mathematising of secondary pre-service teachers. We designed substantial teaching units entitled 'the inquiry intof number partition models' through 4 steps: (1) key problems, (2) integration from the view of partition, (3) defining partition (4) a real practice of inquiry into models. This teaching unit can contribute to secondary pre-service teacher education as follows: first, This teaching unit have pre-service teachers experience mathemtising. second, This teaching unit have pre-service teachers see the connection between school mathematics and academic mathematics. third, This teaching unit have pre-service teachers foster their mathematical creativity.

• Journal of Korea Multimedia Society
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• v.13 no.9
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• pp.1314-1321
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• 2010

In this paper, we study about the vehicle detection algorithm which is in the process of travelling from the road. An input image is segmented by means of split and merge algorithm. And two largest segmented regions are removed for reducing search region and speed up processing time. In order to detect the back side of the front vehicle considers a vertical/horizontal component, uses an integral image with to apply Haar-like methods which are the possibility of shortening a calculation time, classified with SVM. The simulation result of the method which is proposed appeared highly.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.10
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• pp.687-694
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• 2019

A circular composite spar in the wing of ultra-light aircraft is subjected to both bending moment and transverse shear loads. However, the beam being used in the aircraft may be inefficient because the design would not take into account the characteristics of the circular tube that supports the bending moment in top and bottom arc parts and the transverse load in left and right ones. Therefore, it is necessary to efficiently fabricate the circular tube beam by properly selecting the stacking sequences or the laminated composite structure. In order to increase both bending and transverse shear strengths of the beams, in this study, a cross-section of circular tube is divided into four arcs: top, bottom, left and right ones. The commercial program, MSC/NASTRAN is used to calculate vertical displacement and the normal and shear strains with variation of parameters such as division angle of arc and fiber orientation. Based on the results, the effective parameters for the new circular composite beam are presented to increase its bending and shear strengths.