• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.1430-1432
• /
• 2008

We have developed a high-contrast ambient-light rejection projection screen with surface micro-structures for front and rear projection displays with an oblique-angle projector. We have fabricated prototype screens that show a better than $10{\times}$ improvement in contrast compared to a matte-white screen under various ambient lighting conditions and screen luminance.

• 대한자기공명의과학회:학술대회논문집
• /
• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
• /
• pp.43-43
• /
• 2003

Viable myocardium can be distinguished from the infarcted myocardium by contrast-enhanced magnetic resonance imaging (ceMRI). In this study, contrast-enhancement with cine magnetic resonance imaging (cecineMRI) was performed for direct correlation of transmural extent of hyperenhancement and that of contractility.

• 대한자기공명의과학회:학술대회논문집
• /
• 대한자기공명의과학회 2003년도 제8차 학술대회 초록집
• /
• pp.89-90
• /
• 2003

Viable myocardium can be distinguished from the infarcted myocardium by contrast-enhanced magnetic resonance imaging (ceMRI). In this study, contrast-enhancement with cine magnetic resonance imaging (cecineMRI) was performed for direct correlation of transmural extent of hyperenhancement and that of contractility.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2004년도 학술대회지
• /
• pp.867-871
• /
• 2004

In this paper, a new analytic approach for shape preserving contrast enhancement is presented. Contrast enhancement is achieved by means of segmental histogram stretching modification which preserves the given image shape, not distorting the original shape. After global stretching, the image is partitioned into several level-sets according to threshold condition. The image information of each level-set is represented as typical value based on grouped differential values. The basic property is modified into common local schemes, thereby introducing the enhanced effect through extreme discrimination between subsets. The scheme is based on stretching the histogram of subsets in which the intensity gray levels between connected pixels are approximately same In spite of histogram widening, stretched by local image information, it neither creates nor destroys the original image, thereby preserving image shape and enhancing the contrast. By designing local histogram stretching operations, we can preserve the original shape of level-sets of the image, and also enhance the global intensity. Thus it can hold the main properties of both global and local image schemes, which leads to versatile applications in the field of digital epigraphy.

• Childhood Kidney Diseases
• /
• 제21권1호
• /
• pp.26-30
• /
• 2017

Newborn infants with huge and highly vascular sacrococcygeal teratoma (SCT) are frequently subjected to renal hypoperfusion secondary to high-output cardiac failure. Any underlying renal dysfunction is a significant risk factor for the development of contrast-induced nephropathy (CIN). However, reports on CIN in infants are rare. I report here a case of a premature infant born at 28 weeks and 3 days of gestation with a huge SCT who survived preoperative embolization and surgical resection but presented with persistent non-oliguric renal failure that was suggestive of CIN. During radiological intervention, a contrast medium had been administered at about 10 times the manufacturer-recommended dose for pediatric patients. Despite hemodynamic stabilization and normalization of urine output immediately following surgery, the patient's serum creatinine and cystatin-C levels did not return to baseline until 4 months after birth. No signs of reflux nephropathy were observed in follow-up imaging studies. Dosing guidelines for the use of a contrast medium in radiological interventions should be provided for infants or young patients.

• 한국방송∙미디어공학회:학술대회논문집
• /
• 한국방송공학회 1996년도 학술대회
• /
• pp.175-180
• /
• 1996

In this paper, a new image segmentation method based on merging of two low contrast neighbor regions iteratively is proposed. It is suitable for very low bit rate coding. The proposed method reduces efficiently contour information and preserves subjective and objective image quality. It consists of image segmentation using 4-level hierarchical structure based on mathematical morphology and 1-level region merging structure using the contrast difference of two adjacent neighbor regions. For each segmented region of the third level, two adjacent neighbor regions having low contrast difference value in fourth level based on contrast difference value is merged iteratively. It preserves image quality and shows the noticeable reduction of the contour information, so that it can improve the bottleneck problem of segmentation-based coding at very low bit rate.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
• /
• pp.175-177
• /
• 2004

The current JPEG-2000 standard is a wavelet based scheme because wavelet transform have some advantages compare to DCT transform. In compressed images, there are some image degradation factors like contrast distortion by Quantization process. This factor is very important to HVS (Human Visual System). Therefore, In this paper, we propose a new algorithm for contrast enhancement using the properties of wavelet coefficients. This algorithm is processed in the wavelet domain and so it can be applied efficiently to JPEG-2000.

• 복식문화연구
• /
• 제15권5호
• /
• pp.838-851
• /
• 2007

The purpose of this research was to investigate the harmony evaluation and the effects used clues on harmony perception in terms of 128 contrast coloration of male shirt and necktie by male and female students. The results are as follows. Among 128 contrast coloration stimuli, female students evaluated 42 set, male students 50 set, so proved that male's range of harmony more extensive than that of female. It is significant difference between female and male on shirt-necktie coloration; vivid red shirt-vivid green tie, dull red shirt-dark blue tie, light red shirt-dull blue tie, dark red shirt-light blue tie, light green shirt-vivid violet tie, light green shirt-light red tie, light green shirt-dull red tie. Especially, in contrast coloration, it was evaluated as harmonized coloration by both male and female as tie was dark tone on the whole.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2007년도 춘계학술대회 학술발표 논문집 제17권 제1호
• /
• pp.139-142
• /
• 2007

본 논문은 지역 명암대비 향상을 통한 영상의 명암대비 개선 기법을 제안한다. 전역 대비 향상 기법은 영상 전체를 고려하여 대비를 향상시키므로 영상의 특성에 따라 영상이 뿌옇게 되거나 원하지 않는 인공적인 산물이 생성될 수 있다. 그리고 지역 대비 향상 기법은 블록화 및 영상의 화질이 훼손되는 문제점이 있다. 제안하는 기법은 다양한 블록 크기를 사용하여 지역 대비를 향상시켜 지역 대비가 가장 많이 향상된 영상의 히스토그램 평활화 함수를 이용하여 전체 영상의 명암대비를 향상시키는 방법을 제안한다. 명암대비가 낮은 다양한 영상의 실험을 통해서 제안하는 명암대비 향상 기법의 우수성을 입증하였다.

• 음성과학
• /
• 제15권1호
• /
• pp.37-51
• /
• 2008

The main goal of this study is to examine if there is a difference in the utilization of a vowel length cue between Korean and Japanese L2 learners of English in their perception and production of postvocalic coda contrast in English. Given that Japanese subjects' performances on the identification and production tasks were much better than Korean subjects' performance, we may support the prediction based on the Feature Hypothesis which maintains that L1 phonological features can facilitate the perception of L2 acoustic cue. Since vowel length contrast is a phonological feature in Japanese but not in Korean, the tasks, which assess L2 leaners' ability to discriminate vowel length contrast in English, are much easier for the Japanese group than for the Korean group. Although the Japanese subjects demonstrated a better performance than the Korean subjects, the performance of the Japanese group was worse than that of the English control group. This finding implies that L2 learners, even Japanese learners, should be taught that the durational difference of the preceding vowels is the most important cue to differentiate postvocalic contrastive codas in English.