• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.15 no.9
• /
• pp.729-737
• /
• 1990

This paper presents a new method of multilevel estimation of dithered images. A dithered picture, a two-tone picture which gives the illusion of picture with many shades of gray, is obtained by comparing the gray-level picture which gives the illusion of picture with a position-dependent threshold. When the intensity of a picture element exeeds the threshold it is classified as white: otherwise it is black. In the new estimation scheme, the simulation results show the SNR of the new method is improved 0.7dB compared with the old method. And we propose a new progressive image transmission by employing thie method.

• The KIPS Transactions:PartB
• /
• v.12B no.5 s.101
• /
• pp.617-630
• /
• 2005

General scene change detection determines the changes of a scene by using feature comparison of two continuous images that are above the fixed threshold. But existing algerian detects scene change that was used in comparing the features of two images continuously, it usually takes a lot of time in decrypting the image data and false-detection problem occurs when there is an object motion or a change of illumination. In this paper, macroblock were used to extract the information directly from the MPEG compression area and suggests algorithm that will detect scene changes more effectively. Existing algorithm have shown numerous arithmetic problems that were improved in the proposed algorithm. The existing algorithm cannot detect the changes of a scene after analyzing the relationship of the previousand futureimages while the algorithm being proposed can detect the changes of a scene continuously and resolves the problem of false-detection. To this end, the data used in general were tested to prove that this algerian would be able to detect the scene changes faster and more correctly than the existing ones. The performance of the suggested algorithm was analyzed basedontheresultsoftheexperiment. .

• Journal of the Korean Ceramic Society
• /
• v.36 no.1
• /
• pp.7-14
• /
• 1999

TiZrB2 solid solution was synthesized using fine powders of Ti, Zr and B by SHS microwave process. The characterization of the synthesized powder and sintered bodies ws investigated. The combustion temperature and rate were increased with increasing the mole ratio of Zr in temperature profile, and showed the maximum combustion temperature and velocity values of 285$0^{\circ}C$ and 14.6mm/sec in Ti0.2Zr0.8B2 composition. Phase separation has been occured into a composite with TiB2 and ZrB2 phases from TiZrB2 solid solution, which was hot pressed sintering at 30 MPa for an hour at 190$0^{\circ}C$. At the composition of Ti0.8Zr0.2B2 the best properties has been obtained in relative density, bending strength, fracture toughness and hardness, with 99%, 680 MPa, 7.3MPa.m1/2 and 2750 Kg/$\textrm{mm}^2$ respectively.

• Journal of Elementary Mathematics Education in Korea
• /
• v.19 no.3
• /
• pp.371-386
• /
• 2015

There has been little consensus on how to define and use the Korean mathematical terms, bi-ui-gap and bi-yul. This study compares four perspectives of bi-ui-gap and bi-yul proposed and discussed in Korean mathematics education community and examines the ways of using the terms adopted since the 6th national curriculum. Based on the analysis that previously proposed perspectives conflict each other, this study proposes as a way to synthesize different perspectives of bi-ui-gap and bi-yul by analyzing the terms in the internal and external ratio contexts. This study proposes that bi-ui-gap be used to represent 'a value of $A{\div}B$' rather than 'a value originated from a ratio A:B' or 'a fraction form ${\frac{B}{A}}$.' This study also proposes that bi-yul or bae-yul be used in the internal ratio context and a new term, such as dan-wi-yul, be created for the external ratio context.

• Korean Journal of Food Science and Technology
• /
• v.38 no.1
• /
• pp.68-74
• /
• 2006

To utilize sea tangle single cell detritus (SCD) as food additive, SCD noodle was developed using mixture model. Flour improved, whereas water decreased texture of SCD noodles. Texture of SCD noodle decreased initially and then increased as SCD content increased. Flour and SCD increased, whereas water decreased $L^*$ and $b^*$ values of dried and cooked noodles. Flour decreased $a^*$ values of dried and cooked noodles, while SCD increased $a^*$ value of cooked noodle. Response constraint coefficient showed SCD influence on texture, and $L^*$ and $b^*$ values of dried and cooked noodles was higher than those of flour and water, whereas water influence on $a^*$ value was higher than those of flour and SCD. Texture and color values fitted nonlinear model with interaction terms for flour-water, flour-SCD, and water-SCD. Optimum mixing ratio value of flour : water : SCD was 63.3 : 31.0 : 3.7%. Sensory evaluation value of SCD noodles was lower than those of industrial and electrolyzed SCD noodles.

• Journal of Korea Multimedia Society
• /
• v.14 no.5
• /
• pp.607-613
• /
• 2011

In this paper, we propose a hand image segmentation method using the dynamic threshold values on input images with various lighting and background attributes. First, a moving hand silhouette is extracted using the camera input difference images, Next, based on the R,G,B histogram analysis of the extracted hand silhouette area, the threshold interval for each R, G, and B is calculated on run-time. Finally, the hand area is segmented using the thresholding and then a morphology operation, a connected component analysis and a flood-fill operation are performed for the noise removal. Experimental results on various input images showed that our hand segmentation method provides high level of accuracy and relatively fast stable results without the need of the fixed threshold values. Proposed methods can be used in the user interface of mixed reality applications.

• Culinary science and hospitality research
• /
• v.22 no.2
• /
• pp.78-92
• /
• 2016

This study investigated the quality characteristics of white pan bread with banana addition. This analysis was through mixograph and stickiness of dough, fermentation rate, TPA, crumbScan image analysis, color, moisture contents and acceptance test. Mixograph peak time presented 4~5 minutes on every sample. However, CON, B10 and B20 sample presented more than 60%, and B30, B40 presented less than 60% at peak value (%). The result indicated that banana addition increased as the stickiness decreased. The fermentation rate generally increased, but the sample B40 decreased after 75 minutes. The result of crust and inside color, CON was the highest on lightness L value, B40 was the highest on both red a value and yellow b value. The result of pH showed that B40 was the lowest, and more banana addition made pH decreased. Thus, adding banana influences negatively on volume and cost of the product. The image analysis through crumbScan did not show any significant difference on crust thickness and distortion of crumb fineness. On the other hand, CON value was 774.33 that was the lowest, and B40 value was 927.66 which is the highest on the density of crumb fineness. Hardness showed a significant difference; B40 was the lowest, and Control was the highest. Moisture contents generally had a noticeable difference; CON value was the highest, and banana addition increased as the value decreased. At the result of acceptance test, one of the sensory tests, B20 showed the highest grade, and B40 showed the worst. Based on the above results of characteristic difference, banana addition could influence volume of the bread negatively.

• Journal of radiological science and technology
• /
• v.35 no.1
• /
• pp.1-7
• /
• 2012

Dual Energy X-ray Absorptiometry(DEXA) is commonly used to diagnose Osteoporosis. The errors of DEXA bone density operation are caused by operator, bone mineral density meter, blood testing, patient. We focus on operator error then study about how much influence operator's region of intest(ROI) in bone testing result. During from March to July in 2011. 50 patients ware selected respectively from 30, 40, 50, 60, and 70 age groups who came to Korea University Medical Center(KUMC) for their Osteoporosis treatment. A-test was performed with usually ROI and B-test was performed with most widely ROI. Then, We compare A-test and B-test for find maximum difference of T-score error which occurred operator ROI controlling. Standard deviation of T-score of B-test showed 0.1 higher then A-test in femur neck. Standard deviation of B-test showed 0.2 higher then A-test in Ward's area which in Greater trocanter and Inter trocanter. Standard deviation of B-test showed 0,1 lower then A-test in L-1. Bone density testing about Two hundred patients results are as follow. When operator ROI was changed wider than normal ROI, bone density of femur was measured more higher but bone density of L-spine was measured more lower then normal bone density. That means, sometime DEXA bone density testing result is dependent by operator ROI controlling. This is relevant with the patient's medicine and health insurance, thus, tester always keep the size of ROI for to prevent any problem in the patient.

• Restorative Dentistry and Endodontics
• /
• v.21 no.1
• /
• pp.107-120
• /
• 1996

복합레진은 조작이 용이하고 강도가 우수하며 중합시간이 짧고 법랑질과 상아질에 접착이 가능하며 연마성이 뛰어나고 자연스러운 색상을 나타내므로 심미적 수복에 가장 일반적으로 선택되는 재료의 하나이다. 대부분의 복합레진 kit에는 shade guide가 포함되어 있어 이를 기준으로 중합된 후의 복합레진 색조를 예상하여 선택하게 된다. 그러나 이러한 shade guide들은 대개 복합레진이 아닌 plastic으로 제조된 것으로 중합된 복합레진의 실제 색조와는 차이가 생기게 되며 결국 shade guide 자체의 문제점으로 인해 이상적인 색조선택이 어려워진다. 이에 본 연구에서는 국내에 시판되고 있는 5종의 복합레진 제품을 선정하여 분광 광도계를 이용해서 shade guide와 중합된 복합레진 사이의 색조차이를 측정, 비교 연구하였다. 직경 16mm. 두께 1.6mm의 plastic mold에 5종의 광중합형 복합레진(Z100, Prisma TPH, Tetric, Silux Plus, Herculite XR)을 충전하고 응축기에 넣어 압축한 후 제조사의 지시에 따라 광중합기로 중합시킨 후 mold에서 시편을 제거하여 보관했다가 젖은 sandpaper 상에서 순차적으로 연마하였다. shade guide는 step부분을 갈아내어 복합레진 시편과 동일한 두께로 만든후 연마하였다. 분광광도계에 shade guide를 넣고 CIE illuminant D65 하에서 spectral reflectance를 측정하고 해당 색조의 복합레진 시편도 통일한 방법으로 측정하고 $L^*$, $a^*$, $b^*$값과 ${\Delta}E^*$값을 얻은후 분석하여 다음과 같은 결과를 얻었다. 1. Z100의 D3, A3, B2 shade와 Prisma TPH의 B2 shade를 제외한 모든 시편에서 shade guide와 복합레진간에 육안으로 인지할 수 있는 색차(${\Delta}E^*$ > 1.0)가 관찰되었다. 2. 평균적으로 Z100이 가장 적은 색차를 나타내었고 Prisma TPH, Tetric, Silux Plus, Herculite XR 순으로 색차가 증가하였다. 3. Prisma TPH의 A2 shade. Tetric의 W shade. Silux Plus의 YB, U shade, Herculite XR의 L, LY shade는 ${\Delta}E^*$값이 3.3 이상으로 나타났다. 4. Z100, Prisma TPH, Tetric, Silux Plus에서는 복합레진보다 shade guide가 더 높은 $L^*$값을 보이는 경향이 나타났으며, Herculite XR에서만 복합레진이 더 높은 $L^*$값을 나타냈다. 5. 모든 시편에서 $b^*$ 값은 (+)로 관찰되었고, Z100, Prisma TPH, Tetric, Silux Plus의 shade guide는 복합레진에 비해 높은 $b^*$값을 보였다. 6. 모든 시편에서 $a^*$값은 (-)로 관찰되었고. Herculite XR 및 Silux Plus에서는 복합레진이 shade guide 에 비 해 낮은 $a^*$값을 나타냈다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.13 no.6
• /
• pp.1181-1187
• /
• 2009

In this paper, we proposed a method to analyze kind of clouds using a fuzzy reasoning method. In the proposed method, we used the clues that G channel value is dominant from RGB color values in land areas and B channel value is dominant in the sea areas discovered by the analyses of both visible images and infrared images. By these information, R and B channel values are applied to land areas and R and G channel values are applied to the sea areas. Noise areas(areas except cloud areas) are removed from a visible image and an infrared image by a threshold value, and then land areas and the sea areas are discriminated from the noise removed image. Cloud areas are extracted from discriminated areas using R, G, B channel values and a fuzzy reasoning method, and finally kind of clouds is decided by combining same cloud areas included in both the visible image and the infrared image. In comparison with a conventional quantization method, we verified that the performance of cloud analysis by the proposed method is more efficient through experiments.