• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.7
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• pp.489-495
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• 2017

An experimental study on supersonic jets produced by supersonic nozzles at low operating pressure ratio is conducted. In the present experiments, particle image velocimetry (PIV) was employed to quantitatively specify the jet flowfield, and a color Schlieren optical method was applied to observe the same jets qualitatively. Convergent-divergent nozzles were used to generate the jet flow with design Mach numbers of 1.5 and 1.8. Nozzle pressure ratios (NPRs) were varied from 4 to 7. A good comparison of the jet size from the Schlieren images with the theoretical values is obtained. The obtained images clearly showed the major features of the under-expanded jet and over-expanded jet.

• Archives of design research
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• v.18 no.1 s.59
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• pp.253-262
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• 2005

In suddenly changing multimedia periods, department store not only plays the role of local culture centre but also meets keen competition in working out marketing strategies, especially in the field of differentiating Promotion Surroundings Image, in order to cope with the varied consumers' pattern according to customers' pursuing new lifestyle. In particular, cosmetic stores located in the first floor of the department store have high sales rate in spite of its comparative small area, because cosmetic stores have been much essential to women's daily life who are very strong for desiring the Beauty and also in them men's buying trends have been upwards speedily. The color and P.P.(Point of Sale Presentation) of the cosmetic store design are preferred after the quality and the price of the goods, staff's services by this survey of female clients' attitude to buy cosmetics at department store in Seoul. So that cosmetic companies seem to be needed to offer the differentiated color code in each brand and display the goods' P.P.(Point of Sale Presentation) intensively to promote the sales effectively. This thesis aims at suggesting the way how cosmetic firms get and enhance their goods' competitiveness when they develop their visual merchandising strategy by considering each brand's attribute and customers' life style by age, preference factors for buying the goods through showing high qualified sonics in their differentiated displayed stores.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1121-1127
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• 2014

Many studies have been done to measure and analyze color for various purposes. Visual assessment has lack of objectivity and the equipment for color measurement is very expensive. In this study, we developed a device for quantitative analysis of the color using optical elements. With the color sensor, the ratio of RGB was calculated by measuring the light intensity that is reflected from an object. Inverse transformation of optical signal was performed to detect the color density. The suggested color analyzer can detect color information as well as sample concentration. Results of this study are expected to be used in various medical fields such as pH indicator and urine analysis.

• Journal of Korean Library and Information Science Society
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• v.43 no.1
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• pp.321-347
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• 2012

Recently, the expansion of smart phones, wi-fi. and unlimited service changed our life style from personal computer based to mobile device based. With this trend, a lot of companies and government facilities use QR code as an advertising material, and now the QR code is very popular service in our ordinary life. In the meantime, libraries in abroad and university libraries started using QR code in library service about 2 or 3 years ago, and domestic libraries started using it in service due to the increase of establishment of mobile Library websites. In this research, starting with looking into the literature, I analyzed the examples of the use of QR code in libraries. On the base of it, I drew a QR code library service model, and what needs to be considered for the use of it.

• Journal of Korea Multimedia Society
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• v.17 no.1
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• pp.26-33
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• 2014

Video retrieval and indexing are performed by comparing feature similarities between key frames in shot after detecting a scene change and extracting key frames from the shot. Typical image features such as color, shape, and texture are used in content-based video and image retrieval. Many approaches for integrating these features have been studied. However, the issue of these approaches is how to appropriately assign weighting of key frame features at query time. Therefore, we propose a new video retrieval method using adaptively weighted image features. We performed computer simulations in test databases which consist of various kinds of key frames. The experimental results show that the proposed method has better performance than previous works in respect to several performance evaluations such as precision vs. recall, retrieval efficiency, and ranking measure.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.5
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• pp.55-62
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• 2011

In this paper, a temporal color and luminance variation suppression algorithm for a digital video sequence is proposed by considering time-varying light source. When a video sequence is sampled with the periodically emitting illuminant and with a short exposure time, the color rolling phenomenon occurs, where the color and the luminance of the image periodically change from field to field. In conventional signal processing techniques, the luminance variation remaining in the resultant video sequence degrades the constancy of the image sequence. In the proposed method, we obtain video sequences with constant luminance and color by compensating for the inter-field luminance variation. Based on a motion detection technique, the amount of the luminance variation for each channel is estimated on the background of the sequence without the effects of moving objects. The experimental results clearly show that our strategy efficiently estimated the illuminant change without being affected by moving objects, and the variations were efficiently reduced.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.1
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• pp.110-115
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• 2005

This paper proposes the method to detect contours of a face, eyes and a mouth in a color image for making an avatar automatically. First, we use the HSI color model to exclude the effect of various light condition, and we find skin regions in an input image by using the skin color is defined on HS-plane. And then, we use deformable templates and Genetic Algorithm(GA) to detect contours of a face, eyes and a mouth. Deformable templates consist of B-spline curves and control point vectors. Those can represent various shape of a face, eyes and a mouth. And GA is very useful search procedure based on the mechanics of natural selection and natural genetics. Second, an avatar is created automatically by using contours and Fuzzy C-means clustering(FCM). FCM is used to reduce the number of face color As a result, we could create avatars like handmade caricatures which can represent the user's identity, differing from ones generated by the existing methods.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.8
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• pp.55-67
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• 1998

This paper presents an automatic facial feature point extraction algorithm in sequential color images. To extract facial region in the video sequence, a moving color detection technique is proposed that emphasize moving skin color region by applying motion detection algorithm on the skin-color transformed images. The threshold value for the pixel difference detection is also decided according to the transformed pixel value that represents the probability of the desired color information. Eye candidate regions are selected using both of the black/white color information inside the skin-color region and the valley information of the moving skin region detected using morphological operators. Eye region is finally decided by the geometrical relationship of the eyes and color histogram. To decide the exact feature points, the PCA(Principal Component Analysis) is used on each eye and mouth regions. Experimental results show that the feature points of eye and mouth can be obtained correctly irrespective of background, direction and size of face.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.48 no.2
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• pp.102-108
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• 2011

The existing vessels lighting control system has several problems, which are complexity of construction and high cost of establishment and maintenance. In this paper, We designed low cost and high performance lighting control system at digital vessel environment. We proposed a system which recognize the user's emotions after obtaining the biological informations about user's bio information(pulse sensor, blood pressure sensor, blood sugar sensor etc) through wireless sensors controls the LED Lights. This system classified emotions using backpropagation algorithm. We chose 3,000 data sets to train the backpropagation algorithm. As a result, obtained about 88.7% accuracy. And the classified emotions find the most appropriate point in the method of controlling the waves or frequencies to the red, green, blue LED Lamp comparing with the 20-color-emotion models in the HP's 'The meaning of color' and control the brightness or contrast of the LED Lamp. In this method, the system saved about 20% of the electricity consumed.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.5
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• pp.123-131
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• 2016

To capture color and near-infrared images simultaneously, a multi-spectral filter array(MSFA) sensor is used. This is because an NIR band gives additional invisible information to human eyes to see subject under extremely low light level. However, because lenses have different refractive indices for different wavelengths, lenses may fail to focus widely different rays to the same convergence point. This is why a chromatic aberration(CA) problem occurs and images are degraded. In this paper, the image restoration algorithm for an MSFA image, which removes the CA problem, is presented. The obtained MSFA image is filtered by the estimated low-pass kernel to generate a base image. This base image is used to remove CA problem in multi-spectral(MS) images. By modeling the image degradation process and by using the least squares approach of the difference between the high-frequencies of the base and MS images, the desired high-resolution MS images are reconstructed. The experimental results show that the proposed algorithm performs well in estimating the high-quality MS images and reducing the chromatic aberration problem.