• The Transactions of the Korea Information Processing Society
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• v.7 no.2
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• pp.477-487
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• 2000

When volume data is visualized by the ray casting method, the color value of each pixel in the image is obtained by composing the color contributions of the sample points that lie on the ray cast from the pixel point. In most ray tracing methods including Levoy's classical method, the color composition is formulated as a summation of the color contributions of the discrete sample points. However, the more precise color composition is formulated as differential equations over the color contributions of the continuous sample points. The discrete formulation is used, because analytical solutions to the continuous formulations are hard to find. In this paper, however, we have discovered a semi-analytical solution to the continuous formulation of a typical ray tracing of volume data. We have applied both Levoy's method and ours to the same set of data, and compared the visual quality of both results. The comparison shows that our method produces a more fine-grained visualization of volume data.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.8
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• pp.1216-1227
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• 2002

The objective in the part H of this study was to investigate the effects of materials, sleeves, trimming, and perceivers gender on impression formation. Stimuli consisted of 13 color photographs of a female model wearing a wedding dress which were manipulated according to clothing cues. A semantic differential sale of 4 dimensions was used. These were attractiveness, neatness, femininity, and prettiness. Samples were 312 males and females. For the effect of sleeves, there were significant main effects in attractiveness, femininity, neatness, and prettiness. Three-quarters lace ruffled sleeves increased the perception of positive attractiveness, femininity, and prettiness. Flounced sleeves had a positive effect on the perception of neatness. Long-tight sleeves had a negative effect on the perception of attractiveness, femininity, and prettiness. Sleeveless dresses increased the perception of negative neatness. There was an interaction effect between sleeves and the perceivers gender on neatness. For the onぉ of material, there were significant main effects in neatness, femininity, and prettiness. Solid cloth had a positive effect on the perception of neatness and negatively on prettiness. The combination of lace and solid cloth increased the perception of positive femininity and prettiness. lace had a negative effect on the perception of neatness. Satin increased the perception of negative femininity. There was an interaction effect between material and perceivers gender on prettiness. The main effect of trimmings was its effect on prettiness. Ribbons increased the perception of positive prettiness. Not having any trimmings had a negative effect on the perception of prettiness. There was an interaction effect between timings and the perceivers gender on neatness. The results of this study confirm that image perception of wedding dresses becomes different according to the materials, details, and perceiver's gender.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.5
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• pp.379-388
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• 2019

Recently, a technique for acquiring spatial information data using UAV (Unmanned Aerial Vehicle) has been greatly developed. It is a very crucial issue of the GIS (Geographic Information System) mapping system that passes way point in the unmanned airframe and finally measures the accurate image and stable localization to the desired destination. Though positioning using DGPS (Differential Global Navigation System) or RTK-GPS (Real Time Kinematic-GPS) guarantee highly accurate, they are more expensive than the construction of a single positioning system using a single GPS. In the case of a low-priced single GPS system, the stability of the positioning data deteriorates. Therefore, it is necessary to supplement the uncertainty of the absolute position data of the UAV and to improve the accuracy of the current position data economically in the operating state of the UAV. The aim of this study was to present an algorithm enhancing the stability of position data in a single GPS mode of UAV with multiple GPS. First, the arrangement of multiple GPS receivers through the center of gravity of the UAV were examined. Next, MD (Mahalanobis Distance) is applied to detect instantaneous errors of GPS data in advance and eliminate outliers to increase the accuracy of previously collected multiple GPS data. Processing procedure for multiple GPS reception data by applying the center of the triangular method were presented to improve the position accuracy. Second, UAV navigation systems integrated multiple GPS through configuration of the UAV specifications were implemented. Using the unmanned airframe equipped with multiple GPS receivers, GPS data is measured with the TCM (Triangular Center Method). In addition, UAV equipped with multiple GPS were operated in study area and locational accuracy of multiple GPS of UAV with VRS (Virtual Reference Station) GNSS surveying were compared. The result showed that the error factors are compensated, and the error range are reduced, resulting in the reliability of the corrected value. In conclusion, the result in this paper is expected to realize high-precision position estimation at low cost in UAV using multiple low-cost GPS receivers.

• Fashion & Textile Research Journal
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• v.20 no.6
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• pp.656-668
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• 2018

The main object of this study was to understand the body image and body management behavior associated with desiring a thinner and more muscular body. The present study examined whether the drives for thinness and muscularity occur concurrently for both male and female college students, and whether there are gender differences. Moreover, the effects of objectified body consciousness on drive for thinness and drive for muscularity were investigated. A self-administered survey was conducted and a total of 390 data were used for data analysis. Participants included 197 male college students and 193 female students. Results indicated that male students reported significantly lower drive for thinness and higher drive for muscularity than female students. However, the drives for thinness and muscularity were significantly correlated for both male and female college students, and they reported discrepancies between their BMI and self-perceived weight and muscle mass. Findings supported the significant effects of objected body consciousness on the drives for thinness and muscularity for both male and females. Sub-dimensions of objectified body consciousness had differential effects on drive for thinness and muscularity. Specifically, body surveillance and body shame significantly influenced male and female students' drive for thinness, while their control belief did not have significant effects on their drive for thinness. Additionally, body shame emerged as significant unique predictor of drive for muscularity. In terms of gender comparisons, while the effect of body shame was the strongest for the males, the effect of surveillance was as strong as that of body shame for the females.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.29 no.2
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• pp.98-102
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• 2018

Background and Objectives : Detection of vascular abnormalities in vocal cord (VC) leukoplakia is important for the diagnosis of neoplastic change of the mucosa. The aim of this study was to investigate the value of i-scan in the differential diagnosis of VC leukoplakia based on visualization of abnormal vascular features. Material and Methods : Fifty-two patients with leukoplakia were enrolled in the study. Images of their larynx obtained using conventional white light endoscopy and an i-scan-enhanced endoscopy (Pentax DEFINA EPK-3000 Video Processors, with Pentax VNLJ10) were reviewed. The microvascular features of the lesions and vascular changes were analyzed and the results were compared with the histopathologic diagnosis. Results : Among the 52 leukoplakia patients, 7 (13.5%) patients had squamous hyperplasia, 10 (19.3%) mild dysplasia, 2 (3.8%) moderate dysplasia, 14 (26.9%) severe dysplasia, 4 (7.7%) carcinoma in situ, and 15 (28.8%) invasive squamous cell carcinoma on histopathologic examination. Using i-scan-enhanced endoscopy, abnormal vascular change with neoplastic neoangiogenesis was detected in most cases of malignant VC lesion [severe dysplasia : 9/14 (64.3%), carcinoma in situ: 2/4 (50.0%), and invasive squamous cell carcinoma : 11/15 (73.4%)]. Conclusion : i-scan-enhanced endoscopy is a useful optical technique for the diagnosis of VC leukoplakia. Our results suggest that i-scan may be a promising diagnostic tool in the early detection of laryngeal cancer.

• Journal of Digital Convergence
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• v.17 no.7
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• pp.285-292
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• 2019

With the popularization of PC, SNS and IoT, a lot of data is generated and the amount is increasing exponentially. Artificial neural network learning is a topic that attracts attention in many fields in recent years by using huge amounts of data. Artificial neural network learning has shown tremendous potential in speech recognition and image recognition, and is widely applied to a variety of complex areas such as medical diagnosis, artificial intelligence games, and face recognition. The results of artificial neural networks are accurate enough to surpass real human beings. Despite these many advantages, privacy problems still exist in artificial neural network learning. Learning data for artificial neural network learning includes various information including personal sensitive information, so that privacy can be exposed due to malicious attackers. There is a privacy risk that occurs when an attacker interferes with learning and degrades learning or attacks a model that has completed learning. In this paper, we analyze the attack method of the recently proposed neural network model and its privacy protection method.

• Journal of IKEEE
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• v.23 no.2
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• pp.642-651
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• 2019

One of the most important research topics on intelligent transportation systems in recent years is detecting and recognizing a license plate. The license plate has a unique identification data on vehicle information. The existing vehicle traffic control system is based on a stop and uses a loop coil as a method of vehicle entrance/exit recognition. The method has the disadvantage of causing traffic jams and rising maintenance costs. We propose to exploit differential image of camera background instead of loop coil as an entrance/exit recognition method of vehicles. After entrance/exit recognition, we detect the candidate images of license plate using the morphological characteristics. The license plate can finally be detected using SVM(Support Vector Machine). Letter and numbers of the detected license plate are recognized using CNN(Convolutional Neural Network). The experimental results show that the proposed algorithm has a higher recognition rate than the existing license plate recognition algorithm.

• Journal of IKEEE
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• v.25 no.2
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• pp.302-308
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• 2021

A 12-bit 10-MS/s pipeline analog-to-digital converter (ADC) is proposed for image processing applications. The proposed pipeline ADC consists of a sample and hold amplifier, three stages, a 3-bit flash analog-to-digital converter, and a digital error corrector. Each stage is operated by using a 4-bit flash ADC (FADC) and a multiplying digital-to-analog converter (MDAC). The proposed sample and hold amplifier increases the voltage gain using gain boosting for the ADC with high resolution. The proposed pipelined ADC is designed using a 180-nm CMOS process with a supply voltage of 1.8 and it has an effective number of bit (ENOB) of 10.52 bits at sampling rate of 10MS/s for a 1-V_pp differential sinusoidal analog input with frequency of 1 MHz. The measured ENOB is 10.12 bits when the frequency of the sinusoidal analog input signal is a Nyquist frequency of approximately 5 MHz.

• Smart Structures and Systems
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• v.31 no.4
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• pp.421-436
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• 2023

This paper presents a vibration displacement measurement and damage identification method for a space truss structure from its vibration videos. Features from Accelerated Segment Test (FAST) algorithm is combined with adaptive threshold strategy to detect the feature points of high quality within the Region of Interest (ROI), around each node of the truss structure. Then these points are tracked by Kanade-Lucas-Tomasi (KLT) algorithm along the video frame sequences to obtain the vibration displacement time histories. For some cases with the image plane not parallel to the truss structural plane, the scale factors cannot be applied directly. Therefore, these videos are processed with homography transformation. After scale factor adaptation, tracking results are expressed in physical units and compared with ground truth data. The main operational frequencies and the corresponding mode shapes are identified by using Subspace Stochastic Identification (SSI) from the obtained vibration displacement responses and compared with ground truth data. Structural damages are quantified by elemental stiffness reductions. A Bayesian inference-based objective function is constructed based on natural frequencies to identify the damage by model updating. The Success-History based Adaptive Differential Evolution with Linear Population Size Reduction (L-SHADE) is applied to minimise the objective function by tuning the damage parameter of each element. The locations and severities of damage in each case are then identified. The accuracy and effectiveness are verified by comparison of the identified results with the ground truth data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.2D
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• pp.265-273
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• 2006

On the occasion of high price oil generation, we have to promote activation policy for public transportation and hold back to use passenger car, it is very important to improve of sidewalk environment for pedestrian. Evaluation for sidewalk environment will be fixed with sensibility to feel pedestrian. So, study for sensibility about comfort etc. to feel pedestrian will be carried out. In this paper, researchers interests in engineering methods to make material considering sensibility and image of human. Therefore, we carried out recognition experiment for sidewalk environment with Kansei engineering, and made a quantitativedata of sensibility adjective that it was surveyed by semantic deferential method. After grasp factors by principal analysis, we found factor effect to design criterion and sidewalk environment preference. So, we could identify a design factor for comfort environment.