• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.2
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• pp.349-356
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• 2020

This paper introduces the implementation of a driver's condition warning system using eye aspect ratio to prevent a car accident. The proposed driver's condition warning system using eye aspect ratio consists of a camera, that is required to detect eyes, the Raspberrypie that processes information on eyes from the camera, buzzer and vibrator, that are required to warn the driver. In order to detect and recognize driver's eyes, the histogram of oriented gradients and face landmark estimation based on deep-learning are used. Initially the system calculates the eye aspect ratio of the driver from 6 coordinates around the eye and then gets each eye aspect ratio values when the eyes are opened and closed. These two different eye aspect ratio values are used to calculate the threshold value that is necessary to determine the eye state. Because the threshold value is adaptively determined according to the driver's eye aspect ratio, the system can use the optimal threshold value to determine the driver's condition. In addition, the system synthesizes an input image from the gray-scaled and LAB model images to operate in low lighting conditions.

• Journal of Radiation Protection and Research
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• v.45 no.1
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• pp.45-52
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• 2020

Background: Recently, the International Commission on Radiological Protection (ICRP) lowered the dose limit for the eye lens from 150 mSv to 20 mSv, highlighting the importance of accurate lens dose estimation. The ICRP reference computational phantoms used for lens dose calculation are mostly based on the data of Caucasian population, and thus might be inappropriate for Korean population. Materials and Methods: In the present study, a detailed Korean eye model was constructed by determining nine ocular dimensions using the data of Korean subjects. The developed eye model was then incorporated into the adult male and female mesh-type reference Korean phantoms (MRKPs), which were then used to calculate lens doses for photons and electrons in idealized irradiation geometries. The calculated lens doses were finally compared with those calculated with the ICRP mesh-type reference computational phantoms (MRCPs) to observe the effect of ethnic difference on lens dose. Results and Discussion: The lens doses calculated with the MRKPs and the MRCPs were not much different for photons for the entire energy range considered in the present study. For electrons, the differences were generally small, but exceptionally large differences were found at a specific energy range (0.5-1 MeV), the maximum differences being about 10 times at 0.6 MeV in the anteroposterior geometry; the differences are mainly due to the difference in the depth of the lens between the MRCPs and the MRKPs. Conclusion: The MRCPs are generally considered acceptable for lens dose calculations for Korean population, except for the electrons at the energy range of 0.5-1 MeV for which it is suggested to use the MRKPs incorporating the Korean eye model developed in the present study.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.6C
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• pp.572-578
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• 2007

To establish eye contact in video teleconferencing, it is necessary to synthesize a front view image by viewpoint interpolation. We can find the viewing direction of a user, and interpolate an image seen from that viewpoint, which will result in a face image observed from the front. There are two categories of previous research: image based method and model based method. The former is simple to calculate, however, it shows limited performance for complex objects. And the latter is robust to noise while it is computationally expensive. We propose to approximate face images as ellipses and match them to build an ellipsoid and then synthesize a new image from a given virtual camera position. We show that it is simple and robust from various experiments.

• Journal of Korean Society on Water Environment
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• v.30 no.3
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• pp.329-339
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• 2014

This study aims to estimate chlorophyll-a concentration in rivers using multi-spectral RapidEye imagery and Spectral Mixture Analysis (SMA) and assess the applicability of SMA for multi-temporal imagery analysis. Comparison between images (acquired on Oct. and Nov., 2013) predicted and ground reference chlorophyll-a concentration showed significant performance statistically with determination coefficients of 0.49 and 0.51, respectively. Two band (Red-RE) model for the October and November 2013 RapidEye images showed low performance with coefficient of determinations ($R^2$) of 0.26 and 0.16, respectively. Also Three band (Red-RE-NIR) model showed different performance with $R^2$ of 0.016 and 0.304, respectively. SMA derived Chlorophyll-a concentrations showed relatively higher accuracy than band ratio models based values. SMA was the most appropriate method to calculate Chlorophyll-a concentration using images which were acquired on period of low Chlorophyll-a concentrations. The results of SMA for multi-temporal imagery showed low performance because of the spatio-temporal variation of each end members. This approach provides the potential of providing a cost effective method of monitoring river water quality and management using multi-spectral imagery. In addition, the calculated Chlorophyll-a concentrations using multi-spectral RapidEye imagery can be applied to water quality modeling, enhancing the predicting accuracy.

• Journal of the Korea Society of Computer and Information
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• v.13 no.4
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• pp.97-103
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• 2008

This study is to present a fainting motion recognizing method by using fish-eye lens images to sense emergency situations. The camera with fish-eye lens located at the center of the ceiling of the living room sends images, and then the foreground pixels are extracted by means of the adaptive background modeling method based on the Gaussian complex model, which is followed by tracing of outer points in the foreground pixel area and the elliptical mapping. During the elliptical tracing, the fish-eye lens images are converted to fluoroscope images. the size and location changes, and moving speed information are extracted to judge whether the movement, pause, and motion are similar to fainting motion. The results show that compared to using fish-eye lens image, extraction of the size and location changes. and moving speed by means of the conversed fluoroscope images has good recognition rates.

• Journal of Korean Ophthalmic Optics Society
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• v.7 no.2
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• pp.203-207
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• 2002

In this study, by using the eye model of NAVARRO, KOOIJMAN, MAHKICHOONG, the properties of optical system are reserched in a finite ray tracing method, when ametropia is corrected by glasses or contact lens, this study is useful as a reference. Also, when Auto-refractometer for refraction test and Keratomeler are designed, these eye models can be used.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.8
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• pp.4641-4646
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• 2013

Objective: To explore clinical experience and propose new ideas for treating children diagnosed with orbital rhabdomyosarcoma (RMS). Methods: We retrospectively analyzed the clinical data for30 patients (16 males and 14 females, with a median age of 6.2 years) with primary orbital RMS who were enrolled in the Department of Eye Oncology and Pediatrics of our hospital from November 2004 to December 2012. International Rhabdomyosarcoma Organization Staging Standards indicated that among the 30 patients, 4 cases were in phase II, 20 were in phase III, and 6 were in phase IV. All patients underwent a multidisciplinary collaborative model of comprehensive treatment (surgery, chemotherapy, external radiotherapy, $^{125}I$ radioactive particle implantation, and autologous peripheral blood stem-cell transplantation). Results: Follow-up was conducted until March 2013, with a median follow-up time of 47.2 months (5 to 95 months), and 7 deaths occurred. The 2-year estimated survival rate reached 86.1%, the ${\geq}3$-year estimated survival rate was 77%, and the 5-year estimated survival rate was 70.6%. Conclusions: The multidisciplinary collaborative model can be a safe and effective approach to the comprehensive treatment of children with orbital RMS. It has clinical significance in improving the tumor remission rate.

• Toxicological Research
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• v.33 no.3
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• pp.191-203
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• 2017

Human eyes and skin are frequently exposed to chemicals accidentally or on purpose due to their external location. Therefore, chemicals are required to undergo the evaluation of the ocular and dermal irritancy for their safe handling and use before release into the market. Draize rabbit eye and skin irritation test developed in 1944, has been a gold standard test which was enlisted as OECD TG 404 and OECD TG 405 but it has been criticized with respect to animal welfare due to invasive and cruel procedure. To replace it, diverse alternatives have been developed: (i) For Draize eye irritation test, organotypic assay, in vitro cytotoxicity-based method, in chemico tests, in silico prediction model, and 3D reconstructed human cornealike epithelium (RhCE); (ii) For Draize skin irritation test, in vitro cytotoxicity-based cell model, and 3D reconstructed human epidermis models (RhE). Of these, RhCE and RhE models are getting spotlight as a promising alternative with a wide applicability domain covering cosmetics and personal care products. In this review, we overviewed the current alternatives to Draize test with a focus on 3D human epithelium models to provide an insight into advancing and widening their utility.

• Korean Journal of Veterinary Research
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• v.56 no.3
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• pp.155-160
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• 2016

This study was conducted to evaluate three different mixed formulations of sodium hyaluronate (SH) and carboxymethyl cellulose (CMC) using a low-humidity air flow-induced rat dry eye model and determine the most suitable mixture. The total thickness of the cornea, corneal epithelial thickness, corneal stroma thickness, damaged corneal epithelium percentage region, thickness of the bulbar conjunctiva epithelium, number of goblet cells, goblet cell occupation percentage region, and damaged bulbar conjunctiva epithelium percentage region were measured by histomorphological evaluation. After 5 h exposure to drying airflow, the thickness of the cornea and conjunctiva was decreased with desquamation of the corneal and conjunctiva epithelium. However, these dry eye symptoms were markedly inhibited by treatment with the reference and test formulations. More favorable effects on decreased thickness were detected in response to the CMC than the SH. However, SH had a greater protective effect against corneal and conjunctiva epithelial damage. The application of a mixture of 0.1% SH and 0.2% CMC showed more favorable effects on the corneal and conjunctival damage and the stabilization of the ocular surface than SH or CMC alone.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.15-20
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• 2007

본 연구는 시선 추적 방법(Eye-Tracking Method)을 이용한 디지털 컨버전스 제품의 정보 설계 및 평가에 관한 방법론을 제시하였다. Eye-tracking 데이터는 visual search의 효율성 뿐 아니라 타겟의 유의미성이나 가시성등을 측정하는데 유익하다. 응시 횟수와 응시 시간을 통하여 사용자의 심성 모형에 따른 시선 행위와 제품 메뉴 구조간의 전체적인 일치도를 정량적으로 분석하였고, 각 메뉴 item의 세부적인 인지 반응 정도를 평가하였다. 컨버전스 제품의 한 예로 휴대폰을 선정하여 실험을 실시하였으며, 활성화 확산 실험(SAT)을 수행하여 메뉴 항목 상호간의 인지반응 정도를 통한 문제점을 도출한 후 사용자 시나리오를 작성하였다. 1차 테스트를 통하여 피실험자의 시나리오 수행 시 어려움을 알 수 있었으며, 1차 테스트의 결과와 인터뷰 결과를 바탕으로 프로토타입의 메뉴명을 개선하여 2차 테스트를 실시하였다. 실험 결과 개선 전보다 후의 응시 횟수, 응시 시간 또한 감소하여 수행도가 향상됨으로 메뉴 구조의 개선된 결과를 가져왔다. 본 연구는 인간의 눈 움직임 측정치 결과를 토대로 사용자 심성 모형에 부합하여 누구나 접근이 쉬운 정보 구조를 설계할 수 있었다. 그러므로 본 연구에서 제시하는 Eye-tracking Method는 디지털 컨버전스로 인한 복잡한 정보 구조의 설계와 평가에 기여할 것으로 보인다.