• Current Optics and Photonics
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• v.1 no.2
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• pp.125-131
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• 2017

We propose a new graphical method for selecting a pair of optical and housing materials to simultaneously athermalize and achromatize an LWIR optical system. To have a much better opportunity to select the IR glasses and housing materials, an athermal glass map is expanded by introducing the DOE with negative chromatic power. Additionally, from the depth of focus in an LWIR optical system, the tolerable housing boundary is provided to realize an athermal and achromatic system even for not readily available housing material. Thus, we can effectively determine a pair of optical and housing materials by reducing the thermal shift to be less than the depth of focus. By applying this method to design a night vision camera lens, the chromatic and thermal defocuses are reduced to less than the depth of focus, over the specified waveband and temperature ranges.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.12
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• pp.96-100
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• 2006

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.97-103
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• 2023

The purpose of this study is to exploratively examine factors affecting walking at night anxiety among the elderly. Study sample for the analyses was 9,120 persons aged over 65. Factors affecting walking at night anxiety among the elderly were composed of sociodemographic factors, health-related factors, and social perception factors. Sociodemographic factors include gender, age, region, education, having or not having a spouse, household income. Health-related factors include walking ability, vision, subjective health status, cognitive function. Social perception factors include perception about other's compliance with laws and perception about safety from crime. The main results of the analyses are as follows. Among sociodemographic factors, factors that had significant effects on walking at night anxiety among the elderly were gender, age, region, education. Among health-related factors, factors that had significant effects on walking at night anxiety among the elderly were walking ability, vision, subjective health status, cognitive function. Among social perception factors, factors that had significant effects on walking at night anxiety among the elderly were perception about other's compliance with laws and perception about safety from crime. Results of this study show that there is a need for multiple methods to make safe and comfort walking environment for the elderly.

• ETRI Journal
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• v.33 no.1
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• pp.71-77
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• 2011

Up to 10% of the global population suffers from color vision deficiency (CVD) [1], especially deuteranomaly and protanomaly, the conditions in which it is difficult to discriminate between red and green hues. For those who suffer from CVD, their career fields are restricted, and their childhood education is frustrating. There are many optical eye glasses on the market to compensate for this disability. However, although they are attractive due to their light weight, wearing these glasses will decrease visual brightness and cause problems at night. Therefore, this paper presents a supplementary device that comprises a head-mounted display and an image sensor. With the aid of the image processing technique of digital color space adjustment implemented in a high-speed field-programmable gate array device, the users can enjoy enhanced vision through the display without any decrease in brightness.

• International Journal of Aeronautical and Space Sciences
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• v.9 no.2
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• pp.114-120
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• 2008

In the vision-based recovery phase, a terminal guidance for the blended-wing UAV requires visual information of high accuracy. This paper presents the light source target design and detection algorithm for vision-based UAV recovery. We propose a recovery target design with red and green LEDs. This frame provides the relative position between the target and the UAV. The target detection algorithm includes HSV-based segmentation, morphology, and blob processing. These techniques are employed to give efficient detection results in day and night net recovery operations. The performance of the proposed target design and detection algorithm are evaluated through ground-based experiments.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2010.03a
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• pp.195-196
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• 2010

• The Transactions of the Korean Institute of Power Electronics
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• v.14 no.2
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• pp.128-133
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• 2009

This paper describes the development of a miniature high voltage power supply for driving an image intensifier tube (IIT). The IIT is used for portable night vision devices to observe an object in the dark. A small-sized high voltage power supply generating thousands volts from the battery power source is needed to drive the IIT. This paper presents the design and implementation of the high voltage power supply for the IIT. The experimental results are provided to verify the operation of the developed power supply.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.123-126
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• 2017

The information and communication technology that is being developed recently has been greatly influencing the automobile market. In recent years, devices equipped with IT technology have been installed for the safety and convenience of the driver. However, it has the advantage of increased convenience as well as the disadvantage of increasing traffic accidents due to driver 's distraction. In order to prevent such accidents, it is necessary to develop safety systems of various types and ways. In this paper, we propose a method to implement a multi-function camera driving safety system that notifies a pedestrian and lane departure warning without using a radar sensor or a stereo video image, and a study on the analysis of a lane departure alarm software result.

• Journal of dental hygiene science
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• v.20 no.1
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• pp.59-66
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• 2020

Background: This study aims to analyze the job stress of dental hygienists and the factors affecting somatization and to provide basic data for effectively managing job stress and somatization of dental hygienists. Methods: In this study, the data collected from 208 dental hygienists working in Jeollabuk-do Province were analyzed. Job stress was investigated using a questionnaire with 43 questions. In addition, the degree of somatization was evaluated through a simplified psychotherapy examination (Symptom Check List-90-Revision). Results: Age, employment history, position, average monthly income, night duty execution status, and perceived health status were significantly associated with job stress (p<0.05). The job stress sub-items scores based on general characteristics showed significance in 'workload' for those working a five-day workweek and perceived health status (p<0.05). Age, average monthly income, and perceived health status were noted in 'role conflict as a professional'. In 'lack of expertise and skill', it was noted that age, employment history, position, income, and night clinic were implemented. In 'improper treatment and interpersonal issues', level of education and perceived health status were significant (p<0.05). The higher the job stress, the higher the somatization symptom score (p<0.05), and the higher the job stress component, the higher the somatization symptom score (p<0.01). Conclusion: The job stress of dental hygienists should be reduced, and the symptoms of somatization should be mitigated. To improve the quality of medical services and the work efficiency of dental hygienists, proper treatment and compensation systems should be implemented for them to take pride as professional. Further, programs and regulations on mitigating job stress and somatization symptoms should be developed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.687-692
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• 2018

In this paper, the development of an automotive thermal imaging camera providing image information for ADAS (Advanced Driver Assist System) and autonomous vehicles is described and an improved technique to enhance the details of the image is proposed. Thermal imaging cameras are used in various fields, such as the medical, industrial and military fields, for the purpose of temperature measurement and night vision. In automobiles, they are utilized for night vision systems. For their utilization in ADAS and autonomous vehicles, appropriate image resolution and enhanced detail are required for object recognition. In this study, a $640{\times}480$ resolution thermal imaging camera that can be applied to automobiles is developed and the BDE (Block-Range Detail Enhancement) technique is applied to improve the details of the image. In order to improve the image detail obtained in various driving environments, the block-range values between the target pixel and the surrounding 8 pixels are calculated and classified into 5 levels. Then, different factors are added or subtracted to obtain images with high utilization. The improved technique distinguishes the dark part of the image by the resulting temperature difference of 130mK and shows an improvement in the fine detail in both the bright and dark parts of the image. The developed thermal imaging camera using the improved detail enhancement technique is applied to a test vehicle and the results are presented.