• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.2
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• pp.35-40
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• 2024

In this paper, we validate the practicality of the OnePIC app implemented in the previous study by analyzing the execution and storage performance. The OnePIC app is a camera app that allows you to get a photo with a desired focus after taking photos focused on various places. To evaluate performance, we analyzed distance focus shooting time and object focus shooting time in detail. The performance evaluation was measured on actual smartphone. Distance focus shooting time for 5 photos was around 0.84 seconds, the object detection time was around 0.19 seconds regardless of the number of objects and object focus shooting time for 5 photos was around 4.84 seconds. When we compared the size of a single All-in-JPEG file that stores multi-focus photos to the size of the JPEG files stored individually, there was no significant benefit in storage space because the All-in-JPEG file size was subtly reduced. However, All-in-JPEG has the great advantage of managing multi-focus photos. Finally, we conclude that the OnePIC app is practical in terms of shooting time, photo storage size, and management.

• Korean Journal of Optics and Photonics
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• v.33 no.1
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• pp.28-34
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• 2022

We study through computational simulation the focal performance of an infrared (IR) Fresnel lens, composed of a multilayer-graphene zone plate formed under a graphene electrode. Here the Fermi level E_F of the patterned multilayer graphene is adjusted by the overlying graphene electrode. The Fresnel lens effect, with respect to the reflectance contrast between the graphene electrode and the 8-layer graphene zone plate placed on a glass substrate, has been analyzed over a broad wavelength range from 4 to 30 ㎛. As the optimal wavelength of 8 ㎛ (considering the reflectance and the reflectance-contrast ratio) is incident upon the Fresnel lens with a focal length of 240 ㎛, the focal intensity is enhanced by a factor of 4.3 as the E_F of multilayer graphene increases from 0.4 eV to 1.6 eV, and is improved by a factor of 5.8 as the number of graphene layers increases from two to eight. As a result, an all-graphene-based IR Fresnel zone-plate lens, exhibiting multifocal function (240 ㎛ and 360 ㎛) according to the selected E_F, is proposed as an ultrathin lens platform.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.1
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• pp.189-196
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• 2024

Currently, it is almost impossible to move the focus of a previously taken photo to a different location. This paper challenges a technology that can move the focus of a captured photo to another location after shooting. To achieve this goal, this paper proposed and implemented a method for taking photos with various focuses at the moment the camera took pictures and storing them in a single JPEG file to extract photos focused on the user's preferred location. In this paper, two methods are implemented: taking various photos by quickly moving the focal length of the lens from close to far away, and taking various photos focused on each object by recognizing objects in the camera viewfinder. Various photos taken are stored in a single JPEG to maintain compatibility with traditional photo viewers. At this time, this JPEG file used the All-in-JPEG format proposed in previous research to store a variety of images. This paper verified its practicality by implementing these technologies in an Android app named OnePIC.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.850-852
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• 2003

운영체계는 컴퓨팅 시스템에서 가장 중요한 보안 기능 제공자이다. 운영체계는 프로그래밍 환경을 제공하고, 멀티프로 그래밍과 자원의 공유를 가능하게 하며 프로그램 행위에의 제한을 집행하는 기능을 수행한다. 이러한 운영체계에 신뢰성을 부여하기 위하여 1970년대부터 미국의 정부기관을 중심으로 하여 보안 운영체계에 대한 연구가 활발히 진행되어 왔다. 대부분의 연구는 강력하고도 유연한 접근 제어 정책을 운영체계 커널에 포함시키는 내용에 초점을 맞추어 왔다. 그러나 컴퓨팅 시스템이 인터넷 내에서 다른 컴퓨터들과 연결되어 사용되고 있고 내장형 시스템 내에서도 많이 사용되고 있는 등 그 사용 방법과 범위가 계속 변화하고 있으므로 운영체계의 보안에 대해서도 과거의 시야보다는 더 넓은 관점에서 다시 보아야 할 것01다. 본 논문에서는 보안 운영체계에서 제공하여야 할 보안 서비스 요구사항을 정의하고 다음 이들 요구사항을 제공하기 위해 필요한 보안 기능을 포함한 운영체계의 구조에 대한 설계방향을 제안한다.

• Journal of the korean Society of Automotive Engineers
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• v.7 no.1
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• pp.18-23
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• 1985

내연기관은 자동차용 기관에 의하여 일반대중과 접촉하게 되었으며, 특히 20세기 중반에 이르러 자동차라는 기계가 일반가정에서 사용되는 가구로 탈피하는 과정에서 그 중요장치의 하나인 자동차용 기관도 전문가가 취급하는 기계로부터 일반인이 취급하는 가구로의 탈피를 요구함에 따라 크게 발전해 온 것이 사실이다. 종래, 내연기관의 설계에 있어서 그 출력과 연료소비를 가장 중요한 성능평가의 요소로 삼아왔지만, 가구로서의 자동차의 최적화를 위해서는 더욱 중요한 많은 성능평가의 요소가 있다는 것을 인식할 필요가 있다고 생각한다. 실은 최적화에 필요한 많은 요소의 균형을 어떻게 할 것인가 하는 것이 자동차용 기관의 설계에 있어서 가장 중요한 일이라 생각되며, 자동차용 기관을 계획할 때의 목표는 다음과 같은 3가지로 생각된다. (1) 고성능일 것 (2) 우수한 기능을 가질 것 (3) 공해가 없을 것 (1)의 고성능을 추구하는데 있어서는 비출력, 연료소비율 및 양호한 응답성이 중요한 요소로 된다. 이중 응답성의 문제는 연료공급기구나 조속기 등의 기능적인 요소와 깊은 관련이 있다. 그리고 내구성, 신뢰성, 정비점검의 무용성이라는 것이 (2)의 우수한 기능을 보장하기 위한 가장 중요한 배경으로 된다. 또한 진동이나 소음이 없고 정숙할 것이 (3)의 무공해성의 목표와도 관 련되는 중요한 요소이다. 배출가스의 무공해화가 자동차에 의한 공해방지의 입장으로부터 중요한 요소가 되는 것은 주지의 사실이다. 그리고 이 배출가스의 청정화의 문제는 성능향상을 위한 비출력증대의 방향에 대한 방해가 되는 문제이다. 이상 기술한 바와 같은 설계단계에 있어서의 계획목표를 3가지로 설정하고, 이 3가지 목표에 관련되는 요소의 균형을 어떻게 위해야 할 것인가 하는 점에 초점을 맞추어 되도록 쉽게 기술하고자 하였으나, 미비한 점이 많았을 것으로 생각하여, 다만 이 분야에 종사하는 기술자 여러분에게 약간의 도움이라도 되었으면 하는 것이 소망이다.

• Ecology and Resilient Infrastructure
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• v.7 no.1
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• pp.15-25
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• 2020

We've compared and conceptually evaluated the newly emerging concept of nature-based solutions (NbS's), in the aspect of water management, and existing similar solutions of different naming, all of which are based on ecosystem functions. In this study, it is found that NbS's seem significant and meaningful both educationally and understandably in the aspect that it can comprehensively cover and include the existing methodologies and solutions using the functions of natural ecosystem to socio-environmental challenges. It, however, seems not quite different from the broad-meaning of green infra, including Eco-DRR, in terms of the approaching methodologies in water management. The conceptual and spatial hierarchy of each practice in water management considered in this study can be expressed in the narrowing order of NbS-(EE)-BGI-(CRT)-GI-LID. Last, the term LID, which is the best management practice for storm water management in the development project, can be replaced with the term GI for clarification and less confusion both in academia and practice.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.2
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• pp.117-124
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• 2015

Purpose: The purpose of this study was to compare the accommodative function of young adult in their 20s wearing monovision, modified monovision, and aspheric multifocal contact lenses at near task. Methods: Thirty young adults ($23.53{\pm}2.37years$) were fitted with monovision, modified monovision (the application of single vision contact lenses and center-near low addition aspheric multifocal contact lenses), and aspheric center-near multifocal contact lenses. After wearing these modalities during a week for adaption, and after watching visual display at computer for inducing accommodative pressure for 1 hour. The following assessments of accommodative function were made: contrast visual acuity (VA) at distance and near; accommodative response; near accommodative facility; and negative relative accommodation (NRA)/positive relative accommodation (PRA). All measurements were carried out binocularly. Results: In binocular distance VA with contrast of 10%, monovision was the worst among the four modalities (p=0.005). In accommodative response at 1 m (1.00 D), monovision was the lowest (p<0.05) and accommodative response at 40 cm (2.50 D) with monovision was lower than that of modified monovision and multifocal contact lens (p<0.05). We also found that there were no significant differences in accommodative facility and NRA/PRA among the four modalities. Conclusions: In young adult (20s), monovision with low add reduced the accommodative response at near task, however, modified monovision and multifocal lens with center-near type did not affect accommodative relaxation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.4
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• pp.68-80
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• 2016

This study proposes the traffic prediction and optimal traffic control system based on cell transmission model and genetic algorithm in cloud environment. The proposed prediction and control system consists of four parts. 1) Data preprocessing module detects and imputes the corrupted data and missing data points. 2) Data-driven traffic prediction module predicts the future traffic state using Multi-level K-Nearest Neighbor (MK-NN) Algorithm with stored historical data in SQL database. 3) Online traffic simulation module simulates the future traffic state in various situations including accident, road work, and extreme weather condition with predicted traffic data by MK-NN. 4) Optimal road control module produces the control strategy for large road network with cell transmission model and genetic algorithm. The results show that proposed system can effectively reduce the Vehicle Hours Traveled upto 60%.

• Journal of Korean Library and Information Science Society
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• v.46 no.2
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• pp.337-366
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• 2015

This study had begun about the conflict between a lack of social adjustment and integration program for resident foreigners in Korea and a duplication of multicultural service in a specific area. This study was implemented through literature review and interview for analyses of the current status and problems of multicultural policy, subdivided into 3-stages model to reach the multiculturalism as multicultural policy process. The first stage suggested the unification of a channel for establishing a policies, reinforcing the functions of government ministries and the cooperation between the branches of the government. The second stage attempted to build the multicutural institutes network in a specific area unit, considering of the geographical and administrative environments. The third stage focused on the activities of individual organizations and proposed collaboration with library, school, support center for multi-cultural families, social service center, sport center, community center, and cultural facility. Additionally, 3-stages model emphasized on civic organization's role. This study was offered a meta-platform leaded by library community for sharing the information about planning and managing of multicutural programs and also mentioned significances for formulating multicutural policies. As a result, this study was presented and specified the 3-stages model to reach the multiculturalism, and verified the various considerations which have influenced the refinements of the multicultural policies as the demographic and geographical characteristics.

• Korean Journal of Social Welfare Studies
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• v.44 no.2
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• pp.327-358
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• 2013

This study aimed to analyze the trajectories of cognitive function and functional disability, and to identify the impacts of socio-demographic factors on the two variables. Based on the assumption that there are differences according to the progress of cognitive impairment, it focused on examining the differences in trajectories of cognitive function and functional disability between two groups: dementia conversion group and dementia non-conversion group among cognitively normal older adults. This study was conducted based on the data from a 3-wave panel study of a sample of 966 Yeoncheon elderly cohort aged 65 and over between 1997 and 2003. Latent growth curve model and multi-group structural equation modeling were used to examine the hypothesis. Results revealed that dementia conversion group exhibited faster rate of cognitive decline as well as lower initial cognitive level. Difference between two groups was not significant in the initial level of functional disability, yet dementia conversion group showed greater degree of deterioration in the functional disability over time than dementia non-conversion group did. In terms of the influence of socio-demographic factors on cognitive function and functional disability, the cognitive decline was more drastic in the female group, whereas functional decline was more apparent for the male group. The level of education in early life had a strong impact on the cognitive function in later life. Based on these findings, practical implication for high risk groups in cognitive function and functional disability were discussed.