• Title/Summary/Keyword: light adaptation

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Studies on Visual Function Measurements for Building Visual Function Database of the Elderly (고령자의 시각기능데이터베이스 구축을 위한 시각기능계측에 관한 연구)

  • Kim, Dong-Wook;Park, Kwang-Suk;Kim, Jung-Ja;Kim, Nam-Gyun
    • Journal of Biomedical Engineering Research
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    • v.28 no.5
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    • pp.618-627
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    • 2007
  • As our society progresses rapidly toward an aged society, there is a stiff increase in the population of the aged persons who have difficulties in adjusting themselves to environments due to declines of their physical functions. Therefore, there is a great need for the concept of 'Universal Design' that demands the design of overall social structure to care for the elderly. Due to this reason, the physical function of the aged persons should thoroughly be studied for the development of rehabilitation and training equipments to help the recovery of physical functions of the elderly. Among the variety of physical functions of the elderly, visual functions, motion characteristics, hearing functions, and somatosensory functions have significant influence toward everyday lives and are physical functions to study for the construction of urgently needed physical function databases of the elderly. This study concentrates on visual functions among the variety of physical functions of the elderly. To measure various visual functions of the elderly, a measurement room for the elderly has been developed, which can mimic everyday lives and perform measurements of visual functions with subjects in seated position. The measurement items for the construction of the database were capabilities in everyday vision according to changes in arrangement of colors and light intensity and capabilities in everyday vision, color distinction, dark adaptation, and light glare against changes in contrast.

Automotive Adaptive Front Lighting Requiring Only On/Off Modulation of Multi-array LEDs

  • Lee, Jun Ho;Byeon, Jina;Go, Dong Jin;Park, Jong Ryul
    • Current Optics and Photonics
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    • v.1 no.3
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    • pp.207-213
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    • 2017
  • The Adaptive Front-lighting System (AFS) is a part of the active safety system, providing optimized vision to the driver during night time and other poor-sight conditions of the road by automatic adaptation of lighting to environmental and traffic conditions. Basically, an AFS provides four different modes of the passing beam as designated in an United Nations Economic Commission for Europe regulation (ECE324-R123): neutral state or country light (Class C), urban light (Class V), highway light (Class E), and adverse weather light (Class W). In this paper, we first present an optics design for an AFS system capable of producing the Class C/V/E/W patterns requiring only on/off modulation of multi-array LEDs with no need for any additional mechanical components. The AFS optics consists of two separated modules, cutoff and spread; the cutoff module lights a narrow central area with high luminous intensity, satisfying the cutoff regulation, and the spread module forms a wide spread beam of low luminous intensity. Each module consists of two major parts; the first converts a discretely positioned LED array into a full-filled area emitting light source plane, and the second projects the light source plane to a 25 m away target plane. With the combination of these two optics modules, the four beam patterns are formed by simple on/off modulation of multi-array LEDs. Then we report the development of a prototype that was demonstrated to provide the four beam patterns.

Direction of Introduction of Natural Light when Designing Space for Infant and Toddler Daycare Centers (영유아 어린이집 공간설계 시 자연광 도입의 방향성)

  • Jang, Jinha;Lim, Kyungran
    • The Journal of the Korea Contents Association
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    • v.21 no.11
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    • pp.179-192
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    • 2021
  • Human beings going through a series of identification and adaptation steps from the external environment is deeply related to survival, and the physical and mental development process has the task of each growth period. In particular, infants and children are the most active time to take various information from the surrounding environment and develop balanced actions and thinking. Therefore, the space that supports the development of infants and children should be created into a meaningful environment beyond aesthetic and functional roles as a space that provides various senses and experiences. First, this study understood the concept of infant development and 'light environment' and analyzed the need. Second, the relationship between natural light and infants was identified. Third, the characteristics of the inflow of natural light applied to the space were derived by analyzing how the identified functions could be utilized, and based on this, the current status of daycare centers was analyzed to discuss the necessity and direction of 'introduction of natural light'. We hope that this study will be used as a meaningful basis for the active introduction of natural light in the future space design of daycare centers.

A Study on Expressing the Methods of Light for Creating Safe Space (안전한 공간 조성을 위한 빛의 표현방안 연구)

  • Kim, Myoung-Seon;Moon, Jeong-Min
    • Journal of the Korean housing association
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    • v.27 no.3
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    • pp.39-46
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    • 2016
  • On account of the increasing crime rates annually and the consequent rising anxiety, safety has become an important topic in the aspect of environmental formation to provide decent lives to urban dwellers. As a result, great emphasis has been placed in the importance of Crime Prevention through Environmental Design (CPTED), a design method which utilizes physical environmental design to prevent crime. The definition of CPTED encompasses the technological level of crime prevention as well as comprehensive environmental design which takes into consideration fear or terror in view of human recognition and emotion. However, the current application method of CPTED in Korea is still limited to the technical supplementation of facilities, such as CCTV and streetlight, and fragmental modification like village mural paintings. Moreover, the guideline for CPTED in Korea is only a theoretical adaptation of foreign books and does not offer sufficient studies for a practical design method that will improve the life of city dwellers. The purpose of this study is to examine design methods for safe environment construction in accordance with the changing concept of CPTED by understanding the characteristic of space and analyzing the how the methods of light are expressed. This study aims to provide basic material which will serve as a guideline in creating a safe environment in the future.

MICROLEAKAGE OF CL V COMPOSITE RESTORATIONS USING VARIOUS LIGHT CURING METHODS (광중합 복합레진 수복시 여러 광조사 방법에 따른 미세변연누출에 관한 연구)

  • Yang, Chol-Young;Yoo, Hyeon-Mee;Kwon, Hyuk-Choon
    • Restorative Dentistry and Endodontics
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    • v.25 no.2
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    • pp.299-308
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    • 2000
  • The purpose of this in vitro study was to evaluate the microleakage of 5 curing methods in class V composite restorations which are composed of two-step light curing, pulse-delay cure, low curing-light intensity, moderate curing-light intensity and high curing-light intensity. In this study, class V cavities were prepared on buccal and lingual surfaces of 50 extracted human upper or lower molars on cementum margin. Single Bond adhesive and Z-100 shade A2 were applied for each group following the manufacture's instruction. The experimental teeth were randomly divided into 5 groups of 10 samples (20 surfaces) each. Group 1: two-step light curing; Group 2: pulse-delay cure; Group 3: low curing-light intensity; Group 4: moderate curing-light intensity; Group 5: high curing-light intensity. After 500 thermocycling between $5^{\circ}C$ and $55^{\circ}C$, the 60 teeth were placed in 2% methylene blue dye for 24 hours, then rinsed with tab water. The specimens were embedded in clear resin, then sectioned buccolingually through the center of restoration with a low speed diamond saw. The dye penetration on each of the specimen was then observed with a stereomicroscope at ${\times}20$. The composite resin/tooth interfaces were examined under Scanning Electron Microscopy. The results were statistically analyzed using the Kruskal-Wallis One Way ANOVA and Dunn's Method. The results of this study were as follows. 1. In all groups, the leakage values seen at the enamel margin were significantly lower than those seen at the dentin margin(P<0.05). 2. No group in this study showed significant differences in leakage values at both the enamel and the dentin margins(P<0.05). 3. In all groups, the gaps seen at the enamel margin were significantly lower than those seen at the dentin margin(P<0.05). 4. The gaps in this study showed significant differences and two-step light-curing and low curing-light intensity produced significant less gap than high curing-light intensity(P<0.05).

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Simulation and Performance Evaluation of the Self-Adaptive Light Control System (자가-적응 조명 제어 소프트웨어의 시뮬레이션 및 성능 평가)

  • Lee, Junhyi;Lee, Euijong;Baik, Doo-Kwon
    • Journal of the Korea Society for Simulation
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    • v.25 no.2
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    • pp.63-74
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    • 2016
  • This research aims to perform the simulation of self-adaptive lighting control software, and to evaluate the performance of the implemented system. In this text, Self-adaptive software means what detects unexpected changes in surrounding environment by self-monitoring during its run-time, and satisfies demanded condition by adjusting its operation. This is a research about the lighting control system which is operating with the fundamental of self-adaptation concept in IoT(Internet of Things) environment. The system, which is proposed in this text, operates adaptation onto the request of a defined user as recognizing the changes of surrounding environment. This text introduces a relating simulation scenario, system architecture, architecture valuation basis,, and executed evaluation of performance by processing simulations.

ADAPTATION OF RESIN-MODIFIED GLASS IONOMER CEMENT TO DENTIN (상아질에 대한 광중합형 글라스 아이오노머 시멘트의 접합도)

  • Cho, Young-Gon
    • Restorative Dentistry and Endodontics
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    • v.22 no.2
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    • pp.792-800
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    • 1997
  • The purpose of this study was to evaluate the adaptation of self-cured glass ionomer cement and resin-modified glass ionomer cement and polyacid-modified resin composite, which are light-cured giass ionomer cements, to dentin surface. Twelve extracted human maxillary and mandibular molar teeth were used in this study. The entire occlusal dentin surfaces of teeth were exposed with Diamond Wheel Saw and smoothed with sand papers (300, 600, 1200grits). They were randomly assigned into 3 groups according to glass ionomer cements used; Control group- Fuji II, Expeimental group 1 - Fuji II LC, Expeimental group 2 - Dyract. According to the manufacturer's directions, three glass ionomer cements were bonded to exposed dentin surfaces of the tooth crown and cured. Crowns and glass ionomers were trimmed after 24hrs and sectioned horizontally and vertically with diamond saw. The interface of glass ionomer cements and dentin was examined under SEM. The results were as follows : 1. Good adatation between glass ionomer cement and dentin on the horizontal section was showed in control and experimental group 1, but the gap of $20{\mu}m$, which was observed distinct separation between glass ionomer cement and dentin, was showed in experimental group 2. 2. Good adatation between glass ionomer cements and dentin on the vertical section was showed in control and experimental group 1, but the gap of 80-$100{\mu}m$ was showed in experimental group 2. 3. Cohesive fracture within glass ionomer cements in control and experimental group 1 was showed, but no cohesive fracture was showed in experimental group 2.

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The analysis of cultural adaptation patterns and processes experienced by immigrated youths of multi-cultural families in Korea (중도입국청소년의 한국사회 문화적응과정과 유형 분석)

  • Han, Eun-Jin
    • Journal of Family Resource Management and Policy Review
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    • v.17 no.2
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    • pp.195-218
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    • 2013
  • The purpose of this study is to offer suggestions to help immigrated youths of multicultural families become successful members of Korean society while preparing to enter schools or becoming involved in social activities. The study examined the following three issues using grounded theory: (1) the characteristics of cultural adaptation for immigrated youths of multi-cultural families; (2) their acculturation processes; and (3) their different patterns of acculturation experience. The process of acculturation involves (1) feeling timid, (2) feeling regretful and angry, (3) looking around and making an attempt, (4) feeling difficulty and feeling left out, (5) accepting reality and seeing Korea in a positive light. The core of acculturation among the immigrated youths of multicultural families is a limited living in an unfamiliar culture. Five acculturation patterns were found in the current study: (1) Someone who is actively striving for future dreams; (2) someone who adjusts himself/herself to circumstances without plans; (3) someone who passively makes an effort; (4) someone who accepts reality to continue education; and (5) someone who temporarily stays for financial reasons.

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An Analysis on the Spatial Patterns of Heat Wave Vulnerable Areas and Adaptive Capacity Vulnerable Areas in Seoul (서울시 폭염 취약지역의 공간적 패턴 및 적응능력 취약지역 분석)

  • Choi, Ye Seul;Kim, Jae Won;Lim, Up
    • Journal of Korea Planning Association
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    • v.53 no.7
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    • pp.87-107
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    • 2018
  • With more than 10 million inhabitants, in particular, Seoul, the capital of Korea, has already experienced a number of severe heat wave. To alleviate the potential impacts of heat wave and the vulnerability to heat wave, policy-makers have generally considered the option of heat wave strategies containing adaptation elements. From the perspective of sustainable planning for adaptation to heat wave, the objective of this study is to identify the elements of vulnerability and assess heat wave-vulnerability at the dong level. This study also performs an exploratory investigation of the spatial pattern of vulnerable areas in Seoul to heat wave by applying exploratory spatial data analysis. Then this study attempts to select areas with the relatively highest and lowest level of adaptive capacity to heat wave based on an framework of climate change vulnerability assessment. In our analysis, the adaptive capacity is the relatively highest for Seongsan-2-dong in Mapo and the relatively lowest for Changsin-3-dong in Jongno. This study sheds additional light on the spatial patterns of heat wave-vulnerability and the relationship between adaptive capacity and heat wave.

Differential Embryo Development among Tibetan Chicken, DRW and Shouguang Chicken Exposed to Chronic Hypoxia

  • Li, Mei;Zhao, Chun-Jiang;Wu, Chang-Xin
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.3
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    • pp.336-342
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    • 2009
  • Avian embryos at high altitude are independent of maternal protection against hypoxia, which is contrary to mammals. It is well known that chronic hypoxic exposure at key points can significantly impact on avian development. Tibetan Chicken, a Chinese indigenous breed, living in Tibetan areas with an altitude of 2.2 to 4.1 thousand meters, has an adaptive mechanism to hypoxia. In the present study, fertilized eggs of Tibetan Chicken were incubated under 13% and 21% oxygen concentration. Two lowland chicken breeds, Shouguang Chicken, an indigenous chicken breed in Shandong Province of China, and Dwarf Recessive White Chicken, an imported breed in Beijing, were used as control groups. The embryo mass and some organs such as brain, heart, liver, stomach and eye weight in the three species were measured at Hamburger-Hamilton stage 39, 41, 43 and 45 under hypoxic and normal conditions. The results showed that in hypoxia Tibetan Chicken significantly differed from the two lowland chicken breeds in embryo mass at Hamburger-Hamilton stage 41, 43 and 45 (p<0.01). In particular, Dwarf Recessive White Chicken and Shouguang Chicken showed retarded growth in hypoxic incubation (p<0.01), whereas Tibetan Chicken showed no significant difference between hypoxic and normal conditions (p>0.05). In addition, heart and the other organs showed different susceptibility to hypoxia at the studied stages. In conclusion, chronic hypoxia induced a change in the embryo development of the three different species and Tibetan Chicken showed adaptation to hypoxia. Of note, the embryo developmental physiology of Tibetan Chicken in response to hypoxia will shed light on the process of physiological acclimation or evolutionary adaptation as well as the study of clinical disease.