• Title/Summary/Keyword: Poor Illumination

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Energy Efficient LED Lighting Design to utilize the Sun Light (태양광 활용을 위한 효율적 LED 조명기구 설계 방안)

  • Jeong, Hak-Geun;Han, Soo-Bin;Jang, Cheol-Yong
    • Journal of the Korean Solar Energy Society
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    • v.31 no.2
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    • pp.31-36
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    • 2011
  • LED is expected as an environmentally friendly next generation light source with its good reliability and long lifetime. The light sources for illumination have a variety of applications in the indoor and outdoor, and the variation of optical power and color rendering of the light source limits their applications. Therefore, it is necessary to research the LED lamp and its luminaire to minimize the variation of dynamic characteristics and to improve the color rendering due to that illuminating environment. Daylight is very good light source to human and can be used as primary or a secondary light source with benefits of energy, productivity and health.This paper presents the design method of LED lighting system to improve poor property in terms of CR(color redering) characteristic to use daylight effectively.

A Study on Environmental Standards of School Building (교사환경기준에 관한 연구)

  • Hong, Seok-Pyo;Park, Young-Soo
    • The Journal of Korean Society for School & Community Health Education
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    • v.1 no.1
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    • pp.11-43
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    • 2000
  • The purpose of this study was, through analyzing the previous researches, to grasp the present status of environment of school building(ESB), research the sundry records of each element and, through comparative analysis of the standard of ESB in Korea, the United States, and Japan, select the normative standard of ESB, to clarify the point at issue presented in Regulation of Construction & facility Management for Elementary and and Secondary School in Korea, and to suggest an alternative preliminary standard of ESB. To carry out a research for this purpose, these were required: 1. to investigate the existing present status of ESB, 2. to make a comparative analysis of the standard of ESB in each country, 3. to suggest the normative standard of preliminary standard of ESB, 4. to analyze the controversial points of the standard of ESB in Korea, 5. to suggest an alternative preliminary standard of ESB. The conclusions were as follows: 1. Putting, through analyzing the previous researches, the existing present status of ESB together, it seemed that lighting environment, indoor air environment and noise environment were all in poor conditions. 2. In the result of a comparative analysis of the standard of ESB in Korea, Japan and the United States, in Korea the factors of each lighting and indoor air environment were not presented properly, in Japan, in lighting environment aspect, the standard on natural lighting and the factors on brightness were not presented., and in the USA the essential factors of each environment were throughly presented. In the comparison of the standards on each factor, Korea showed that the standard level presented was less properly prescribed than those of the USA and Japan but it also showed that the standard levels prescribed in the USA and in Japan were mostly similar to the standard levels in records investigated. 3. With the result of the normative standard selection on School Builiding environment factor of prescribed in this study, the controversial points of the standard of ESB in Korea were analyzed and the result was utilized to suggest new preliminary standard of ESB. 4. As the result of the analysis of the controversial points of the standard of ESB in Korea, it was found that the standard of ESB in Korea should be established on a basis of School Health Act and be concretely presented in School Health Regulation and School Health Rule. The factors of each environment was improperly presented in the existing standard of ESB in Korea. Moreover the standard of them was inferior to that of the records investigated and those of in the USA and in Japan and it also showed that the standard of it in Korea was improper to maintain Comfortable Learning Environment. 5. A suggested preliminary standard of ESB acquired through above study as follows: 1) In this study a new kind of preliminary standard of ESB is divided into lighting environment, indoor air environment, noise environment, odor environment and for above classification, reasonable factor and standard should be established and the controling way on each standard and countermeasures against it should be considered. 2) In lighting environment, the factors of natural lighting are divided into daylight rate, brightness, glare. In the standard on each factor, daylight rate should secure 5% of a mean daylight rate and 2% of a minimum daylight rate, brightness ratio of maximum illumination to minimum illumination should be under 10:1, and in glare there should not be an occurrence factor from a reflector outside of the classroom. And the factors of unnatural lighting are illumination, brightness, and glare. In the standard on each factor, illumination should be 750 lux or more, brightness ratio should be under 3 to 1, and glare should not occur. And Optimal reflection rate(%) of Colors and Facilities of Classroom which influences lighting environment should be considered. 3) In indoor air environment factors, thermal factors are divided into (1) room temperature, (2) relative humidity, (3) room air movement, (4) radiation heat, and harmful gases (5) CO, (6) $CO_2$ that are proceeded from using the heating fuel such as oval briquettes, firewood, charcoal being used in most of the classroom, and finally (7) dust. In the standard on each factor, the next are necessary; room temperature: $16^{\circ}C{\sim}26^{\circ}C$(summer : $E.T18.9{\sim}23.8^{\circ}C$, winter: $E.T16.7{\sim}21.7^{\circ}C$), relative humidity: $30{\sim}80%$, room air movement: under 0.5m/sec, radiation heat: under $5^{\circ}C$ gap between dry-bulb temperature and wet-bulb temperature, below 1000 ppm of ca and below 10ppm of $CO_2$, dust: below 0.10 $mg/m^3$ of Volume of dust in indoor air, and ventilation standard($CO_2$) for purification of indoor air : once/6 min.(about 7 times/40 min.) in an airtight classroom. 4) In the standard on noise environment, noise level should be under 40 dB(A) and the noise measuring way and the countermeasures against it should be considered. 5) In the standard on odor environment, odor level under Physical Method should be under 2 degrees, and the inspecting way and the countermeasures against it should be considered.

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Fruit-body Formation of Flammulina velutipes on the Synthetic Medium -Part 3. Environmental Characteristics- (합성배지(合成培地)를 이용(利用)한 팽나무버섯의 자실체(子實體) 형성(形成) -제삼보(第三報). 환경적(環境的) 특성(特性)에 관하여-)

  • Kim, Hyong-Soo;Hong, Jai-Sik;Kim, Myung-Kon
    • Applied Biological Chemistry
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    • v.27 no.1
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    • pp.34-39
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    • 1984
  • Environmental effects of light. temperature, and pH of culture media on mycelial growth and fruit-body formation of Flammulina velutipes in synthetic media were investigated. Illumination inhibited mycelial growth, but illumination during the latter part of vegetative growth induced primordia formation. The optimum light intensity and exposure time were $100{\sim}1000$ lux and $4{\sim}8$ hours per day, respectively. High intensity of light was injurous, and in darkness primordia developed into very poor fruit-bodies. The optimum temperature was $25^{\circ}C for mycelial growth and $15^{\circ}C$ for fruit-body formation. The optimum pH range for mycelial growth was found to be from 5.0 to 7.0 and for fruit-body formation from 5.0 to 6.0. In low temperature treatments, a temperature of $15^{\circ}C$ was more effective than $5^{\circ}C\;or\;10^{\circ}C$, it took about 12 hours for primordium formation, but at $5^{\circ}C\;or\;10^{\circ}C$ about 48 hours. The most excellent fruit-body formation were produced from the mycelium growth for 7 to 10 days.

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Clinical Utility of an Automated Pupillometer in Patients with Acute Brain Lesion

  • Park, Jeong Goo;Moon, Chang Taek;Park, Dong Sun;Song, Sang Woo
    • Journal of Korean Neurosurgical Society
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    • v.58 no.4
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    • pp.363-367
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    • 2015
  • Objective : The purpose of this study was to evaluate the clinical utility and validity of using a pupillometer to assess patients with acute brain lesions. Methods : Pupillary examinations using an automated pupillometer ($NeurOptics^{(R)}NPi^{TM}$-100 Pupillometer) were performed every 4 hours and were simultaneously assessed using the Glasgow Coma Scale (GCS) and for intracranial pressure (ICP), from admission to discharge or expire in neuro-intensive care unit (NICU). Manual pupillary examinations were also recorded for comparison. By comparing these data, we evaluated the validity of using automated pupillometers to predict clinical outcomes. Results : The mean values of the Neurologic Pupillary index (NPi) were different in the groups examined manually. The GCS correlated well with NPi values, especially in severe brain injury patients (GCS below 9). However, the NPi values were weakly correlated with intracranial pressure (ICP) when the ICP was lower than 30 cm $H_2O$. The NPi value was not affected by age or intensity of illumination. In patients with a "poor" prognosis who had a Glasgow Outcome Scale (GOS) of 1 or 2, the mean initial NPi score was $0.88{\pm}1.68$, whereas the value was $3.89{\pm}0.97$ in patients with a "favorable" prognosis who had a GOS greater than 2 (p<0.001). For predicting clinical outcomes, the initial NPi value of 3.4 had the highest sensitivity and specificity. Conclusion : An automated pupillometer can serve as a simple and useful tool for the accurate measurement of pupillary reactivity in patients with acute brain lesions.

A Study on the Night Lighting Environment by Outdoor Space Types of an Apartment Complex (공동주택단지 외부공간 유형별 야간 빛 환경에 대한 연구)

  • Han, Jeong-Won;Ahn, Jil-Hye
    • Korean Institute of Interior Design Journal
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    • v.23 no.3
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    • pp.164-172
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    • 2014
  • The purpose of this study is to identify current condition of night lighting plan for the outdoor space in an apartment complex and to examine how residents perceive that environment. For this purpose, considerations and standards for safe and agreeable night lighting environment were examined through literature study. And a field study to determine the current state of the night lighting environment was conducted, and finally a survey was executed to find out residents' satisfaction, requirements and consciousness on that lighting environment of apartment complex. Findings of this study can be summarized as follows. Firstly, most standards for night lighting environment focus on the urban environment as a whole, so they have very few clear standards exclusive for the outdoor space of the apartment complex. Secondly, most of outdoor spaces surveyed in this study have met the basic illumination standard, but some spaces had parts where lights were off or out of order forming dark zones, and in some parts lights were screened by trees causing shades, poor safety and a narrowed sight. Thirdly, residents had interest in the night lighting environment of the outdoor space, but they were not fully satisfied with that environment. Fourthly, residents were negative about such factors of the environment as safety, convenience, recognition and aesthetics. These factors should be reflected in planning and improving the night lighting. It is expected that this study provides basic information necessary to plan safer and more agreeable night lighting, and to satisfy the residents' need for liveable apartment complex.

Lane Information Fusion Scheme using Multiple Lane Sensors (다중센서 기반 차선정보 시공간 융합기법)

  • Lee, Soomok;Park, Gikwang;Seo, Seung-woo
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.12
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    • pp.142-149
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    • 2015
  • Most of the mono-camera based lane detection systems are fragile on poor illumination conditions. In order to compensate limitations of single sensor utilization, lane information fusion system using multiple lane sensors is an alternative to stabilize performance and guarantee high precision. However, conventional fusion schemes, which only concerns object detection, are inappropriate to apply to the lane information fusion. Even few studies considering lane information fusion have dealt with limited aids on back-up sensor or omitted cases of asynchronous multi-rate and coverage. In this paper, we propose a lane information fusion scheme utilizing multiple lane sensors with different coverage and cycle. The precise lane information fusion is achieved by the proposed fusion framework which considers individual ranging capability and processing time of diverse types of lane sensors. In addition, a novel lane estimation model is proposed to synchronize multi-rate sensors precisely by up-sampling spare lane information signals. Through quantitative vehicle-level experiments with around view monitoring system and frontal camera system, we demonstrate the robustness of the proposed lane fusion scheme.

A Novel Least Square and Image Rotation based Method for Solving the Inclination Problem of License Plate in Its Camera Captured Image

  • Wu, ChangCheng;Zhang, Hao;Hua, JiaFeng;Hua, Sha;Zhang, YanYi;Lu, XiaoMing;Tang, YiChen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.12
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    • pp.5990-6008
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    • 2019
  • Recognizing license plate from its traffic camera captured images is one of the most important aspects in many traffic management systems. Despite many sophisticated license plate recognition related algorithms available online, license plate recognition is still a hot research issue because license plates in each country all round the world lack of uniform format and their camera captured images are often affected by multiple adverse factors, such as low resolution, poor illumination effects, installation problem etc. A novel method is proposed in this paper to solve the inclination problem of license plates in their camera captured images through four parts: Firstly, special edge pixels of license plate are chosen to represent main information of license plates. Secondly, least square methods are used to compute the inclined angle of license plates. Then, coordinate rotation methods are used to rotate the license plate. At last, bilinear interpolation methods are used to improve the performance of license plate rotation. Several experimental results demonstrated that our proposed method can solve the inclination problem about license plate in visual aspect and can improve the recognition rate when used as the image preprocessing method.

Image Contrast Enhancement Technique Using Clustering Algorithm (클러스터링 알고리듬을 이용한 영상 대비 향상 기법)

  • Kim, Nam-Jin;Kim, Yong-Soo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.14 no.3
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    • pp.310-315
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    • 2004
  • Image taken in the night can be low-contrast images because of poor environment and image transmission. We propose an algorithm that improves the acquired low-contrast image. MPEG-2 separates chrominance and illuminance, and compresses respectively because human vision is more sensitive to luminance. We extracted illumination and used K-means algorithm to find a proper crossover point automatically. We used K-means algorithm in the viewpoint that the problem of crossover point selection can be considered as the two-category classification problem. We divided an image into two subimages using the crossover point, and applied the histogram equalization method respectively. We used the index of fuzziness to evaluate the degree of improvement. We compare the results of the proposed method with those of other methods.

The Effect of VDT Work on Vision and Eye Symptoms among Workers in a TV Manufacturing Plant (텔레비젼(TV)생산업체 근로자들의 영상단말기(VDT)작업이 시력과 안증상에 미치는 영향)

  • Woo, Kuck-Hyeun;Choi, Gwang-Seo;Jung, Young-Yeon;Han, Gu-Wung;Park, Jung-Han;Lee, Jong-Hyeob
    • Journal of Preventive Medicine and Public Health
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    • v.25 no.3 s.39
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    • pp.247-268
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    • 1992
  • This study was conducted to evaluate the effect of VDT work on eyes and vision among workers in a TV manufacturing plant. The study subjects consisted of 264 screen workers and 74 non-screen workers who were less than 40 years old male and had no history of opthalmic diseases such as corneal opacities, trauma, keratitis, etc and whose visual acuity on pre-employment health examination by Han's test chart was 1.0 or above. The screen workers were divided into two groups by actual time for screen work in a day : Group I, 60 workers, lesser than 4 hours a day and group II, 204 workers, more than 4 hours a day. From July to October 1992 a questionnaire was administered to all the study subjects for the general charateristics and subjective eye symptoms after which the opthalmologic tests such as visual acuity, spherical equivalent, lacrimal function, ocular pressure, slit lamp test, fundoscopy were conducted by one opthalmologist. The proportion of workers whose present visual acuity was decreased more than 0.15 in comparison with that on the pre-employment health examination by Han's test chart was 20.6% in Group II. 15.0% in Group I and 14.9% in non-screen workers. However, the differences in proportion were not statistically significant. The proportion of workers with decreased visual acuity was not associated with the age, working duration, use of magnifying glass and type of shift work (independent variables) in all of the three groups. However, screen workers working under poor illumination had a higher proportion of persons with decreased visual acuity than those working under adequate illumination (P<0.05) . The proportion of workers whose near vision was decreased was 27.5% in Group II, 18.3% in Group I, and 28.4% in non-screen workers and these differences in proportion were not statistically significant. Changes of near vision were not associated with 4 independent variables in all of the three groups. Six out of seven subjective eye symptoms except tearing were more common in Group I than in non-screen workers and more common in Group II than in Group I (P<0.01). Mean of the total scores for seven subjective symptoms of each worker(2 points for always, 1 point for sometimes, 0 point for never) was not significantly different between workers with decreased visual acuity and workers with no vision change. However, mean of the total scores for Group II was higher than those for the Group I and non-screen workers (P<0.01). Total eye symptom scores were significantly correlated with the grade of screen work, use of magnifying glass, and type of shift work. There was no independent variable which was correlated with the difference in visual acuity between the pre-employment health examination and the present state, the difference between far and near visions, lacrimal function, ocular pressure, and spherical equivalent. Multiple linear regression analysis for the subjective eye symptom scores revealed a positive linear relationship with actual time for screen work and shift work(P<0.01). In this study it was not observed that the VDT work decreased visual acuity but it induces subjective eye symptoms such as eye fatigue, blurred vision, ocular discomfort, etc. Maintenance of adequate illumination in the work place and control of excessive VDT work are recommended to prevent such eye symptoms.

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Presown Seed Treatments to Elevate Seedling Emergence of Codonopsis pilosula $N_{ANNF}$ (만삼의 입묘율 향상을 위한 파종전 종자처리의 모형화)

  • Kang, Jin-Ho;Shim, Young-Do;Jeon, Byong-Sam
    • Korean Journal of Medicinal Crop Science
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    • v.9 no.2
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    • pp.99-107
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    • 2001
  • Germination of Codonopsis pilosula seeds and afterward their seedling emergence have been occasionally very poor due to their dormancy and structural defects. The study was done to determine the treatment effects of priming, $GA_3$, agitation and washing during and after priming, drying and water imbibition after drying on germination of its seeds and then of the successive three combined treatment after priming on the its seedling emergence to model its presown seed treatment. While agitation at the speed of 10 rpm was made or not, priming using $Ca(NO_3)_2$ and $GA_3$ under their different concentrations and light quality illuminated for 12 hours a day were done separately. Then their two best results were compared to determine the better one. Using the above determined best result, washing was done 3 minutes in the tap water or not, and drying of washed seeds was made under 4 different lights, and water imbibition of the dried seeds with differed period were successively done to deduce its presown seed treatment. In the comparison of the best germination rate of priming and $GA_3$, the former showed considerably higher rate than the latter; the priming treatment was done at agitated $Ca(NO_3)_2$ 150 mM solution under darkness or 12 hour red light illumination a day for 2 days. Washing after priming enhanced the rate compared to no-washing. Drying was the best way at which seeds washed were desiccated under $35^{\circ}C$ and 4 hour red light illumination. Water imbibition immediately before sowing must be made for 2 days. Seedling emergence rate was the highest at the seeds from successive 4 treatments, priming, washing, drying and water imbibition before sowing of two others, the priming and washing, or the priming, washing and water imbibition, meaning that its presown seed treatment must follow the procedure of the above 4 successive ones.

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