• Fashion & Textile Research Journal
• /
• v.21 no.2
• /
• pp.231-236
• /
• 2019

This study investigated the proper dyeing conditions, color fastness and functionality of wool fabrics dyed with Zizania latifolia Turcz. We also tried to improve light fastness through treatment with benzophenone ultraviolet absorber. The dyeing of wool fabrics using Zizania latifolia Turcz was good even without pretreatment or mordanting treatment. Optimal wool fabric dyeing conditions were colorant concentration of 200% (o.w.f.), dyeing temperature of $100^{\circ}C$, dyeing time of 80 minutes and a dye bath pH of 3. Color fastness of dyed wool fabrics to washing, rubbing, perspiration and light was 4-5, 5, 4-4-5 (acidic), 4-5 (alkaline) and 2 respectively. The results after treatment with ultraviolet absorber for improving the fastness of daylight were improved to 3-4 grade. The UV protection rate were increased after dyeing and the deodorization of ammonia gas improved to 98%. Bacterial reduction rate (Staphylococcus aureus) of wool fabrics was excellent at 99.9%. All dye fastness (except for light fastness) was excellent; in addition, the functionality of wool fabrics dyed with Zizania latifolia Turcz also improved. The results are expected to be applied to various fields because they indicate excellent results after treatment with ultraviolet absorber for improving the fastness of daylight.

• Fisheries and Aquatic Sciences
• /
• v.22 no.1
• /
• pp.4.1-4.10
• /
• 2019

Russian sturgeon (Acipenser gueldenstaedtii) is commercially important in Korea because its caviar is highly prized. Although the early ontogeny of the species has been described, behavioral modifications in response to various light intensities or diel photoperiodicity patterns have not been studied extensively. The objective of the present study was to examine the behavioral characteristics of hatchery-produced A. gueldenstaedtii prelarvae over a diel photoperiodic cycle. During a diel light cycle comprising 16 h of daylight (450 lx), 4 h of dim light (10 lx), and 4 h of darkness (< 1 lx), newly hatched A. gueldenstaedtii prelarvae exhibited negative phototaxis in daylight (day 0-day 2), and this early behavior was not significantly affected by changes of light intensities. Rheotactic and non-rheotactic aggregation into schools was typical between days 3 and 6. Under the diel light cycle conditions described, rheotaxis was not influenced by environmental light intensity as much as non-rheotactic schooling behavior. Post-schooling behavior, which progressed from day 7 to day 8, did not change significantly during the diel light cycle. The data from the present study could be of practical value in developing a visual guide for assessing the fitness and quality of Russian sturgeon prelarvae under diel light cycle conditions in hatcheries.

• Science of Emotion and Sensibility
• /
• v.13 no.1
• /
• pp.69-78
• /
• 2010

LED technology offers versatile lighting control while having a very low environmental impact. Consequently, increasing attention is being paid to the emotional impact of LED lighting. This study investigated whether the chromacity of LED lighting influences people's time perception. To this end, two empirical studies were conducted: First, in experiment I(N=28), the subjects compared their perception of the time duration, which was varied from 3s to 20s, for 6 chromatically nuanced lighting conditions, respectively, with that under a daylight condition. The results showed that, in warm-color nuanced lighting conditions, the subjects perceived time to pass more slowly than in the daylight condition. On the contrary, in cool-color nuanced lighting conditions, the subjects perceived time to pass more rapidly than in the daylight condition. Then, in experiment II(N=39), the subjects were asked to count for 90 seconds while simultaneously performing some cognitive tasks. Confirming the results found in experiment I, the subjects perceived time to pass more rapidly in cool-color nuanced lighting conditions than in warm-color nuanced lighting conditions, although the difference was not statistically significant(p>0.05). In addition, the subjects tended to perceive the time to be shorter when the nuanced color of the light was closer to their preferred color.

• KIEAE Journal
• /
• v.10 no.3
• /
• pp.43-50
• /
• 2010

Natural lighting is directly connected with our mental and physical health. For working or learning effect, the proper natural lighting is required for improving our living conditions. School facilities, especially, are the place where includes students' ordinary activities with learning behaviors during the school years from elementary to high school. This study was carried out for the purpose introducing a basic database in that planning a school by researching on the actual in the natural lighting system of some schools' classroom, estimating, and analyzing through a simulation, which resulted in a method of improving the natural lighting system. As a result of measuring and analyzing Daylight Factor(DF) during the time from 9 am to 3 pm when students are activating in their classroom, generally DF range of the sides near to window and aisle seats zone are not distributed well. Besides, two out of four school which are researched would not reach the standards of the law for school sanitary while rest of the schools meet the standards; Average DF 5% and Minimum DF 2%. And the result of a simulation by RADIANCE program shows the most appropriate DF range when it is applied in variable numbers about an oriehows the- South-east 15, south-east 30, south-east 45, south-west 15, south-west 30, and south-west 45 degrees. When it is applied in the variable numbers about glass transmittance - 60%, 70%, and 80% in condition facing south of a classroom, the result shows that the DF range of 80% transmittance is relatively higher than other glasses in the classroom. Thus, when a school is built, plans for an orientation is necessary for improve of elementary schools' environment with the glass installation which is made for high transmittance and is regarded with the students' activities time.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.33 no.9
• /
• pp.89-96
• /
• 2005

This paper discusses the daytime atmospheric conditions and the possibility of daytime star detection with the purpose of practical use of the star sensor for daylight navigation. In order to estimate the daytime atmospheric data, we use the standard atmospheric model (LOWTRAN 7), from which atmospheric transmittance and radiance from background sky are calculated. Assuming the star sensor with an optical filter to reduce background radiation, different separation angles between the star sensor and the sun are set up to express the effect of the solar radiation. As considerations of field of view (FOV) of the star sensor, the variation of the sky background radiation and the star density of the detectable star are analyzed. In addition, the integration time to achieve a required signal-to-noise ratio and the number of the radiation-caused electrons of the charge coupled detector(CCD) working as the limit to daylight application of the star sensor are calculated.

• Journal of Astronomy and Space Sciences
• /
• v.34 no.1
• /
• pp.67-73
• /
• 2017

In this paper, we investigate the observations of Venus in daytime that are recorded in the Goryeosa (History of the Goryeo Dynasty, A.D. 918-1392). There are a total of 167 accounts of such observations in this historical book, spanning a period of 378 yr (from 1014 to 1392). These include six accounts where the days of the observation are not specified and two accounts where the phase angles are outside the calculation range of the equation used in our study. We analyze the number distribution of 164 accounts in 16 yr intervals covering the period from 1023 to 1391. We find that this distribution shows its minimum at around 1232, when the Goryeo dynasty moved the capital to the Ganghwa Island because of the Mongol invasion, and its maximum at around 1390, about the time when the dynasty fell. In addition, we calculate the azimuth, altitude, solar elongation, and apparent magnitude of Venus at sunset for 159 observations, excluding the eight accounts mentioned above, using the DE 406 ephemeris and modern astronomical algorithms. We find that the average elongation and magnitude of Venus on the days of those accounts were ${\sim}40^{\circ}$ and -4.5, respectively, whereas the minimum magnitude was -3.8. The results of this study are useful for estimating the practical conditions for observing Venus in daylight with the naked eye and they also provide additional insight into the corresponding historical accounts contained in the Goryeosa.

• The Bulletin of The Korean Astronomical Society
• /
• v.42 no.2
• /
• pp.70.1-70.1
• /
• 2017

We reexamine the Goryeosa (History of the Goryeo Dynasty, A.D. 918-1392) account that Halley's Comet was seen during the daytime on September 9, 1222. To verify whether the referenced "daytime" refers to twilight or daylight (i.e., when the Sun is above horizon), we determine the absolute magnitude and heliocentric power-law exponent for Halley's Comet using observations made around the perihelion in 1986 and a formula considering the brightness enhancement by forward-scattering. We then apply the results to estimate the light curve of Halley's Comet in the 1222 event and find that the total visible magnitude could reach a maximum of -1.7 on September 8, one day before the Goryeosa's account. Therefore, we think that Halley's Comet with a coma of -1.7 mag and tail-length of about $20^{\circ}$ was actually observed during the day on September 9 because the observational conditions on that day were so good that Venus was visible in daylight. Furthermore, we think that the event might have been witnessed in the morning sky because the contents of Venus's culmination (occurred around September 9.07 TT) continue on the same day account.

• Journal of the Korean Solar Energy Society
• /
• v.35 no.6
• /
• pp.1-7
• /
• 2015

This paper deals with the design and operation of a hybrid daylighting system that uses natural and artificial lighting to enhance visual comfort in buildings. The system was developed using an AVR micro controller for solar tracking in conjunction with dimming controls, which, acting together, enables the maximum use of natural daylight and also improves energy efficiency in buildings. Experimental results clearly demonstrates the usefulness of the present system capable of enhancing indoor lighting conditions when sufficient daylight is available and distributed appropriately in harmony with artificial lighting.

• KIEAE Journal
• /
• v.8 no.3
• /
• pp.101-106
• /
• 2008

The use of daylighting has been increased recently due to energy and visual comfort. The aims of interior daylighting are to adequately illuminate visual tasks, to create an attractive visual environment, and to save electrical energy. Lightpipe can improve the distribution of light to interior spaces. This study aims to evaluate the comparative daylighting performance of lightpipe under different sky conditions with mock-up model, sized $6m{\times}6m{\times}4m$ ($w{\times}d{\times}h$). For the purpose, perpendicular lightpipe system was designed as 650 diameter, with an aspect ratio of 2. Totally 49 measuring points of and two of outdoor illuminance on the horizontal plane were monitored from 09:00 to 18:30 on April 29 and May 15 2008. Agilent data logger and photometric sensor were used. Light factor were used to analyse daylight performance under different sky condition. Under overcast sky condition and clear sky condition, the lightpipe system is suitable for KS recommendation level of illuminance.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.12
• /
• pp.7393-7402
• /
• 2014

This study focused on improving the Biotope Area Ratio, which has existing availability as a legal and institutional method for the architectural and urban fields to respond rapidly to recently growing demands for urban agriculture. The existing Biotope Area Ratio indicators only considers the depth and permeability of soil among a range of conditions for plant growth; they can be used for landscaping plants management but have difficulties in dealing with plants that are the major factors in urban agriculture. This study aimed to verify this hypothesis and suggest a direction of improvement in the Biotope Area Ratio. The study discovered that the management of plant growth only using the Biotope Area Ratio indicators has limitations.