• Korean Journal of Plant Resources
• /
• v.17 no.1
• /
• pp.43-47
• /
• 2004

The effect of plant growth regulators and gelling agents for plant regeneration from leaf segment of Chrysanthemum zawadskii ssp. coreanum was investigated. NAA was more effective than BA for plant regeneration. MS medium supplemented with NAA 1 mg/L was the most effective in plant regeneration. The effect of agar and gelite as gelling agent was compared. Agar(0.8%) was more effective than gelite(0.2%) in plant regeneration. Regenerated shoots was successfully increased by shoot grafting in MS medium supplemented with NAA 0.1 mg/L in vitro, and hardened by shoot grafting in artificial soil mix(Peatmoss : Perlite = 1 : 1).

• Journal of the Korean Solar Energy Society
• /
• v.37 no.3
• /
• pp.1-12
• /
• 2017

This paper deals with the effectiveness of a fiber optic solar lighting system that uses a Fresnel lens mounted on a two-axis solar tracker. A series of comparative analyses were made concerning its performance as compared to fluorescent lighting by using a simulation model based on ECOTECT and RADIANCE as well as referring to actual data. ECOTECT was used to model the test room (space) while RADIANCE was used for its indoor lighting conditions (environment). It was found that the average indoor light levels of fluorescent lighting fully satisfy the KS standard (KS A 3011, general office, class [G]: 300-400-600 lux) whereas those of the solar lighting with light diffusers depends on the occlusion factor of roller shades installed on the south window.

• The Korean Journal of Ecology
• /
• v.8 no.4
• /
• pp.201-204
• /
• 1985

The author reared the bandwinged grasshoppers, Oedaleus infernalis infernalis in the growth cabinet controlled as temperature of 25。C and 30。C under the conditiion of photoperiod 16L:8D, light intensity 510$\pm$240lux, relative humidity 65$\pm$3%. The results are summarized as follows: The female has six instars and male five instars. The larva reared in the temperature of 25。C died at the second larva stage, and the development to the third instar was impossible. The developmental periods of the egg stage of both sexes in the 30。C are 24.06 days. In the larval development periods, the fourth statge (19.73 days) was longer than that of any stage, and the second stage has the shortest period (9.9 days) in female. In male, the developmental period (9.59 days). The total developmental periods of female and male from the egg to the fifth instar were approximately 95.02 and 95.04 days, respectively. The total developmental period of female was as long as the period (15.75 days) of sixth instar which is not in the male. The survivorship curve in the temperature of 30。C shows concave type.

• Industrial Engineering and Management Systems
• /
• v.9 no.2
• /
• pp.157-164
• /
• 2010

The objective of this study is to determine the dominance effects of environmental factors such as Illuminance, humidity and Wet Bulb Globe Temperature (WBGT) on the operators' productivity at Malaysian electronic industry. A case study was carried out at an electronic components assembly factory. The environmental factors examined were the Illuminance (lux), humidity and WBGT of the surrounding workstation area. Two sets of representative data including the illuminance, humidity and WBGT level and production rate were collected during the study. The production rate data were collected through observations and survey questionnaires while the illuminance level was measured using photometer model RS 180-7133, the humidity and WBGT level were measured by using Quest Temp apparatus and humidity. Taguchi Method was utilized to find the sequence of dominant factors that contributed to the productivity of operator at that specified production workstation. The study reveals that the dominant factor contributed to the productivity was WBGT, followed by illuminance and humidity.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.31 no.1
• /
• pp.139-142
• /
• 1998

To obtain informations for construction of a mass culture system, factors affecting on the specific growth rate of marine Chlorella sp. purchased from the Chungmu Laboratory of the South Sea Fisheries Institute, the National Fisheries Research and Development Agency were investigated using a vertical tubular photobioreactor (VT-PBR) system. Optimal temperature, illumination intensity, air- and $CO_{2-}$ flow rate for Chlorella sp. were $20^{\circ}C$, 6,000 lux, 0,56 vvm and 0.028 vvm, respectively.

• Advances in environmental research
• /
• v.5 no.1
• /
• pp.61-77
• /
• 2016

$NanoTiO_2$ was synthesized by ultrasonication assisted sol-gel process and subjected to iron doping and carbon-iron codoping. The synthesized catalysts were characterized by XRD, HR-SEM, EDX, UV-Vis absorption spectroscopy and BET specific surface area analysis. The average crystallite size of pure $TiO_2$ was in the range of 30 - 33 nm, and that of Fe-$TiO_2$ and C-Fe $TiO_2$ was in the range of 7 - 13 nm respectively. The specific surface area of the iron doped and carbon-iron codoped nanoparticles was around $105m^2/g$ and $91m^2/g$ respectively. The coupled semiconductor photo-Fenton's activity of the synthesized catalysts was evaluated by the degradation of a cationic dye (C.I. Basic blue 9) and an anionic dye (C.I. Acid orange 52) with concurrent investigation on the operating variables such as pH, catalyst dosage, oxidant concentration and initial pollutant concentration. The most efficient C-Fe codoped catalyst was found to effectively destruct synthetic dyes and potentially treat real textile effluent achieving 93.4% of COD removal under minimal solar intensity (35-40 kiloLUX). This reveals the practical applicability of the process for the treatment of real wastewater in both high and low insolation regimes.

• Current Optics and Photonics
• /
• v.5 no.3
• /
• pp.298-305
• /
• 2021

Modern distance sensing methods employ various measurement principles, including triangulation, time-of-flight, confocal, interferometric and frequency comb. Among them, the triangulation method, with a laser light source and an image sensor, is widely used in low-cost applications. We developed an omnidirectional two-dimensional (2D) distance sensor based on the triangulation principle for indoor floor mapping applications. The sensor has a range of 150-1500 mm with a relative resolution better than 4% over the range and 1% at 1 meter distance. It rotationally scans a compact one-dimensional (1D) distance sensor, composed of a near infrared (NIR) laser diode, a folding mirror, an imaging lens, and an image detector. We designed the sensor layout and configuration to satisfy the required measurement range and resolution, selecting easily available components in a special effort to reduce cost. We built a prototype and tested it with seven representative indoor wall specimens (white wallpaper, gray wallpaper, black wallpaper, furniture wood, black leather, brown leather, and white plastic) in a typical indoor illuminated condition, 200 lux, on a floor under ceiling mounted fluorescent lamps. We confirmed the proposed sensor provided reliable distance reading of all the specimens over the required measurement range (150-1500 mm) with a measurement resolution of 4% overall and 1% at 1 meter, regardless of illumination conditions.

• Journal of Ecology and Environment
• /
• v.45 no.4
• /
• pp.218-227
• /
• 2021

Background: Artificial light at night has recently been identified as a major factor adversely affecting global insect diversity. Here, we compared the insect diversity in Gwangneung Forest Biosphere Reserve, specifically in the Korea National Arboretum (with no artificial light at night), with that of three nearby urban sites with a gradient of artificial light at night (five locations at each site). We analyzed the effects of the artificial night lighting index, mean annual temperature, and field light intensity (lux) at night on the insect community structure. Results: The urban sites generally exhibited higher species richness and abundance as well as clear indicator species compared with the control site. The size distribution of the collected insects markedly differed between the control and the three urban sites. The abundance of herbivorous and omnivorous insects increased and decreased, respectively, with the increase in light intensity. Species richness of herbivorous and omnivorous insects was likely correlated with the field light intensity at night and artificial night lighting index, respectively. Conclusions: This study demonstrates the association between nighttime environment and marked changes in insect community structure and revealed consequent transition of ecosystem services by changes in trophic group composition.

• Journal of Ecology and Environment
• /
• v.48 no.2
• /
• pp.128-136
• /
• 2024

Background: Prasiola japonica is a freshwater green algae species that can only be seen in Korea and Japan. The various conditions necessary for its growth and reproduction have not been fully elucidated. Therefore, in this study, we aimed to investigate conditions related to the growth and reproduction of P. japonica for the purpose of conserving and producing this species. We first examined differences in growth according to various conditions in different habitats to understand the growth environment of P. japonica. Results: The experimental results revealed that the optimal temperature for growth and reproduction of P. japonica was between 10℃-15℃, and the optimal light intensity was 1,000-1,500 lux. Furthermore, when Provasoli enriched seawater with iodine (PESI) agar was used, the growth of P. japonica was found to be at least 1.5-8 times greater than that of the general Sohan Valley water sample, and it also showed 2-4.5 faster growth rate to reach 30 ㎛. These results emphasize the importance of PESI agar in the culture of P. japonica, and are expected to be helpful in suggesting ways to utilize and conserve P. japonica resources. Conclusions: Through these research findings, we suggest new methods for conserving and producing P. japonica, highlight the importance of preserving the P. japonica ecosystem, and explore ways to utilize P. japonica resources. This research promotes the understanding and protection of P. japonica resources in Korea and beyond, and underscores the need for further research and conservation efforts.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.22 no.2
• /
• pp.145-157
• /
• 2024

Undeclared nuclear activities are challenging given the lack of information from the sites involved in such activities. Wide-area environmental sampling (WAES) can be an effective method to detect undeclared nuclear activities. However, it is crucial to address the potential risks during the WAES, including sample tampering or extortions. Therefore, tracking and monitoring of various on-site data is imperative to accurately interpret the status of samples and workers throughout the WAES process. 'Environmental and Geographical Data Transfer (EGDT)' was developed for the real-time monitoring of integrated on-site data. EGDT module is equipped with various sensors and can be attached to a worker's uniform or a sample storage box. This study demonstrated the technical effectiveness of EGDT by exploring three experimental methodologies for feasibility assessment. Compared to the Normal Operation case, the inference of the Sample Extortion case was predominantly based on changes in lux and dose rate. The inference of the Out-of-Work-Area case primarily relied on changes in dose rate and acceleration. Finally, the preliminary evaluation of the performance of the developed prototype was conducted, and a foundation was established for enhancing the application in the WAES process.