• Journal of Bio-Environment Control
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• v.17 no.2
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• pp.96-100
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• 2008

To extend the shelf-life of kidney bean (Phaseolus vulgaris L.) after harvest, we investigated the effect of packaging material and storage temperature. In case of film package, there was no weight loss during storage, but in paper-box package, remarkable weight loss occurred as storage period extended and storage temperature risen. Firmness of kidney bean was greater in low temperature than ambient temperature storage. Content of vitamin C was decreased rapidly during storage, and in paper package, low temperature storage group had lower decrease of vitamin C than that of room temperature. Total chlorophyll content was not difference among storage temperatures in film package treatments. However, in paper-box package, decrease of chlorophyll in room temperature storage was greater than that of low temperature ($8{\sim}10^{\circ}C$). In terms of freshness of kidney bean, we suggest that shelf-life by low temperature storage ($8{\sim}10^{\circ}C$) after PP film or paper package was 8 days, but that by room temperature storage after paper package was 4 days.

• Progress in Medical Physics
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• v.17 no.2
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• pp.77-82
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• 2006

The image display is an Important component of PACS and of medical digital imaging chain. Displayed image qualify is affected by the physical characteristics of display device, appropriate clinical settings and calibrations, and ambient lighting conditions. The performance of display systems is continuously degraded over time due to luminance deterioration and changes of clinical setting parameters. A routine QC is recommended because the performance of display systems is continuously degraded over time. Ten flat panel monochrome LCD display devices were included in the evaluation of the QC effect. The effect of QC on primary class LCD medical display devices for selected QC tests was evaluated by comparing the performances, luminance response, luminance dependencies, display resolution and display chromaticity in this study, of before and after the calibration procedures. The effects of the QC are significant to luminance response and luminance spatial dependencies test and the other side, are slight to the display resolution and display chromaticity test. A routine QC of display device is essential for the consistency of medical image display and presentation. The study of the QC effects of display devices will play an important role in practical QC procedures of display devices.

• Journal of Pharmaceutical Investigation
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• v.36 no.1
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• pp.23-29
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• 2006

A rapid, selective and sensitive reversed-phase HPLC method for the determination of promethazine in human serum was developed, validated, and applied to the pharmacokinetic study of promethazine. Promethazine and internal standard, chlorpromazine, were extracted from human serum by liquid-liquid extraction with n-hexane containing 0.8% isopropanol and analyzed on a Capcell Pak CN column with the mobile phase of acetonitrile-0.2 M potassium dihydrogen phosphate (42:58, v/v, adjusted to pH 6.0 with 1 M NaOH). Detection wavelength of 251 nm and flow rate of 0.9 mL/min were fixed for the study. The assay robustness for the changes of mobile phase pH, organic solvent content, and flow rate was confirmed by $3^{3}$ factorial design using a fixed promethazine concentration (10 ng/mL) with respect to its peak area and retention time. In addition, the ruggedness of this method was investigated at three different laboratories using same quality control (QC) samples. This method showed linear response over the concentration range of 1-40 ng/mL with correlation coefficients greater than 0.999. The lower limit of quantification using 1 mL of serum was 1 ng/mL, which was sensitive enough for pharmacokinetic studies. The overall accuracy of the quality control samples ranged from 96.15 to 105.40% for promethazine with overall precision (% C.V.) being 6.70-11.22%. The relative mean recovery of promethazine for human serum was 63.54%. Stability (freeze-thaw and short-term) studies showed that promethazine was stable during storage, or during the assay procedure in human serum. However, the storage at $-80^{\circ}C$ for 4 weeks showed that promethazine was not stable. Extracted serum sample and stock solution were not allowed to stand at ambient temperature for 12 hr prior to injection. The peak area and retention time of promethazine were not significantly affected by the changes of mobile phase pH, organic solvent content, and flow rate under the conditions studied. This method showed good ruggedness (within 15% C.V.) and was successfully used for the analysis of promethazine in human serum samples for the pharmacokinetic studies of orally administered Himazin tablet (25 mg as promethazine hydrochloride) at three different laboratories, demonstrating the suitability of the method.

• Journal of the Korea Concrete Institute
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• v.23 no.6
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• pp.773-780
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• 2011

In this study, thermal stress analysis are carried out considering material properties, curing condition, ambient temperature, and casting date of the mass concrete placed in bottom slab and side wall of the in-ground type LNG tank as a super massive structure. Also, based on the numerical results, cracking possibility is predicted and counter measures to prevent the cracking are proposed. For the tasks, two optimum mix proportions were selected. From the results of the thermal stress analysis, the through crack index of 1.2 was satisfied for separately caste concrete lots except for the bottom slab caste in 2 separate sequences. For the double caste bottom slab, it is necessary introduce counter measures such as pre-cooling prior to the site construction. Also, another crack preventive measure is to lower the initial casting temperature by $25^{\circ}C$ or less to satisfy 1.2 through crack index criterion. In the $1^{st}$ and $2^{nd}$ caste bottom slab, the surface crack index was over 1.2. Therefore, the surface cracks can be controlled by implementing the curing conditions proposed in this study. Since the side wall's surface crack index was over 1.0, it is safe to assume that the counter preventive measures can control width and number of cracks.

• Korean Journal of Environment and Ecology
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• v.24 no.6
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• pp.648-656
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• 2010

Global warming brings changes of natural ecosystems and affects on the plant growth response. Quercus acutissima and Q. variabilis are taxonomically similar and dominant native species in deciduous forests in South Korea. In order to understand the growth response of Q. acutissima and Q. variabilis to global warming condition, we cultivated the seedling of the two oak species in ambient condition(control) and treatment with elevated $CO_2$(700~800ppm) and increased air temperature(approximately $3^{\circ}C$ above than control). Then we measured the growth characteristic among them and analyzed the relationship between two species using PCA ordination. Stem length and total plant weight of Q. acutissima were significantly affected by elevated $CO_2$ concentration and increased air temperature. Stem diameter and weight of Q. variabilis were significantly affected by elevated $CO_2$ concentration and increased air temperature(p<0.05). The variation characteristics of Q. acutissima were changed more than Q. variabilis by elevated $CO_2$ concentration and increased air temperature. These result suggested that Q. acutissima was more sensitive to global warming situation than Q. variabilis in central region of Korea. PCA ordination showed that two species were arranged by two distinct groups based on 10 characters by elevated $CO_2$ and increased air temperature.

• Asian Journal of Turfgrass Science
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• v.15 no.4
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• pp.169-179
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• 2001

This study was conducted to determine the effect of root zone cooling on growth and quality of turfgrasses including Kentucky bluegrass (Poa pratensis L.‘Nuglade’), perennial ryegrass (Lolium perenne L.‘Accent’), tall fescue (Festuca arundinacea Schreb.‘Pixie’), and Japanese lawngrass (Zoysia japonica Steud.) in simulated athletic field during summer season in Korea. Mineral contents in clippings of turfgrasses grown at different soil mixtures and temperatures were also analyzed. Root zone cooling (approximately 4~6$^{\circ}C$ lower than that of untreated-control) resulted in good uniformity, little disease incidence and higher level of chlorophyll contents in cool-season turfgrasses. The effectiveness of root zone cooling in protecting disease incidence from high temperature stress was the most manifest in perennial ryegrass compared to others. Fresh clipping weight in treatment of root zone cooling was increased approximately 2 times in Kentucky bluegrass and perennial ryegrass, and 2.5 times in tall fescue compared to those of control. There was higher growth rate in a soil mixture composed of 80% peat moss ＋10% sand ＋10% soil (v/v/v) than in that of 80% pea moss ＋20% sand (v/v), Mineral contents of N, P, K, Ca, and Mg in clippings of three species of cool-season turfgrasses were significantly increased in treat-ment of root zone cooling but this was not found in Japanese lawngrass. Results showed that root zone cooling has a benefit in keeping good quality and growth of cool-season turfgrasses in sports field under supraoptimal ambient temperature during summer season.

• Wind and Structures
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• v.38 no.1
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• pp.15-42
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• 2024

A flexible-base coupled-two-beam (CTB) discrete model with equivalent tuned mass dampers is used to assess the effect of soil-structure interaction (SSI) and different types of lateral resisting systems on the design of passive dynamic absorbers (PDAs) under the action of along-wind and across-wind loads due to vortex shedding. A total of five different PDAs are considered in this study: (1) tuned mass damper (TMD), (2) circular tuned sloshing damper (C-TSD), (3) rectangular tuned sloshing damper (R-TSD), (4) two-way liquid damper (TWLD) and (5) pendulum tuned mass damper (PTMD). By modifying the non-dimensional lateral stiffness ratio, the CTB model can consider lateral deformations varying from those of a flexural cantilever beam to those of a shear cantilever beam. The Monte Carlo simulation method was used to generate along-wind and across-wind loads correlated along the height of a real shear wall-frame building, which has similar fundamental periods of vibration and different modes of lateral deformation in the xz and yz planes, respectively. Ambient vibration tests were conducted on the building to identify its real lateral behavior and thus choose the most suitable parameters for the CTB model. Both alongwind and across-wind responses of the 144-meter-tall building were computed considering four soil types (hard rock, dense soil, stiff soil and soft soil) and a single PDA on its top, that is, 96 time-history analyses were carried out to assess the effect of SSI and lateral resisting system on the PDAs design. Based on the parametric analyses, the response significantly increases as the soil flexibility increases for both type of lateral wind loads, particularly for flexural-type deformations. The results show a great effectiveness of PDAs in controlling across-wind peak displacements and both along-wind and across-wind RMS accelerations, on the contrary, PDAs were ineffective in controlling along-wind peak displacements on all soil types and different kind of lateral deformation. Generally speaking, the maximum possible value of the PDA mass efficiency index increases as the soil flexibility increases, on the contrary, it decreases as the non-dimensional lateral stiffness ratio of the building increases; therefore, there is a significant increase of the vibration control effectiveness of PDAs for lateral flexural-type deformations on soft soils.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.1
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• pp.31-37
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• 2024

In this study, we propose a machine vision-based pedestrian signal detection algorithm that operates efficiently even in computing resource-constrained environments. This algorithm demonstrates high efficiency within limited resources and is designed to minimize the impact of ambient lighting by sequentially applying HSV color space-based image processing, binarization, morphological operations, labeling, and other steps to address issues such as light glare. Particularly, this algorithm is structured in a relatively simple form to ensure smooth operation within embedded system environments, considering the limitations of computing resources. Consequently, it possesses a structure that operates reliably even in environments with low computing resources. Moreover, the proposed pedestrian signal system not only includes pedestrian signal detection capabilities but also incorporates IoT functionality, allowing wireless integration with a web server. This integration enables users to conveniently monitor and control the status of the signal system through the web server. Additionally, successful implementation has been achieved for effectively controlling 50W LED pedestrian signals. This proposed system aims to provide a rapid and efficient pedestrian signal detection and control system within resource-constrained environments, contemplating its potential applicability in real-world road scenarios. Anticipated contributions include fostering the establishment of safer and more intelligent traffic systems.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.373-383
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• 2012

Soybean, C.V. Daewonkong, was planted on 25 May and 25 June in 2011, and four temperature gradient, control (ambient temperature in field plot), control + $3^{\circ}C$, control + $4^{\circ}C$, and control + $5^{\circ}C$, were artificially created by controlling the green house system. The obtained results indicated that vegetative growth of soybean plant was beneficially facilitated by planting on May (PM) than planting on June (PJ). The 100-seed weight was significantly higher in PM, and positively affected by increasing temperature, whereas the weight was reduced in control + $5^{\circ}C$ plot. Isoflavone content and fatty acid composition were analyzed to determine the effects of plating date and growth temperature. Isoflavone content was higher in PJ plot ($1479.8{\mu}g/g$) than in PM plot ($1201.8{\mu}g/g$), however, the influence of growth temperature varied with planting date. The composition of oleic acid was positively affected by increasing temperature, whereas the proportions of linoleic and linolenic acid were reduced. The numbers of node was considered as a major variable in the regression equations estimated using forward stepwise regression analysis for isoflavone content and unsaturated fatty acid under different environmental conditions.

• Korean Journal of Environment and Ecology
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• v.31 no.3
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• pp.279-286
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• 2017

We investigated growth response and variation of ecological niche breadth of Hibiscus hamabo according to light, moisture and nutrient when global warming is proceeded by elevated $CO_2$ concentration and temperature. H. hamabo was cultivated in experimental condition in the greenhouse that are divided by control(ambient condition) and treatment(elevated $CO_2$ concentration and temperature). Light, moisture and nutrient gradients were treated within the control and the treatment. Although H. hamabo prefers higher light intensity(up to L3) to lowers', Hamabo mallow doesn't like excessive light intensity($787{\pm}77.76{\mu}mol\;m^{-2}s^{-1}$). Also, H. hamabo was difficult to grow in absent nutrient(0%) and excessive nutrient(20%). However, there was no trend with moisture gradients. The death rate of H. hamabo in the treatment was higher in all gradients except for the highest light intensity condition than control. It means that range of tolerance about light is narrowed when concentration of $CO_2$ gas and temperature is elevated. There was no trend of death rate according to moisture gradient, comparing between control and treatment. The death rate in all nutrient gradients within the treatment is lower than the controls'. It means that range of tolerance about nutrient is widened. The ecological niche breadth of H. hamabo in the treatment was narrower as 30.1% in light gradients but wider as 8.6% in moisture gradients and 30% in nutrient gradients than in the control. In the conclusion, when global warming is proceeded by elevated $CO_2$ concentration and temperature, growth of H. hamabo would be restricted by light intensity.