• Journal of Broadcast Engineering
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• v.28 no.1
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• pp.21-30
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• 2023

Computer-generated holography requires much more computation costs and memory space rather than image processing. We implemented the diffraction calculation with low-precision and mixed-precision floating point numbers and compared the processing time and quality of the hologram with various precision. We compared diffraction quality with double, single and bfloat16 precision. bfloat16 shows 5.94x and 1.52x times faster performance than double precision and single precision. Also, bfloat16 shows lower PSNR and SSIM and higher MSE than other precision. However, there is no significant effect on reconstructed images. These results show low precision, like bfloat16, can be utilized for computer-generated holography.

• Asian Journal of Turfgrass Science
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• v.26 no.1
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• pp.24-34
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• 2012

The study was carried out to investigate the effects of polymer, calcium, perlite and chitosan on the growth of perennial ryegrass (Lolium perenne L., PR) and to provide a basic information needed for their practical application when establishing garden, parks, athletic field and golf courses with these materials. A total of 24 treatment combinations were applied in the study. Treatments were made of water-swelling polymer (WSP), calcium, perlite and chitosan mixed in soil organic amendment (SOA). Germination rate, turfgrass coverage, turfgrass density and top growth were evaluated in PR under greenhouse conditions. Significant differences were observed for these growth characteristics among the treatments. Turfgrass density and plant height, evaluated on a weekly basis, varied with time after seeding. A proper mixing rate of WSP was considered to be lower 3% for the growth of PR with an exception of being below 6% for turfgrass density. Germination rate and early survival capacity were greatly influenced by calcium and chitosan among the elements of calcium, perlite, and chitosan. But there was little effect by perlite. Calcium and chitosan were most effective one for turfgrass density and coverage, respectively. Top leaf-growth was influenced by all three elements, but the greatest effect was highly linked with calcium. Chitosan was very effective in early germination and vertical leaf growth, as compared with the others. Future studies are required for measuring the effect of WSP, calcium, perlite and chitosan on the turf growth characteristics in root zone mixtures of sand+SOA before a practical field use.

• Korean Journal of Optics and Photonics
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• v.13 no.1
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• pp.9-14
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• 2002

A surface plasmon sensor has been fabricated for detection of concentration and refractive-index of a mixed solution. Based on the Kretschmann-Raether attenuated-total-reflection configuration, the sensor consists of 54 nm-thick Ag metal layer under a prism and a cell containing the mixed solution. We have observed a nonlinear refractive-index change as the ethanol-water concentration increased. The experimental results show us that the detection limit of the SPR sensor is 3$\times$10$^{-2}$ % in ethanol mass ratio. The concentration-to-index curve shows a linear increase in the range of ethanol concentration from 0% to 50%, but a nonlinearity is observed beyond 50%. We have modeled the nonlinearity and compared it with the experimental results.

• Journal of Korea Foresty Energy
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• v.25 no.2
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• pp.28-33
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• 2006

This study was conducted to find potentialities of the leaves of gingko tree (Gingko biloba L.) which has been planted as a roadside tree in Korea because of its resistance on air pollution, insect, fungi, etc. Various amounts of the leaves were mixed with wasted wood particles to manufacture particleboard. Their influences on physical and mechanical properties and the formaldehyde emission of PB were investigated. Physical and mechanical properties, such as density, modulus of rupture (MOR), and internal bond (IB) strength, of manufactured particleboard were not much different from those of control board. Formaldehyde emission values were decreased with increasing amount of leaves in PB prepared. Especially, particleboard made with 3 percent of leaves was decreased to $1.66mg/{\ell}$ in formaldehyde emission, which is about 40% lower emission than that of control. From these results, the leaves of gingko tree may be considered as a formaldehyde emission lowering additive in a functional PB manufacturing process.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.169-174
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• 2014

Practical deployment methods for sensor nodes are demanding as applications using sensor nodes increase. In particular, node connectivity is crucial not only for the network longevity but also for direct impacts on sensing and data collection capability. Economic requirement at building sensor networks and often limited access for sensor fields due to hostile environment force to remain at random deployment from air. However, random deployment often result in lost connection problem and inefficient network topology issue due to node irregularity. In this paper, mixed deployment of key nodes that have better communication capability is proposed to support the original deployment into working in an efficient way. Node irregularity is improved by introducing mixed nodes and an efficient mixed node density is also analyzed. Simulation results show that the mixed deployment method has better performance than the existing deployment methods.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.714-719
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• 2017

The contaminated engine oil by fuel can intimidate driver safety due to vehicle problems such as engine abrasion, fire and sudden unintended acceleration. In this study, we investigate various functional properties of the engine oil contaminated with fuel. The test results indicated that the engine oil contaminated with fuel had relatively low values of the flash point, pour point, density, kinematic viscosity and cold cranking simulator. Furthermore, a four ball test suggested that the contaminated engine oil increased wear scar due to the poor lubricity. Moreover, SIMDIST (simulated distillation) using ASTM D2887 was applied to analyze fuel characteristics in an engine oil. The SIMDIST analysis result showed a lower carbon number, and the fuel was detected at an earlier retention time than that of using engine oil in chromatogram. Also, it is possible to quantitatively analyze for fuel contents in the engine oil. The SIMDIST method for the diagnosis of oil conditions can be used whether the fuel was involved or not, instead of analyzing other physical properties that require various analytical instruments, large volumes of oil samples, and long analysis time.

• Korean Journal of Plant Resources
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• v.14 no.3
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• pp.286-294
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• 2001

Soil-borne barley viruses were investigated in 42 regions during 1999-2003, in Korea. BaYMV, BaMMV and SbWMV symptoms were found in 37 regions. Crops resistance to mosaic viruses were investigated by growing them on 10 regions infected with soil-borne viruses. It was found that 10 unhulled barley, 6-beer bar]ey, 16 rye and 2 wheat species showed resistance to virus. Most of 15 Japanese cultivars showed infection symptoms but many of them showed relatively higher resistance in Ikasan, Youngkwang and Yesan areas region. Mixed virus infection was investigated and it was found that inter-regional species except in 10 areas, were mix infected with BaYMV and BaMMV. But in Youngkwang area all of crop species except Secheon-6 were infected only with BaYMV. Japanese cultivars were mixed infected with BaMMV and BaYMV except at Yesan that were infected only with BaYMV.

• Journal of the Korean Geosynthetics Society
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• v.18 no.2
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• pp.1-10
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• 2019

This study was intended to evaluate the water permeability and structure for calcium bentonite-sand mixtures to utilize calcium bentonite as a liner. This study conducted physico-chemical properties tests, compaction tests, permeability test and Scanning Electron Microscopy analysis (SEM) analysis. It was found the higher the ratio of calcium bentonite, the lower the dry density with coefficient of permeability, and the higher the optimum moisture content. In particular, SEM analysis was found the higher the ratio of calcium bentonite, the higher the area of the montmorillonite particles. In conclusion, the optimum coefficient of permeability that finds the landfill liner condition (must be less than $1{\times}10^{-7}cm/sec$) was obtained when the ratio of calcium bentonite was 40% or higher. These findings may improve the understanding of the calcium bentonite as a liner. Calcium bentonite shows a similar permeability to sodium bentonite 7% when mixed at 40% or more. Therefore, it is considered that calcium bentonite can be utilized as a liner.

• Journal of the Korean Wood Science and Technology
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• v.32 no.1
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• pp.67-72
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• 2004

Wood/polyethylene panels were manufactured from Populus alba × glandulosa particles and low density polyethylene particles at three mixing rates, 50:50, 60:40, and 70:30. A total of 15 wood/polyethylene panels was made at 145℃ and 5 minutes hot-press time. Wood/polyethylene panels were tested for internal bond, bending, and dimensional stabilities such as thickness swell and water absorption. Panel performance data were analyzed using the SAS programing package. The test results of the wood/polyethylene panels showed that as the polyethylene mixing rates were increased, the panel property values increased. Based on panels' dimensional stabilities, the optimum wood/polyethylene mixing ratio appeared to be 60:40.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.885-888
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• 2002

Prevalence of food allergic disease was examined by identifying the most common foods implicated in allergic reactions in Korea. Patients were subjected to test determining the amount of specific IgE antibody in serum against food allergens by CAP system. A total 9054 CAP analyses on egg white, egg yolk, cow milk, ${\alpha}-lactalbumin,\;{\beta}-lactoglobulin$, casein, wheat, rice, buckwheat, soybean, peach, crab, shrimp, pork, beef, chicken, tuna, salmon, mackerel, and food mix were undertaken. The results were considered to be positive when CAP value was same and/or greater than +2 (0.7 U/mL). Positive results of CAP analyses were 11.3% (1022/9054 cases), consisting of 336 on egg white, 266 on cow milk, 95 on egg yolk, 76 on soybean, 69 on ${\alpha}-lactalbumin$, 61 on casein, 58 on ${\beta}-lactoglobulin$, 39 on buckwheat, 12 on wheat, 3 on beef, 2 on crab, and 1 on rice, shrimp, pork, chicken or mackerel, and 0 on peach, tuna or food mix. Egg, cow milk, soybean, buckwheat, and wheat were identified as the most common allergic foods in Korea, showing an average of two different food sources for allergy per patient.