• Asian Journal of Turfgrass Science
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• v.5 no.2
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• pp.75-80
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• 1991

The purpose of this experiment was in order to detect the effect of cutting height on the growth and thatch accumulation in Zoysio japonica Cutting height treatments were 2.5, 3.8, 5.1cm and no cutting, respectively. The results were obtained as follows : 1.Cutting treatments great]y affected to the growth of Zoysia japonica and thatch accumulation. 2.The dry weight of Leaf and shoot had the highest at 5.1cm. So 5.1cm treatment was desirable level for the top growth of Zoysia japonica 3.The dry weight of leaf, shoot, root and coverage of control were obtained the higher than cutting treatments. 4.The dry weight of thatch of control were less than cutting treatments, and 5.1cm treatment were more than tow cutting height. 5.Retationships of dry weight of thatch with thatch depth and C/F ratio were positive significant differences at 5% level. 6. Relationship between dry weight of shoot and coverage showed a positive significant difference at 5% level.

• Nuclear Engineering and Technology
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• v.53 no.9
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• pp.2899-2908
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• 2021

The laser transport system of the high power laser facility is mainly composed of large-aperture laser transport mirrors (TMs). Obtaining the high-resolution online damage images during the operation, which is of great significance for operating safely of the mirrors and the facility. Based on wavefront coding, pan-tilt scanning and image stitching technologies, an online laser-damage images detection system is designed, and it can achieve high-precision detection of surface characteristics of large-aperture laser transport mirrors. The preliminary simulation proves that the system can solve the depth of field matching problem caused by pan-tilt tilt imaging and achieve higher resolution.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.20-26
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• 2021

Considering the role of a financial analyst that directly affects investors as an information mediator, management's decision to disclose to maximize corporate value will have an important impact on investors as well. On the other hand, whether or not managers vary the level of disclosure depending on the corporate form will have great implications for policy authorities. However, there is no domestic research on the relationship between the corporate form and the quality of voluntary disclosure. Our study shows that the corporate form tends to deepen the negative relationship between the proprietary information cost and the quality of disclosure. Examining whether the relationship between proprietary information cost and management disclosure decision making is valid for domestic companies is expected to provide meaningful implications for investors and regulators. Depending on the corporate form, if an entity makes a discriminatory disclosure, the cost of capital will be affected. A more in-depth follow-up study on this should be done.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.52-71
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• 2018

RO membranes, the core elements for RO process formed using polyamide, have found prominent space in membrane technology. RO membranes with better application perspective could be achieved by precise controlling the kinetics of IP reaction and surface modification strategy. Despite huge progresses, great challenges still exist in trade-off between flux, rejections and fouling. More works are necessary to enhance the performance and stability of RO membranes via surface modification. Further insights into the use of natural monomers are necessary. It is anticipated that this article can provide clues for further in-depth evaluation and research in exploring more advanced RO membranes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.7
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• pp.2407-2424
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• 2022

Recently, Transformer has made great progress in video retrieval tasks due to its high representation capability. For the structure of a Transformer, the cascaded self-attention modules are capable of capturing long-distance feature dependencies. However, the local feature details are likely to have deteriorated. In addition, increasing the depth of the structure is likely to produce learning bias in the learned features. In this paper, an improved Transformer structure named TransDCS (Transformer with Dynamic Convolution and Shortcut) is proposed. A Multi-head Conv-Self-Attention module is introduced to model the local dependencies and improve the efficiency of local features extraction. Meanwhile, the augmented shortcuts module based on a dual identity matrix is applied to enhance the conduction of input features, and mitigate the learning bias. The proposed model is tested on MSRVTT, LSMDC and Activity-Net benchmarks, and it surpasses all previous solutions for the video-text retrieval task. For example, on the LSMDC benchmark, a gain of about 2.3% MdR and 6.1% MnR is obtained over recently proposed multimodal-based methods.

• The Bulletin of The Korean Astronomical Society
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• v.45 no.1
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• pp.66.2-66.2
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• 2020

We propose a deep learning analysis technique with a convolutional neural network (CNN) to predict the evolutionary track of the Epoch of Reionization (EoR) from the 21-cm differential brightness temperature tomography images. We use 21cmFAST, a fast semi-numerical cosmological 21-cm signal simulator, to produce mock 21-cm maps between z = 6 ~ 13. We then apply two observational effects, such as instrumental noise and limit of (spatial and depth) resolution somewhat suitable for realistic choices of the Square Kilometre Array (SKA), into the 21-cm maps. We design our deep learning model with CNN to predict the sliced-averaged neutral hydrogen fraction from the given 21-cm map. The estimated neutral fraction from our CNN model has great agreement with the true value even after coarsely smoothing with broad beam size and frequency bandwidth and heavily covered by noise with narrow beam size and frequency bandwidth. Our results show that the deep learning analyzing method has the potential to reconstruct the EoR history efficiently from the 21-cm tomography surveys in future.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.31 no.3
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• pp.101-114
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• 2019

In this study, we carry out the numerical simulation to trace the yearly shoreline change of Mang-Bang beach, which is suffering from erosion problem. We obtain the basic equation (One Line Model for shoreline) for the numerical simulation by assuming that the amount of shoreline retreat or advance is balanced by the net influx of longshore and cross-shore sediment into the unit discretized shoreline segment. In doing so, the energy flux model for the longshore sediment transport rate is also evoked. For the case of cross sediment transport, the modified Bailard's model (1981) by Cho and Kim (2019) is utilized. At each time step of the numerical simulation, we adjust a closure depth according to pertinent wave conditions based on the Hallermeier's analytical model (1978) having its roots on the Shield's parameter. Numerical results show that from 2017.4.26 to 2017.10.15 during which swells are prevailing, a shoreline advances due to the sustained supply of cross-shore sediment. It is also shown that a shoreline temporarily retreats due to the erosion by the yearly highest waves sequentially occurring from mid-October to the end of October, and is followed by gradual recovery of shoreline as high waves subdue and swells prevail. It is worth mentioning that great yearly circulation of shoreline completes when a shoreline retreats due to the erosion by the higher waves occurring from mid-March to the end of March. The great yearly circulation of shoreline mentioned above can also be found in the measured locations of shoreline on 2017.4.5, 2017.9.7, 2017.11.7, 2018.3.14. However, numerically simulated amount of shoreline retreat or advance is more significant than the physically measured one, and it should be noted that these discrepancies become more substantial for the case of RUN II where a closure depth is sustained to be as in the most morphology models like the Genesis (Hanson and Kraus, 1989).

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.4
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• pp.254-259
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• 1991

The present study was carried out to investigate the effect of nitrogen(urea) application on the seasonal change in pH content of Bray No.1-P, organic matter, and exchangeable cations along the grassland soil profile and further to provide the fundamental information for optimizing the rate of fertilizer application to grassland. Soil samples were taken 20cm intervals upto 100cm soil depth in spring(May 26), summer(July 27), and autumn (October 18) of 1990. The obtained results are summerized as follow 1. In spring and summer, soil pH at 0-20cm soil depth of 28kg N/10a treatment was lowered by 0.7 and 1.0 in comparison with those the same soil depth of 0 kg N/10a treatment and the tendency in pH decrease during all season at the soil depth below 20cm was in the order of summer>spring>autumn. 2. Although Bray No.1-P content at the soil depth 0-20cm of 28kg N/10a treatment was lowered by 20ppm compared to 0 kg N/10a treatment in summer, there was no great difference in its content between 0kg N/10a and 28kg N/10a treatment at all soil depth in spring and summer. In autumn, its content at soil depth below 20cm of 28kg N/10a treatment was higher than that of in summer. 3. Organic matter content at 0-20cm soil depth of 0 and 28kg N/10a treatment in autumn was slightly lowered and on the whole there was very little change in it by soil depth and nitrogen application. 4. The calcium content of 0 and 28kg N/10a treatment was also slightly lowered by increase in soil depth and Mg and K contents were below 0.4 and 0.2 me/100g during all seasons, respectively. 5. Positive correlations were shown among the $NH_4-N$ content and pH, organic matter, Ca and Mg of 0 kg N/10a treatment, however, there was negative correlation ($r=-0.534^{*}$) between $NO_3-N$ content and pH of 28kg N/10a treatment in summer.

• Journal of Science Education
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• v.36 no.2
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• pp.369-380
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• 2012

The purpose of this study was to investigate middle students' conceptions of buoyancy. The questionnaires composed of 9 items which asked the reasons for situations with buoyancy; recognized of buoyancy, the facts affecting buoyancy(bottom of the Area of the object, the shape of the object, the depth of the object in the water, amount of water, the degree of the object submerged in the water, volume of the object, weigh of the object), the relationship between the amount of replaced fluid and buoyancy. The subjects were 140 students from the Busan Area who answered questionnaires composed of 9 items which asked the reasons for situations with buoyancy. Among the 140, 132 students were selected who answered all of question in the test. The students' answer types were follow: 1. Related to the shape of the submerged object, students answered that buoynacy depended on the bottom dimensions or the surface area of the object. 2. Students confused press, water press and buoyancy, who answered buoyancy was great when the water press was great. 3. Students answered that the weight and the size of the buoyancy of the object was same in the water. 4. Students answered, gravity was smaller in the water. Students recognized the existence of buoyancy but the reason of the answer depend on their experience. Also students answered using the words that water pressure, pressure, force instead of buoyancy. Students didn't understand the factors affecting the buoyancy. Many students responded that buoyancy was changed depend on weight of object, sinking depth, shape and others. It was considered that these responses didn't understand the cause of buoyancy.

• Proceedings of the KSRS Conference
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• v.1
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• pp.34-37
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• 2006

When tsunami waves propagate across open ocean they are steered by Coriolis force and refraction due to gentle gradients in the bathymetry on scales longer than the wavelength. When the wave encounters steep gradients at the edges of continental shelves and at the coast, the wave becomes non-linear and conservation of momentum produces squirts of surface current at the head of submerged canyons and in coastal bays. HF coastal ocean radar is well-conditioned to observe the current bursts at the edge of the continental shelf and give a warning of 40 minutes to 2 hours when the shelf is 50-200km wide. The period of tsunami waves is invariant over changes in bathymetry and is in the range 2-30 minutes. Wavelengths for tsunamis (in 500-3000 m depth) are in the range 8.5 to over 200 km and on a shelf where the depth is about 50 m (as in the Great Barrier Reef) the wavelengths are in the range 2.5 - 30 km. It is shown that the phased array HF ocean surface radar being deployed in the Great Barrier Reef (GBR) and operating in a routine way for mapping surface currents, can resolve surface current squirts from tsunamis in the wave period range 20-30 minutes and in the wavelength range greater than about 6 km. There is a trade-off between resolution of surface current speed and time resolution. If the radar is actively managed with automatic intervention during a tsunami alert period (triggered from the global seismic network) then it is estimated that the time resolution of the GBR radar may be reduced to about 2 minutes, which corresponds to a capability to detect tsunamis at the shelf edge in the period range 5-30 minutes. It is estimated that the lower limit of squirt velocity detection at the shelf edge would correspond to a tsunami with water elevation of less than 5 cm in the open ocean. This means that the GBR HF radar is well-conditioned for use as a monitor of small and medium scale tsunamis, and has the potential to contribute to the understanding of tsunami genesis research.