• Journal of Wetlands Research
• /
• v.19 no.4
• /
• pp.375-382
• /
• 2017

In this study, general characteristics of dynamic behavior of stormwater runoff from a small impervious catchment was investigated from a series of simulations for a radial type surface runoff. Based on the simulation results, a better placement strategy for stormwater inlets to improve performance of a structural best management practice (BMP) was suggested. The degree of pollutant first flush from an ideal radial type impervious catchment was simulated using a 1-D diffusion wave equation coupled with a pollutant transport equation. The results showed that the first flush of the chemical oxygen demand was the strongest when the catchment length ranged 30-50m at a bed slope of 0.02. This result suggested that a required degree of the first flush can be intentionally obtained by just changing the locations and numbers of stormwater inlets, and thereby adjusting the catchment length. Particularly, the overall performance of a structural BMP in reducing pollutant load can be improved by placing the stormwater inlets at locations for obtaining a required first flush strength.

• Korean Journal of Environmental Agriculture
• /
• v.15 no.1
• /
• pp.116-127
• /
• 1996

Recent development in Japan on jumbo formulation of pesticides for paddy application by hand throw was reviewed. In addition, the diffusion of liquid formulations in water was examined to establish the research strategy for the jumbo formulation. Research on jumbo formulation in Japan has been focused on gas-generating formulations and self-emulsifiable formulations. Although continuous efforts to minimize the problem of pesticide deposit on the treated site have been made for the gas-generating formulations, much work is still needed to establish a generally acceptable formulation method and to commercialize a herbicide formulation. The self-emulsifiable jumbo formulations have recently been investigated. These formulations could simply be processed and showed relatively high biological efficacy. The emulsifiable concentrate was more diffusible than the suspension concentrate in water. The diffusion of the emulsifiable concentrate was not greatly disturbed by floating obstacles. And the diffusion rate was high when the specific grabity was lower than one.

• Journal of Digital Convergence
• /
• v.11 no.12
• /
• pp.387-392
• /
• 2013

The purpose of this study investigate the main factors of the diffusion of digital contents and consumer's participation behavior, consumption culture and examine the experiential perspective to consumer's information selection behavior. In digital network, the social presence, challenge, self-presentation, arousal and emotional feeling were significant variables to flow experience. Experiential perspectives focused on the search of identity and self-determination were main basic perspective to explain the diffusion of digital contents, consumer participation. This research result applied to media and device strategy to up-coming digital convergence and adapted to product planning and development, user friendly navigation and emotional human-centered service module.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.3
• /
• pp.260-266
• /
• 2018

The concept of customer utility, which affects customer's adoption, is important to understand the process of technology diffusion and substitution regarding multiple generation technology. This research defined the concept of attribute-based customer utility and developed a model for measuring attribute-based customer utility. Based on the literature review and modeling, we provided the definition and a model regarding customer utility and the accuracy of the model is verified through a case study of the semiconductor industry. Customer utility for a multiple generation technology needs to consider changes by generation, or time within the same generation, and is defined as the summation of both technological and economic utilities. In addition, we can model the measurement of customer utility after converting technological and economical attributes into utilities. This research is valuable in understanding not only customer utility as a driver of customer adoption, but also for establishing technological strategy after forecasting diffusion and substitution paths based on customer utility.

• The Journal of the Korea Contents Association
• /
• v.16 no.9
• /
• pp.751-768
• /
• 2016

The success of the journey to the west of tvN's shows the positive prospect of web entertainment. This study highlights how viewers actively select web progrmas and how they diffuse the infomrmation of web programs to explore the possibility of success of web program and the change of viewing environment. This study revealed the attention of viewers affected the diffusion of programs via social media. The highness of the viewer's attention cause the highness of active interaction between users. The production company of web entertaninment has to focus on the high hits strategy. In the view of journalists, they covered on the appearance of the heroin rather than the content of the program. The relationship of viewing type and viral type via SNS is related with the activity of viewers. If viewers participate in viewing they express their opinion on the web entertainment actively.

• Korean Journal of Materials Research
• /
• v.31 no.2
• /
• pp.68-74
• /
• 2021

Zinc-ion Batteris (ZIBs) are recently being considered as energy storage devices due to their high specific capacity and high safety, and the abundance of zinc sources. Especially, ZIBs can overcome the drawbacks of conventional lithium ion batteris (LIBs), such as cost and safety issues. However, in spite of their advantages, the cathode materials under development are required to improve performance of ZIBs, because the capacity and cycling stability of ZIBs are mainly influenced by the cathode materials. To design optimized cathode materials for high performance ZIBs, a novel manganese oxide (MnO2) coated graphite sheet is suggested herein with improved zinc-ion diffusion capability thanks to the uniformly decorated MnO2 on the graphite sheet surface. Especially, to optimize MnO2 on the graphite sheet surface, amounts of percursors are regulated. The optimized MnO2 coated graphite sheet shows a superior zinc-ion diffusion ability and good electrochemical performance, including high specific capacity of 330.8 mAh g-1 at current density of 0.1 A g-1, high-rate performance with 109.4 mAh g-1 at a current density of 2.0 A g-1, and remarkable cycling stability (82.2 % after 200 cycles at a current density of 1.0 A g-1). The excellent electrochemical performance is due to the uniformly decorated MnO2 on the graphite sheet surface, which leads to excellent zinc-ion diffusion ability. Thus, our study can provide a promising strategy for high performance next-generation ZIBs in the near future.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.22 no.2
• /
• pp.143-149
• /
• 2022

The diffusion of OTT service has brought the fundamental changes in the value chain of the existing media industry. OTT service based on the public Internet has increased the number of subscribers by using dominant marketing capability, making the pay TV platform player's ability to connecting users powerless. This study examined the changes in the media market and pay TV industry in the USA due to the diffusion of OTT service and analyzed the changing strategies of media firms. The number subscribers of the expensive pay TV service in the USA has diminished, experiencing cord cutting and cord shaving due the diffusion of OTT. OTT players are changing the media market, showing the dramatic excellence in making original contents and distributing the newly released movies. Examination of the recent merger and acquisition cases of media firms tells that the investment in making original contents has increased in order to have the competitiveness in OTT business. The future media industry will be rapidly reshaped mainly based OTT service and strategic judgement is important to maintain the competitiveness of all media firms in the existing value chain of media industry.

• Korean Journal of Remote Sensing
• /
• v.25 no.1
• /
• pp.21-30
• /
• 2009

The purposes of this paper are to present a selection method of neighboring pixels whose local statistics are similar to the center pixel and combine the selection result with mean curvature diffusion filter to reduce noises in remote sensed imagery. The order of selection of neighboring pixels is critical, especially for finding a pixel belonging to the homogeneous region, since the statistics of the homogeneous region vary according to the selection order. An effective strategy for selecting neighboring pixels, which uses rank-order differences vector obtained by computing the intensity differences between the center pixel and neighboring pixels and arranging them in ascending order, is proposed in this paper. By using region growing method, we divide the elements of the rank-ordered differences vector into two groups, homogeneous rank-ordered differences vector and outlier rank-ordered differences vector. The mean curvature diffusion filter is combined with a line process, which chooses selectively diffusion coefficient of the neighboring pixels belonging into homogeneous rank-ordered differences vector. Experimental results using an aerial image and a TerraSAR-X satellite image showed that the proposed method reduced more efficiently noises than some conventional adaptive filters using all neighboring pixels in updating the center pixel.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.38 no.11
• /
• pp.771-780
• /
• 2001

It is indispensable to use the process and device simulation tool in order to analyze accurately the electrical characteristics of ULSI CMOS devices, in addition to developing and manufacturing those devices. The 3D Monte Carlo (MC) simulation result is not efficient for large-area application because of the lack of simulation particles. In this paper is reported a new efficient simulation strategy for 3D MC ion implantation into large-area application using the 3D MC code of TRICSI(TRansport Ions into Crystal Silicon). The strategy is related to our newly proposed split-trajectory method and ion-splitting method(ion-shadowing approach) for 3D large-area application in order to increase the simulation ions, not to sacrifice the simulation accuracy for defects and implanted ions. In addition to our proposed methods, we have developed the cell based 3D interpolation algorithm to feed the 3D MC simulation result into the device simulator and not to diverge the solution of continuous diffusion equations for diffusion and RTA(rapid thermal annealing) after ion implantation. We found that our proposed simulation strategy is very computationally efficient. The increased number of simulation ions is about more than 10 times and the increase of simulation time is not twice compared to the split-trajectory method only.

• Journal of Mechanical Science and Technology
• /
• v.20 no.9
• /
• pp.1436-1448
• /
• 2006

This paper describes the effects of injection rate shaping on the combustion, fuel consumption and emission of $NO_x$ and soot of a medium duty diesel engine. The focus is on the influence of four different injection rate shapes, square type 1, square type 2, boot and ramp, with a variation of maximum injection pressure and start of injection (SOI). The experiments were carried out on a 1 liter single cylinder research diesel engine equipped with an amplifier-piston common rail injection system, allowing the adjustment of the injection pressure during the injection event and thus injection rate as desired. Two strategies to maintain the injected fuel mass constant were followed. One where rate shaping is applied at constant injection duration with different peak injection pressure and one strategy where rate shaping is applied at a constant peak injection pressure, but with variable injection duration. Injection rate shaping was found to have a large effect on the premixed and diffusion combustion, a significant influence on $NO_x$ emissions and depending on the followed strategy, moderate or no influence on soot emission. Only small effects on indicated fuel consumption were found.