• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.6 no.1
• /
• pp.43-50
• /
• 1986

A research was performed to examine the applicability of aerobic fixed-biofilm reactors for removal of biodegradable organics in raw waters. Crushed briquette ashes or granite were utilized as media. Experiments were carried out by feeding packed bed reactors with a synthetic raw water prepared by dissolving phenol in tap water with other inorganic nutrients. Results of the research showed that the effluent TBOD concentrations were lower than 6 mg/l when the influent BOD concentrations were kept below 50 mg/l and a detention time of about 2.7 hours was provided. The SBOD concentrations of the treated waters should be less than 5 mg/l since the effluent SS could be removed by conventional water treatment methods such as coagulation and filtration. It was also found that most of the SS in the effluents were humic materials since the effluent SS caused little BOD. This means the biofilm in the reactor was in endogenous respiration phase due to low F/M ratio. According to the results of this study, it is recommended to pretreat any raw water contaminated with biodegradable organics in an aerobic fixed biofilm reactor with a detention time of 2 to 3 hours.

• Journal of Broadcast Engineering
• /
• v.24 no.5
• /
• pp.879-891
• /
• 2019

This paper provides performance evaluations of various channel estimation schemes for Advanced Television Systems Committee (ATSC) 3.0 multiple-input multiple-output (MIMO) system under a fixed reception environment. ATSC 3.0 MIMO system can obtain high spectral efficiency and improved reception performance compared to conventional terrestrial broadcasting systems. The ATSC 3.0 MIMO defines Walsh-Hadamard and null pilot encoding algorithms and the amplitude and phase of MIMO pilots are different from those of single-input single-output pilots. At the receiver, linear and discrete Fourier transform (DFT)-based interpolations can be used for the channel estimation. This paper provides the various combinations of the interpolation schemes for channel estimation in time and frequency dimensions, and then analyzes the performance of the various combinations through the computer simulation. The results of computer simulation show that the combination of the linear interpolation in the time dimension and then DFT-based interpolation in the frequency dimension can obtain the best performance among the considered combinations.

• Journal of Broadcast Engineering
• /
• v.24 no.1
• /
• pp.132-141
• /
• 2019

The necessity of transmitting video data over a narrow-bandwidth exists steadily despite that video service over broadband is common. In this paper, we propose a scalable video coding framework for low-resolution video transmission over a very narrow-bandwidth network by super-resolution of decoded frames of a base layer using a convolutional neural network based super resolution technique to improve the coding efficiency by using it as a prediction for the enhancement layer. In contrast to the conventional scalable high efficiency video coding (SHVC) standard, in which upscaling is performed with a fixed filter, we propose a scalable video coding framework that replaces the existing fixed up-scaling filter by using the trained convolutional neural network for super-resolution. For this, we proposed a neural network structure with skip connection and residual learning technique and trained it according to the application scenario of the video coding framework. For the application scenario where a video whose resolution is $352{\times}288$ and frame rate is 8fps is encoded at 110kbps, the quality of the proposed scalable video coding framework is higher than that of the SHVC framework.

• Journal of Broadcast Engineering
• /
• v.19 no.6
• /
• pp.767-788
• /
• 2014

The worldwide transition from analog to digital broadcasting has now been completed and the need to study next generation standards for Ultra High Definition TV (UHDTV) broadcasting, and broadcasting & communication convergence systems is rapidly growing. In particular, high resolution mobile broadcasting services are needed to satisfy recent consumers. Therefore, the development of highly efficient convergence broadcasting systems that provide fixed/mobile broadcasting through a single channel is needed. In this paper, a service scenario and requirements for providing 4K UHD & HD convergence broadcasting services through a terrestrial single channel are analyzed by employing the latest transmission and A/V codec technologies. Optimized transmission parameters for 6 MHz & 8 MHz terrestrial bandwidths are drawn, and receiving performances are measured under Additive White Gaussian Noise (AWGN) and time-varying multipath channels. From the results, in a 6 MHz bandwidth, the reliable receiving of HD layer data can be achieved when the receiver velocity is maximum 140 Km/h and is not achieved when the velocity is over 140 Km/h due to the limit of bandwidth. When the bandwidth is extended to 8 MHz, the reliable receiving of both 4K UHD and HD layer data is achieved under a very fast fading multipath channel.

• Archives of design research
• /
• v.18 no.1 s.59
• /
• pp.17-26
• /
• 2005

Nowadays, display-contents are developing to an informative environment. that is under the logic of the media operating system. To perceive the media-environments and produce the cultural contents, the cultural designers seek to understand a skin structure from making up for shape. To appreciate operating system in data and database is not only systematization of form and contents of visual contents but also variety contents into multiple-platform and integrative environments. These days, the spectacle exhibition try to express for their surface design between algorithm of data and database. the information is expressing aesthetic which means presents the integrated contents through the play instinct environment to end-user. That was given web or game to participation is developing with the cellular device and ubiquitous computing system. in the linear perspective, the end-user should be immerse more and more hyper-simulation system because of the operating algorithm of database. To do this, human have need to get the information-ability from multi-platform society. In the virtual environment, database offer the experience of an unheard-of event to end-user that prepare the participants the circumstances priority of signifiers. To do that already based on a fixed sensibility endow with narrative of the freshness- experience.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.12 no.3
• /
• pp.175-179
• /
• 1979

One of the major problems in tile activated sludge system has been difficulty in separating the microbial solids from the treated effluent and in returning them to the aeration tank. Another problem has been the digestion of the excess activated sludge. In constrast, it has not been difficult to separate the microbial solids from the treated effluent from the biological fixed-film systems(RBC process, Trickling Filter, FAST process). These systems have also featured less sludge production. Recently, it was proposed to experiment with the RESMAS process in order to eliminate the settling tank and sludge concentration facilities and to reduce the quantity of excess sludge for final disposal. The effluent quality could be predicted by .the concept of the maximum accumulation capacity. However, the hydraulic characteristics of the screen media in the RESMAS reactor were not dynamic. The object of the present study is to evalute the sludge accumulation rate and effluent quality prediction in the REMSMAS process designed in the dynamic hydraulic structure. This process can eliminate the final sedimentation tank and sludge concentration tank needed in the RBC, CMAS, Trickling Filter and FAST processes. Also, the effluent quality is desirable to compare with other processes. It appeared that the value of the sludge holding capacity was higher than those of the RESMAS and FAST processes, and the periods of the critical operating time were proportional to the substrate hydraulic loadings.

• Journal of Korean Neurosurgical Society
• /
• v.29 no.12
• /
• pp.1584-1591
• /
• 2000

Objective : Until now, it has been little known about the biological mechanisms associated with the genesis, growth, and rupture of intracranial aneurysm. This study was performed to investigate and understand a part of these mechanisms. Materials and Methods : Immunohistochemical stains for angiogenesis growth factors(basic fibroblast growth factor (bFGF) and vascular endothelial growth factor(VEGF)) and selected vascular wall matrix proteins(alpha smooth muscle actin(${\alpha}SMA$) and collagen Type IV) were performed in fixed sections from a normal circle of Willis artery which was taken from the autopsy specimen as a control vessel and 17 aneurysmal wall specimens which was taken during surgical clipping of aneurysms. The staining intensity and distribution of immunoreactivity to angiogenesis growth factors and selected wall matrix proteins in control vessel and aneurysmal wall were examined and compared with each other. The difference of staining intensity according to the size of aneurysm was also investigated. Results : There was no immunoreactivity to bFGF and VEGF in the control vessel. bFGF immunoreactivity was exhibited in 15 of 17 aneurysm specimens around smooth muscle cells within the media of aneurysm. VEGF immunoreactivity was also exhibited in all aneurysm specimens in patches or diffusely affecting all layers of the aneurysmal wall. The degrees of intensity of bFGF and VEGF immunoexpression were proportionate roughly to the size of aneurysm. Strong immunoexpression of both factors were noticed in large aneurysm. A regularly arranged and defined band of immunoreactivity of ${\alpha}SMA$ was noticed in the media of the control vessel, whereas diffuse, faint, irregularly arranged ${\alpha}SMA$ was noticed in the aneurysmal wall. A regularly defined band of collagen Type IV immunoreactivity was also noticed in the subendothelium of the control vessel, whereas diffuse disorganized immunoreactivity of collagen Type IV was noticed in the entire wall of the aneurysm. Conclusion : These results indicate substantial evidences of abnormal expression of angiogenesis factors and changes of selected vascular wall matrix proteins in the wall of intracranial aneurysm. The unbalanced changes of angiogenesis factors and vascular wall matrix proteins in the wall of aneurysm may be one of the biological mechanisms for the growth and rupture of aneurysm.

• The Journal of the Korea Contents Association
• /
• v.19 no.9
• /
• pp.535-549
• /
• 2019

The purpose of this study was to examine what kind of images were presented on movie stars in the newspaper. For the purpose, we classified the time period according to the movie industry and media trend, selected representative stars by period, and collected 798 related articles reported in newspapers. As a result of analyzing the reporting trend, domestic and foreign topics, news format, and gender difference in collected movie star articles, it was found that the image of movie stars reproduced in newspaper articles had mostly neutral images that do not represent specific gender. Since the 2000s, news coverage was changed to reproduce various images rather than being fixed to particular images, and the subject of report became more diversified through comparison of domestic and foreign topics. In addition, articles in the form of book review decreased and the interview-type articles increased in number, and in the case of male movie stars, the proportion of articles based on works was high in comparison to female movie stars. This study has significance in that it explored the changes in the process of reproducing star images diachronically from the initial stage of stars to the modern times. And it is hoped that this study will serve as basic data for the follow-up studies on the process of reproducing various images in the multi-media era.

• Journal of Broadcast Engineering
• /
• v.27 no.1
• /
• pp.104-123
• /
• 2022

Style transfer based on neural network provides very high quality results by reflecting the high level structural characteristics of images, and thereby has recently attracted great attention. This paper deals with the problem of resolution limitation due to GPU memory in performing such neural style transfer. We can expect that the gradient operation for style transfer based on partial image, with the aid of the fixed size of receptive field, can produce the same result as the gradient operation using the entire image. Based on this idea, each component of the style transfer loss function is analyzed in this paper to obtain the necessary conditions for partitioning and padding, and to identify, among the information required for gradient calculation, the one that depends on the entire input. By structuring such information for using it as auxiliary constant input for partition-based gradient calculation, this paper develops a recursive algorithm for super high-resolution image style transfer. Since the proposed method performs style transfer by partitioning input image into the size that a GPU can handle, it can perform style transfer without the limit of the input image resolution accompanied by the GPU memory size. With the aid of such super high-resolution support, the proposed method can provide a unique style characteristics of detailed area which can only be appreciated in super high-resolution style transfer.

• Smart Media Journal
• /
• v.13 no.3
• /
• pp.18-26
• /
• 2024

Road surface monitoring is essential for maintaining road environment safety through managing risk factors like rutting and crack detection. Using autonomous driving-based UGVs with high-performance 2D laser sensors enables more precise measurements. However, the increased energy consumption of these sensors is limited by constrained battery capacity. In this paper, we propose a fusion sensor system for efficient surface monitoring with UGVs. The proposed system combines color information from cameras and depth information from line laser sensors to accurately detect surface displacement. Furthermore, a dynamic sampling algorithm is applied to control the scanning frequency of line laser sensors based on the detection status of monitoring targets using camera sensors, reducing unnecessary energy consumption. A power consumption model of the fusion sensor system analyzes its energy efficiency considering various crack distributions and sensor characteristics in different mission environments. Performance analysis demonstrates that setting the power consumption of the line laser sensor to twice that of the saving state when in the active state increases power consumption efficiency by 13.3% compared to fixed sampling under the condition of λ=10, µ=10.