• Journal of Korean Society on Water Environment
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• v.22 no.6
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• pp.1022-1030
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• 2006

Activated sludge reactors maintaining an MLSS of 3,000 mg/L and packed Bio Contact Media (BCM fixed beds) was studied in lab-scale to determine the optimal packing ratio and an HRT of aerobic reactor in terms of organic removal, nitrification, denitrification efficiencies. At all HRTs of 3 hr, 5 hr, 7 hr respectively, reactors without BCM, control reactors, had the lowest TCODcr removal efficiency about 74.6%, and reactors with the BCM packing ratios of 10%, 15%, 20% had a greater TCODcr removal efficiency above 81.4%. As HRT decreased, the TCODcr removal efficiency decreased also in all reactors. However, a better utilization of TCODcr even at a higher organic loading was observed in reactors with BCM. The nitrification efficiency at all reactors was greater than 94%, and reactor with 20% packing of BCM had the highest nitrification efficiency at 97.9% while the TKN loading increased at $0.085mgTKN/m^3{\ast}day$ as HRT decreased, In terms of denitrification efficiency, the reactor without BCM ranged from 11.6% to 13.7%, and the reactors with BCM ranged from 28.3% to 63.4% which suggests that the more BCM is packed in the reactors, the higher the denitrification efficiency is achieved. Two parallel $A^2/O$ systems maintaining an MLSS of 3,000 mg/L were operated to investigate the effect of BCM packing ratio of 20% on organic removal, nitrification, denitrification efficiencies. Packing with BCM in system of aerobic reactor affected the SCODcr removal efficiency that increased from 73% to 78%. The nitrification efficiency for both systems with or without BCM was greater than 95%. The denitrification efficiency of systems with BCM and without BCM was 85.8% and 81.8%, respectively which appears that the denitrification efficiency was increased slightly by packing BCM. Compared denitrification efficiency in $A^2/O$ system to previous experimental study with activated sludge reactors operates with the same HRT $A^2/O$ system showed only 29% greater denitrification efficiency. It suggests that $A^2/O$ system with BCM can achieve a similar level of denitrification efficiency when the HRT of anoxic reactor is decreased to some extent.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.12
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• pp.1695-1701
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• 2002

The purposes of this study were to optimize the in vitro maturation (IVM) and culture (IVC) systems of rabbit oocytes. Cytoskeletal structures in the germinal vesicle stage (GV) and during IVM are also investigated. Ovaries were transported from local slaughterhouses and the cumulus-oocyte complexes (COCs) were collected from ovarian follicles (${\geq}1mm$). COCs were randomly allocated to TCM199-based medium ($T_1$, TCM-199) supplemented with $NaHCO_3$, glucose, sodium pyruvate and FSH ($T_2$), $T_2+E_2+LH$ ($T_3$), $T_3+FBS$ ($T_4$), or $T_1+E_2+LH+FSH+FBS$ ($T_5$), for IVM. In Experiment 1, COCs were retrieved from the follicles and 51 GV oocytes were fixed in the fixative (MTSB-XF) for nuclear and cytoplasmic examinations. In Experiment 2, progressive changes of both the nucleus and the cytoskeleton were examined at 0, 6, 16, and 20 h after IVM. Maturation (MR) and developmental rates were assessed in Experiment 3. Cytoplasmic microtubules (MT) were clearly observed in rabbit GV oocytes. To our knowledge, this is the first report that describes the appearance of MT structures in the GV stage ooplasm. Tremendous variations in cytoskeletal alterations were observed among treatments with the exception of the vitelline ring (VR), which is constantly visible and unchanged during maturation. Germinal vesicle breakdown (GVBD) does not occur at 6 h after onset of maturation culture. When the oocytes for IVM were collected within 2 h, results from Experiment 3 showed that rates of nuclear maturation were 42, 8, 42, 37 and 65% at 16 h of IVM for $T_1$ through $T_5$, respectively, in which $T_1$, $T_4$ and $T_5$ had significantly greater MR than those in other groups (p<0.05). Morula/blastocyst development after parthenogenetic activation ranged from 20 to 63% with significantly greater rates in $T_3$, $T_4$ and $T_5$ (p<0.05). These results suggested that oocytes recovered from slaughterhouse ovaries can be matured and parthenogenetically activated in vitro, but the MR remained low in this study. Addition of $E_2$ and LH in the medium may be beneficial for cytoplasmic maturation, but FBS exerts a nega- tive role in the subsequent development of parthenogenetic embryos when energy substrates are provided in the IVC media. More studies are required for improving the MR and further development of the GV stage rabbit oocytes.

• Journal of Broadcast Engineering
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• v.25 no.4
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• pp.518-527
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• 2020

360 VR technology is used not only in movies, but also in performing arts such as music, theater, dance, and so on due to the characteristics of immersion and presence. The technology allows the audience can be perceived a feel of participation in a story. This study is conducted an analysis of the techniques of 360 video shooting in order to find the answers of the following questionaries: how to make viewers enhance to a better understanding of a space, how to make the viewer feel comfortable ceding control of the experience, how to generate greater empathy with a 360 video. Thirty cases were analysed 360-degree videos of live performances performed on stage among 360-degree images of music performance content shared on Youtube from 2015 to 2020. The result shows that live performances are performed with the audience, so the stage shape and the layout of the audience seats are preferred to the characteristics of the performance. It was also shown that directing using a 360 VR camera was also greatly affected by the stage and audience placement. The stage is manly classified into three types, and the camera layout and characteristics mainly used are organized according to the number of 360 VR cameras, whether fixed or mobile cameras are used.

• Journal of Broadcast Engineering
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• v.13 no.4
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• pp.452-462
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• 2008

In this paper, we address issues associated with the real-time implementation of the MPEG-1/2 Layer-II (or MUSICAM) and MPEG-4 ER-BSAC decoders for Digital Multimedia Broadcasting (DMB) on TMS320C64x+ that is a fixed-point DSP processor with a clock speed of 330 MHz. To achieve the real-time requirement, they should be optimized in different steps as follows. First of all, a C-code level optimization is performed by sharing the memory, adjusting data types, and unrolling loops. Next, an algorithm level optimization is carried out such as the reconfiguration of bitstream reading, the modification of synthesis filtering, and the rearrangement of the window coefficients for synthesis filtering. In addition, the C-code of a synthesis filtering module of the MPEG-1/2 Layer-II decoder is rewritten by using the linear assembly programming technique. This is because the synthesis filtering module requires the most processing time among all processing modules of the decoder. In order to show how the real-time implementation works, we obtain the percentage of the processing time for decoding and calculate a RMS value between the decoded audio signals by the reference MPEG decoder and its DSP version implemented in this paper. As a result, it is shown that the percentages of the processing time for the MPEG-1/2 Layer-II and MPEG-4 ER-BSAC decoders occupy less than 3% and 11% of the DSP clock cycles, respectively, and the RMS values of the MPEG-1/2 Layer-II and MPEG-4 ER-BSAC decoders implemented in this paper all satisfy the criterion of -77.01 dB which is defined by the MPEG standards.

• Journal of Broadcast Engineering
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• v.25 no.5
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• pp.665-671
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• 2020

MPEG-I is actively working on standardization on the coding of immersive video which provides up to 6 degree of freedom (6DoF) in terms of viewpoint. 3DoF+ video, which provides motion parallax to omnidirectional view of 360 video, renders a view at any desired viewpoint using multiple view videos acquisitioned in a limited 3D space covered with upper body motion at a fixed position. The MPEG-I visual group is developing a test model called TMIV (Test Model for Immersive Video) in the process of development of the standard for 3DoF+ video coding. In the TMIV, the redundancy between a set of input view videos is removed, and several atlases are generated by packing patches including the remaining texture and depth regions into frames as compact as possible, and coded. This paper presents an atlas generation method that removes small-sized blocks in the atlas for more efficient 3DoF+ video coding. The proposed method shows a performance improvement of BD-rate bit savings of 0.7% and 1.4%, respectively, in natural and graphic sequences compared to TMIV.

• Journal of Energy Engineering
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• v.25 no.3
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• pp.104-113
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• 2016

This study analyzes correlation between methane gas production and injection of food waste water to motivate to expand renewable energy as a way of GHG (Green House Gas) mitigation to achieve the national GHG target proposed for the climate agreement in Paris last year. Pretreatment of food waste water was processed with pH 6 at $35^{\circ}C$ and used the fixed-bed upflow type reactor with the porous media. As a result of operation of pilot-scaled bioreactor with food waste water, the methane gas production was 6 times higher than the methane gas production of control group with rain water. The average production of methane was $56{\ell}/day/m^3$ which is possible to produce $20m^3$ of methane in $1m^3$ of landfill. As a way of energy source, when it is applied to the landfill over $250,000m^3$, it is also able to achieve financial feasibility along with GHG reduction effect. GHG reductions of $250,000m^3$ scale landfill were assessed by registered CDM project and the annual amount of reductions was 40,000~50,000 $tCO_2e$.

• Analytical Science and Technology
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• v.16 no.5
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• pp.349-357
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• 2003

The universality of low molecular weight metabolites (i.e. amino acids, steroid hormones) allows rapid and straightforward investigation of biochemistry of genetically un-characterized species. Thus in vivo metabolic profiling of amino acid in combination with multivariate data analysis (metabolomics) offers great potential in comparative biology. In this paper, amino acid profiles in biological fluid (media) were studied by using HPLC/FLD. HPLC procedure for amino acids require the formation of derivatives due to the low absorption of the free compounds. o-Phthalaldehyde (OPA) used in association with a thiol, such as 3-mercaptopropionic acid (3-MPA), is one of the most popular and sensitive reagents, which yield quickly fluorescent iso-indoles at room temperature. To improve unstability of OPA/3-MPA derivatization, we optimized injector programs for fixed injection times. Linear regressions for the standard curves were linear in the range 0.5 - 100.0 ppb, giving correlation coefficents above 0.99. The detection limit were 1.70 pmol(GLU) - 23.81 pmol(SER). It is practically useful when the amount of sample is very low on single cells.

• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.474-486
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• 2010

In this paper, we propose a new method for detection moving object contour using spatial and temporal edge. In general, contour pixels of the moving object are likely present around pixels with high gradient value along the time axis and the spatial axis. Therefore, we can detect the contour of the moving objects by finding pixels which have high gradient value in the time axis and spatial axis. In this paper, we introduce a new computation method, termed as temporal edge, to compute an gradient value along the time axis for any pixel on an image. The temporal edge can be computed using two input gray images at time t and t-2 using the Sobel operator. Temporal edge is utilized to detect a candidate region of the moving object contour and then the detected candidate region is used to extract spatial edge information. The final contour of the moving object is detected using the combination of these two edge information, which are temporal edge and spatial edge, and then the post processing such as a morphological operation and a background edge removing procedure are applied to remove noise regions. The complexity of the proposed method is very low because it dose not use any background scene and high complex operation, therefore it can be applied to real-time applications. Experimental results show that the proposed method outperforms the conventional contour extraction methods in term of processing effort and a ghost effect which is occurred in the case of entropy method.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.276-285
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• 2006

When polluted stream water was treated with biological aerated filter(BAF) in pilot plant, all operation with 90, 60, 45 and 30 min of EBCT at fixed $0.1m^3air/m^2min$ of aeration showed 80% or higher treatment efficiency of particle materials(SS, turbidity and Chl.-a) and 85% or higher efficiency of ammonia nitrogen removal. It was thought that, in case of BOD, biological stability may sufficiently be assured with BAF because grade III or IV inflow water was changed to grade I for outflow water. In case of $COD_{Mn}$, about 60% of removal efficiency was found. When the mechanism of the result was investigated, about 30% of COD materials was produced by algae clogged in the reactor. There was almost no biological decomposition because specific substrate utilization rate of algogenic organic materials were $0.0245mg{\cdot}COD_{Mn}/mg{\cdot}VSS{\cdot}day$, thus partial backwashing(washing the media in 1 m upper of the reactor once a day) was required. It is thought that elevation of removal rate about 10% of $COD_{Mn}$ and 5.5% of $BOD_5$ could be obtained with partial backwashing resulting in assurance of biologically more stable raw water and that saving backwashing water may be significant.

• The Transactions of the Korea Information Processing Society
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• v.5 no.12
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• pp.3047-3062
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• 1998

This paper deseribes the desihn and the implementation of the Realtime Transport Protocol(RTP)/ Rdaltime Control Protocol(RTCP) (RFC 1889,1890) that is used to transmit the audio/video data to any destination and to feedback the Quality of Service (QoS) information of the received media data to the sender, in the teleconferencing systems proposed by ITU-T. These protocols are implemented with multi thead technique and run on top of UDP/IP-Multicast through the socket interface as the underlying protocol. The upper layer is impelmented such that in can be accessed by the H245 comference control protocol. The RTP packetizes the digitized audio/video data from the encoder info a fixed format, and multieast to the participants. The RTCP monitors RTP packets and extracts the QoS values from it such as round-trip delay, jiter and packet loss to form RTCP packets and non periokically sends them to the sender site. In this Paper, we also descritx the study of measurement and analysis for QoS factors that observed on performing teleconferencing system over Internet. The results from this experiment is indicate that RTT and Jitter value are acceptable even entwork load is high. However, it appears that packet loss rate is high in daytime and most losses periods have length one or two.