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Evaluation of the Feasibility of Eliminating Non-point Source Pollution Using Waste Sewage Sludge Bio-blocks (하수슬러지를 이용한 Bio-block의 비점오염물질 제거 가능성 평가)

  • Han, Sang Moo;Kim, Do Hyeong;Jeong, Byung Gon
    • Journal of Korean Society on Water Environment
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    • v.37 no.5
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    • pp.363-368
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    • 2021
  • On the assessment results of the non-point source pollutant removability of bio-block using waste sewage sludge, at the reactor's initial operation stage, the removal efficiency of COD was slightly unstable. However, after the reactor was stabilized, the COD removal efficiency was higher in the reactor filled with bio-blocks compared to the reactor filled with broken stones. In terms of nitrogen and phosphorus, their removal efficiency was unstable at the initial stage of the reactor operation. This phenomenon was investigated through the bio-block elution experiments. Results indicated that nitrogen and phosphorus were eluted from the bio-blocks affecting their removal at the initial operation. Furthermore, based on elution tests conducted after the dry ashing of the waste sewage sludge, part of the nitrogen and phosphorus was eluted similar to the bio-block elution test results, although considerable amounts of nitrogen and phosphorus were reduced compared to the sludge cake. Prior to the use of the waste sewage sludge bio-blocks as a filter medium to remove non-point source pollutants, a stabilization period of 10 days was required. After the stabilization process, results showed similar characteristics as general aggregates. Moreover, to use the bio-block as a filter medium for the non-point pollutant removal, the filling ratio of 75% was the most suitable as it resulted in the highest nitrogen removal efficiency after the stabilization. The results of this study suggested that waste sewage sludge can be suitably recycled as a mixed raw material for the bio-blocks, with satisfactory application as a filter medium in artificial wetlands, stormwater runoff problems, stream water pollutants to eliminate non-point source pollutants.

Fundamental Study on the Wastewater Reuses for Agriculture (하수처리수의 농업용수 재이용에 관한 기초 연구)

  • Kang, Moon-Seong;Park, Seung-Woo;Kim, Sang-Min
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2002.10a
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    • pp.393-396
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    • 2002
  • The objectives of the paper are to develop the infra-technologies for reclaiming the effluents from wastewater treatment plants and reusing for agriculture water. The Suwon wastewater treatment plant has been selected for wastewater reuse tests and the water quality and treatment efficiencies are investigated. Three levels of wastewater treatments that are the effluent from the plant, sand filtering, and ultra-violet treatment are applied in the pilot system. The randomized block method was applied to wastewater application to paddy rice with five treatments, three blocks, and two replica. The control was the plots with groundwater irrigation, the other treatments are to use polluted stream flow by pumping, in addition to three wastewater treatments. The block test plots and field plots have been monitored for the water quality, soil pollution, and health hazards during the crop stages.

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ATM Interface Technologies for an ATM Switching System

  • Park, Hong-Shik;Kwon, Yool;Kim, Young-Sup;Kang, Seok-Youl
    • ETRI Journal
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    • v.18 no.4
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    • pp.229-244
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    • 1997
  • Realization of the economical, reliable, and efficient ATM interface block becomes an important key to development of the ATM switching system when we consider new issues raised recently. In this paper, we summarize requirements for the ATM interface block and present the UNI (User Network Interface)/NNI (Network Node Interface) architecture to meet these requirements. We also evaluate the performance of the multiplexer adopting the various multiplexing schemes and service disciplines. For ATM UNI/NNI interface technologies, we have developed a new policing device using the priority encoding scheme. It can reduce the decision time for policing significantly. We have also designed a new spacer that can space out the clumped cell stream almost perfectly. This algorithm guarantees more than 99 % conformance to the negotiated peak cell rate. Finally, we propose the interface architecture for accommodation of the ABR (Available Bit Rate) transfer capability. The proposed structure that performs virtual source and virtual destination functions as well as a switch algorithm can efficiently accommodate the ABR service.

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Equal Gain Block Decomposition Methods for Multiuser MIMO Networks

  • Hwang, Insoo;Kang, Inseok;Hwang, Intae;You, Cheolwoo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.3
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    • pp.1156-1173
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    • 2021
  • In this paper, we propose a new joint precoder and postcoder design strategy to support multiple streams per user in multiuser multiple-input multiple-output (MIMO) systems. We propose two step precoding strategies using equal channel gain decomposition and block diagonalization at the transmitter. With the proposed precoder, the multiuser MIMO channel can be decomposed into multiple parallel channels with equal channel gain per user. After applying receive postcoder which is generated and sent by the transmitter, we can use ML based decoder per stream to achieve full receive diversity. Achievable sum rate bound and diversity performance of the proposed algorithm are presented with feedback signaling design and quantitative complexity analysis. Simulation results show that the proposed algorithm asymptotically approaches to the sum rate capacity of the MIMO broadcast channel while maintaining full diversity order.

Frequency Planning and Interference Rejection with Co-Channel Dual-Polarization Technique in B-WLL Applications (코채널 이중편파 기술을 적용한 B-WLL 의 주파수 배치 및 채널간섭 제거기에 대한 연구)

  • 이재원;서경환;정한욱
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.821-824
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    • 1999
  • In this article, as a way of pursuing high spectral efficiency and flexible cell planning, co-channel dual-polarization techniques are suggested for B-WLL applications. It provides a double down stream capacity compared with conventional scheme and also makes some flexibility in cell planning. In order to implement co-channel B-WLL system, some frequency plans, interference cancellation methods, and system block diagrams are presented here.

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On a Multiple-cycle Binary Sequence Genrator Based on S-box (S-box 형태의 다 수열 발생기에 관한 연구)

  • Lee, Hun-Jae
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.5
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    • pp.1474-1481
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    • 2000
  • The number of keystream cycle sequences has been proposed as a characteristic of binary sequence generator for cryptographic application, but in general the most of binary sequence generators have a single cycle. On the other hand, S-box has been used to block cipher for a highly nonlinear element and then we apply it to the stream cipher with a high crypto-degree. In this paper, we propose a multiple-cycle binary sequence generator based on S-box which has a high nonlinearity containing SAC property and analyze its period, linear complexity, randomness and the number of keystream cycle sequences.

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Geology and Landscape of Mt. Mudeung Province Park, Korea (무등산 도립공원의 지질과 경관)

  • Ahn, Kun-Sang
    • The Journal of the Petrological Society of Korea
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    • v.19 no.2
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    • pp.109-121
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    • 2010
  • Mt. Mudeung is located in Gwangju city, Damyang-Gun, Hwasun-Gun and its round form give us the mood of soft and rich. Its location is $126^{\circ}06'-127^{\circ}01'E$ and $35^{\circ}06'-35^{\circ}10'N$ and its highest peak is Cheonwang-bong with the height of 1,187 m. The Gwangju city is located in the West of Mt. Mudeng and the mountain range with a small basin in its East. The pavilion such as the Soswaewon, Songganjeong, Sigyongjeong are distributed along the stream in the north of Mt. Mudeung. The mountain is formed from the volcanic activity, Gwangju cauldron during the Cretaceous. The top part of Mt. Mudeung is composed of dark gray quartz-andesite and its K-Ar whole rock age is $48.1{\pm}1.7Ma$. The composition of the north area, where the Wonhyosa temple is located, is micrographic granite, whereas the composition of south area is rhyolite mainly. The main ridge of Mt. Mudeung runs from North, starting from the Bukbong, to south, passing Cheonwangbong, Jangbuljae and ending Anyangsan. Geologic feature of the mountain includes volcanic landform, mountaineous landform, and stream landform. The Seosukdae, Ipseokdae, Gyubongam, which are main ridges and formed from volcanic activity, are composed of mainly columnar joint. Saeinbong and Majipbong in the south-west are composed of mainly cliff and dome. The typical erosion landform of the mountain has three different types of the weathering-cave, each of which reflect the property of the original rock. Four different area of wide block stream, they makes the geological feature of spring-water, though its scale is small compared to that of water fall.

Application of In-situ Produced Cosmogonic $^{10}$ Be and $^{26}$ Al for Estimating Erosion Rate and Exposure Age of Tor and Block Stream Detritus: Case Study from Mt. Maneo, South Korea (우주기원 방사성 핵종을 이용한 만어산 암설지형의 침식률 및 노출연대 측정)

  • Yeong Bae Seong;Jong Wook Kim
    • Journal of the Korean Geographical Society
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    • v.38 no.3
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    • pp.389-399
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    • 2003
  • CRN (Cosmogenic radionuclide) methodology has been a versatile tool applicable to a wide range of geomorphology. This study was underiaken to ascertain the rate of erosion and exposure age of mountain-top detritus (tors and block streams) on Mt. Maneo by employing the concentrations of in-situ produced cosmogenic $^{10}$ Be and $^{26}$ Al from bedrock surfaces that are exposed to cosmic rays. The results suggest that tors on the summit were positioned here during the glacial period but no later than 65ka and block streams have been stabilized also since the last glacial period but no later than 38ka. The tors on the summit have been eroded at a slower rate (9m/Ma) than blocks on the hillslope (15m/Ma) since the initial abrupt exposure of each landform to cosmic rays, suggesting that there is a slight difference in the rate of erosion between the summit and the hillslope, and that the local relief between the two areas has been increased. When the $^{26}$ Al/$^{10}$ Be-$^{10}$ Be concentrations from samples are plotted in Lal's steady-state erosion island, one sample (from a for) has complex exposure histories, which can be explained by the occurrence of multiple chipping event of 5cm to 60cm in length on the surface of the rock.

A study on landforms in Gosung, Gangwon province (강원도 고성 일대의 지형 경관에 대한 연구)

  • Kim, Jong Yeon
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.3
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    • pp.65-81
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    • 2011
  • The landforms based on granite and basalt in Gosung, Gangwon province were analysed. Some part of this area experienced volcanic activities while most of the area was experiencing erosion of weathered mantle(saprolites) of mesoic granites during cenozoic period. Two different lithologies affect the mode of landscape evolution. The basalt covers the mountain tops as a 'cap rock' with flat surfaces. It shows relatively fresh rock surface with cliff or steep slops at the boundary with weathered granite. The blocks detached from the cliff accumulated at the foot of the cliff(talus) or moved and filled the valley(block streams). These debris slopes cover the deeply weathered granites. In the case of Oeum Mt. and Duibaekjae, the number of point of origin of the basalt flow is not clear. The orientation of blocks from block stream coincides with slope aspects and it can be assumed that the bolcks were moved by solifluction. The landscape change of the block streams are dominated by removal of weathered material from beneath of the valley rather than removal of bedrock blocks themselves.

Performance of 3D HDTV Transmission with Block LDPC Codes (블록 LDPC 부호를 사용한 3D HDTV 전송 성능개선 방안 연구)

  • Kim, Min-Ki;Kim, Dong Ho
    • Journal of Satellite, Information and Communications
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    • v.8 no.4
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    • pp.21-25
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    • 2013
  • The dual-stream based stereoscopic 3D HDTV broadcasting service was launched recently. Although the dual-stream based HDTV service has been successfully provided, the 3D HDTV broadcasting system requires more bandwidth efficient transmission schemes because it should convey both left and right HD resolution images simultaneously in the finite 6MHz bandwidth. In this paper, we consider more advanced ATSC transmission schemes that use higher modulation such as 16-QAM and concatenated RS code and block LDPC codes. Compared with conventional ATSC system and the modified ATSC system in [2], the proposed system has about 2.97dB and 1.12dB SNR gain at the payload data rate of 19.44Mbps compared with the existing ATSC system and the modified ATSC system [2]. Also, the proposed scheme requires only 1.05dB power increase for the 3D HDTV service, which is reasonable SNR increase value and applicable to the advanced 3D high definition broadcasting realization in limited 6MHz bandwidth.