• Journal of Environmental Health Sciences
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• v.46 no.3
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• pp.256-266
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• 2020

Objectives: The concentrations and distribution characteristics of volatile organic compounds (VOCs) in an industrial complex and surrouding affected residential areas were investigated in an effort to support the efficient management of VOCs. Methods: The atmospheric concentrations of VOCs were analyzed at sites around the Sihwa-Banwol complex located in the cities of Siheung and Ansan and in the surrounding affected residential areas. The appearance of VOCs and the characteristics of their temporal and spatial distribution were evaluated. Results: The total VOC concentrations in the industrial complex were detected at 1.9-2.3 times higher than in the affected areas, but the daily VOCs distributions showed similar patterns in both sites. In particular, it was confirmed that the composition ratio of the VOCs and concentration fluctuations over time in the affected areas are similar to those in the adjacent industrial complex. VOC levels in the affected areas were higher than in residential areas in cities without an industrial complex. Conclusions: VOCs in residential areas near an industrial complex were highly distributed due to the influence of continuous pollutant emissions from the industrial complex. Therefore, the management of VOCs in the atmosphere of the affected area is important for identifying and managing the sources of VOCs detected in high concentrations in the industrial complex.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.371-377
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• 2009

In this study, simultaneous nitrification and denitrification (SND) from synthetic wastewater were performed to evaluate dissolved oxygen(DO) effects on chemical oxygen demand(COD) and nitrogen removal in a single membarne bio-reactor(MBR). DO levels in MBR at Run 1, 2, and 3 were 1.9~2.2, 1.3~1.6, and 0.7~1.0 mg/L, respectively. Experimental results indicated that DO had an important factor to affect COD and total nitrogen(TN) removal. SND were able to be accomplished in the continuous-aeration MBR by controlling ambient DO concentration. It is postulated that, because of the oxygen diffusion limitation, an anoxic micro-zone was formed inside the flocs where the denitrification might occur. From the results of this study, 96% of COD could be removed at DO of 0.7mg/L. At run 2 72.92% of nitrogen was removed by the mechanisms of SND (7.75mg-TN/L in effluent). In this study, SND was successfully occurred in a MBR due to high MLSS that could help to form anoxic zone inside microbial floc at bulk DO concentrations of 1.3~1.6mg/L.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.375-384
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• 2014

Kenaf (Hibiscus cannabinus L.) was recognized as a potential source of forage. But the domestic cultivation techniques are not set standards yet. So we tested the basic culture techniques during 2012~2013 for getting a high yield and good grade forage production system. The best seeding method for mechanized planting (corn planter used) was hill seeding with $20{\times}20cm$ seeding distance. When we treated hill seeding with $20{\times}20cm$, the yield what we could get was 13,641 kg/10a and it was 32% more than that of conventional practice hill seeding with $20{\times}30cm$ seeding distance. The proper seeding date for getting high yield was May 1. In May 1, the yield per 10a was reached 13,423 kg, and it was 30% more than that of seeding at May 30. More over the crude protein content which was important factor for determinating forage nutritive value was 12.7% and it was higher 1.8% (relatively 16.5% high) than that of May 30 seeding. The most effective herbicide for kenaf was Fluazipof-p-butyl. It's herbicidal rate was 97% and phyto-toxicity was less than 5%. Regional adaptability for Jeollabuk-Do including Imsil Gun, Kochang Gun and Sunchang Gun were identified that the stable cultivation were possible in these area with average yield 12,400 kg/10a and it was about 1.7 times as compared to corn harvest.

• The Korean Journal of Mycology
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• v.40 no.3
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• pp.145-151
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• 2012

Two strains Pleurotus eryngii KNR2312 and A8B10 (Na) which have good traits in cap quality and speedy growing were selected to breed a new strain carrying the two traits. KNR2312-2636-$10{\times}18$ (Ga) with 45.2 cap lightness and 6.5 quality was breeded by a consecutive inbreeding between KNR2312-derived monokaryons. $Ga5{\times}Na5$ came from outcrossing between Ga and Na was backcrossed with KNR2312-derived monokaryons twice to improve quality in cap color and shape. Therethrough Ga5NaKNR2312-47KNR2312-$12{\times}38$ carrying lightness of 49.5, quality of 7.3 and weight of 95.1 g was selected. The selected strain possesses good quality and dark color of cap. Especially its edge is 24 mm thick, therefore it is not likely damaged during processing and distribution.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.552-553
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• 2006

The present study investigates the behavior of the sintering and hardness of stainless steel samples reinforced with NbC and TaC. Matrixes of pure stainless steel were compacted with addition of up to 3% wt NbC or TaC in a cylindrical die of steel $(\phi\;=\;5,0\;mm)$ at 700 MPa and sintered in an electrical resistance furnace under argon atmosphere. The sintered samples were characterized by density and hardness measurement, optical microscopy and scanning electron microscopy (SEM). The preliminary results show that the size and distribution of carbides influence in the sintering and hardness of the sintered samples.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2019.11a
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• pp.259-260
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• 2019

MPEG-I Visual group is actively working on enhancing immersive experiences with up to six degree of freedom (6DoF). In virtual space of 3DoF+, which is defined as an extension of 360 video with limited changes of the view position in a sitting position, looking at the scene from another viewpoint (another position in space) requires rendering additional viewpoints using multiple videos taken at the different locations at the same time. In the MPEG-I Visual workgroup, methods of efficient coding and transmission of 3DoF+ video are being studied, and they released Test Model for Immersive Media (TMIV) recently. This paper presents the enhanced clustering method which can pack the patches into atlas efficiently in TMIV. The experimental results show that the proposed method achieves significant BD-rate reduction in terms of various end-to-end evaluation methods.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.141-144
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• 2011

최근 무선통신의 발전과 스마트 폰 사용자의 급격한 증가로 인하여 멀티미디어 콘텐츠에 대한 사용이 증가되면서 트래픽 량과 네트워크 속도 증가에 대한 요구가 급속히 증대되고 있다. 이를 위해 LTE, LTE-Advanced, Mobile WiMAX 등 차세대 이동통신 플랫폼 및 연관 기술들이 많이 제안되고 있다. 이에 따라 차세대 이동 통신 프로토콜 개발 단계부터 안정화 단계까지 프로토콜 검증 및 분석을 위한 프로토콜 분석기가 필요하게 되었다. 본 논문에서는 LTE-Advanced 망에서 L3 프로토콜들을 분석할 수 있는 분석기를 제안한다. 제안하는 분석기는 연동 메시지를 XML 메타데이터로 기술하여 분석 시 활용하며, ASN.1 인코딩된 연동 메시지나 바이너리 인코딩된 메시지를 디코딩하여 분석할 수 있는 기법을 적용하였다. 자체 설계된 LTE-Advanced 망과의 연동 테스트를 통해 본 시스템을 검증하였다.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.214-217
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• 2011

When paprika is cultivated during summer season, thrips starts to occur in the early growing season and reaches its peak in late June. In the treatment using Orius laevigatus and Neoseiulus cucumeris, natural enemies to thrips, thrips density was 87.6/trap and 51.3/trap on June 23. After Orius laevigatus and Neoseiulus cucumeris were treated twice on June 24 and July 23, the number decreased considerably. On August 23, it was 36.9/trap and 40.3/trap and from the mid August to early September thrips density remained low. Effect of Orius laevigatus and Neoseiulus cucumeris on suppression of thrips density was 35.7% and 44.6% on July 22, however, the number went up to 88.8% and 80.5% on September 3.

• Journal of Preventive Medicine and Public Health
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• v.23 no.1 s.29
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• pp.106-116
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• 1990

This study was conducted to investigate of water qualities in the upper and middle reaches of the Han River. For this purpose, water was sampled at Kwangjin and 1st Han-River Bridges of the Han River in Seoul and analysed from August, 1988 to September, 1989. The results are summarized as follows : 1. Water quality at 1st Han-River Bridge was more polluted than that at Kwangjin Bridge. 2. Except biological oxygen demand (BOD), turbidity, suspended solid (SS), dissolved oxygen (DO), DO saturation (DOS), ammonia nitrogen ($NH_3-N$), nitrite nitrogen ($NO_2-N$) and chloride ion ($Cl^-$) at Kwangjin and 1st Han-River Bridges were lower as compared with the previous data before redevelopment of the Han River. 3. SS, DO and pH at Kwangjin and 1st Han-River Bridges could be classified to the 1st grade in environmental water quality standard. DOS at Kwangjin Bridge was over 100% and that at 1st Han-River Bridge was below 100% in the Han River. BOD at Kwangjin Bridge could be classified to End grade and that at 1st Han-River Bridge to 3rd grade in environmental water quality standard. 4. The higher the level of water was, the lower the levels of turbidity and SS, and $NH_3-N$ was decreased with increasing water level at 1st Han-River Bridge. DO was decreased as water temperature went up but DOS was increased with DO. BOD was positively correlated with nitrite-nitrogens. 5. Turbidity and SS at the both sites and Chloride ion ($Cl^-$) at Kwangjin Bridge were increased in July and August. And DO at the both sites and $NH_3-N$ at 1st Han-River Bridge were decreased in at July and August.

• Korean Journal of Materials Research
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• v.5 no.8
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• pp.945-952
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• 1995

The effect of Zr content on the thermal stability of mechanically alloyed Al-8wt.% (Ti+Zr) alloys was investigated. As the Zr to Ti addition ratio increased the decrease of hardness due to the long time exposure at high temperature reduced so that the thermal stability of the alloy was improved. From the TEM work it was found that the coarsening of precipitates was responsible for the decrease of hardness and the coarsening of precipitates could be suppressed by the addition of Zr, XRD, SAD and EDS analyses confirmed that these precipitates were consisted of DO$\sub$22/, and DO$\sub$23/ type Al$_3$(Ti+Zr) ternary in termetallic compounds. Especially for the DO$\sub$23/ Al$_3$(Ti+Zr), the lattice parameter changed toward the smaller lattice mismatch between the precipitate and Al matrix as the Zr content increased. Therefore, it was considered that the improvement of thermal stability of Al-8wt.% (Ti+Zr) alloys was due to the formation of the ternary Al$_3$( Ti + Zr) intermetallic compounds.