• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.37-38
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• 2007

It needs several large reservoirs and long time to remove suspended solid like steel fines and iron oxide in hot rolling coolant. If removing rate of suspended solid in rolling coolant is improved by using high gradient magnetic separation (HGMS) system, the productivity of working process can be increased and the area of reservoir can be reduced. Pre-treatment process that react magnetic floc with inorganic and organic flocculant in coolant was studied. Horizontal type superconducting HGMS system was manufactured successfully, which was constituted with automatic filter transportation apparatus, 6 T He-free superconducting magnet system and water circulation system. The solid suspension removal ratio in hot rolling coolant was increased by flocculation with inorganic and organic flocculant.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.1-4
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• 2002

The numerical alaysis of optical device, silicabased device, are presented. The purpose of this paper is to simulate and to design a 8-channel optical wavelength division multiplexer(OWDM) based on Mach-Zehnder Interferometer(MZI) with wavelength spacing between channels Δλ=0.8 nm at central wavelength λ=1.55 ${\mu}{\textrm}{m}$. In initial condition fur simulating, we assumed as follows. A channel waveguide is made from silica based P-doped SiO2 core layers in order to coupling with a fiber easily and its core dimension was 6 ${\mu}{\textrm}{m}$$\times$6 ${\mu}{\textrm}{m}$. The core and clad index of channel waveguide were 1.455 and 1.444, separately, at λ=1.55 ${\mu}{\textrm}{m}$. Where, the separation between channel waveguides in coupling region was 3 ${\mu}{\textrm}{m}$. As a result of analysis, a group mode index of channel waveguide was 1.4498370, was gained by Hermite-Gaussian Method(HGM). Also, the channel spacing was determined by the waveguide arm length difference and was Δλ=0.8 nm as like a proposed condition. The central wavelength of a designed-multiplexer was activated about wavelength λ=1.55 ${\mu}{\textrm}{m}$, and we certificated that it can be used to 8-channel optical wavelength division multiplexer/demultiplexer.

• Journal of Periodontal and Implant Science
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• v.25 no.3
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• pp.668-678
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• 1995

In order to evaluate the therapeutic effect of argon laser irradiation on hypersensitive root, 60 mandibular premolars that had been extracted due to periodontal disease were treated by thorough scaling, root planing and root conditioning with tetracycline HCI(100mg/ml, 5 min.) for induction of hypersensitive root. Within middle one third of root mesial surface(30) or distal surface(30) was randomly irradiated by 0.5W-, 0.75W- and 1.0W-power for 2 minutes argon laser(HGM Inc., USA) with or without topical application of 1.23% acidulated phosphate fluoride gel(Pascal, USA). After all teeth were maintained in 2% methylene blue solution for 48 hours and cross-sectioned through irradiated surface of dried roots, methylene blue stained area was compared between irradiated side and nonirradiated side. Following results were obtained : 1. Methylene blue stained area was significantly less in the laser irradiated group than control group(p<0.05). 2. There was no significant difference in methylene blue stained area between 0.5W-power and 0.75W-power group(p>0.1) and between 0.75W-power and 1.0W-power group(p>0.1), but there was significant difference between 0.5W-power and 1.0W-power group(p<0.05). 3. There was no significant difference in methylene blue stained area between two groups with and without topical application of 0.12% acidulated phosphate fluoride gel(p>0.1). The results suggest that argon laser irradiation on hypersensitive root may reduce the hypersensitivity by obstruction of dentinal tubules.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.1
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• pp.119-132
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• 2018

This study was conducted to suggest an assessment indices to evaluate the ecosystem services of the unique functions of wetlands as well as economic value provided by the village wetlands. The assessment indicators applied in this study were used by the RAM indices. The results of RAM assessment on the village wetlands in Cheonan city were analyzed by item and critical functions of the village wetland. They were derived by assessment indicators of ecosystem services, and the village wetland ecosystem were presented by Focus Group Interview (FGI). The 20 critical indices were selected from 52 different indices by analyzing the wetland function assessment items. 13 indicators excluding duplicate indexes by function, were selected as ecological service impact indicators. Finally, ecosystem services were evaluated by using AHP analysis to calculate the weight of each assessment indices and apply it to the 9 village wetlands. The results of this study confirmed that the functions of the village wetlands are compliant with the ecosystem services. Based on this assessment of the unique functions of wetlands, it will serve as a methodology for assessing ecosystem services. The study was also conducted on 49 wetlands in Cheonan. The detailed assessment of wetland ecosystem services based on the wetland ecosystem function proposed by this study, was further developed as a follow-up study. It suggested that the wetland areas should be compared and be used as a general standard. In addition to the assessment of the economic value of ecosystem services provided by the village wetlands, it would be useful to assess the unique features and convert them into value.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.1
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• pp.11-20
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• 1996

본 조사는 경기도 용인에 위치한 명지대학교의 남녀 대학생 202명의 대상으로 일반 환경과 혈철지질, 혈압, 체지방량 측정 검사를 중심으로 이루어졌으며, 조사 분석한 결과를 요약하면 다음과 같다. 1. 조사 대상자의 신체발달 상황을 보면 남자의 평균 신장과 체중 및 비체중치는 173.1cm, 65.9kg, 38.03이였고, 여자는 16.7cm, 52.4kg, 32.6로 한국인 성인의 표준치와 매우 유사한 수치였다. 체지방량 비율은 남자 16.4, 여자 24.0으로 나타 설별에 따른 차이가 뚜렸하였다. 2, 조사 대상자들의 수축기와 이완기의 혈압은 평균 $125\pm123mmHg,$ $77.2\pm11.1mmHg이고,$ 남자와 여자의 수축기 혈압은 각각 $132.3\pm1.9mmHg,$ $118.1\pm1.6mmhg로$ 정상 범위였다.확장기 혈압은 남녀 각각 $80.5\pm11.0mmHgm$ $73.9\pm102.m,Hg였으며$ 역시 정상범위에 포함되었다. 3. 혈청 지질의 검사 결과는 Tc는 남자 175.2mg/dl, 여자 183.6mg/dl로 나타났고 TG는 남자 108.4mg/dl, 여자 72.0mg/dl로 나타나 통RP적으로 유의한 차이가 있었다. (p<0.05). 또한 HDL-C는 남자 59.6mg/dl , 여자 64.3mg/dl 로 성별에 다른 유의적인 차이를 보였고 (p<0.05), LDL-C도 역시 남자 93.9mg/dl, 여자 104.8mg/dl로 나타나 통계적으로 성별에 다른 차이가 뚜렷하였다. (p<0.01). 조사결과 다른 연령층의 성인과는 달리 TG를 제외한 TC, H이-C, L이-C에 있어서 남자가 여자 보다 더 낮은 수치를 보였다. 4. 혈압에 따라 세 그룹으로 분류한 후 혈청 지질과의 관계를 보면, 수축기 혈아이 증가함에 따라 TC, TG, LDL-C은 증가하는 경향을 보였으며, HDL-C은 감소되었으나 통계적으인 유의성은 없었다. 이완기혈압의 겨우 89mmHg 이하 보다 90~94mmHg의 경우에 유의적으로 증가되었으며 (p<0.05) HDL-C은 감소하였으나 유의성은 없었다. 5. 혈정 지질과 비만도의 관계는 남녀 모두 양의 상관관계를 나타냈으나 여자보다 남자에서 뚜fut이 나타났다. 남자의 겨우 TC의 수치가 KI에 따라 110% 미만일 때 $169.7\pm31.5mg/dl,$ 110~120%일 때 $193.8\pm36.8mg/dl,$ 120% 이상 일 때 $202.2\pm29.3mg/dl로$ 비만도에 따른 유의적인 증가를 (p<0.05)보여주었으나 여자의 경우는 유의적인 차이가 없었다. TG의 수치는 남자의 경우 KI가 110%미만인 그룹은 $102.9\pm108.2mg/dl,$ 120% 이상인 그룹은 $112.2\pm40.0mg/dl로$ 비만도가 증가함에 따라 TG가 증가되었으나 유의적인 차이는 없었으며, 여자의 경우 유의적인 차이가 없었다. 남자의 경우 HDL-C은 비만도가 증가함에 따라 유의적으로 감소하는 경향을 보였으나(p<0.05) 여자의 경우는 유의적인 차이가 없었다. 6. 조사 대상자의 체지방량 측정결과 체기방률은 남자의 겨우 16.4% 여자의 겨우 24.0%로 나타나 여자의 체지방률이 남자보다 높았다. 7. 신체계측치, 혈압, 혈청 지질간의 상관관계를 살펴보면 TC, TG는 KI, BMI와 유의적인 양의 상관관계를 보였고 (p<0.01), HCL-C은 비체중, BMI, LBM, TBM와 유의적인 음의 상관관계를 보였으며, (p<0.01), KI, SBP와도 음의 상관관계를 보였다. (p<0.05), LCL-C는 KI와 유의적이인 양의 상관관계를 나타내었으며 (p<0.01) BF%, TBF, BMI와도 양의 상관관계를 나타냈었다. (p<0.05). 또한 LPH, Al는 모두 나이, 비체중, BMI, KI와 유의적인 양의 상관관계를 나타내었다. (p<0.01). 이상을 종합해 보면 본 조사 대상자들은 비만도가 높아질수록 혈청 지질 수준이 놓았으며, 이완기 혈압도 형철 지질과 상관관계를 나타났다. 대학생의 혈청 지질과 체지방에 대한 자료가 부족함을 고려할 때, 본 조사자료가 학생의 혈청지질의 체지방에 대한 기초 자료로서 이용될 것을 기대하며 보다 다각적인 연구가 이루어지기를 바라는 바이다.