• Title/Summary/Keyword: Se Balance

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Study on the Multi-Zone Furnace Analysis Method for Power Plant Boiler (발전용 보일러에 대한 다중영역분할 화로해석 기법의 활용성 연구)

  • Baek, SeHyun;kim, Donggyu;Lee, Jang Ho
    • KEPCO Journal on Electric Power and Energy
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    • v.6 no.4
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    • pp.427-432
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    • 2020
  • In this study, a multi-zone furnace analysis method that couples a 1D energy and mass balance calculation with a 3D radiative heat transfer calculation is tested in order to verify its reliability. The calculated results for a domestic 500 MW capacity coal-fired boiler furnace were compared with the design data of the boiler manufacturer and CFD analysis, and a good agreement was achieved. Although this calculation method is less sophisticated than the CFD furnace analysis, it has an advantage in terms of calculation time while being able to provide the furnace behavior according to the fuel characteristics and operational variable changes. Therefore, it is expected to be useful for boiler operation diagnosis and daily fuel/operation planning.

Mass balance equation을 이용한 대형 진공용기의 진공도 계산과 측정

  • Kim, Se-Hyeon
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.356-356
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    • 2011
  • 챔버 내부의 압력은 gauge가 달려 있는 몇몇 지점에만 국한되어 읽을 수 있었기 때문에 gauge를 이용한 압력 측정을 통해 보다 상세한 진공도를 구하기란 쉽지 않다. 챔버 내부의 압력은 빔 운전에 적합한 초고진공을 유지하여야 하고, 균일하여야 하므로 신뢰 할 수 있는 방법으로 진공도를 정확히 계산해 볼 필요가 있다. 그리하여 압력에 영향을 미치는 여러 가지 진공 시스템 내부의 요소인 Outgassing, 배기속도, 컨덕턴스, 압력 등을 mass balance equation을 이용해 수식화 하여 정리한다. 이 수식을 가지고 FEA(Finite element analysis)프로그래밍을 이용해 진공도를 계산한다. FEA 프로그래밍에 쓰이는 프로그램은 Matlab, excel을 이용하였다. 이 프로그래밍 결과에 따라 Pressure Profile을 작성 하고, 시간이 변함에 따라 진공도가 어떻게 변하는지 실제로 계산하여 time constant를 구한다. 이 값들을 챔버를 가지고 측정한 데이터와 비교하여본다.

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Reflectivity of Sn Solder for LED Lead Frame

  • Xu, Zengfeng;Gi, Se-Ho;Park, Sang-Yun;Kim, Won-Jung;Jeong, Jae-Pil
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2011.05a
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    • pp.184-185
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    • 2011
  • In this study, in order to obtain a high reflectivity for the LED lead frame, tin dip coating and tin plating were conducted respectively, and wettability of LED lead frame with tin solder also was tested by wetting balance tester. A Cu sheet was plated in Cu brighten electroplating bath and followed by immersion in a Sn electro-less plating bath [1]. On the other hand, in the dip coating process, a Cu sheet was dipped into molten tin. In the progress of wetting test, besides wetting balance curve, the maximum measured force($F_m$), the maximum withdrawal force($F_w$) and zero-cross time($t_0$) were obtained in various temperatures. With the maximum withdrawal force, the surface tension was calculated at different temperatures. The Cu sheet plated with bright Cu and Sn show a silver bright property while that of Cu dipped with Sn possessed a high reflectance density of 1.34GAM at $270^{\circ}C$.

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Noninvasive Monitoring of ion Energy Distribution in Plasma Etching (플라즈마 식각 공정 시 비 침투적 방법으로 이온에너지 분포 측정 연구)

  • Oh, Se-Jin;Chung, Chin-Wook
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.2069-2071
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    • 2005
  • 본 연구에서는 플라즈마 식각 공정 시 식자률, 선택비, wafer 손상등과 중요한 관련이 있는 이온 에너지 분포(IED)를 측정하기 위해서 챔버 내에 직접적으로 분석기를 설치하지 않고 챔버 외부에서 비 침투적(noninvasive)인 방법을 사용하여 측정하였다. 이 방범은 신호선 중 한 곳에 측정 점을 잡기 위한 연결 장치만 필요하며 그곳에서의 전안 신호와 전류 신호를 오실로스코프에서 측정한 후 미리 얻어진 챔버 구조 모델링 계수 등을 통해 실제 바이어스 전극에 걸리는 전압 및 전극에서 플라즈마로 흐르는 전류를 유추한다. 전압 및 전류측정값과 power balance와 particle balance를 적용하여 얻은 플라즈마 특성 상태 변수들을 사용하여 oscillating step sheath model을 기반으로 한 분석 프로그램을 통해 실시간 이온에너지 분포 결과를 얻었다. 실제 공정 시 바이어스 주파수 변화, 바이어스 파워 변화, 소스 파워변화 조건 등에 따른 이온 에너지 분포 측정 및 분석을 통해 비 침투적측정방법 적용의 가능성과 장점을 확인하였다.

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A clinical review of Zexie-tang in vertigo and gait inbalance patients -2 case (택사탕(澤瀉湯)으로 회전성 현훈과 보행장애 치험 2례)

  • Lee, Eun;Ko, Heung
    • The Journal of Internal Korean Medicine
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    • v.21 no.3
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    • pp.511-514
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    • 2000
  • We diagnosis two patients who have severe vertigo and gait inbalance as ‘dizziness due to retention of phlegm’ (痰暈) and gave Zexie-tang(澤瀉湯). They improved enable to walk balance and no more vetigo. Therefore we could assume that Ku-ren-xuan-mao(苦人眩冒) which is the main symptom of Zexie-tang means the vertigo and gait imbalance due to vestibular disorder.

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The effects of natural medicinal herb extracts on a lipoprotein lipase activity

  • Hwang, Jeong-Lyeor;Chung, Seung-Sik;Lee, Sung-Hyung;Choung, Se-Young
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.392.3-393
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    • 2002
  • The increase of triglyceride in blood can be a signal of an increasing danger of arterial diseases when insulin resistance. diabetes. HDL -cholesterol decrease is accompanied. It is adjusted to triglyceride level in blood by a balance. which seems to be absorbed from VLDL metabolism in liver and by lipoprotein lipase activity. The hyper-triglyceride disease treatment proposal role should match with suppression does into liver or elimination of a triglyceride. (omitted)

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Long-term International Oil Trade Model for the Analysis of Oil Price and Economic Growth (세계원유가격 및 경제성장분석을 위한 장기국제원유무역모형)

  • Kim, Se-Heon
    • Journal of Korean Institute of Industrial Engineers
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    • v.11 no.2
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    • pp.165-172
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    • 1985
  • Since energy consumption of developing countries is expected to grow rapidly over the coming decades, the oil-importing developing countries are likely to encounter chronic balance-of-payments difficulties. To analyze the quantitative impacts of this problem, we develop a computable model of international trade. This paper presents four alternative cases - varying the assumptions with respect to energy supplies. This shows that relatively small difference in supplies can lead to 100% differences in the energy prices projected for 1990.

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Effects of 3-Dimensional Spinal Stabilization Exercise on Static Balance in chronic low back patients (만성요통환자에게 적용한 3차원 척추안정화운동이 정적균형에 미치는 영향)

  • Park, wan-seo;Kim, kyung-yun;Bae, se-hyun
    • Proceedings of the Korea Contents Association Conference
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    • 2017.05a
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    • pp.347-348
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    • 2017
  • 만성요통 환자 15명을 대상으로 4주간, 주 3회 3차원 척추안정화운동과 허리안정화운동을 실시한 후 3차원 척추안정화검사를 통하여 허리심부근력을 측정하고 Tetrax장비를 통하여 신체균형능력을 평가하였다. 단기간일지라도 3차원척추안정화운동을 통해 정확한 방법으로 운동을 실시하였더니 만성요통환자의 허리근력과 자세균형에 긍정적인 효과를 주었다.

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Estimation of Submarine Groundwater Discharge in Il-Gwang Watershed Using Water Budget Analysis and Rn Mass Balance (물 수지 방법과 라돈 물질수지 방법을 이용한 일광유역의 해저용출수 평가)

  • Gwak, Yong-Seok;Kim, Sang-Hyun;Lee, Yong-Woo;Hamm, Se-Yeung;Kim, In-Soo;Khim, Boo-Keun
    • Journal of Environmental Science International
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    • v.20 no.9
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    • pp.1165-1182
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    • 2011
  • The evaluation of potential submarine groundwater is an important research topic for exploring an alternative water resource. Two different approaches, water budget analysis and Rn mass balance method, were employed to investigate the annual variation of submarine groundwater discharge in 2010 at a marine watershed located at the south-eastern part of Korean Peninsula. In order to obtain reliable hydrological data during study period, temporal and spatial variations of rainfall and soil moisture had been collected and hydro-meterological data such as temperature, humidity and wind speed were collected The runoff response was simulated using SCS-CN method with spatial distributions of landuse and soil texture from GIS analysis. Six different methods were used to estimate the monthly variation of evapotranspiration and field measurements of soil moisture were used to account for the infiltration. Comparisons of infiltration and surface runoff between simulation and water balance with measurements showed coincidence. The water budget analysis and Rn mass balance method provide mean daily submarine groundwater as 5.35 and 4.07 $m^3/m/day$ in 2010, respectively.

The Effects of Exercise Program on Pain and Balance ability in Patients with Total Knee Replacement : Meta-analysis

  • Park, Se-Ju
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.5
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    • pp.119-126
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    • 2021
  • This study attempted to systematically and comprehensively analyze individual studies in which exercise program on total knee replacement patients. The electronic database for literature search used the Korean educational Academic Information (RISS), Korean Academic Information (KISS) and Nuri Media (DBPIA). We investigated a prior study of exercise program applied to total knee replacement patients from 2015 to February 2021. For meta-analysis, effect size of each individual study was extracted using R project for Statistical computing version 4.0.3. Rob 2.0 tool, developed by the Cochrane group, was used to evaluate the quality of each individual study. The overall effect size exercise program with pain and balance was 0.99 (95% CI=0.53-1.44), which was significantly different than large effect size (p<0.05). The sub-group for pain was analyzed, for effect size of 0.62 and the effect size of balance scale(timed up and go test) was 1.00. Through these results, it was found that exercise program is an effective exercise for total knee replacement patients, and further research is needs.