• 제목/요약/키워드: T74

검색결과 2,005건 처리시간 0.029초

자연형 소하천정비에 따른 수질변화 특성 (Quality of Water Change Special Quality by Nature Style Stream Construction)

  • 윤정환;정재훈;정해원;박승기
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2005년도 학술발표논문집
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    • pp.620-625
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    • 2005
  • It was monitored 3 years from 2003 to 2005 that the variational quality of water according to the arrangement toward natural shape of stream, and the variational characteristics of the each contents on water quality were analyzed after the separation into three periods of before, among and after arrangement construction. The quality monitoring results showed that the averages of water temperature, pH, DO, SS, BOD, T-N and T-P were $17.1{\sim}21.4^{\circ}C$, $6.44{\sim}7.74$, $7.02{\sim}8.36mg/L,\;0.7{\sim}51.9mg/L,\;0.310{\sim}1.044mg/L,\;0.41{\sim}2.43mg/L$ and $0.003{\sim}0.008mg/L$, respectively. The measured values of BOD, T-N and T-P were high just after construction, but the amounts were lowered as time passed, and finally stabilized in 2005. It ranged from 0.337 to 0.912 that the coefficients of correlation on linear regression between the discharges of water and BOD, T-N and T-P at each monitoring points, respectively.

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유한 요소법을 이용한 저압 배전용 전선퓨즈의 I-t 특성 해석 (An Analysis of the I-t Characteristic of Low Voltage Distribution Line Fuse Using the FEM)

  • 황명환;박두기;이세현;한상옥
    • 한국조명전기설비학회지:조명전기설비
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    • 제11권6호
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    • pp.74-80
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    • 1997
  • 본 논문에서는 저압 배전용 전선퓨즈의 I-t 특성을 다루었다. 전선퓨즈 엘리먼트는 과전류 영역을 담당하는 낮은 온도 용융영역(LTME)과, 대전류 영역을 담당하는 높은 온도 용융영역(HTME)으로 나누어 진다. 이들부분에 의하여 퓨즈의 용단특성이 결정되는 것이다. 따라서 이들 부분에 대한 열적, 전기적인 특성을 시뮬레이션하므로서, 퓨즈 엘리먼트 설계의 타당성을 이론적으로 검증하였다. 유한요소법(Finite Element Method)을 이용하여 전선퓨즈의 I-t특성을 시뮬레이션 하였다. 그리고 시뮬레이션 결과와 실혐결과를 비교해 보았을 때 대전류영역과 소전류영역에서의 상당히 유사한 결과를 얻을 수 있었다.

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ITU-T SG17(보안) 국제 표준화 회의 주요 결과 및 차기 연구회기(2025-2028)를 위한 구조조정 논의

  • 고재남;박성채;오흥룡;염흥열
    • 정보보호학회지
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    • 제33권4호
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    • pp.65-74
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    • 2023
  • 국제전기통신연합(ITU)은 국제연합(UN) 산하 정보통신기술(ICT)에 대한 전문 국제 표준화기구이다. 193개 회원국, 약 900개 기업 및 학계 멤버 등으로 구성되어 있으며, 산하에 전기통신표준화부문(ITU-T), 전기통신개발부문(ITU-D), 그리고 전파통신 부문(ITU-R) 등 3개의 부문으로 구성되어 있다[1]. ITU-T는 역할과 임무에 따라 11개의 연구반(SG, Study Group)으로 구성되어 있으며, 각 업무에 맞는 선도 그룹(Lead Study Group)을 지정하여 국제 표준을 개발하고 있다. 정보보안 분야 국제 표준은 ITU-T SG17(보안)에서 담당한다[2]. ITU-T 국제 표준화 조직은 4년 주기의 연구회기(Study Period)로 연구반 구조조정, 의장단 선출 및 표준화 추진 방향을 WTSA(World Telecommunication Standardization Assembly) 총회에서 결정한다. 다음 총회는 2024년 10월에 인도에서 열릴 예정이다. 본 논문에서는 지난 2022년 8/9월과 2023년 2/3월 스위스 제네바에서 열린 ITU-T SG17 회의에서 한국이 주도적으로 수행한 정보보호 표준화 활동 결과를 알아보고, 차기 연구회기(2025-2028)를 위한 SG17 구조조정에 대해 2023년 2/3월 SG17 회의 결과와 서신 그룹(CG, 5월-7월) 회의의 주요 결과를 중심으로 제시한다.

Objectively Measured Physical Activity of Vietnamese Adults With Type 2 Diabetes: Opportunities to Intervene

  • Do, Vuong Van;Jancey, Jonine;Pham, Ngoc Minh;Nguyen, Chung Thanh;Hoang, Minh Van;Lee, Andy H.
    • Journal of Preventive Medicine and Public Health
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    • 제52권2호
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    • pp.101-108
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    • 2019
  • Objectives: To objectively determine and compare the physical activity (PA) levels of adults newly diagnosed with type 2 diabetes (T2D) and adults without T2D in Vietnam using an accelerometer. Methods: A total of 120 participants with newly diagnosed T2D and 120 adults without T2D were recruited from a large hospital in Hanoi, the capital city of Vietnam. All participants wore an ActiGraph GT3X accelerometer for at least 5 days, including 1 weekend day. Freedson cut-off points were used to estimate different intensities of PA. In addition, comparisons between groups were made with respect to achieving the World Health Organization (WHO) and International Diabetes Federation (IDF) recommended PA guidelines. Results: Men with T2D had significantly lower levels of PA than men without T2D. The respective multivariable-adjusted mean values of daily step count, daily light-intensity, moderate-intensity, and moderate-to-vigorous-intensity PA were approximately 14%, 19%, and 22% lower in the men with T2D than in their non-T2D counterparts. However, women with T2D accumulated a greater number of steps per day than women without T2D. Only 59.2% of the adults with T2D met the minimum recommended level of PA (WHO and IDF), compared to 74.2% of adults without T2D (p<0.05). After adjusting for potential confounders, participants with T2D experienced 50.0% significantly lower odds of achieving PA recommendations. Conclusions: Vietnamese men with T2D were less physically active than those without T2D, and adults with T2D were less likely to meet PA guidelines. The results suggest a need for integrating PA into the self-management of this chronic condition.

강원도산(江原道産) 소나무천연림생태계(天然林生態系)의 Biomass 및 Net Primary Production에 관(關)한 연구(硏究) (Biomass and Net Primary Productivity of Pinus densiflora Natural Ecosystem in Kangwondo, Korea)

  • 이수욱
    • 한국산림과학회지
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    • 제71권1호
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    • pp.74-81
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    • 1985
  • 강원도산(江原道産) 소나무천연림(天然林)의 생산성(生産性)을 파악(把握)하기 위하여 10본(本)의 표본목(標本木)을 벌도(伐倒)하고 각(各) 부위별(部位別) 및 총(總) biomass와 biomass 추정방정식(推定方程式) 모형으로는 $Wt=aD^bH^c$가 가장 적합(適合)하였다. 2) 임분(林分) biomass 추정량(推定量)은 지상부(地上部) 총량(總量)이 198.82 t/ha였으며 부위별(部位別)로는 수간목부(樹幹木部)가 136.82 t/ha, 생지부(生枝部)가 32.81 t/ha, 수피부(樹皮部)가 10.72 t/ha 엽량(葉量)이 9.07 t/ha 죽은가지가 7.30 t/ha 였다. 3) 순생산량(純生産量)은 지상부총량(地上部總量)이 15.87 t/ha/yr였으며 부위별(部位別)로는 수간목부(樹幹木部)가 7.04 t/ha/yr., 생지부(生枝部)가 4.91 t/ha/yr., 엽량(葉量)이 2.21 t/ha/yr., 소지(小枝)가 1.13 t/ha/yr., 수피(樹皮)가 0.52 t/ha/yr 였다. 4) Leaf efficiency는 1.876으로서 연간지상부(年間地上部) 총생산량(總生産量) 15.87 t/ha/yr와 비교적 잘 연관되어 있다.

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환경 일기 쓰기를 통한 환경 소양 함양 (Cultivating Environmental Literacy through Journal Writing on the Environment)

  • 박정해;최돈형
    • 한국환경교육학회지:환경교육
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    • 제21권3호
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    • pp.13-25
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    • 2008
  • This study examined the educational effects of journal writing on environmental literacy of elementary students. Thirty-one 3rd grade students were involved in the journal writing which is considered as one of the most frequently performed writing activities in elementary students. Topics for the journal writing were chosen from a textbook on the environment. Before and after the journal writing, an instrument was used to measure the environmental literacy of the students. The environmental literacy instrument was originally developed by Jin (2004) then were modified by Kim (2005) for elementary students. The results of this study are as follows. The environmental literacy of the students, on average, was improved from 140.84 (74.5%) to 161.84 (85.6%) after the journal writing and the difference was statistically significant(t=7.46, p<.001). The environmental literacy scores were significantly improved in every variable after the journal writing: ecological knowledge(t=3.60, p<.01), environmental sensitivity(t=2.54, p<.05), knowledge of environmental issues(t=3.11, p<.01), environmental attitude(t=5.92, p<.001), environmental concern(t=5.27, p<.001), sense of environmental crisis(t=2.97, p<.01), environmental issue investigation and action strategy knowledge (t=2.34, p<.05), environmental skill(t=4.86, p<.001), locus of control(t=5.63, p<.001), and responsible environmental behavior(t=4.64, p<.001). This study also shows that improvement of the students was statistically significant in each of the four levels of goals in environmental education: EE goal level I (t=4.22, p<.001), level II (t=7.53, p<.001), level III(t=5.01, p<.001), and level IV(t=5.46, p<.001). The results imply that the journal writing on the environment is effective in cultivating elementary students' environmental literacy and in achieving goals in environmental education.

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Comparison of the Diagnostic Accuracies of 1.5T and 3T Stress Myocardial Perfusion Cardiovascular Magnetic Resonance for Detecting Significant Coronary Artery Disease

  • Min, Jee Young;Ko, Sung Min;Song, In Young;Yi, Jung Geun;Hwang, Hweung Kon;Shin, Je Kyoun
    • Korean Journal of Radiology
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    • 제19권6호
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    • pp.1007-1020
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    • 2018
  • Objective: To compare the diagnostic performance of cardiovascular magnetic resonance (CMR) myocardial perfusion at 1.5- and 3-tesla (T) for detecting significant coronary artery disease (CAD), with invasive coronary angiography (ICA) as the reference method. Materials and Methods: We prospectively enrolled 281 patients (age $62.4{\pm}8.3$ years, 193 men) with suspected or known CAD who had undergone 1.5T or 3T CMR and ICA. Two independent radiologists interpreted perfusion defects. With ICA as the reference standard, the diagnostic performance of 1.5T and 3T CMR for identifying significant CAD (${\geq}50%$ diameter reduction of the left main and ${\geq}70%$ diameter reduction of other epicardial arteries) was determined. Results: No differences were observed in baseline characteristics or prevalence of CAD and old myocardial infarction (MI) using 1.5T (n = 135) or 3T (n = 146) systems. Sensitivity, specificity, positive and negative predictive values, and area under the receiver operating characteristic curve (AUC) for detecting significant CAD were similar between the 1.5T (84%, 64%, 74%, 76%, and 0.75 per patient and 68%, 83%, 66%, 84%, and 0.76 per vessel) and 3T (80%, 71%, 71%, 80%, and 0.76 per patient and 75%, 86%, 64%, 91%, and 0.81 per vessel) systems. In patients with multi-vessel CAD without old MI, the sensitivity, specificity, and AUC with 3T were greater than those with 1.5T on a per-vessel basis (71% vs. 36%, 92% vs. 69%, and 0.82 vs. 0.53, respectively). Conclusion: 3T CMR has similar diagnostic performance to 1.5T CMR in detecting significant CAD, except for higher diagnostic performance in patients with multi-vessel CAD without old MI.

ALC(Autoclaved Light-weight Concrete)를 이용한 생물학적 반응벽체에 관한 연구

  • 박근민;이재영;오병택;최상일
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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    • pp.402-406
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    • 2006
  • The physical and chemical characteristics of ALC were analyzed and showed 2.2 of specific gravity and 9.05 of pH. The results of leaching tests with standard method for soil and waste indicated heavy metals(Cu, Cd, Pb, $Cr^{6+}$) were under maximum concentration level. The anaerobic digestion sludge was attached in the surface of ALC within 90 hours. As the results of batch test, pH of the ALC and Bio-ALC were decreased from initial pH of ALC to 8.7 and 7.8 respectively Also, the concentration of heavy metals was rapidly eliminated in the solution with the batch test. The result of column experiment indicates that the removal efficiency of ALC was showed 66% of T-P, 60% of T-N, and 67% of CODcr. Also, removal efficiency of Bio-ALC was slightly higher than that of ALC in T-N (64%) and CODcr (74%).

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형상비가 다른 T형벽체의 유효폭 산정을 위한 비선형 FEM 해석 (A Study on Nonlinear FEM Analysis for the Effective Widths of T-shaped Structural Walls with Different Aspect Ratios)

  • 조남선;하상수;오영훈;이리형
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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    • pp.67-74
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    • 2001
  • In domestic, irregular walls such as T, L, H and Box shapes are considered as rectangular wall in the design of bearing wall apartment building. The strengths of walls, therefore, can be underestimated in case of using the current design process. Irregular walls are connected to each other as rigid joint so that part of the load can be resisted by the wall perpendicular to the load direction. This resistance can be caused by the effective width of perpendicular wall. This additional resistance by the perpendicular wall increases the strength of structural walls. The objective of this study is to evaluate the effective widths of flanged walls with different aspect ratios by using FEM analyses. the results from finite element method are compared with effective flange widths of some code provisions.

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