• 제목/요약/키워드: Intensity level

검색결과 2,081건 처리시간 0.03초

하천 분광특성을 이용한 수질항목 모니터링 연구 - 울산 지역 (Monitoring of Water Quality Parameters using Spectroscopic Characteristics of River Water - Ulsan Area)

  • 허진;김미경;신재기
    • 한국물환경학회지
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    • 제23권6호
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    • pp.863-871
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    • 2007
  • Spectroscopic characteristics of river water from four major watersheds in the Ulsan area were measured to examine their potential for estimating water quality parameters. The total 176 river samples were collected from 44 sites of small streams within the watersheds during the year 2006. Spectroscopic characteristics investigated included protein-like fluorescence (FLF) intensity, fulvic-like fluorescence (FLF) intensity, terrestrial humic-like fluorescence (TLF) intensity, UV absorbance at 254 nm, and UV absorbance difference at 220 nm and 254 nm. Protein-like fluorescence intensity showed linear relationships with biochemical oxygen demand (BOD), chemical oxygen demand (COD), total phosphorous (TP) concentrations of the samples with the correlation of 0.784, 0.779, and 0.733, respectively. Due to the UV absorption characteristics of nitrate at 220 nm, UV absorbance difference at 220 nm and 254 nm was selected to represent total nitrogen (TN) concentration. Exclusion of some samples with PLF intensity higher than 5.0 improved the correlation between the UV absorbance difference and TN as demonstrated by the increase of the correlation coefficient from 0.392 to 0.784. Instead, for the samples with PLF intensity lower than 5.0, the highest correlation of TN was achieved with UV absorbance at 254 nm. The results suggest that PLF intensity could be used as the estimation index for BOD, COD, and TP concentration of river water, and as the primary screening index for the prediction of TN using UV absorbance difference. Some BOD-based water quality levels among the river water were statistically discriminated by the PLF intensity. Low p-values were obtained from the t-tests on the samples with the first level and the second level (p=0.0003) and the samples with the second and the third levels (p=0.0413). Our combined results demonstrated that the selected spectroscopic characteristics of river water could be utilized as a tool for on-site real-time monitoring and/or the primary estimation of water quality.

Community-level facilitation by macroalgal foundation species peaks at an intermediate level of environmental stress

  • Scrosati, Ricardo A.
    • ALGAE
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    • 제32권1호
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    • pp.41-46
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    • 2017
  • In rocky intertidal habitats, abiotic stress due to desiccation and thermal extremes increases with elevation because of tides. A study in Atlantic Canada showed that, at low elevations where conditions are benign due to the brief low tides, fucoid algal canopies (Ascophyllum nodosum and Fucus spp.) do not affect the structure of benthic communities. However, at middle and high elevations, where low tides last longer, fucoid canopies limit abiotic extremes and increase the richness (number of invertebrate and algal species, except fucoids) of benthic communities. Using the data from that study, this paper compares the intensity of facilitation and its importance (relative to all other sources of variation in richness) between middle and high elevations, which represent intermediate and high stress, respectively. Facilitation intensity was calculated as the percent increase in benthic richness between quadrats with low and high canopy cover, while the importance of facilitation was calculated as the percentage of variation in richness explained by canopy cover. Data for 689 quadrats spanning 350 km of coastline were used. Both the intensity and importance of facilitation were greater at middle elevations than at high elevations. As canopies do not affect benthic communities at low elevations, this study suggests that the facilitation-stress relationship at the community level is unimodal for this marine system. Such a pattern was found for some terrestrial systems dominated by canopy-forming plants. Thus, it might be ubiquitous in nature and, as further studies refine it, it might help to predict community-level facilitation depending on environmental stress.

무한 탄성 평판상의 기준점에 전달되는 진동인텐시티의 능동제어 (Active Control of Vibrational Intensity at a Reference Point in an Infinite, Elastic Plate)

  • 김기만
    • 한국소음진동공학회논문집
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    • 제11권4호
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    • pp.22-30
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    • 2001
  • In this paper, active control of vibrational intensity at a reference point in an infinite, elastic plate was discussed. The plate is excised harmonically by a vibrating source, which has a vertical point force. The optimal condition of controller was investigated to minimize the vibrational intensity being transmitted from the vibrating source to a reference point. Hence the method of feedforward control was employed for the control strategy and then the cost function was evaluated to find the optimal control force. Three types of control force (Vertical force, Moment, and Coupling force (a set of vertical force and moment) ) and controller's positions were examined to define the optimal condition of the controller. The vibrational intensity at a reference point was found to be reduced down to a zero level, compared with the uncontrolled case. Especially maximum reduction of vibrational intensity was achieved when the controller was collinearly positioned between a vibrating source and a reference point.

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진동 인텐시티 해석을 통한 원유운반선의 거주구 횡방향 진동 저감 연구 (Transverse vibration reduction at navigation bridge deck of the shuttle tanker using structural intensity analysis)

  • 김기선;김희원;주원호
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2012년도 추계학술대회 논문집
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    • pp.251-255
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    • 2012
  • Structural intensity has been mainly utilized to identify vibration energy flow in a vessel. In this paper, the structural intensity of a shuttle tanker subjected to H-moment of the main engine was calculated using a finite element model. From the analysis, it was found that the top-bracing elements, which support the main engine onto the hull structure to prevent the excessive transverse vibration of the main engine, play the role of the dominant path and sink for vibration energy flow from the main engine. Therefore, the structural intensity was controlled by the modification of stiffness and damping characteristics of the top-bracing elements. As a result, it is observed that the transverse vibration level at the center of navigation bridge deck decreased after the control of structural intensity.

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최근 30년간 한반도 일 강수강도의 지역적 특성 (The Regional Characteristics of Daily Precipitation Intensity in Korea for Recent 30 Years)

  • 김은희;김맹기;이우섭
    • 한국지구과학회지
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    • 제26권5호
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    • pp.404-416
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    • 2005
  • 이 연구는 최근 30년 동안 21개 지상관측소 일강수량 자료를 사용하여 한반도의 강수일수 및 강수강도의 지역성 및 계절성을 조사하였다. 일강수량 80 mm를 기준으로 다우와 소우로 나누어 그 특성을 조사하였으며, 강수일수 및 강도의 일차 선형경향도 함께 연구하였다. 호남 지방에서 소우에 의한 강수일수는 모든 계절에서 다른 지역에 비해 많으며, 특히 가을과 겨울철의 기여도가 상대적으로 컸다. 그러나 다우에 의한 강수일수는 대구를 중심으로 한 영남 지역에서 매우 적은 것으로 나타났다. 남해안 지방에서 강수량은 많고 강수일수가 적어 강수강도가 모든 계절에서 가장 크게 나타났으며, 연강수량에 대한 기여도는 다우와 소우 모두 다른 지역에 비해 크게 나타났다. 최근 30년간 대부분 지역에서 연강수량은 증가하는 선형경향을 보였는데, 대부분 다우에 의한 영향으로 나타났다. 한반도의 연 강수일수는 전반적으로 감소하는 선형경향을 보이지만, 다우에 의한 연 강수일수는 증가하는 선형경향을 보였다. 특히 충청과 경기지방에서 강수강도의 선형경향이 유의한 지역이 다수 발견되었는데, 이는 이 지역이 집중호우에 대한 위험도가 적지 않은 지역임을 말해주는 것이다.

가속도와 JMA진도 관계를 이용한 댐 시설의 지진 안정성 평가 (Assessment of Dam Seismic Safety using the Relationship between Acceleration and JMA Intensity)

  • 강기천;최병습;차기욱;정상인;이종욱
    • 한국지진공학회논문집
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    • 제18권6호
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    • pp.271-278
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    • 2014
  • Seismic intensity deduced from instrumental data has been evaluated using the empirical relationship between intensity and peak ground acceleration (PGA) during an earthquake. The Japan Meteorological Agency (JMA) developed a seismic intensity meter, which can estimate the real-time seismic intensity from seismic motions observed at a local site to evaluate the damage during the earthquake more correctly. This paper proposes a practical application of the JMA intensity to dams during the 2013 earthquake in Yeongcheon, Korea. In the present paper, seismic intensity was estimated from the relationships between accelerations observed at Yeongcheon Dam. Estimated seismic intensities were in the range of 0 to 3, which was verified from the displacements of dams and the variation of the ground water level observed at Yeongcheon dam during the earthquake. The JMA intensity, which is determined by considering the frequency, duration of cyclic loading, etc., was 0 (zero) and there was no damage to Yeoncheon dam during the earthquake.

Enhancing Astaxanthin Accumulation in Haematococcus pluvialis by Coupled Light Intensity and Nitrogen Starvation in Column Photobioreactors

  • Zhang, Wen-wen;Zhou, Xue-fei;Zhang, Ya-lei;Cheng, Peng-fei;Ma, Rui;Cheng, Wen-long;Chu, Hua-qiang
    • Journal of Microbiology and Biotechnology
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    • 제28권12호
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    • pp.2019-2028
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    • 2018
  • Natural astaxanthin mainly derives from a microalgae producer, Haematococcus pluvialis. The induction of nitrogen starvation and high light intensity is particularly significant for boosting astaxanthin production. However, the different responses to light intensity and nitrogen starvation needed to be analyzed for biomass growth and astaxanthin accumulation. The results showed that the highest level of astaxanthin production was achieved in nitrogen starvation, and was 1.64 times higher than the control group at 11 days. With regard to the optimization of light intensity utilization, it was at $200{\mu}mo/m^2/s$ under nitrogen starvation that the highest astaxanthin productivity per light intensity was achieved. In addition, both high light intensity and a nitrogen source had significant effects on multiple indicators. For example, high light intensity had a greater significant effect than a nitrogen source on biomass dry weight, astaxanthin yield and astaxanthin productivity; in contrast, nitrogen starvation was more beneficial for enhancing astaxanthin content per dry weight biomass. The data indicate that high light intensity synergizes with nitrogen starvation to stimulate the biosynthesis of astaxanthin.

색채동통척도의 신뢰도 연구 (Testing the Reliability of the Pain Color Circle Measurement Tool)

  • 김주희
    • 대한간호학회지
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    • 제21권3호
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    • pp.339-348
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    • 1991
  • The study problem was to determine the reliability of the Stewart pain circle measurement tool with Korean subjects. The purpose was to assess the tool for potential use in research in Korea. The subjects were 95 primary school students and 103 university students in Seoul. The study was conducted from May to June 1990, using Stewart's pain color circle tool. To determine the difference in the rated intensity of the order of the pain color circles, statistical mean and standard deviation were employed. Item reliability and test - retest reliability were used to test for reliability. ANOVA and t-test were used to explore for differences in the rated intensity of the order of the pain color circles according to the subjects' general characteristics. The findings were as follows ; 1. Higher level pain intensity was assigned to color circle numbers 2, 4, and 6 (These contain large amounts of color). Lower level pain intensity was assigned to numbers 1, 3, and 5(These contain small amounts of color). Higher and lower levels of pain intensity selection patterns were the same as Stewart's but the highest rating of pain was different. The highest pain intensity rating was given to the color red in this study instead of black as in Stewart's test. 2. University students and primary school students' ratings were not very difteferent. 3. Pain color circle reliability was $\alpha$=0.3468, Test - retest reliability was supported (t=0.02~0.97, p=0.337~0.988) 4. Differences in the rating of the pain intensity order were related to the subjects' age and sex, but not to religion. It was concluded that the pain color circle measurement tool is worth for further study as a research instrument with both Korean adult and child clients for validity and reliability.

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성대마비와 성대구증의 강도 변화에 따른 최대발성지속시간 비교 (Comparison of Maximum Phonation Time Associated with the Changes in Vocal Intensity in Patients with Unilateral Vocal Fold Palsy and Sulcus Vocalis)

  • 최세진;최홍식;김재옥;최예린
    • 말소리와 음성과학
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    • 제4권1호
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    • pp.125-131
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    • 2012
  • The patients with incomplete glottic closure have an important feature decreasing the maximum phonation time (MPT) because airflow rate or air leakage is greater than people without voice disorders. Also they can appear a problem in the intensity regulation. This study analyzed MPT difference based on the comfortable intensity and louder intensity and the correlation between MPT and respiration volume of unilateral vocal fold palsy (UVFP) and sulcus vocalis (SV) group. The twenty with UVFP, the 21 with SV, the 21 normal subjects measured MPT in /a/ vowel prolongation task with comfortable intensity and louder intensity and compared analysis by measuring FVC, $FEV_1$, $FEV_1/FVC$ to analyze the correlation between MPT and respiration volume. First, a comparison of MPT according to the intensity between groups is that MPT of the normal group was statistically significant long compared to the patient group in comfortable intensity, but MPT between groups was not statistically significant difference in the louder intensity. Second, an analysis of the correlation between MPT and respiration volume is that this was statistically significant correlation between MPT in comfortable intensity and MPT in louder intensity. But this did not show statistically significant correlation between intensity and respiration volume. This study can be supported the preceding study results deduced that shorting MPT of the patient group compared to the normal group was originated in the problem of laryngeal valving mechanism at the level of vocal folds rather than a problem of respiratory function. Also at the phonation by varying the intensity, the result can deduce that in the case of patient group, the length of MPT had been improved by increasing the glottal closure ratio in the louder intensity. These results can support the theoretical basis that should be applied to the clinicians by varying the intensity at the voice evaluation and voice therapy for the patients with the glottis incompetence.

초임교사 교직 적응을 위한 지원 방안 (Ways of Support for Beginning Teacher Induction in Elementary School)

  • 성병창
    • 수산해양교육연구
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    • 제19권2호
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    • pp.310-322
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    • 2007
  • This study is to find ways of support for beginning teacher induction in elementary school with constructing model of professional development. To achieve this purpose, this study reviewed significance of beginning teacher induction program, the bridge to life learning, and constructed the model of professional development for beginning. The final conclusion about ways of support as support intensity are orientation based on demanding of beginning teacher, bridge connection with veteran teacher, coordination of working conditions, collaboration among peer teacher, and strengthening computer network at week intensity level. At strong intensity level, the ways of support for beginning teacher are institutionalization on election and training of mentor, institutionalization on compulsory induction for 1 year, development and operation of teacher education center, and furtherance of school learning organization.