• 제목/요약/키워드: Short-term period

검색결과 1,050건 처리시간 0.026초

서울시 대기 중 수은농도의 장기변동 특성 1997~2002 (The Long-term Variation Patterns of Atmospheric Mercury in Seoul, Korea from 1997 to 2002)

  • 김민영;김기현
    • 한국대기환경학회지
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    • 제19권2호
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    • pp.179-189
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    • 2003
  • The concentration of gaseous elemental mercury (Hg) was measured concurrently with relevant environmental parameters from Yang-Jae monitoring station in Seoul during Sept. 1997 to June 2002. Although data collection was disrupted for certain periods, the grand mean concentration of Hg for this five year period was found at 5.32 $\pm$ 3.53 ng m$^{-3}$ (N = 27,170). Because of short resolution of data acquisition, we were able to examine the temporal variability of Hg at varying time scale. The diurnal variability of Hg, when investigated for each of those five years, indicated consistently the dominance of nighttime over daytime. If examined at seasonal scale, Hg level was systematically higher during winter/spring than summer/fall period. The results of this short-term variability were best explained by the combined effects of such factors as meteorological conditions (formation of inversion layer and seasonal changes) and anthropogenic source processes. However, examination of long-term variation Pattern was much more complicated to explain. Thus, extension of our study is needed to diagnose the future direction in long-term trend of Hg behavior.

ICR 마우스를 대상으로 대두 가수분해물 분획물의 식욕 억제 및 Ghrelin 분비에 대한 연구 (Effects of Soy Hydrolysate Fractions on Appetite Suppression and Ghrelin Releasing in ICR Mice)

  • 정은영;서형주
    • 한국식품영양학회지
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    • 제27권2호
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    • pp.225-230
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    • 2014
  • The objective of this study was to investigate the effects of soy hydrolysate fractions on appetite suppression and ghrelin releasing. In a short-term experiment, the cumulative food intake and serum ghrelin level were decreased significantly (p<0.05) during a 4-hr period after the interperitoneal injection of soy hydrolysate fractions (0.5, 1 g/kg BW), following a 12-hr period of food deprivation. In a long-term experiment, food efficiency ratio (FER) was also reduced significantly (p<0.05), when soy hydrolysate fractions (0.5, 1% in drinking water) were given orally for 8 wks. Therefore, we found that soy hydrolysate fractions affected food intake through appetite and ghrelin releasing in short-term and long-term experiments. In conclusion, this study indicated that soy hydrolysate fractions would diminish the sensation of hunger by reducing the secretion of orexigenic factors such as ghrelin that send satiety signals to the brain, terminating food intake.

On Long-term Prediction Scheme in Ocean Engineering

  • Kwon, Sun-Hong;Kim, Dea-Woong
    • International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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    • 제3권1호
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    • pp.29-34
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    • 2000
  • This paper proposes a long-term prediction of offshore structures in ocean waves. All short-term statistics is generated by the simulation for all the combinations of significant wave heights and spectral peak periods. The simulation has been tested first on linear system, whose analytic solution is known, to verify if the simulation works accurately. Then the scheme was applied to the nonlinear system. This paper demonstrated that the proposed scheme could be an efficient tool in estimating the response of offshore structures.

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STM(Short-term Memorable) Information의 속성 및 정보표현 (Attributes and Expression of STM(Short-term Memorable) Information)

  • 한지애;류시천
    • 한국콘텐츠학회논문지
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    • 제10권9호
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    • pp.201-211
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    • 2010
  • 본 연구의 목적은 정보 디자인 유형 중에서 상대적으로 "노출 시간이 짧지만 정보 전달력이 강한 정보" 즉, STM 정보(Short-term Memorable Information)” 에 대한 사용자의 인지력을 높이기 위한 방법을 모색하는 것이다. 연구를 통해 STM 정보의 디자인 속성을 고찰하고 거시적 관점에서 디자인적 표현 방법을 다음과 같이 제안하였다. STM 정보는 기능변수의 조작, 방법, 사건, 사용 예라는 네 가지 시각화 속성을 기준으로 시각적 재현 측면에서 '이해도(Understandable)', '접근성(Accessibility)' 속성이 충족되어야 한다. 또한 사용자 조작 측면에서는 '무오류(Errorless)', '적정성(Timeliness)' 속성이 충족되어야 한다. 각 측면에서의 거시적 표현 방법으로써, 시각적 재현 측면에서 "속성이론", "인식모형", "정보 주도성(Proactivity)의 최대화", "잉여 정보의 최소화", "이중부호의 사용"을 제안했으며, 사용자 조작측면에서 "맥락효과", 일차적 독특성을 중심으로 한 "기억부호화", "정보 주사(Scanning)"의 두 가지 방법을 제안했다. 사용자 설문 인터뷰를 통해서 앞서 제안한 8가지 표현 방법의 효율성에 관한 확증 및 STM 정보에 대한 사용자 인지패턴을 발견하였다. 본 연구에서의 주요 발견점을 토대로 향후에는 노출시간별 효과적인 정보 표현 및 그에 따른 응용 방법에 관한 연구가 진행될 필요가 있다.

Outcomes of dental implant treatment in patients with generalized aggressive periodontitis: a systematic review

  • Kim, Kyoung-Kyu;Sung, Hun-Mo
    • The Journal of Advanced Prosthodontics
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    • 제4권4호
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    • pp.210-217
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    • 2012
  • PURPOSE. The purpose of this study was to analyze the current literatures and to assess outcomes of implant treatment in patients with generalized aggressive periodontitis. MATERIALS AND METHODS. Studies considered for inclusion were searched in Pub-Med. The literature search for studies published in English between 2000 and 2012 was performed. Our findings included literature assessing implant treatment in patients with a history of generalized aggressive periodontitis (GAP). All studies were screened according to inclusion criteria. The outcome measures were survival rate of superstructures, marginal bone loss around implant and survival rate of implants. All studies were divided into two follow-up period: short term study (< 5 years) and long term study (${\geq}5$ years). RESULTS. Seven prospective studies were selected, including four short-term and three long-term studies. The survival rates of the superstructures were generally high in patients with GAP, i.e. 95.9-100%. Marginal bone loss around implant in patients with GAP as compared with implants in patients with chronic periodontitis or periodontally healthy patients was not significantly greater in short term studies but was significantly greater in long term studies. In short term studies, the survival rates of implants were between 97.4% and 100% in patients with GAP-associated tooth loss, except one study. The survival rates of implants were between 83.3% and 96% in patients with GAP in long term studies. CONCLUSION. Implant treatment in patients with GAP is not contraindicated provided that adequate infection control and an individualized maintenance program are assured.

음성신호 적응분할방법에 의한 특징분석 (Features Analysis of Speech Signal by Adaptive Dividing Method)

  • 장승관;최성연;김창석
    • 음성과학
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    • 제5권1호
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    • pp.63-80
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    • 1999
  • In this paper, an adaptive method of dividing a speech signal into an initial, a medial and a final sound of the form of utterance utilized by evaluating extreme limits of short term energy and autocorrelation functions. By applying this method into speech signal composed of a consonant, a vowel and a consonant, it was divided into an initial, a medial and a final sound and its feature analysis of sample by LPC were carried out. As a result of spectrum analysis in each period, it was observed that there existed spectrum features of a consonant and a vowel in the initial and medial periods respectively and features of both in a final sound. Also, when all kinds of words were adaptively divided into 3 periods by using the proposed method, it was found that the initial sounds of the same consonant and the medial sounds of the same vowels have the same spectrum characteristics respectively, but the final sound showed different spectrum characteristics even if it had the same consonant as the initial sound.

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Integrate-and-Fire Neuron Circuit and Synaptic Device with Floating Body MOSFETs

  • Kwon, Min-Woo;Kim, Hyungjin;Park, Jungjin;Park, Byung-Gook
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제14권6호
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    • pp.755-759
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    • 2014
  • We propose an integrate-and-fire neuron circuit and synaptic devices with the floating body MOSFETs. The synaptic devices consist of a floating body MOSFET to imitate biological synaptic characteristics. The synaptic learning is performed by hole accumulation. The synaptic device has short-term and long-term memory in a single silicon device. I&F neuron circuit emulate the biological neuron characteristics such as integration, threshold triggering, output generation, and refractory period, using floating body MOSFET. The neuron circuit sends feedback signal to the synaptic transistor for long-term memory.

Mortality Burden Due to Short-term Exposure to Fine Particulate Matter in Korea

  • Jongmin Oh;Youn-Hee Lim;Changwoo Han;Dong-Wook Lee;Jisun Myung;Yun-Chul Hong;Soontae Kim;Hyun-Joo Bae
    • Journal of Preventive Medicine and Public Health
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    • 제57권2호
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    • pp.185-196
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    • 2024
  • Objectives: Excess mortality associated with long-term exposure to fine particulate matter (PM2.5) has been documented. However, research on the disease burden following short-term exposure is scarce. We investigated the cause-specific mortality burden of short-term exposure to PM2.5 by considering the potential non-linear concentration-response relationship in Korea. Methods: Daily cause-specific mortality rates and PM2.5 exposure levels from 2010 to 2019 were collected for 8 Korean cities and 9 provinces. A generalized additive mixed model was employed to estimate the non-linear relationship between PM2.5 exposure and cause-specific mortality levels. We assumed no detrimental health effects of PM2.5 concentrations below 15 ㎍/m3. Overall deaths attributable to short-term PM2.5 exposure were estimated by summing the daily numbers of excess deaths associated with ambient PM2.5 exposure. Results: Of the 2 749 704 recorded deaths, 2 453 686 (89.2%) were non-accidental, 591 267 (21.5%) were cardiovascular, and 141 066 (5.1%) were respiratory in nature. A non-linear relationship was observed between all-cause mortality and exposure to PM2.5 at lag0, whereas linear associations were evident for cause-specific mortalities. Overall, 10 814 all-cause, 7855 non-accidental, 1642 cardiovascular, and 708 respiratory deaths were attributed to short-term exposure to PM2.5. The estimated number of all-cause excess deaths due to short-term PM2.5 exposure in 2019 was 1039 (95% confidence interval, 604 to 1472). Conclusions: Our findings indicate an association between short-term PM2.5 exposure and various mortality rates (all-cause, non-accidental, cardiovascular, and respiratory) in Korea over the period from 2010 to 2019. Consequently, action plans should be developed to reduce deaths attributable to short-term exposure to PM2.5.

신규 댐 건설 전후의 수질변동 분석: 영주댐 상류유역을 중심으로 (Analysis of Water Quality Characteristics According to Short-term Fluctuation of Water Level in the New Dam: Focused on the Upstream Watershed of Yeongju Multipurpose Dam)

  • 이새로미;박재로;황태문;안창혁
    • 한국물환경학회지
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    • 제36권5호
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    • pp.431-444
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    • 2020
  • The relationship between dam construction and water quality has recently come to be considered an important issue. A dam is a physical factor which causes changes to the river system around it. Considering these points, this study was conducted to obtain basic data by analyzing the relationship between water level fluctuations and water quality parameters in the short-term. In terms of methodology, the new construction of the Yeongju Dam (M5) in 2016 was divided into Stage 1 as the lotic system and Stage 2 as the lentic system, with four years in each period, and the water level fluctuations and water quality were analyzed using official data. As a result of this study, M5, a stagnant area in which organic matter and nutrients accumulate, was found to be an important factor in water quality management. In addition, the water level changed rapidly (0.9±0.2 m → 10.9±7.1 m) as the river environment condition was converted from the lotic system to the lentic system. In addition, water quality parameters such as BOD, COD, TOC, and Chl-a significantly changed in the short-term. Further, since the transport of organic matter and nutrients occurred well in the lotic system, sedimentation was expected to be dominant in the lentic system. Therefore, it was determined that when the river flow is blocked, autochthonous organic matter is an important factor for long-term water quality management in the future. This process can increase the trophic state of the water body. As a result of this study, the TSIKO value was converted from mesotrophic in Stage 1 to eutrophic in Stage 2. Eventually, short-term changes in the river environment will affect not only changes in water level but also changes in water quality. Thus, a comprehensive and strategic approach is needed for long-term water quality management in the future.