• 제목/요약/키워드: Long-term Time Series

검색결과 581건 처리시간 0.025초

기후변화와 동해안에서의 명태 자원의 고갈 (Climate Change and Depletion of Walleye Pollock Resources in the East Sea)

  • Kim, Jong-Gyu;Kim, Joong-Soon
    • 한국환경보건학회지
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    • 제44권3호
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    • pp.259-266
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    • 2018
  • Objectives: Considered the "national fish" in Korea, the walleye pollock (Gadus chalcogrammus) has disappeared in the East Sea (Sea of Japan), a main habitat and fishing ground for the species. The reason for the disappearance is still a matter of controversy. This study was performed to investigate the long-term relationship between the walleye pollock catch and various meteorological and oceanographic factors in these waters. Methods: Fishery data on walleye pollock and data on meteorological and marine environmental factors over the 30 years (1981-2010) were obtained from the official national database. Time series analysis and correlation and regression analyses were performed to study the relationships. Results: Both air temperature and sea surface temperature in the East Sea rose over these 30 years, and the latter became more prominent. Salinity and dissolved oxygen showed a tendency to decrease while concentrations of nutrients such as nitrite nitrogen and nitrate nitrogen showed an increasing tendency. Sea surface temperature, air temperature, atmospheric pressure, and wind grade were negatively correlated with the catch size of walleye pollock (p<0.05), but salinity was positively correlated (p<0.001). Conclusion: The results of this study indicate that climate change, especially ocean warming, affected the habitat of walleye pollock. The results also indicate that lower sea surface and air temperatures, milder wind grade, and higher salinity were preferred for the survival of the fish species. It is necessary to pay attention to changes of the ocean ecosystem in terms of environmental pollution as well as seawater temperature.

Calibration and Validation Activities for Earth Observation Mission Future Evolution for GMES

  • LECOMTE Pascal
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.237-240
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    • 2005
  • Calibration and Validation are major element of any space borne Earth Observation Mission. These activities are the major objective of the commissioning phases but routine activities shall be maintained during the whole mission in order to maintain the quality of the product delivered to the users or at least to fully characterise the evolution with time of the product quality. With the launch of ERS-l in 1991, the European Space Agency decided to put in place a group dedicated to these activities, along with the daily monitoring of the product quality for anomaly detection and algorithm evolution. These four elements are all strongly linked together. Today this group is fully responsible for the monitoring of two ESA missions, ERS-2 and Envisat, for a total of 12 instruments of various types, preparing itself for the Earth Explorer series of five. other satellites (Cryosat, Goce, SMOS, ADM-Aeolus, Swarm) and at various levels in past and future Third Party Missions such as Landsat, J-ERS, ALOS and KOMPSAT. The Joint proposal by the European Union and the European Space Agency for a 'Global Monitoring for Environment and Security' project (GMES), triggers a review of the scope of these activities in a much wider framework than the handling of single missions with specific tools, methods and activities. Because of the global objective of this proposal, it is necessary to put in place Multi-Mission Calibration and Validation systems and procedures. GMES Calibration and Validation activities will rely on multi source data access, interoperability, long-term data preservation, and definition standards to facilitate the above objectives. The scope of this presentation is to give an overview of the current Calibration and Validation activities at ESA, and the planned evolution in the context of GMES.

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Topex/Poseidon 고도계자료를 이용한 동북아시아 연변해역의 해수면 변화 연구 (Sea Level Variabilities in the East Asian Marginal Seas by Topex/Poseidon Altimeter Data)

  • Yoon, Hong-Joo
    • 한국정보통신학회논문지
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    • 제5권6호
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    • pp.1190-1194
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    • 2001
  • TOPEX/POSEIDON(T/P) 위성의 7년 간 고도계자료를 사용하여 동북아시아지역에서의 해수면 순환과 해수면 변화에 대하여 연구하였다. 헌장 조위자료와 고도계자료간의 비교에서, 고도계에 포함되어 있는 60일의 tidal aliasing(M$_2$ 및 S$_2$의 해양조석 성분)의 영향을 제거한 후 순수 해수면 성분을 구하였다. 해수면 변동을 보면 쿠로시오 해류가 사행을 하면서 강하게 흘러가는 일본 동남부해역에서 뚜렷한 와류의 형성과 함께 높은 해수면 변화 값을 보였다. 이것은 쿠로시오의 확장과 해저지형의 영향과 기인하다. 평균해수면은 황해 및 동해에 비해서 북태평양해역에서 높게 나타났다.

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노인요양시설 요양층의 기능별 면적구성과 상관요인에 관한 연구 (A Study on the Functional Area Composition and Correlation Factors of Elderly Care Floor in Nursing Home)

  • 윤소희;김석태
    • 한국실내디자인학회논문집
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    • 제24권3호
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    • pp.156-164
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    • 2015
  • Nursing Homes do not have a defined standard in the space area nor does it have a detailed standard facility requirement by law. This can possibly lead to the deterioration of the facility and the system. This directly affects the medical treatment space area within the nursing home. The medical treatment area provides medical treatment to seniors and this is where the seniors get most of their daily services. Therefore, this is research is about the study of the space area of the medical center and the ratio trend of the space area for the medical treatment facility located in senior nursing homes. Ten facilities have been selected in this study to analyze the correlation factors between space area and its trends. The analysis performed includes the conditions relating to the area and what affects the center. We have followed up with a proposal for improvement of the facility and area configuration for the medical treatment facility. Based on the analysis, the following conclusion can be made: First, the senior welfare centers are mostly used as a residence purpose followed a temporary stay of residence facility for the seniors. Second, research indicates that the bigger the facility, nursing and public functions took a larger portion of the space area compared to other services within the senior welfare centers. Third, the study shows the management space area took up about 1%~6% of the entire medical center within the nursing home which is a narrow space area because of the integrated management. Fourth, analysis based on the trend in the time-series indicate after the adoption of the system, there is a continued decline in the space area of nursing, management and public areas. Lastly, since before and after 2008, the space area composition of the nursing facility shows a continuous decline in our study. We can safely conclude that the revised senior welfare act's construction plan has an effect in the facility and is effectively working to meet its requirement. Therefore, the revision of the law is required to reflect the social needs of the residents.

Clinical Factors and Perioperative Strategies Associated with Outcome in Preinjury Antiplatelet and Anticoagulation Therapy for Patients with Traumatic Brain Injuries

  • Pang, Chang Hwan;Lee, Soo Eon;Yoo, Heon
    • Journal of Korean Neurosurgical Society
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    • 제58권3호
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    • pp.262-270
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    • 2015
  • Objective : Long-term oral anticoagulation or antiplatelet therapy has been used with increasing frequency in the elderly. These patients are at increased risk of morbidity and mortality from expansion of intracranial hemorrhage. We conducted a single-center retrospective case control study to evaluate risk factors associated with outcomes and to identify the differences in outcome in traumatic brain injury between preinjury anticoagulation use and without anticoagulation. Methods : A retrospective study of patients who underwent craniotomy or craniectomy for acute traumatic cerebral hemorrhage, between January 2005 and December 2014 was performed. Results : A consecutive series of 50 patients were evaluated. The factors significantly differed between the two groups were initial Prothrombin Time-International Normalized Ratio, initial platelet count, initial Glasgow Coma Scale score, and postoperative intracranial bleeding. Mean Glasgow Outcome Scale (GOS) score were similar between the two groups. In the patient with low-energy trauma only, no significant differences in GOS score, postoperative bleeding and many other factors were observed. The contributing factors to postoperative bleeding was preinjury anticoagulation and its adjusted odds ratio was 12 [adjusted odds ratio (OR), 12.242; p=0.0070]. The contributing factors to low GOS scores, which mean unfavorable neurological outcomes, were age (adjusted OR, 1.073; p=0.039) and Rotterdam scale score for CT scans (adjusted OR, 3.123; p=0.0020). Conclusion : Preinjury anticoagulation therapy contributed significantly to the occurrence of postoperative bleeding. However, preinjury anticoagulation therapy in the patients with low-energy trauma did not contribute to the poor clinical outcomes or total hospital stay. Careful attention should be given to older patients and severity of hemorrhage on initial brain CT.

Bayesian HMM 기반의 건강 상태 분류 및 예측 (Health State Clustering and Prediction Based on Bayesian HMM)

  • 신봉기
    • 정보과학회 논문지
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    • 제44권10호
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    • pp.1026-1033
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    • 2017
  • 본 논문은 계층적 디리슐레 과정(HDP)과 은닉 마르코프 모형(HMM)이 결합된 베이스 통계학적 방법과 HMM의 상태 지속 정보를 이용한 건강 상태 예측 방법을 제안한다. HDP-HMM은 베이스 방법의 HMM 확장 모형으로서 건강의 동적 특성을 고려하여 불확실하고 가늠하기조차도 어려운 건강 상태의 수를 추정할 수 있게 해준다. 모의 데이터와 실제 건건 검진 데이터를 이용한 시험을 통하여 흥미 있는 행동 특성을 볼 수 있었으며 최대 5년까지로 제한한 미래 예측도 충분한 가능함을 확인하였다. 미래는 불확실하며 예측 문제는 본질적으로 어렵다. 그러나 본 연구의 실험 결과로 동적인 문맥 하에서 다중 후보 가설을 제시함으로서 실용 가능한 건강상태의 장기 예측이 가능하다는 것을 읽을 수 있었다.

Trend Analysis of GPS Precipitable Water Vapor Above South Korea Over the Last 10 Years

  • Sohn, Dong-Hyo;Cho, Jung-Ho
    • Journal of Astronomy and Space Sciences
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    • 제27권3호
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    • pp.231-238
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    • 2010
  • We analyzed global positioning system (GPS)-derived precipitable water vapor (PWV) trends of the Korea Astronomy and Space Science Institute 5 stations (Seoul, Daejeon, Mokpo, Milyang, Sokcho) where Korea Meteorological Administration meteorological data can be obtained at the same place. In the least squares analysis, the GPS PWV time series showed consistent positive trends (0.11 mm/year) over South Korea from 2000 to 2009. The annual increase of GPS PWV was comparable with the 0.17 mm/year and 0.02 mm/year from the National Center for Atmospheric Research Earth Observing Laboratory and Atmospheric InfraRed Sounder, respectively. For seasonal analysis, the increasing tendency was found by 0.05 mm/year, 0.16 mm/year, 0.04 mm/year in spring (March-May), summer (June-August) and winter (December-February), respectively. However, a negative trend (-0.14 mm/year) was seen in autumn (September-November). We examined the relationship between GPS PWV and temperature which is the one of the climatic elements. Two elements trends increased during the same period and the correlation coefficient was about 0.8. Also, we found the temperature rise has increased more GPS PWV and observed a stronger positive trend in summer than in winter. This is characterized by hot humid summer and cold dry winter of Korea climate and depending on the amount of water vapor the air contains at a certain temperature. In addition, it is assumed that GPS PWV positive trend is caused by increasing amount of saturated water vapor due to temperature rise in the Korean Peninsula. In the future, we plan to verify GPS PWV effectiveness as a tool to monitor changes in precipitable water through cause analysis of seasonal trends and indepth/long-term comparative analysis between GPS PWV and other climatic elements.

신문 빅데이터를 바탕으로 본 국내 정보화의 경향과 도서관의 역할 (Trends of South Korea's Informatization and Libraries' Role Based on Newspaper Big Data)

  • 나경식;이지수
    • 한국콘텐츠학회논문지
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    • 제18권9호
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    • pp.14-33
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    • 2018
  • 본 연구는 경향신문, 국민일보, 한겨레, 한국일보 총 4개의 신문기사에서 정보화 및 도서관과 관련해서 1998년부터 2017년까지 20년간의 객관적인 신문 데이터를 통해 한국의 정보화 트렌드를 분석해 보고자 수행되었다. 이에 본 연구는 뉴스 빅데이터 시스템인 빅카인즈(BigKinds)를 활용하여 메타데이터 및 연관어(공기어) 분석 결과를 바탕으로, 키워드 '정보', '정보화'와 '도서관'의 시대별, 분야별로 단순빈도 분석과 군집 및 분류 등의 결과를 분석하여 제시하였고, 이를 바탕으로 정부기관의 발행물인 '정보화백서'와 문헌정보학 분야의 '학술지'의 연구 주제와 비교를 통해 언론과 연구에서 나타나는 정보화의 경향을 비교, 분석해 보았다. 본 연구는 언론을 바탕으로 형성된 국내 정보화의 트렌드를 해석하고자 시도했으며, 장기시계열적 데이터인 신문기사의 빅데이터를 활용하여 분석하였다는데 그 의의가 있다. 연구결과를 바탕으로 국내의 정보화와 함께한 도서관의 성장과 발전의 함의와 시사점을 제시하였다. 또한 향후 지속적인 연구를 통해 정보화와 도서관정보화정책 발전방향의 기본적인 틀을 만들 수 있을 것이라 기대한다.

TWO-COLOR VR CCD PHOTOMETRY OF THE INTERMEDIATE POLAR `RXS J062518.2+733433

  • Kim, Yong-Gi;Andronov Ivan L.;Park, Sung-Su;Chinarova Lidia L.;Baklanov Alexey V.;Jeon, Young-Beom
    • Journal of Astronomy and Space Sciences
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    • 제22권3호
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    • pp.197-210
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    • 2005
  • Results of 7 nights of CCD VR photometry of the intermediate polar 1RXS J062518.2+733433 obtained at the Korean 1.8m telescope are reported. The corrected ephemeris for the orbital minimum is BJD (Orb.min) = 2453023.6159(42)+0.1966431(33) (E-1735). The corrected ephemeris for the spin maximum is BJD (spin max) = 2452893 78477 (10)+0.01374116815 (17) (E-15382) (cycle numbering corresponds to that of Staude et al.2003). The variations of the shape of the individual spin variations are highly correlated in V and R. The phase of the spin maximum is found to be dependent on the orbital phase. The corresponding semi-amplitude of sinusoidal variations of phase is $0.11{\pm}0.03.$ This new phenomenon is explained by the changing viewing conditions of the accreting magnetic white dwarf, and should be checked in further observations this star and for other intermediate polars. To avoid influence of this effect on the analysis of the long-term spin period variations, the runs of at least one orbital period are recommended. Results of time series analysis are presented in tables.

Studies on Evaluation for Long-Term Structural Performance of Pinus densiflora Sieb. et Zucc. (I) -Shear Creep and Mechano-Sorptive Behavior of Drift Pin Jointed Lumber-

  • Hong, Soon-Il;Park, Jun-Chul
    • Journal of the Korean Wood Science and Technology
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    • 제34권5호
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    • pp.11-18
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    • 2006
  • This study was carried out to evaluate the mechano-sorptive deflection of shear creep of drift pin jointed solid wood. Specimens were the solid wood of Pinus densiflora. The joint was composed with steel plate and drift pin, 85mm in length and 10mm in diameter. The creep tests were conducted under the constant loads in an variable environment. Five different shearing loads were applied parallel to the grain of specimens. The shearing loads applied were 170, 340, 510, 680 and 850 kgf. The stress levels were 10, 20, and 30, 40 and 50% of the bearing strength obtained from the tension-type lateral strength test. The creep tests for specimens were carried out for 10300 hours. A few general conclusions could be drawn from this study: The mechano-sorptive deflection (${\delta}$ ms) is defined as ${\delta}\;ms={\delta}\;t-({\delta}\;c+{\delta}\;sh)-{\delta}\;o$, where ${\delta}$ t is the total deflection, ${\delta}$ c is the pure creep, ${\delta}$ sh is shrinkage-swelling behavior, and ${\delta}$ o is the initial deflection. Changes of relative humidity may cause more severe creep deflection than those of constant humidity, especially during the drying process. The mechano-sorptive behaviors of specimens, except the effects of shrinkage and swelling, gradually increased with increasing time. The deflection is increased in desorption process and recovered in adsorption process. The deflections of drift pin jointed solid wood under different loads showed almost same tendency in all specimens. Although the creep deflection tendencies of each series are very similar, the specimens subjected to a large shearing load exhibit large creep deflections in the desorption process than do those to the small shearing load specimens.