• 제목/요약/키워드: long-term change

검색결과 2,253건 처리시간 0.031초

천초근의 발암성 연구를 위한 분석 및 안정성 시험 (Stability Test and Analysis of Rubia cordifolia for Carcinogenicity Study)

  • 김대현;박진호;김승현;성상현
    • 생약학회지
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    • 제43권2호
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    • pp.147-151
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    • 2012
  • The marker constituent was isolated from Rubia cordifolia as a major compound. Quantitative method for the marker of the natural medicine was developed using HPLC-DAD and using established method the extract of Rubia cordifolia was evaluated. In addition, long term and accelerated stability test in the extract was examined for six months. No significant change in content of the marker constituent of the extract observed during the period of long term test.

제 2단계 견봉하 충돌증후군에서 관절경적 감압술(5년에서 12년의 장기추시관찰 결과) (Arthroscopic Decompression in Stage II Subacromial Impingement - Five to Twelve Years Follow up -)

  • 최종혁
    • Clinics in Shoulder and Elbow
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    • 제2권2호
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    • pp.99-105
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    • 1999
  • We investigated the effectiveness of arthroscopic decompression in stage Ⅱ subacromial impingement after long term follow up. Arthroscopic subacromial decompression was done in 104 consecutive patients who had stage Ⅱ sub­acromial impingement. After average of 8.4 years follow up, the final results were as following; 57 shoulders(55%) in excellent, 25(24%) in good, 16(15%) in fair and 6(6%) in poor. All parameters-pain, function, muscle strength and motion-were improved significantly(p<0.00l). Rotator cuff tear was developed in 10 shoulders after decompression. Among them, 8 shoulders had unfavorable results including two poor. In 6 failures, two had rotator cuff tear, three had recurrence of impingement with degenerative change and reflex sympathetic dystrophy was developed in one. Reoperations were done in 4 shoulders. Improvement of impingement symptoms was maintained in the most of patients(79%) after long term follow up. Arthroscopic decompression surgery was very effective means for stage Ⅱ impingement syndrome.

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시스템 다이나믹스를 이용한 도시 물수요 장기 예측의 동적 모델 연구 (Dynamic Model of a Long-term Water Demand Using System Dynamics)

  • 이상은;최동진;박희경
    • 상하수도학회지
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    • 제21권1호
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    • pp.75-82
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    • 2007
  • When one forecasts urban water demand in a long-term, multivariate model can give more benefits than per capita requirement model. However, the former has shortcomings in that statistically high explanatory power cannot be obtained well, and change in customer behavior cannot be considered. If the past water consumption effects the future water demand, dynamic model may describe real water consumption data better than static model, i.e. the existing multivariate model. On these grounds, this study built dynamic model using system dynamics. From a case study in Seoul and Busan city, dynamic model was expected to forecast water demand more descriptively and reliably.

지종열 활용에 따른 온도변화 모니터링 (Monitoring of Subsurface Temperature Variation as Geothermal Utilization)

  • 이태종;심병완;송윤호
    • 한국지열·수열에너지학회논문집
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    • 제6권1호
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    • pp.29-35
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    • 2010
  • Long-term temperature monitoring has been performed for ground heat exchanger at the Earthquake Research Center (ERC) building in Korea Institute of Geoscience and Mineral Resources (KIGAM). For the 3 years of monitoring, overall temperature increases are observed at various depths within a borehole heat exchanger. But monitoring of ground temperature variation at the monitoring well beforehand showed that geothermal utilization is not the only source for the temperature increase, Because various kinds of sources can cause the ground temperature change, more thorough investigation should be followed.

시스템다이내믹스 기반의 다세대 확산 수요 예측 : 이동통신 가입자 수요 예측 적용사례 (Forecasting Multi-Generation Diffusion Demand based on System Dynamics : A Case for Forecasting Mobile Subscription Demand)

  • 송희석;김재경
    • Journal of Information Technology Applications and Management
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    • 제24권2호
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    • pp.81-96
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    • 2017
  • Forecasting long-term mobile service demand is inevitable to establish an effective frequency management policy despite the lack of reliability of forecast results. The statistical forecasting method has limitations in analyzing how the forecasting result changes when the scenario for various drivers such as consumer usage pattern or market structure for mobile communication service is changed. In this study, we propose a dynamic model of the mobile communication service market using system dynamics technique and forecast the future demand for long-term mobile communication subscriber based on the dynamic model, and also experiment on the change pattern of subscriber demand under various scenarios.

미세 환경조건에 따른 콘크리트 탄산화 깊이 예측 (Prediction of Depth of Concrete Carbonation According to Microenvironmental Conditions)

  • 박동천
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2021년도 가을 학술논문 발표대회
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    • pp.158-159
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    • 2021
  • When the porous concrete is exposed to the external environment, the internal relative humidity changes from time to time due to the inflow and outflow of moisture. This change in moisture is affected by temperature. The temperature and humidity of concrete is dominant in the carbonation rate, the largest cause of deterioration of concrete. In this study, actual weather data were used as boundary conditions. A carbonization model of concrete temperature and humidity and calcium hydroxide was constructed to perform long-term analysis. There is a slight error in the carbonation formula of the Japanese Academy of Architecture applying the Kishtani coefficient, a representative experimental formula related to carbonization, and the analysis result values. However, considering that it behaves very similarly, it is thought that a fairly reliable numerical analysis model has been established. A slight error is believed to be due to the fact that the amount of residual calcium hydroxide in the carbonated site has not yet been clearly identified.

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A Study on Long-Term Cycling Performance by External Pressure Change for Pouch-Type Lithium Metal Batteries

  • Seong-Ju Sim;Bong-Soo Jin;Jun-Ho Park;Hyun-Soo Kim
    • Journal of Electrochemical Science and Technology
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    • 제15권2호
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    • pp.314-320
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    • 2024
  • Lithium dendrite formation is one of the most significant problems with lithium metal batteries. The lithium dendrite reduces the lithium metal batteries' cycling life and safety. To apply consistent external pressure to a lithium metal pouch cell, we design a press jig in this study. External pressure creates dense lithium morphology by preventing lithium dendrite formation. After 300 cycles at 1 C, the cells with the external pressure perform far better than the cells without it, with a cycling retention of 97.8%. The formation of stable lithium metal is made possible by external pressure, which also enhances safety and cyclability.

하악골 결손의 재건을 위한 혈행화된 비골 이식술에서의 장기간의 체적변화 (LONG TERM EVALUATION OF VOLUME CHANGE IN FREE VASCULARIZED FIBULAR FLAP MANDIBLE RECONSTRUCTION)

  • 김윤태;전승호;염학렬;안강민;명훈;황순정;서병무;최진영;정필훈;김명진;이종호
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • 제32권2호
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    • pp.138-141
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    • 2006
  • Introduction : In recent years, vascularized, i.e., living bone grafts, have been widely applied in the field of oral and maxillofacial surgery, as a method of treatment of congenital or acquired non-unions, and a large defects in mandible. The vascularized fibular graft has been especially used for this purpose because of its shape and mechanical strength. The postoperative hypertrophy of grafted fibula is of particular interest to us. Material and methods : This study was undertaken to determine the volume change(indirect methods) and radiographic appearance of a free vascularized fibular graft as it responds to the mechanical and physiologic features of its new environment. In order to elucidate the long term effect on fibular mass after mandibular reconstruction, change in various method of volume change was utilized as indirect measure of change in long-term. Results : The younger the patient, the more prominent and rapid the hypertrophy of the graft. the hypertrophy of the graft never exceeded the diameter of the recipient bone, except for callus enlargement after stress fracture of the grafted bone. Conclusion : Etiologic explanations for this phenomenon have not been clarified in the previeous literature. some of the factors implicated include a periosteal reaction or new bone formation, as seen at the onset of bone union after a fracture in a child, a reaction to the mechanical loading on the graft and a reaction to the circulatory changes resulting from the grafting procedure.

기후변화 대응 산림의 장기 기후변화 연구시설 (Review of Long-term Climate Change Research Facilities for Forests)

  • 서동진;김현철;이현석;이솔지;이위영;한심희;강준원
    • 한국농림기상학회지
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    • 제18권4호
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    • pp.274-286
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    • 2016
  • 전체 온실가스 배출량의 약 72%를 차지하는 이산화탄소($CO_2$)는 지구온난화를 야기하는 대표적인 온실가스로 분류되어 있다. IPCC의 제5차 기후변화 종합평가보고서(2014)에 의하면, 지난 100년간 지구 대기의 $CO_2$는 약 35% 증가했으며 지구의 온난화는 최근 30년간 심화되는 것으로 나타났다. 이에 따라 지구 온난화에 따른 기후변화, 기상이변으로 산림식생대의 이동과 식물계절 변화가 유발되고 있다. 산림은 교토의정서에서 인정한 유일한 온실가스 흡수원으로서 보전 및 증진 필요성이 있으며 기후변화에 대한 수목 반응의 연구는 미래의 산림생태계 변화를 예측하는데 필수불가결한 요소이다. 따라서 장기 기후변화 연구시설을 이용한 수목의 생리 생태적 반응 연구와 실제 산지에서 이루어지는 장기 모니터링 연구를 결부하여 이용한다면 기후변화로 인한 미래 산림생태계의 변화를 예측하고 대응하는데 크게 기여할 것이다.

기후변화 적응의 신기후체제 합의: 전망을 위한 접근방법 (Outlook for a New International Agreement on Climate Change Adaptation: How to Approach)

  • 이승준
    • 환경정책연구
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    • 제14권3호
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    • pp.75-94
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    • 2015
  • 본 연구의 목적은 유엔기후변화협약 최초로 법적 효력을 갖는 기후변화 적응 관련 합의문을 도출하는 시기에 앞서 적응과 관련한 당사국 간의 핵심 쟁점을 분석하고 이를 토대로 최종 합의점을 전망하는 이론적 틀을 제공하는 것이다. 유엔기후변화협약 내의 문서와 적응활동 및 신기후체제 합의문 도출을 위한 협상의 논의과정을 분석한 결과 협약에서 적응은 협약의 기본원칙인 '공통의 그러나 차별화된 책임 및 각자의 능력 원칙'에 따라 선진국의 개도국에 대한 지원 중심으로 이루어지고 있음을 알 수 있다. 신기후체제 합의문 도출을 위한 더반 플랫폼 특별 작업반 회의를 통해 적응과 관련하여 장기 및 전 지구적 측면, 의무 및 기여와 행동, 모니터링 및 평가, 제도적 장치, 손실과 피해를 주요 의제로 도출하였다. 이에 따라 각 의제와 관련하여 선진국과 개도국 간 대립되는 쟁점을 토대로 가능한 합의점의 스펙트럼을 설정하고, 본 연구에서 제시하는 협상과정에서 당사국의 입장에 영향을 주는 세 가지 요소인 자국의 이익, 실제 적응문제, 사회적 흐름을 고려하여 최종 합의점을 예측할 수 있다. 신기후체제에 관한 당사국 간 협상이 장기적 측면에서 전 지구적 적응행동을 강화하기 위한 지속성 있는 합의문을 도출하고자 한다면 세 가지 요소를 균형 있게 고려해야하며, 이는 실제 협약 외부에서 이루어지는 적응활동이나 적응과 관련한 사회적 흐름과 수요를 충분히 고려한 합의문이 도출되어야 함을 의미한다. 2015년 제21차 당사국총회의 최종 협상과정에서 당사국들이 국제사회의 기대를 충분히 반영한다면, 신기후체제에 관한 합의가 장기적 측면에서 전 지구적으로 기후변화에 대한 취약성 감소와 회복탄력성 제고를 달성할 수 있는 계기가 될 수 있을 것으로 전망된다.

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