• 제목/요약/키워드: Circulation Frequency

검색결과 219건 처리시간 0.027초

맹방해빈의 일 년에 걸친 대순환과정 수치해석 - 2017.4.26부터 2018.4.20까지의 해안선 변화를 중심으로 (Numerical Analysis of the Grand Circulation Process of Mang-Bang Beach-Centered on the Shoreline Change from 2017. 4. 26 to 2018. 4. 20)

  • 조영진;김인호;조용준
    • 한국해안·해양공학회논문집
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    • 제31권3호
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    • pp.101-114
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    • 2019
  • 현재 상당한 침식이 진행되고 있는 맹방해빈을 대상으로 년 간 해안선 변화량을 수치모의 하였다. 수치모의는 이산화된 해안선 단위 격자에 표사 순유입량과 해안선 전진 혹은 퇴각량은 서로 균형을 이룬다는 개념으로부터 유도한 해안선 모형(One Line Model for shore line)에 기초하여 수행하였다. 이 과정에서 연안 표사량의 경우 Energy flux 모형, 횡단 표사량의 경우 Bailard와 Inman(1981) 계열의 수정 모형(Cho and Kim, 2019)을 활용하였다. 수치모의 과정에서 closure depth는 파랑에 종속하는 것으로 해석하였으며, closure depth는 Shiled's parameter에 기반한 Hallermeier(1978)의 해석모형을 활용하여 산출하였다. 모의결과 너울이 우세한 2017.4.26부터 2017.10.15까지는 횡단 표사가 지속적으로 유입되어 해안선이 전진하는 것으로 모의되었다. 또한 10월 중순과 10월 말 사이에 연이어 발생한 년 최대 고파랑 내습에 따른 침식과 이로 인한 해안선의 일시적 퇴각, 이 후 파랑이 잦아들면서 다시 출현하는 너울에 의한 횡단표사 유입과 이로 인한 해안선 복원, 삼월중순부터 삼월말까지 연이어 발생한 고파랑에 의한 해안선 퇴각 등 일 년에 걸친 해안선 대순환과정이 상세하게 모의되는 것을 확인할 수 있었다. 전술한 해안선 대순환 과정은 2017년 4월5일, 9월 7일, 11월 7일, 2018년 3월14일에 실측된 해안선 위치에서도 유사하게 관측할 수 있다. 그러나 해안선이 전진 혹은 퇴각되는 양은 실측치에 비해 수치모의에서 크게 관측되며, 이러한 차이는 대부분의 지형모형(Genesis: Hanson and Kraus, 1989)처럼 closure depth를 $h_c=8.09m$로 일정하게 유지한 경우에 더욱 증가하였다.

Precision Evaluation of Recent Global Geopotential Models based on GNSS/Leveling Data on Unified Control Points

  • Lee, Jisun;Kwon, Jay Hyoun
    • 한국측량학회지
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    • 제38권2호
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    • pp.153-163
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    • 2020
  • After launching the GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) which obtains high-frequency gravity signal using a gravity gradiometer, many research institutes are concentrating on the development of GGM (Global Geopotential Model) based on GOCE data and evaluating its precision. The precision of some GGMs was also evaluated in Korea. However, some studies dealt with GGMs constructed based on initial GOCE data or others applied a part of GNSS (Global Navigation Satellite System) / Leveling data on UCPs (Unified Control Points) for the precision evaluation. Now, GGMs which have a higher degree than EGM2008 (Earth Gravitational Model 2008) are available and UCPs were fully established at the end of 2019. Thus, EIGEN-6C4 (European Improved Gravity Field of the Earth by New techniques - 6C4), GECO (GOCE and EGM2008 Combined model), XGM2016 (Experimental Gravity Field Model 2016), SGG-UGM-1, XGM2019e_2159 were collected with EGM2008, and their precisions were assessed based on the GNSS/Leveling data on UCPs. Among GGMs, it was found that XGM2019e_2159 showed the minimum difference compared to a total of 5,313 points of GNSS/Leveling data. It is about a 1.5cm and 0.6cm level of improvement compare to EGM2008 and EIGEN-6C4. Especially, the local biases in the northern part of Gyeonggi-do, Jeju island shown in the EGM2008 was removed, so that both mean and standard deviation of the difference of XGM2019e_2159 to the GNSS/Leveling are homogeneous regardless of region (mountainous or plain area). NGA (National Geospatial-Intelligence Agency) is currently in progress in developing EGM2020 and XGM2019e_2159 is the experimentally published model of EGM2020. Therefore, it is expected that the improved GGM will be available shortly so that it is necessary to verify the precision of new GGMs consistently.

Nursery depopulation 기법에 의한 돼지 호흡기질병 상재돈군의 호흡기 병인체 전파방지에 관한 연구 (Elimination of respiratory pathogens in endemically infected swine herds by nursery depopulation)

  • 김봉환;주한수
    • 대한수의학회지
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    • 제37권4호
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    • pp.755-763
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    • 1997
  • Recently new technologies for the establishment of high health herds are becoming efficient tools in the control of PRRS virus and secondary infections. Medicated early weaning(MEW) and nursery depopulation(ND) have shown to be one of the most successful procedures in the eradication and control of pathogens. Indirect evidence of the role of PRRSV in precipitating secondary infection comes from successful improvement in growth and in decreasing mortality on farms that have eliminated PRRSV through ND. Hence the present experiments were conducted in an effort to compare ND with MEW procedures as a means of eliminating PRRSV controlling secondary pathogens and improving performance of pigs in endemically infected swine herds. Following MEW and ND procedures practiced in the farms, some benefits obtained were as follows: 1. A decrease in PRRSV circulation in the nursery, but no entire elimination. 2. Decrease in the frequency of secondary bacteria and in the use of antibiotics. 3. Mycoplasma hyopneumoniae infection was prevented during the nursery stage. 4. ND protocol had a lower cost and management changes than MEW techniques. 5. Nursery performance was improved after the depopulation, cleaning and disinfection procedures, even though PRRSV still being cycled in the old nursery rooms. These studies revealed that the MEW and ND protocols are not always successful for PRRS virus elimination but it's great effect on control of secondary pathogens and improvement of performance make MEW and ND an efficient tools for the establishment of healthier and more efficient herds.

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심실중격결손증의 임상적 고찰 (Clinical Analysis of Ventricular Septal Defect)

  • 인강진
    • Journal of Chest Surgery
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    • 제22권4호
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    • pp.620-629
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    • 1989
  • A clinical analysis of 138 cases of ventricular septal defect operated on from 1983 to June 1988 at the department of Thoracic and Cardiovascular Surgery, School of Medicine, Chung-nam National University was done. The following results were obtained. 1. The VSD were 27.6 % and 41.0 % respectively of 500 open heart surgery cases and 334 congenital heart disease. 2. The range of age when the VSD was repaired was 3 months to 45 years, the mean age was 10.4 years and the 53.6 % of patients were under 7 years. The sex ratio was 6:4 in males favor. 3. The two common symptoms were frequent upper respiratory infection and dyspnea whose frequency was 62.5 % and 58.7% respectively. 4. 52% of the patients was below 25 percentile of the standard body weight. 5. The most common chest PA findings were cardiomegaly and increased pulmonary vascularity. 6. On anatomical classification, perimembranous type was most common [65.5%], subpulmonary arterial type was 27.6 %, perimembranous plus subpulmonary arterial type was 3.4 % multiple VSD was 0.8 % and LV-RA defect was 2.6 %. 7. Associated cardiac anomalies were founded in 39 cases [35.5 %] and PDA and aortic valve prolapse were most common associated anomalies and extracardiac anomalies were founded in 6.7 % of patients. 8. Mean extracorporeal circulation time was 68 min. and mean aortic cross-clamping time was 42 min. 9. The postoperative complications developed in 26 % of patients and the most common one was minor wound infection. 10. Right bundle branch block developed in 54.8% of the patients who had right ventriculotomy, 40.0% of the patients who had right atriotomy and 10.5% of the patients who had pulmonary arteriotomy. 11. The overall operative mortality was 5.1 % and the operative mortality of the patients who body weigh under 10 Kg was 23.8%.

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CMIP5 기후모델에서 나타나는 열대저기압 생성빈도의 연진동과 경년변동성: 잠재생성지수의 이용 (Annual Cycle and Interannual Variability of Tropical Cyclone Genesis Frequency in the CMIP5 Climate Models: Use of Genesis Potential Index)

  • 권민호
    • 한국지구과학회지
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    • 제33권7호
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    • pp.583-595
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    • 2012
  • 대기 및 해양의 대규모 환경에서 열대저기압 발생의 잠재적 빈도는 잠재생성지수(GPI; Genesis Potential Index)를 이용하여 예측할 수 있다. 본 연구에서는 18개의 CMIP5 기후모델을 이용하여 GPI의 연진동 및 경년변동성이 분석되었다. 비교를 위하여 재분석자료로부터 계산된 GPI의 연진동이 재조명되었다. 특히 CMIP5 기후모델과 재분석자료에 의한 GPI가 비교되었고, 그 차이에 대한 가능한 해석이 논의되었다. ENSO (El Nino and Southern Oscillation)는 열대 저기압 발생 및 경로에 영향을 주는 열대 기후현상이다. 잠재생성지수가 네 개의 대규모 매개변수의 함수임을 이용함으로써 열대저기압발생에 대한 역학적 해석이 제시되었다. 본 연구에서는 엘니뇨 혹은 라니냐 해에 GPI 편차를 논의하였고, 그 편차에 가장 영향을 많이 주는 인자를 찾았다. 또한 여러 대규모 인자를 활용하여 북태평양지역 열대저기압 발생에 대하여 가능한 기작을 논의하였다.

뇌졸중 환자의 보완대체요법 이용실태 (Utilization of Alternative Complementary Remedies of Stroke Patients)

  • 목순악;조명옥
    • 성인간호학회지
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    • 제16권3호
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    • pp.432-441
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    • 2004
  • Purpose: This descriptive survey was conducted to investigate out the utilization of alternative complementary remedies for stroke patients. Method: The subject for this study were 194 patients, selected from inpatients department of 11 major medical center at Busan and Ulsan. Data were collected from August 19th to November 12th, 2002 through interview schedule designed by the investigator. Data was analyzed with frequency, percentage, and ${\chi}^2$-test by using SPSS Win 10.0. Results: 71.6% of objects has used alternative complementary remedies. The use of alternative complementary remedies according to disease-related features was statistically significant in concurrent diseases(${\chi}^2=15.03$, p=0.001), rehabilitation treatment(${\chi}^2=6.341$, p=0.012) and the level of ADL(${\chi}^2=19.63$, p=0.000). The most frequently used therapies were diet and nutrition(31.8%). The patients with less than 3month onset and in the mid-period of treatment frequently used remedies. The reason for using remedies were the belief in it's effects on treatment, but most patients responded was not effective(30.9%) or not much improvement after using remedies. Most of the patients were recommended to use remedies by their neighbors(27.3%) and family members(25.2%). The family members were most supportive in therapy(56.1%). The 28.1% of patients responded that the remedies were effective in promoting blood circulation and 95% of the patients had not experienced side effects. Conclusion: These results could be the basic material in developing nursing intervention for cerebral apoplexy patients.

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군집분석과 상세기상모델을 통한 포항지역 계절별 바람장 특성 (The Characteristics of Seasonal Wind Fields around the Pohang Using Cluster Analysis and Detailed Meteorological Model)

  • 정주희;오인보;고대권;김유근
    • 한국환경과학회지
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    • 제20권6호
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    • pp.737-753
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    • 2011
  • The typical characteristics of seasonal winds were studied around the Pohang using two-stage (average linkage then k-means) clustering technique based on u- and v-component wind at 850 hpa from 2004 to 2006 (obtained the Pohang station) and a high-resolution (0.5 km grid for the finest domain) WRF-UCM model along with an up-to-date detailed land use data during the most predominant pattern in each season. The clustering analysis identified statistically distinct wind patterns (7, 4, 5, and 3 clusters) representing each spring, summer, fall, and winter. During the spring, the prevailed pattern (80 days) showed weak upper northwesterly flow and late sea-breeze. Especially at night, land-breeze developed along the shoreline was converged around Yeongil Bay. The representative pattern (92 days) in summer was weak upper southerly flow and intensified sea-breeze combined with sea surface wind. In addition, convergence zone between the large scale background flow and well-developed land-breeze was transported around inland (industrial and residential areas). The predominant wind distribution (94 days) in fall was similar to that of spring showing weak upper-level flow and distinct sea-land breeze circulation. On the other hand, the wind pattern (117 days) of high frequency in winter showed upper northwesterly and surface westerly flows, which was no change in daily wind direction.

Sox12 Is a Cancer Stem-Like Cell Marker in Hepatocellular Carcinoma

  • Zou, Song;Wang, Chen;Liu, Jiansheng;Wang, Qun;Zhang, Dongdong;Zhu, Shengnan;Xu, Shengyuan;Kang, Mafei;He, Shaozhong
    • Molecules and Cells
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    • 제40권11호
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    • pp.847-854
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    • 2017
  • Recent studies on molecular carcinogenesis suggest that the chemo-resistance of some cancers is largely due to presence of cancer stem cells (CSCs), which affect the chemotherapy outcome for hepatocellular carcinoma (HCC). However, currently no consensus on a CSC phenotype in HCC has been obtained. Here, we examined Sox12 as a novel CSC marker in HCC. Sox12+ versus Sox12- cells were purified from HCC cell lines. The Sox12+ cells were compared with Sox12- HCC cells for tumor sphere formation, chemo-resistance, tumor formation after serial adoptive transplantations in nude mice, and the frequency of developing distal metastasis. We found that compared to Sox12- HCC cells, Sox12+ HCC cells generated significantly more tumor spheres in culture, were more chemo-resistant to cisplatin, were detected in circulation more frequently, and formed distal tumor more frequently. Moreover, Sox12 appeared to functionally contribute to the stemness of HCC cells. Thus, we conclude that Sox12 may be a novel marker for enriching CSCs in HCC.

유정란 태아외부혈관 내부 혈액유동에 대한 혈류역학적 연구 (Hemodynamic Analysis of Blood Flows in the Extraembryonic Blood Vessels of Chicken Embryos)

  • 이정엽;이상준
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.6-9
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    • 2008
  • Analyzing the characteristics of blood flow in the blood vessels is very important to diagnose the circulatory diseases. In order to investigate the hemodynamic characteristics in vivo, the measurements of blood flows inside the extraembryonic arterial and venous blood vessels of chicken embryos were carried out using an in vivo micro-PIV technique. The circulatory diseases are closely related with the formation of abnormal hemodynamic shear stress regions, thereby it is important to get blood velocity and vessel's morphological information according to the vessel configuration and the flow conditions. In this study, the flow images of RBCs in blood vessels were obtained using a high-speed CMOS camera with a spatial resolution of approximately 14.6${\mu}$m${\times}$14.6${\mu}$m in the whole circulation network of blood vessels. The blood flows in the veins and arteries show steady laminar and unsteady pulsatile flow characteristics, respectively. The mean blood flows merged (in veins) and bifurcated (in arteries) smoothly into the main blood vessel and branches, respectively, without any flow separation or secondary flow which accompanying large variation of shear stress. Vorticity was high in the inner regions for both types of vessels, where the radius of curvature varied greatly. The instantaneous flows in the arterial blood vessels showed noticeable pulsatility due to the heart beat, and the main features of the velocity waveforms, including pulsatile shape, retrograde flow, mean velocity, maximum velocity and pulsatile frequency, were significantly dependent on the pulsatile condition which dominates the arterial blood flow. In near future, these in vivo experimental results of blood flow measured in various extraembryonic blood vessels would be very useful to understand the hemodynamic characteristics of human blood flows and various blood flow researches for clinically useful hemodynamic discoveries as well.

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공간사용자의 본능적 시선탐색활동에 나타난 주사경로 알고리즘 특성 (The feature of scanning path algorithm shown at natural visual search activities of space user)

  • 김종하;김주연
    • 감성과학
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    • 제17권2호
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    • pp.111-122
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    • 2014
  • 본 연구는 지하철 로비공간을 대상으로 한 주시실험을 통해 공간정보의 본능적 시선탐색과정에서 나타나는 주시특성에 나타난 주사경로 알고리즘을 분석하였다. 주시기간 구간별 분석에서 주시시간이 오래 경과할수록 주사유형 횟수가 증가하고 있었는데, 오래 주시할수록 주시단절이 많이 일어난 것으로 해석이 가능하며, 주시에 따른 피로나 활발한 탐색이 자연스러운 공간탐색과정에서 일어나는 과정에서 화상범위를 벗어나는 경우가 많았던 것으로 보인다. 또한 시간구간의 변화에 따른 주사유형의 변화를 추세선으로 살펴본 결과, "집중"은 시간구간의 증가와 함께 가파른 증가, "대각 수직"은 완만한 증가를 보이는 반면, "순환 혼합 수평"은 감소 경향을 보이고 있다. 공간을 주시한 피험자의 주시데이터에는 다양한 시각정보가 포함되어 있는데, "주의집중"에 나타난 주사유형을 분석한 결과, 이상과 같은 의미 있는 결론을 도출할 수 있었다. 이러한 주사유형의 증감특성은 시간의 경과에 따른 주사경향을 파악함에 있어 기초자료가 될 수 있다.