• 제목/요약/키워드: partial changes

검색결과 810건 처리시간 0.026초

Atelomix in Ethiopian Highland Lakes: their role in phytoplankton dynamics and ecological features

  • Solomon Wagaw;Assefa Wosnie;Yirga Enawgaw
    • Fisheries and Aquatic Sciences
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    • 제26권7호
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    • pp.423-436
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    • 2023
  • The objectives of this review were to synthesize the community structure of phytoplankton and the role of atelomix in the phytoplankton dynamics in Ethiopian highland lakes. Changes in a lake's physical structure, light dynamics, and availability of nutrients are closely associated with phytoplankton ecology, and phytoplankton assemblages provide insight into phytoplank- ton responses to these environmental changes. Based on the available information, a total of 173 species of phytoplankton are grouped under seven classes, Chlorophyceae (80 taxa), Bacillariophyceae (55 taxa), Cyanophyceae (24 taxa), Dinophyceae (6 taxa), Eugleonophyceae (6 taxa), Xanthophyceae (1 taxon), and Cryptophyceae (1 taxon) were recorded in five different tropical Ethiopian highland lakes. Chlorophyceae and Bacillariophyceae dominated in terms of species composition. Partial atelomixis, seasonality, and low nutrient concentrations seem to be the main drivers in structuring phytoplankton composition and abun-dances in Ethiopian highland lakes, characterized by a high diversity of atelomix-dependent benthic diatoms and desmids. Thus, this review will help understand the role of atelomix and nutrient availability in the phytoplankton composition and biomass of tropical highland lakes of Ethiopia.

Fault Detection in Automatic Identification System Data for Vessel Location Tracking

  • Da Bin Jeong;Hyun-Taek Choi;Nak Yong Ko
    • Journal of Positioning, Navigation, and Timing
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    • 제12권3호
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    • pp.257-269
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    • 2023
  • This paper presents a method for detecting faults in data obtained from the Automatic Identification System (AIS) of surface vessels. The data include latitude, longitude, Speed Over Ground (SOG), and Course Over Ground (COG). We derive two methods that utilize two models: a constant state model and a derivative augmented model. The constant state model incorporates noise variables to account for state changes, while the derivative augmented model employs explicit variables such as first or second derivatives, to model dynamic changes in state. Generally, the derivative augmented model detects faults more promptly than the constant state model, although it is vulnerable to potentially overlooking faults. The effectiveness of this method is validated using AIS data collected at a harbor. The results demonstrate that the proposed approach can automatically detect faults in AIS data, thus offering partial assistance for enhancing navigation safety.

Pulse Wave Velocity(PWV)와 혈청지질수치를 포함한 심혈관 질환 위험 요인들과의 상관관계 연구 (The Relationship between Pulse Wave Velocity (PWV) and Risk Factors of Cardiovascular Disease including Serum Lipid Values)

  • 정승환;엄은진;박우람;이범준;나병조
    • 대한한방내과학회지
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    • 제30권3호
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    • pp.525-533
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    • 2009
  • Objectives : There are lots of reports that cardiovascular disease, including hypertension, cerebro-vascular accident, and coronary heart disease, is related to atherosclerotic changes. Increased serum levels of lipids could play a role in these changes. This study aimed to investigate the relationship between PWV and risk factors of cardiovascular disease, including serum lipid values. Methods : This study included 261 subjects ($49.32{\pm}11.79$ years, 112 male) who underwent PWV and serum lipid evaluation. We investigated the correlation between serum lipid values, blood pressure, body mass index (EMI) and PWV. Pearson's correlation and partial correlation analysis were applied to examine the relationship between PWV and risk factors of cardiovascular disease. Results : Serum triglyceride, total cholesterol, systolic blood pressure, and diastolic blood pressure were significantly correlated with PWV. Partial correlation coefficient adjusted by age yielded significant correlation between serum triglyceride, systolic blood pressure, diastolic blood pressure and PWV. Conclusion : In this study, it seems that there are significant relationships between PWV, triglyceride and blood pressure. We could suggest that PWV might have some relationships with Dam-eum and blood stasis in oriental theory.

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혈희석 체외순환에 의한 개심수술: 16례 수술 경험 (Clinical Experience of Open Heart Surgery Under The Extracorporeal Circulation With Partial Hemodilution: Operation 16 Cases)

  • 유회성
    • Journal of Chest Surgery
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    • 제10권2호
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    • pp.299-314
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    • 1977
  • Clinical experience on 16 cases of open heart surgery under the extracorporeal circulation with mild or moderate hypothermia and partial hemodilution technique at the National Medical Center during the period from June 1976 to October 1977. Nine of sixteen were congenital heart disease and seven were acquired heart disease. The age of the patient ranged between 6 and 48 years. The body weight varied from 18.5kg to 60kg and body surface area 0. 79-1.70m2. The average priming volume of pump oxygenator was 2080 ml, which was consisted fresh ACD blood, buffered Hartmann`s solution, Mannitol, 50% dextrose in water and Vit. C. The average hemodilution rate was 27%. The average flow 2.3 L/min/m2 or 80 ml/min and the duration of perfusion varied from 31 min to 270 min with average of 107 min. The perfusion was carried out under the mild or moderate hypothermia using core cooling alone in 10 cases, core cooling and local myocardial cooling with $0-4^{\circ}C$ physiologic saline in 2 cases. From a hemodynamic point of view, the blood pressure dropped down around 80 mmHg after the initiation of perfusion follwed by increase to safety level and stable during the perfusion. The central venous pressure remained within normal limits. In most cases, hemoglobin and hematocrit decreased during and after the perfusion. Hemogiobin level was decreased, average of 20.6 %, hematocrit 18.6%, pletelets 55% postoperatively. Plasma hemoglobin increased moderately, from preperfusion average valve of 7.79 mg % to post-perfusion value of 54.7 mg %. Electrolytes changes during cardiopulmonary bypass showed definite hypokalemia but changes of Na, Ca were not definite. Arterial blood gas analysis during cardiopulmonary bypass suggested that the metabolic acidosis which was accompanied by respiratory alkalosis which was corrected postoperatively. As the opera tive complication, transient hemoglobinuria in 4 cases and neurological signs in 2 cases were all cured. There were 2 death cases and operative mortality rate was 12.5%.

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온침(溫鍼)의 표준화를 위한 애주의 밀도에 따른 온도 측정 연구(硏究) (Study on Moxa density-related Changes in Warm Needle Temperature)

  • 김윤홍;이승호;여수정;최일환;김영곤;임사비나
    • 대한한의학회지
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    • 제29권3호
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    • pp.11-20
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    • 2008
  • Objectives: Warm-needling is a method combining the effects of acupuncture with the effects of moxibustion. We need to standardize the characteristics of warm-needling in order to achieve consistency in its operational mechanisms and effects, which will improve clinical ability in the field of Eastern medicine. Methods: In this study, using the LabVIEW system on the warm-needling technique, we measured and compared partial temperature changes which varied according to the density of the moxa cone and the moxa cone's core peak temperature. Results& Conclusions: Examination of the warm-needle's partial temperature in relation to the cone density of the 0.8g moxa specimen suggests that a lower density of the moxa cone corresponds to a higher peak temperature and but with a shorter duration. During the effective stimulus time, the lower the density of the moxa cone, the shorter the duration of the effective stimulus time and the higher the mean temperature. Conversely, the higher the density of the moxa cone, the longer the effective stimulus time and lower the mean temperature.

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상·하부 T-stub 접합부의 초기회전강성 평가 (Evaluation of the Initial Rotational Stiffness of a Double Split Tee Connection)

  • 김희동;양재근;이재윤;이형동
    • 한국강구조학회 논문집
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    • 제26권2호
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    • pp.133-142
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    • 2014
  • 상 하부 T-stub 접합부는 보와 기둥의 강성비, T-stub의 기하학적 형상변화, 긴결재의 개수, 패널존 효과 등의 영향에 따라서 보통모멘트골조 및 특수모멘트골조에 적합한 거동특성을 나타내는 완전강도 부분강접 접합부(full strength partial restrained connection)이다. 이러한 상 하부 T-stub 접합부가 구조적으로 안전하게 거동하기 위해서는 충분한 강도, 강성, 연성능력을 나타내어야 한다. 이 연구는 T-stub의 기하학적 형상변화가 상 하부 T-stub 접합부의 모멘트-회전각 관계에 미치는 영향을 파악하고, 이에 따른 상 하부 T-stub 접합부의 초기회전강성을 평가하기 위해 진행하였다. 이를 위하여 T-stub의 기하학적 형상변수 ${\alpha}^{\prime}$값을 변화시킨 2개의 상 하부 T-stub 접합부 실험체를 제작하여 접합부 실험을 수행하였고, 3차원 비선형 유한요소해석도 수행하였다.

An Analysis of the Impact of Climate Change on the Korean Onion Market

  • BAEK, Ho-Seung;KIM, In-Seck
    • 산경연구논집
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    • 제11권3호
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    • pp.39-50
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    • 2020
  • Purpose: Agriculture, which is heavily influenced by climate conditions, is one of the industries most affected by climate change. In this respect, various studies on the impact of climate change on the agricultural market have been conducted. Since climate change is a long-term phenomenon for more than a decade, long-term projections of agricultural prices as well as climate variables are needed to properly analyze the impact of climate change on the agricultural market. However, these long-term price projections are often major constraints on studies of climate changes. The purpose of this study is to analyze the impacts of climate changes on the Korean onion market using ex-post analysis approach in order to avoid the difficulties of long-term price projections. Research design, data and methodology: This study develops an annual dynamic partial equilibrium model of Korean onion market. The behavioral equations of the model were estimated by OLS based on the annual data from 1988 to 2018. The modelling system is first simulated to have actual onion market conditions from 2014 to 2018 as a baseline and then compared it to the scenario assuming the climatic conditions under RCP8.5 over the same period. Scenario analyses were simulated by both comparative static and dynamic approach to evaluate the differences between the two approaches. Results: According to the empirical results, if the climate conditions under RCP8.5 were applied from 2014 to 2018, the yield of onion would increase by about 4%, and the price of onion would decrease from 3.7% to 17.4%. In addition, the average price fluctuation rate over the five years under RCP8.5 climate conditions is 56%, which is more volatile than 46% under actual climate conditions. Empirical results also show that the price decreases have been alleviated in dynamic model compared with comparative static model. Conclusions: Empirical results show that climate change is expected to increase onion yields and reduce onion prices. Therefore, the appropriate countermeasures against climate change in Korean onion market should be found in the stabilization of supply and demand for price stabilization rather than technical aspects such as the development of new varieties to increase productivity.

자율주행자동차의 사회 수용에 미치는 영향 요인과 정책적 시사점 (Influencing Factors on Social Acceptance of Autonomous Vehicles and Policy Implications)

  • 이지혜;장형식;박영일
    • 기술혁신학회지
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    • 제21권2호
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    • pp.715-737
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    • 2018
  • 자율주행자동차의 도입은 자동차의 산업생태계 변화뿐만 아니라 사회적, 문화적, 경제적 변화를 가져올 것이다. 사회적 수용성은 자율주행자동차 상용화가 성공하기 위한 중요한 영향 요인 중 하나이다. 본 연구는 수요자 관점에서 자율주행자동차의 수용에 영향을 주는 요인들이 무엇인지 분석하였다. 본 연구에서는 운전자의 개입 여부에 따라 부분자율주행자동차(PAV)와 완전자율주행자동차(FAV)로 정의하였다. 설문은 운전자뿐만 아니라 비운전자도 포함하여 20세 이상을 대상으로 수행되었다. 그 결과 PAV와 FAV 수용에 영향을 미치는 요인들은 다르게 나타났다. PAV의 경우 운전자와 직접적인 관련이 있는 요인들이 수용성에 영향을 미쳤고, FAV의 경우 외부 환경 요인들이 자율주행자동차의 수용에 영향을 미치는 것으로 나타났다. 이러한 결과는 PAV와 FAV의 수용 확산을 위해서는 서로 다른 전략이 필요하다는 것을 보여주었다.

임대주택(賃貸住宅)의 내재적(內在的) 특성(特性)에 관(關)한 연구(硏究) - 서울의 공동거주형(共同居住型) 임대주택(賃貸住宅)의 사례(事例)를 중심(中心)으로 - (A Study on Latent Characteristics of Rental Housing - A Case Study on 'Co-deweling' of Rental Housing in Seoul -)

  • 이윤희;정재국
    • 한국주거학회논문집
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    • 제21권4호
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    • pp.51-58
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    • 2010
  • In the modernization process of the city, urbanization raised a variety of social issues. Urbanization brought noticeable changes in dwelling patterns, such as drastic changes in the housing lifestyle, that revolved around the metropolitan areas of Seoul and Busan etc. before and after the expansion of economic growth. Especially in 1985, when 23.8% of the country's population was concentrated in Seoul, the imbalance of housing supply and demand caused a vast range of housing shortage. The shortage, that resulted from public sector mishandling of natural housing demand, lead to the occurrence of private sector rental housing. The occurrence of this abnormal rental housing supply, became a major cause of Korea's typical lease system called 'Co-dwelling', where the leaseholder and tenant physically lives in the same residence. The leaseholder and tenant's 'Co-dwelling' started from partial renting of traditional Korean-style housing and transformed with the transition of dwelling form and time. However, after 1985, legalization of multi-family housing, Korean rental housing started to be planned in the beginning of it's housing construction and to be produced as an independent space with separate circulation. Also in terms of facility, it changed from partial renting of a space within the residence to an assembly of small individual spaces. However, the background of this deep-rooted 'Co-dwelling' lease system, in different forms and periods of residence, is still based on the lack of public sector rental housing supply and private sector supply of rental space to utilize extra space, 'Jeonsei' payment.