• 제목/요약/키워드: Causes of Decline

검색결과 162건 처리시간 0.028초

EDISON_전산열유체를 활용한 풍력발전기 타워의 후류 불안정성 억제에 관한 수치연구 (NUMERICAL ANALYSIS FOR SUPPRESSING UNSTEADY WAKE FLOW ON WIND TURBINE TOWER USING EDISON_CFD)

  • 김수용;진도현;이근배;김종암
    • 한국전산유체공학회지
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    • 제18권1호
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    • pp.36-42
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    • 2013
  • The performance of the wind turbine is determined by wind speed and unsteady flow characteristics. Unsteady wake flow causes not only the decline in performance but also structural problems of the wind turbine. In this paper, conceptual designs for the wind turbine tower are conducted to minimize unsteady wake flow. Numerical simulations are performed to inspect the shape effect of the tower. Through the installation of additional structures at the rear of the tower, the creation of Karman vortex is delayed properly and vortex interactions are reduced extremely, which enhance the stability of the wind turbine. From the comparative analysis of lift and drag coefficients for each structure, it is concluded that two streamwise tips with a splitter plate have the most improved aerodynamic characteristics in stabilizing wake flow.

유해화학물질 차단을 위한 고무약품 배합자동화장치 개발 (Development of Rubber Chemicals Automatic Mixed System for Toxic Chemical Block)

  • 김재열;송경석;최철준;곽남수
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.305-306
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    • 2006
  • In process for production of Rubber Scheme Product that have the most inferior Working Environment is Medicine mixture and Scheme processing. Applying automation and Environment Treatment technology to the hazardous chemical and mixture processing, Through developed 'Mixture Automatic Machine for hazardous chemical Interruption type that is occurred at mixing rubber medicines', we try to decline worker's intensity of labour, Also overcomes solution of work evasion phenomenon and manpower supply and demand's difficulty by forming agreeable working environment and through the automatic scheme and mixture processing by preventing that hazardous chemical had known as disease causes of various importance disease is exposed to worker during the work. and we plan to do so that production of high added value product may be available.

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인지저하 노인의 금융거래교육시스템 개발을 위한 사용자 시나리오 연구 (A Study on the User Scenario for Development of Financial Transaction Education System for the Elderly with Cognitive Impairment)

  • 최훈;최유정
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2018년도 추계학술대회
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    • pp.128-129
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    • 2018
  • 우리나라는 최근들어 급속한 고령화 사회로 진입하고 있다. 고령화 사회로 인한 노인들의 문제는 여러 분야에서 나타나게 된다. 신체적 취약점으로 인한 문제 뿐 아니라 인지적 저하로 인한 문제 역시 많은 문제가 발생하게 된다. 인지적 저하는 노인들의 일상생활을 수행하는데 어려움을 야기시키게 되며 이로인한 노인들의 삶의 질 역시 부정적으로 나타나게 된다. 본 연구에서는 인지적 저하 노인들을 대상으로 일상생활 수행이 원활하게 이루어질 수 있는 금융관련 교육콘텐츠를 개발하기 위한 사용자 분석을 실시하고자 한다. 이를 통해 인지저하가 나타날 수 있는 대표적 노인 사례를 개발하고 이를 기반으로 금융관련 교육콘텐츠 개발의 기반을 마련하고자 한다.

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중국의 출산시 성비와 남아선호 (Sex Ratio at Birth and Son Preference in China)

  • Gu, Baochang;Li, Yongping
    • 한국인구학
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    • 제17권2호
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    • pp.116-135
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    • 1994
  • China's population and family planning program has heen successful. Women's fertility as measured by total fertility rate (TFR) has declined from 5.8 in 1970 to 2.3 in 1990, accordingly the annual crude birth rate(CBR) has declined from 34 per thousand in 1970 to 21 per thousand in 1989, and the annual natural growth rate from 2.6 percent in 1970 to 1.4 percent in 1989 (Coale and Chen, 1987; SSB, 1991; Gu, 1994). While this is indeed an astonishing achievement for a developing country to have its fertility down to replacement within a short period, some new issues emerging along with the rapid fertility decline require careful considerations. One of them is the uprising of the sex ratio at birth in China. The 1990 population census reported the sex ratio at birth in China of 113.8 in 1989, which is ohviously much higher than the acceptable level of normal ratio around 106. It has received since then a lot of tention in China and abroad, among demographic professionals and governmental agencies alike (Hull, 1990; Johansson and Nygren, 1991; Xuand Guo, 1991; Tu, 1993; Gu and Xu, 1994; among others). Based on the available demographic data and research results this paper will first have a review of the patterns and trends of sex ratio at birth in China, then turn to the immediate causes of abnormal sex ratio at birth and the determinants of the son preference, followed with a conceptual framework for understanding of the phenomenon, and finally the policy implications and recommendations will be discussed.

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소화기 증상을 보이는 소아 정신신체 질환에 대한 정신과적 고찰 (Psychiatric Considerations on Pediatric Psychosomatic Disorders with Gastrointestinal Symptoms)

  • 유한익;백경원
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제12권sup1호
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    • pp.85-92
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    • 2009
  • Gastrointestinal (GI) symptoms in children and adolescents are influenced by diverse psychiatric components such as psychosocial stresses, familial environment, school-related situations, and comorbid psychiatric conditions. Absolutely psychiatric symptoms of pediatric patients are also affected by problems of GI system. Lots of symptoms including anorexia, dyspepsia, nausea and so on are commonly originated from either GI or psychiatric causes or both. Sometimes the negative interactions between GI and psychiatric problems aggravate the severity and eventually decline the functions of children and adolescents with GI symptoms. We summarized the common GI and psychiatric conditions which have GI and psychiatric associations. To a clinician who manages pediatric GI disorders, psychiatric considerations can be beneficial to understand the clinical manifestations of patients and to find the way to relieve them. This short and somewhat superficial review may help to have a bird's-eye view on this topic.

O/S 정보를 이용한 침입탐지 처리성능 향상에 관한 시스템 설계 및 구현 (Designing and Realization of the System for the Improvement of Processing Capability of Intrusion Detection by Using O/S Information)

  • 손만경;이동휘;김귀남
    • 융합보안논문지
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    • 제6권2호
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    • pp.91-99
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    • 2006
  • 네트워크의 속도가 빨라지고 인터넷의 보편화로 인하여 웜, 이메일 바이러스 등 악의적인 공격이 급증하였으며. 네트워크의 악의적인 공격에 대한 방어로 기존의 방화벽을 비롯하여 최근 침입방지시스템에 이르기까지 수많은 방어기법이 생겨났다. 또한 악의적인 공격의 형태가 바뀜과 동시에 방어의 기법도 달라지게 된다. 가장 대표적인 방어 기법으로 Snort를 들 수 있으며 공격형태가 바뀜에 따라 Snort의 Rules 파일이 증가하게 된다. 따라서 탐지수행능력이 점점 떨어지게 된다. 본 논문에서는 Snort의 Rule 파일을 O/S별로 구분하여 처리성능 향상을 위한 구조를 제안하고 설계 및 구현한다. 이 시스템은 Snort의 기본 구성보다 처리성능을 향상시킬 수 있다.

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아질산에 노출된 뱀장어(Anguilla japonica)의 혈액학적 반응과 항산화효소의 활성 변화 (Changes in Hematological Responses and Antioxidative Enzyme Activities of Japanese Eel Anguilla japonica Exposed to Elevated Ambient Nitrite)

  • 조수현;김흥윤
    • 한국수산과학회지
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    • 제47권6호
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    • pp.860-868
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    • 2014
  • The study was performed to investigate changes in hematological responses and antioxidative enzyme activities (superoxide dismutase, SOD; catalase, CAT) of Japanese eel Anguilla japonica following exposure to 0 (control), 2.33, 4.60, 6,64 and 8.78 mM nitrite-N in fresh water for 48 h. Hematological parameters such as plasma nitrite, electrolytes, cortisol, glucose, glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), hemoglobin (Hb), methemoglobin (metHb) and NADH-methemoglobin reductase (NMR) were measured. Plasma nitrite, cortisol, metHb and NMR increased directly with increasing ambient nitrite concentration, while Hb content showed a progressive decline. Levels of plasma potassium, GOT and GPT of the eel exposed to 6.64 mM ambient nitrite were significantly higher than the control fish. The activity of SOD and CAT in plasma, gill and liver of the eel following exposure to nitrite were augmented by increasing ambient nitrite. Levels of plasma nitrite, metHb, NMR, cortisol, glucose and antioxidative enzyme activities of the eel exposed to 2.33 mM ambient nitrite were significantly higher than the control fish. This study suggested that the eel acutely exposed to elevated ambient nitrite causes nitrite-induced stress responses, changes in antioxidative enzyme activities and hematological parameters.

정부가족계획사업의 현황과 대책 -제 5 차 5 개년계획을 중심으로-

  • 조남동;장영식
    • 한국인구학
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    • 제6권1호
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    • pp.70-89
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    • 1983
  • China's population and family planning program has heen successful. Women's fertility as measured by total fertility rate (TFR) has declined from 5.8 in 1970 to 2.3 in 1990, accordingly the annual crude birth rate(CBR) has declined from 34 per thousand in 1970 to 21 per thousand in 1989, and the annual natural growth rate from 2.6 percent in 1970 to 1.4 percent in 1989 (Coale and Chen, 1987; SSB, 1991; Gu, 1994). While this is indeed an astonishing achievement for a developing country to have its fertility down to replacement within a short period, some new issues emerging along with the rapid fertility decline require careful considerations. One of them is the uprising of the sex ratio at birth in China. The 1990 population census reported the sex ratio at birth in China of 113.8 in 1989, which is ohviously much higher than the acceptable level of normal ratio around 106. It has received since then a lot of tention in China and abroad, among demographic professionals and governmental agencies alike (Hull, 1990; Johansson and Nygren, 1991; Xuand Guo, 1991; Tu, 1993; Gu and Xu, 1994; among others). Based on the available demographic data and research results this paper will first have a review of the patterns and trends of sex ratio at birth in China, then turn to the immediate causes of abnormal sex ratio at birth and the determinants of the son preference, followed with a conceptual framework for understanding of the phenomenon, and finally the policy implications and recommendations will be discussed.

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하악 무치악 환자에서 Locator$^{(R)}$를 이용한 임플란트 피개의치 수복 증례 (Implant Supported Overdenture using Locator$^{(R)}$ System on Mandibular Edentulous Patient)

  • 유정현;신수연
    • 구강회복응용과학지
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    • 제28권4호
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    • pp.397-406
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    • 2012
  • 치아가 상실되면 주위 치조골의 개조와 흡수가 일어나면서 위축성 무치악을 초래하게 되고, 치은부착은 점차적으로 감소된다. 이에 따라 총의치의 지지력 감소, 저작 효율의 저하와 통증으로 인해 무치악 환자들은 의치 사용의 어려움을 경험한다. 이를 개선하기 위해 하악에 2개의 임플란트를 식립하고 어태치먼트를 장착하는 피개의치의 형태가 유지력 측면에서 바람직한 치료 방법으로 우선적으로 고려되고 있다. 본 증례는 오래된 상, 하악 무치악을 가진 환자로 하악에 2개의 임플란트를 식립하고, 상악은 총의치, 하악은 Locator$^{(R)}$ attachment를 이용한 임플란트 피개의치로 제작하였다. 본 증례에서 기능적, 심미적으로 만족스러운 결과를 얻었기에 수복 과정과 결과에 대하여 보고하고자 한다.

알츠하이머병의 최신지견 (Recent Advances in Diagnosis and Treatment of Alzheimer's Disease)

  • 이정재;이석범
    • 생물정신의학
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    • 제23권2호
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    • pp.48-56
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    • 2016
  • Alzheimer's disease (AD) is a neurodegenerative disorder in which neuronal loss causes cognitive decline and other neuropsychiatric problems. It can be diagnosed based on history, examination, and appropriate objective assessments, using standard criteria such as the Diagnostic and Statistical Manual of Mental Disorders or the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA). Brain imaging and biomarkers are making progress in the differential diagnoses among the different disorders. The cholinesterase inhibitors, donepezil, rivastigmine and galantamine and N-methyl-D-aspartate receptors antagonist memantine are approved by the US Food and Drug Administration for AD. Recently some acetylcholinesterase inhibitors gained approval for the treatment of severe AD and became available in a higher dose formulation or a patch formulation. Optimal care in AD is multifactorial and it should include early diagnosis and multidisciplinary care with pharmacological and nonpharmacological interventions including exercise interventions, cognitive interventions and maintenance of social networks.