• 제목/요약/키워드: Accelerating flow

검색결과 79건 처리시간 0.024초

Review of Domestic Sleep Industry Classification Criteria and Aanalysis of characteristics of related companies

  • Yu, Tae Gyu
    • International journal of advanced smart convergence
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    • 제11권1호
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    • pp.111-116
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    • 2022
  • After COVID-19, the number of people with sleep disorders around the world is increasing. In particular, in the flow of the 4th industrial revolution, the differentiation of types and characteristics of the sleep industry is accelerating. Therefore, in this study, the characteristics of each type of sleep-related industry were reclassified from an industrial point of view, and based on this, an attempt was made to review the classification system that can help companies develop sleep products and improve related national systems. Based on the 10th standard industry classification, we compared input cost, value, and usability and analyzed common characteristics, treatments, and preventive effects based on this. A comprehensive taxonomy using matrix analysis was reviewed. As a result, in terms of cost (A), the most common sleeping products are general mattresses and general bedding. It is an IOT device (auxiliary device), and the value aspect (B, B/D) included sleep cafe, bedding rental and management service, and sleep consulting. In terms of utility (A/B), a total of 6 product groups including sleep aids (health functional foods) belong to this category, and in terms of treatment (A/C), a total of 3 product groups including sleep clinics (medical services) belong to this category. As for the product group (A/D) with both properties, it was found that non-insurance sleep treatment medical devices, sleep-related over-the-counter drugs, and some sleep monitoring applications belong to this category. Ultimately, it was found that the sleep industry classification enables the most active product development and composition according to the relative relationship between cost and utility, and treatment and utility. appeared to be necessary.

자윤탕이 뇌혈류 변화에 미치는 영향 (The Effects of Jayun-tang on the Changes of Cerebral Flow)

  • 김용진;전상윤;안정조;최창원;홍석
    • 대한한의학회지
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    • 제26권3호
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    • pp.188-203
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    • 2005
  • Objectives : This study was designed to investigate the effects of Jayun-tang extract (JYT) on the change of cerebral hemodynamics [regional cerebral blood flow (rCBF), pial arterial diameter (PAD) and mean arterial blood pressure (MABP)] in normal and cerebral ischemic rats, na to determine the mechanisms of action of JYT. Methods : We investigated whether JYT inhibits lactate dehydrogenase activity in neuronal cells and cytokines production in serum of cerebral ischemic rats. Results : 1. JYT significantly increased rCBF and PAD in a dose-dependent manner, but MABP was not changed by injecting JYT. These results suggested JYT significantly increased rCBF by dilating PAD. 2. The JYT-induced increase in rCBF was significantly inhibited from pretreatment with indomethacin (1mg/kg, i.p.), an inhibitor of cyclooxygenase and methylene blue $(10{\mu}g/kg, i.p.)$, an inhibitor of guanylate cyclase. 3. The JYT-induced dilation in PAD was significantly inhibited from pretreatment with indomethacin, but was increased by pretreatment with methylene blue. 4 The JYT-induced increase in MABP was reduced by pretreatment with indomethacin and methylene blue. 5. JYT significantly inhibited lactate dehydrogenase activity in neuronal cells. These results suggest that JYT prevented the neuronal death. 6. Both rCBF and PAD were significantly and stably increased by JYT $(10{\mu}g/kg,\;i.p.)$ during the Period or cerebral reperfusion, which contrasted with the findings of rapid and marked increase in the control group. 7. In cytokine production in the serum drawn from femoral artery 1hr after middle cerebral artery occlusion, the sample group showed significantly decreased production of $IL-1\beta$ and $TNF-\alpha$ as well as increased production of IL-10 and $TGF-\beta$ compared with rho control group. 8. In cytokine production in the serum drawn from femoral artery 1hr after reperfusion, the sample group showed significantly decreased production of $IL-1\beta$ and $TNF-\alpha$ as well as significantly increased production of IL-10 and $TGF-\beta$ compared with the control group. Conclusions : JYT mediated by cyclooxygenase had an inhibitive effect on brain damage by inhibiting lactate dehydrogenase activity, $IL-1\beta$ and $TNF-\alpha$ production, and by accelerating IL-10 and $TGF-\beta$ production. The author feels that JYT had anti-ischemic effects through the improvement of cerebral hemodynamics and inhibitive effects on brain damage.

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팔물탕이 뇌혈유력학 변화에 미치는 작용기전 (Mechanism of Palmul- Tang on the Change of Cerebral Hemodynamics in Rats)

  • 박철훈;김계엽;정현우
    • 동의생리병리학회지
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    • 제18권6호
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    • pp.1714-1721
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    • 2004
  • This experimental study was designed to investigate the mechanism of Palmul-Tang(PMT) on the changes of cerebral hemodynamics in rats. The changes of cerebral hemodynamics in normal rats were as follows ; The PMT-induced increase in regional cerebral blood flow was significantly inhibited by pretreatment with indomethacin(1㎎/㎏, i.p.), an inhibitor of cyclooxygenase, and was inhibited by methylene blue(10㎍/㎏, i.p.), an inhibitor of guanylate cyclase. The PMT-induced dilation in pial arterial diameter was significantly inhibited by pretreatment with indomethacin and methylene blue. The PMT-induced increase in mean arterial blood pressure was significantly inhibited by pretreatment with indomethacin but was increased by methylene blue. This results were suggested that the mechanism of PMT was mediated by cyclooxygenase. The changes of cytokine production in cerebral ischemic rats were as follows ; In cytokine production of serum by drawing from femoral arterial blood after middle cerebral arterial occlusion 1hr, sample group was decreased IL-1β and TNF-α production compared with control group, IL-10 production of sample group was similar to that of control group, but sample group was significantly increased TGF-β production compared with control group. In cytokine production of serum by drawing from femoral arterial blood after reperfusion 1hr, sample group was significantly decreased IL-1β production compared with control group and decreased TNF-α production compared with control group. IL-10 production of sample group was similar to that of control group, but sample group was significantly increased TGF-β production compared with control group. In cytokine production of serum by drawing from femoral arterial blood after reperfusion 4 hrs, sample group was significantly decreased IL-1β production compared with control group, but IL-10 production of sample group was similar to that of control group. sample group was increased TNF-α and TGF-β production compared with control group. These results suggested that PMT had inhibitive effect on the brain damage by inhibiting IL-1β and TNF-α production, but by accelerating TGF-β production. The present author thought that PMT had an anti-ischemic effect through the improvement of cerebral hemodynamics and inhibitive effect on the brain damage.

순기활혈탕(順氣活血湯)의 뇌허혈(腦虛血) 억제효과(抑制效果)에 관한 실험적(實驗的) 연구(硏究) (The Experimental Study of Sunkihwalhyul-Tang against Inhibitive Effects on the Brain Ischemia)

  • 홍석;안정조;전상윤;최창원;정영득
    • 대한한의학방제학회지
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    • 제13권1호
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    • pp.49-69
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    • 2005
  • This Study was designed to investigate the effect of Sunkihwalhyul -Tang extract(SHT) on the change of cerebral hemodynamics [regional cerebral blood flow(rCBF), pial arterial diameter(PAD) and mean arterial blood pressure(MABP)] in normal and cerebral ischemic rats, and further to determine the mechanisms of action of SHT on hemodynamics. In addition, this study was designed to investigate whether SHT inhibits lactate dehydrog enase(LDH) activity in neuronal cells and cytokines production in serum of cerebral ischemic rats. The results were as follows 1. SHT significantly increased rCBF and PAD in a dose-dependent manner, but MABP was not changed by injecting SHT. These results suggest that SHT significantly increases rCBF by dilating PAD. 2. The SHT-induced increase in rCBF was significantly inhibited by pretreatment with indomethacin(IDN, 1 mg/kg, i.p.), an inhibitor of cyclooxygenase and methylene blue(MTB, $10{\mu}g/kg$, i.p.), an inhibitor of guanylate cyclase. 3. The SHT-induced dilation in PAD was significantly inhibited by pretreatment with IDN and MTB. 4. The SHT-induced some increase in MABP was significantly increased by pretreatment with IDN. These results suggest that the mechanism of action of SBT is mediated by guanylate cyclase. 5. Both rCBF and PAD were significantly and stably increased by SHT(10 mg/kg, i.p.) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in control group. 6. SBH significantly inhibited LDH activity in neuronal cells. These results suggest that SHT prevents the neuronal death. 7. In cytokine production in the senlm drawn from femoral artery 1 hr after middlecerebral arterial occlusion, sample group showed significantly decreased production of IL-1$\beta$ production, decreased production TNF-$\alpha$ and increased Production of IL-10 compared with control group. 8. In cytokine production in the serum drawn femoral artery 1 hr after reperfusion, sample group showed significantly decreased production of IL-1$\beta$ and TNF-$\alpha$ as wellas significantly increased production of IL10 compared with control group. These results suggest that SHT mediated by guanylate cyclase has inhibitive effect on the brain damage by inhibiting LDH activity, IL-1$\beta$ and TNF-$\alpha$ production, and by accelerating IL-10 production. The present author thinks that SHT has an anti-ischemic effects through the improvement of cerebral hemodynamics and inhibitive enects on the brain damage.

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Performance of Beam Extractions for the KSTAR Neutral Beam Injector

  • Chang, D.H.;Jeong, S.H.;Kim, T.S.;Lee, K.W.;In, S.R.;Jin, J.T.;Chang, D.S.;Oh, B.H.;Bae, Y.S.;Kim, J.S.;Cho, W.;Park, H.T.;Park, Y.M.;Yang, H.L.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.240-240
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    • 2011
  • The first neutral beam injector (NBI-1) has been developed for the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. A first long pulse ion source (LPIS-1) has been installed on the NBI-1 for an auxiliary heating and current drive of KSTAR core plasmas. Performance of ion and neutral beam extractions in the LPIS-1 was investigated initially on the KSTAR NBI-1 system, prior to the neutral beam injection into the main plasmas. The ion source consists of a JAEA magnetic bucket plasma generator with multi-pole cusp fields and a set of KAERI prototype-III tetrode accelerators with circular apertures. The inner volume of plasma generator and accelerator column in the LPIS-1 is approximately 123 liters. Final design requirements for the ion source were a 120 kV/ 65 A deuterium beam and a 300 s pulse length. The extraction of ion beams was initiated by the formation of arc plasmas in the LPIS-1, called as an arc-beam extraction method. A stable ion beam extraction of LPIS-1 has been achieved up to an 100 kV/42 A for a 4 s pulse length and an 80 kV/25 A for a 14 s pulse length. Optimum beam perveance of 1.21 microperv has been found at an accelerating voltage of 80 kV. Neutralization efficiency has been measured by using a water flow calorimetry (WFC) method of calorimeter and an operation of bending magnet. The full-energy species of ion beams have been detected by using the diagnostic method of optical multichannel analyzer (OMA). An arc efficiency of the LPIS was 0.6~1.1 A/kW depending on the operating conditions of arc discharge.

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Swash대역에서의 해빈표사 부유거동에 관한 연구 (Suspension of Sediment over Swash Zone)

  • 조용준;김권수;유하상
    • 대한토목학회논문집
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    • 제28권1B호
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    • pp.95-109
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    • 2008
  • 본 연구에서는 LDS 난류응력 모형, Van Rijn의 pick up 함수를 활용하여 일정 경사부에서의 파랑의 이행과 천수, 연이은 쇄파현상, plunging breaker에 후행하는 해저질의 역동적인 부유와 down rush와 후행 파랑에 의한 표사의 재분배를 수치모의 하였다. 이 과정에서 해저질과 소통하는 저면 유체력에 대한 quadratic law를 중심으로 한 기존의 연구 성과들은 정상상태에 기초하여 급속히 가속되고 감속되는 swash 대역의 수리특성을 반영할 수 없다는 결론에 도달하고 이러한 인식에 기초하여 새로운 산출방법이 제시되었다. 새로운 산출방법을 토대로 수치모의하여 비선형 천수과정의 일반적인 특징, 동조 비동조 고차 조화성분으로 전이된 파랑에너지로 인해 상당히 예리하고 왜도된 파형, 파형의 마루로부터 시작되는 물입자 자유낙하, 착수로 인한 커다란 물보라의 형성, 물보라 형성층의 해변으로의 이행, wave finger (Narayanaswamy와 Dalrymple, 2002), swash 대역에서 진행되는 부유사 순환과정, swash 대역에서 처오름으로 인해 부유된 부유사 무리의 off shore 방향으로의 순 이동 등이 비교적 정확히 재현되는 등 상당히 고무적인 결과를 얻을 수 있었다. 이러한 결과는 기존의 Euler 좌표계에서 정의되는 파랑모형과 이동경계 기법의 한계를 뛰어 넘는 것으로 향후 보다 정확한 침식해석이 가능 할 것으로 판단된다.

재관류가 허혈 심근세포의 미세구조에 미치는 영향 : 재관류 손상에 관한 연구 (Effect of Reperfusion after 20 min Ligation of the Left Coronary Artery in Open-chest Bovine Heart: An Ultrastructural Study)

  • 이종욱;조대윤;손동섭;양기민;라봉진;김호덕
    • Journal of Chest Surgery
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    • 제31권8호
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    • pp.739-748
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    • 1998
  • 연구배경: 재관류 없이 허혈 심근세포의 기능이나 형태학적 변화를 원래의 상태로 회복시킬 수 없음은 주 지의 사실이나 재관류가 반드시 유익하지만은 않다는 실험결과들이 있으므로 국소적으로 일과성 허혈을 유도하여 심근세포에서 일어나는 형태학적 변화를 관찰하고 재관류가 허혈심근에 미치는 영향을 알아보고자 하였다. 재료 및 방법: 생후 12개월 내외의 홀슈타인종 소를 사용하여 정맥 마취하에서 흉부를 열고 왼쪽 관상동맥 의 전하방 가지를 20분 동안 결찰하여 국소허혈을 유도하고 결찰을 풀어 재관류를 유도하였다. 위험부위의 심근조직 을 재관류 직후, 재관류후 1, 2, 3, 6, 12시간 및 재관류 12시간후 1시간동안 보조호흡과 수액공급만을 한 후 각각 생검하여 통상적인 방법으로 처리하여 투과전자현미경으로 관찰하였다. 결과: 20분 동안의 국소허혈로 심근세포는 경도에서 중등도에 이르는 미세구조적 변화들이 나타났는데 특히 세포막하, 핵, 사립체, 심근원섬유 등의 소기관에서 많은 변화들이 관찰되었다. 그러나 재관류를 시작하여 1시간이 지나면 허혈심근세포에서는 회복을 시사하는 소견들이 나타나기 시작하였으며 미세혈관 내에서 혈전형성이나 내강의 협착 등이 관찰되었으나 재관류가 계속됨에 따라 심근세포의 미세구조적 변화들은 서서히 회복되어 가는 양상을 나 타내었다. 그러나 시간이 경과함에 따라 심내막하 심근세포의 일부에서는 재관류 손상으로 추측되는 미세구조적 변 화들이 관찰되었다. 결론: 이상의 결과로 미루어 미세혈관은 허혈에 대한 저항력이 심근세포보다 강하며 허혈 심근세포는 재관류 없이는 회복될 수 없고, 회복에는 비교적 장시간이 요구되며, 따라서 혈관폐쇄로 인한 허혈시 혈관성형술이나 혈전 용해를 촉진하는 물질을 이용한 치료는 타당성이 있는 것으로 생각되나 재관류 유발성 세포손상에 대한 주의가 요망 된다.

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초기기업에 대한 정량적 가치평가 모델 구축에 관한 탐색적 연구 (The Study about Developing More Rational Valuation Model to the Early Stage Companies)

  • 강상욱;양영석;양수희
    • 벤처창업연구
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    • 제12권4호
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    • pp.15-24
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    • 2017
  • 본 연구는 보편적 기업가치 평가법인 현금흐름할인법(DCF)의 주관적 추정에 따른 한계성을 보완하기 위해 최신 스타트업 가치평가에 적용되고 있는 정량적 할인지표를 결합하여 새로운 정량적 가치평가 모델을 제시함으로써 초기 창업팀과 투자자들이 가치평가를 준비하고 협상함에 있어 실효적 기여를 하는데 목표가 있다. 이에 대한 본 연구의 주요 연구내용은 다음과 같다. 첫째, 유의미한 수익창출 이전의 기업가치 평가방법에 대한 선행연구들로 가장 중요도가 높게 인식되는 버커스평가법과 스코어카드평가법 그리고 위험요소합산법 등을 분석 정리하여 정량적 할인지표에 대한 기저를 구축하였다. 둘째, 전통적인 평가방식인 현금흐름할인법을 초기기업에 적용할 경우 위험요인을 충분히 반영하여 적정한 할인율을 산출할 수 있도록 하는 DCF-프라임 방식의 선행연구를 분석, 정리하였다. 셋째 초기기업의 가치평가를 함에 있어 객관적 협상이 가능하도록 DCF-프라임 방식과는 다른 새로운 방식의 가치평가 방식인 DCF-플러스 모델을 제시하였는데, 전통적 평가방식인 현금흐름할인법에 정량적 할인지수 방식을 결합함으로써 평가자의 주관적 개입과 불확실성의 한계를 보완할 수 있음을 보여주었다. 본 연구는 초기기업의 기업가치평가 시 자기중심 예측에 의한 자의성 및 오차의 개입이 투자자와 창업자간 투자조건 협상을 하는데 걸림돌이 되고 있는 상황에서, 본 연구의 결과물인 정량적 할인지수 방식을 결합한 새로운 가치평가 방식이 투자자와 창업팀 모두 투자협상에 임하는데 있어 효과적인 가이드라인으로 제공됨은 물론 창업팀에게도 기업가치 증대를 위해 스스로 검증하는데 기여할 수 있다는 면에서도 의의가 있다.

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특허생산과 기술성과: 기업 혁신전략의 역할 (Patent Production and Technological Performance of Korean Firms: The Role of Corporate Innovation Strategies)

  • 이주관;정진화
    • 기술혁신연구
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    • 제22권1호
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    • pp.149-175
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    • 2014
  • 본 연구는 기업의 혁신전략이 특허생산 및 기업의 기술변화와 신제품개발에 미치는 영향을 분석함으로써 기업의 기술성과를 증대시키는 데 필요한 혁신전략을 도출하고자 하였다. 사용자료는 한국직업능력개발원의 "인적자본기업패널조사"(HCCP)의 1~4차년도 자료와 한국신용평가원의 기업재무자료, 특허청의 기업별 특허출원자료를 결합한 자료이다. 특허생산함수는 영과잉음이항회귀모형(ZINB)을 사용하여 추정하였다. 기업의 기술성과 결정요인은 특허의 내생성을 고려하여 2단계 추정방법을 사용하였고, 2단계 회귀식은 순위로짓모형을 사용하였다. 분석결과, 기업의 혁신전략이 특허생산 및 기업의 기술변화와 신제품개발에 중요한 영향을 미치는 것을 확인할 수 있었다. 첫째, 특허생산에서는 기업의 연구개발투자와 인적자원이 중요한 투입요소로 나타났다. R&D집약도가 높을수록 특허생산이 활발하게 이루어지되 한계 생산은 체감하였고, 기업이 보유하고 있는 특허스톡이 많을수록 신규특허의 생산이 활발하였다. 기업의 인적자원수준이 높고 인적자원투자가 많을수록 특허생산이 활발하였고, 기업이 시장선도전략이나 빠른 추종자전략을 추구할 때 안정형 전략을 구사하는 기업에 비해 특허생산이 많았다. 둘째, 기업의 기술성과 결정요인으로는 인적자원의 역할이 중요하였고, R&D 집약도는 대기업의 신제품개발에 유의한 영향을 미쳤다. 시장선도전략이나 빠른 추종자전략을 택한 기업의 기술성과가 안정형 전략의 기업보다 높았다. 특허생산이 활발한 기업일수록 기술성과가 높으나, 이는 상당부분 특허의 내생성에 기인한다. 본 연구의 분석결과는 특허의 생산뿐 아니라 특허와 신제품개발과 같은 기술성과와의 연계성을 높이는 전략이 필요하며, 기업특성에 따른 차별화 전략이 필요하다는 것을 시사한다.