• 제목/요약/키워드: rate-sensitive

검색결과 1,573건 처리시간 0.028초

민자유치사업의 리스크 관리를 위한 민감요인 분석 - BTL 사업을 중심으로 - (A Sensitivity Analysis for Risk Management of Private Investment Projects - Focused on BTL Projects -)

  • 김선국;박동규
    • 한국건설관리학회논문집
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    • 제7권1호
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    • pp.168-175
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    • 2006
  • 2005년 1월 민간투자법의 개정에 따라 전국적으로 44개 국공립 시설 뿐 아니라 사립대학을 중심으로 BTL사업의 발주가 급증하고 있다. 그러나 BTL사업은 시설의 기획, 설계, 시공, 운영 및 관리까지 포함하여 20여년 이상의 프로젝트 관리 과정을 대상으로 하는 포괄적 사업방식이다. 따라서 각 단계별로 다양한 리스크 인자들이 발생하게 된다. 그러나 사업제안단계에서 재무적 리스크를 정량적으로 분석할 수 있는 민감요인은 공사비, 차입금리, 할인율, 부대사업 임대료, 운영비용 등이 있다. 본 연구에서는 BTL사업 제안단계에서 사업에 영향을 미치는 리스크 요인들의 특성을 고찰하고 이 요인들이 사업성에 미치는 영향도를 분석하고 이에 대한 대응방안을 제시하는 것을 목적으로 한다.

Trends of Post-fire Forest Recovery in the South Sikhote-Alin Mountains, Russian Far East

  • Komarova, Tatiana A.;Sibirina, L.A.;Papaik, M.J.;Park, J.H.;Kang, HoSang
    • 한국환경복원기술학회지
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    • 제16권3호
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    • pp.83-95
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    • 2013
  • To understand natural regeneration and stand development after fire in mixed broadleaved-coniferous forests of Sikhote-Alin Mountains, ten sample plots of $50m{\times}50m$ size were established in 1975 and 1983 at the stands burned by wildfires in 1973 and 1982, respectively. And, the number of naturally regenerated seedlings were monitored in two $50m{\times}4m$ subplots in each plot. The most fire-sensitive conifer species is Abies nephrolepis, while Betula costata is the most fire-sensitive broadleaved tree species. The most fire-resistant species were Q. mongolica, T. taquetii and A. mono. The results of 20 and 30 years after the fire showed that pioneer tree species, e.g. Populus, Salix, and Betula, were regenerated immediately at the early stage of stand development and grew where there is a mono canopy layer with high density. On the other hand, the densities of successors, e.g. Pinus koraiensis, Picea jezoensis, Abies nephrolepis, Acer mono and Tilia taquetii, which were present in the study plots before the fire, increased gradually. Naturally regenerated tree species after forest fire by the growth rate were divided into three groups according to their annual height growth. The seral tree species (Betula costata, Betula platyphylla, Padus maackii, Populus tremula and Sarix caprea) belong to the first group and have the highest growth rate (from 40 to 96 cm per year). The late successional broad-leaved trees (Tilia taquetii, Acer mono and Quercus mongolica) belong to the second group and have intermediate annual height growth (from 3.7 to 13.5 cm per year). The late successional coniferous species (Picea jezoensis, Pinus koraiensis and Abies nephrolepis) form the third group and have the least annual height growth (from 1.4 to 3.5 cm per year).

영양생장기 습해 처리에 따른 콩 품종의 해부형태학적 특성 비교 (Comparisons in Anatomical Morphology Between Soybean Cultivars of Different Flooding Tolerance under Early Vegetative Flooding Conditions)

  • 이충열;조진웅
    • 한국작물학회지
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    • 제52권3호
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    • pp.320-324
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    • 2007
  • 본 실험은 내습성 품종과 감수성 품종을 5엽기에 9일간 침수 처리한 후 잎과 배축을 대상으로 횡단면을 해부학적 특성을 광학현미경으로 관찰하여 그 결과 다음과 같다. 1. 엽록소함량, 광합성, 책상조직 수, 엽두께 및 잎 건물중은 습해에 의해 급격히 감소되었으며 풍산나물콩보다 소백나물콩의 감소가 더 많았다. 2. 잎 조직의 책상조직의 치밀함은 습해에 의해 급격히 감소되었고 품종간 차이도 관찰되었으며, 풍산나물콩은 주맥의 통도조직 중 목부의 발달을 볼 수 있었다. 3. 배축의 통기조직 형성은 소백나물콩은 보이지 않았으나 풍산나물콩은 피층에 파생통기조직이 형성되는 것을 볼 수 있었다.

Synthesis and Characterization of Novel pH-Sensitive Hydrogels Containing Ibuprofen Pen dents for Colon-Specific Drug Delivery

  • Mahkam, Mehrdad;Poorgholy, Nahid;Vakhshouri, Laleh
    • Macromolecular Research
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    • 제17권9호
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    • pp.709-713
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    • 2009
  • The aim of this study was to develop novel intestinal specific drug delivery systems with pH sensitive swelling and drug release properties. The carboxyl group of ibuprofen was converted to a vinyl ester group by reacting ibuprofen and vinyl acetate as an acylating agent in the presence of catalyst. The glucose-6-acrylate-1, 2, 3, 4-tetraacetate (GATA) monomer was prepared under mild conditions. Cubane-1, 4-dicarboxylic acid (CDA) linked to two 2-hydroxyethyl methacrylate (HEMA) group was used as the crosslinking agent (CA). Methacrylic-type polymeric prodrugs were synthesized by the free radical copolymerization of methacrylic acid, vinyl ester derivative of ibuprofen (VIP) and GATA in the presence of cubane cross linking agent. The structure of VIP was characterized and confirmed by FTIR, $^1H$ NMR and $^{13}C$ NMR spectroscopy. The composition of the cross-linked three-dimensional polymers was determined by FTIR spectroscopy. The hydrolysis of drug polymer conjugates was carried out in cel-lophane membrane dialysis bags, and the in vitro release profiles were established separately in enzyme-free simulated gastric and intestinal fluids (SGF, pH 1 and SIF, pH 7.4). The detection of a hydrolysis solution by UV spectroscopy at selected intervals showed that the drug can be released by hydrolysis of the ester bond between the drug and polymer backbone at a low rate. Drug release studies showed that increasing the MAA content in the copolymer enhances the rate of hydrolysis in SIP. These results suggest that these polymeric prodrugs can be useful for the release of ibuprofen in controlled release systems.

졸겔법에 의한 박막형 습도센서 소재개발에 관한 연구 (III) (A Study on the Development of Thin Film Type Humidity Sensor Materials by Sol-Gel Method (III))

  • 유도현;강대하;이은학;육재호;정순용;이덕출
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1995년도 하계학술대회 논문집 C
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    • pp.1162-1164
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    • 1995
  • In this paper, $TiO_2$-xmol%$V_2O_5$, x=0.0, 1.0, 2.0, 3.0 specimens are fabricated by Sol-Gel method. For the improvement of humidity sensitive characteristics for specimens, their microstructures are analysed and the optimum processing condition is established. Grain size increases with substitution rate of $V^{5+}$, on $Ti^{4+}$ site. Their humidity sensitive characteristics is good at 1mol% of $V_2O_5$ rate and heat-treated at $700^{\circ}C$. The capacitance of specimens decreases with frequency.

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과량수혈이 혈역학에 미치는 영향 (Hemodynamic effects of induced overtransfusion of blood in dogs)

  • 기노석
    • Journal of Chest Surgery
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    • 제17권3호
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    • pp.418-423
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    • 1984
  • Appreciation of the large volume deficits which may occur in surgical or trauma patients due to blood loss has led to vigorous transfusion techniques designed to overt hypovolemic shock and ischemic damage to vital organs which may develop in minutes during the hypovolemic state. In a significant proportion of patients treated with massive rapid blood or fluid transfusion, hypervolemia occurs and life threatening pulmonary edema may develop. Especially, hypervolemia may occur during transfusion for preventing development of the so-called low output syndrome following cardiac surgery. However, the most effective indicator which reveals the adequate level of transfusion is not settled yet. The present study was aimed to compare the effectiveness of the indicators suggested thus far and to determine the most sensitive one. Eight dogs were experimentally studied in terms of left atrial pressure, pulmonary arterial systolic pressure, central venous pressure, mean systemic arterial pressure and heart rate before and after induced hypervolemia with infusion of 600ml heparinized homologous blood. Immediately after induced overtransfusion of the blood, pulmonary arterial systolic pressure increased 75.0%, in omparison with the control before transfusion, left atrial pressure 58.8%, central venous pressure 44.6%, and mean systemic arterial pressure 10.1%, one hour after transfusion, pulmonary arterial systolic pressure 40.0%, left atrial pressure 21.2%, central venous pressure 14.5%, and mean systemic arterial pressure 3.2%, central venous pressure 14.5%, and mean systemic arterial pressure 3.2%, respectively. Heart rate showed no significant change throughout the experiment. These result suggested that the changes of the pulmonary arterial systolic pressure is the most sensitive indicator for detection of hypervolemia during blood transfusion.

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Development of Transdermal Drug Delivery System for the Combination of Physostigmine and Procyclidine

  • 박순철;최호근
    • Journal of Pharmaceutical Investigation
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    • 제31권3호
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    • pp.181-184
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    • 2001
  • The purpose of this study was to develop transdermal drug delivery system (TDDS) for the combination of physostigmine and procyclidine. The effects of various pressure sensitive adhesives (PSA) on the percutaneous absorption of procyclidine across hairless mouse skin were evaluated to select an appropriate PSA. In addition, the influences of various vehicles on the percutaneous absorption of procyclidine from PSA matrix across hairless mouse skin were evaluated using flow-through diffusion cell system at $37^{\circ}C$. Physostigmine did not have any influence on the permeation rate of procyclidine. The flux of procyclidine was the highest in silicone and PIB and was relatively lower in SIS, Acryl, and SBS adhesive matrices, however, their use was limited by the crystallization of the drug in the matrix. Among acrylic adhesives, the permeability of procyclidine was the highest from poly (ethylene oxide) grafted acrylic adhesive. Some enhancers show different enhancing effect depending on the drug, however, many of the tested enhancers showed enhancing effect for the permeation of both procyclidine and physostigmine to some extent. $Crovol^{\circledR}$ EP 40 showed the highest enhancing effect on the permeation of both compounds. The size of TDDS to provide required permeation rate was estimated to be $35\;cm^2$ based on available information.

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이상 유동 이론에서의 평면 변형 벤딩 (Plane-strain bending based on ideal flow theory)

  • ;이원오;정관수
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 춘계학술대회 논문집
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    • pp.233-236
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    • 2004
  • The major objective of this paper is to clarify the effect of constitutive laws on bulk forming design based on the ideal flow theory. The latter theory is in general applicable for perfectly/plastic materials. However, its kinematics equations constitute a closed-form system, which are valid for any incompressible materials, therefore enabling us to extend design solutions based on the perfectly/plastic constitutive law to more realistic laws with rate sensitive hardening behavior. In the present paper, several constitutive laws commonly accepted for the modeling of cold and hot metal forming processes are considered and the effect of these laws on one particular plane-strain design is demonstrated. The closed form solution obtained describes a non-trivial nonsteady ideal process. The design solutions based on the ideal flow theory are not unique. To achieve the uniqueness, the criterion that the plastic work required to deform the initial shape of a given class of shapes into a prescribed final shape attains its minimum is adopted. Comparison with a non-ideal process is also made.

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Effects of KATP Channel Blocker, cAMP and cGMP on the Cardiovascular Response of Adenosine A1 Agonist in the Spinal Cord of the Rats

  • Shin In-Chul
    • Biomolecules & Therapeutics
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    • 제14권2호
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    • pp.119-124
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    • 2006
  • This study was performed to investigate the influence of the spinal adenosine $A_1$ receptors on the central regulation of blood pressure (BP) and heart rate (HR), and to define whether its mechanism is mediated by cyclic AMP (cAMP), cyclic GMP (cGMP) or potassium channel. Intrathecal (i.t.) administration of drugs at the thoracic level were performed in anesthetized, artificially ventilated male Sprague-Dawley rats. I.t. injection of adenosine $A_1$ receptor agonist, $N^6$-cyclohexyladenosine (CHA; 1, 5 and 10 nmol) produced dose dependent decrease of BP and HR and it was attenuated by pretreatment of 50 nmol of 8-cyclopentyl-1,3-dimethylxanthine, a specific adenosine $A_1$ receptor antagonist. Pretreatment with a cAMP analogue, 8-bromo-cAMP, also attenuated the depressor and bradycardiac effects of CHA (10 nmol), but not with cGMP analogue, 8-bromo-cGMP. Pretreatment with a ATP-sensitive potassium channel blocker, glipizide (20 nmol) also attenuated the depressor and bradycardiac effects of CHA (10 nmol). These results suggest that adenosine $A_1$ receptor in the spinal cord plays an inhibitory role in the central cardiovascular regulation and that this depressor and bradycardiac actions are mediated by cAMP and potassium channel.

수도작용 붐 방제기의 피복특성에 관한 실험적 연구 (A Experimental Study on Coverage Characteristic of a Self-Propelled Boom Sprayer for Paddy Field)

  • 정창주;이강걸;이중용;조성인;최영수;최중섭
    • Journal of Biosystems Engineering
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    • 제22권2호
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    • pp.137-150
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    • 1997
  • To investigate the feasibility of a boom sprayer in the paddy field, an experimental boom sprayer for both broadcast and directed spraying to the lower part of rice plants was developed. The droplet deposition characteristics of the boom sprayers were experimentally compared to those of power sprayer. Water sensitive papers(WSP) and a machine vision system were used to evaluate the coverage rate and droplet density. It was shown that the broadcast application by the boom sprayer was the best coverage among the tested sprayers. Coverage tate and droplet density were affected by the distance between nozzles and the sprayer ground speed, The best result was obtained when the distance of 30cm and the speed of 1.7km/hr. The directed application showed inconsistency in overall droplet distribution. The inconsistency was judged to be caused by conflict between plants and boom extenders. The power sprayer showed a very wide range of droplet size distribution, relatively larger droplets and inconsistency in cove The power sprayer was judged to be inadequate for the low-volume precision application because of inconsistency in performance and difficulty in adjusting the spraying rate. Based on the droplet coverage characteristics, it was concluded that the self-propelled boom sprayer for the broadcast application was feasible for an alternative to the power sprayer in case of low volume, precision application in paddy condition.

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