• 제목/요약/키워드: U-coefficient

검색결과 764건 처리시간 0.027초

Analysis of Japanese Demand for Alaska Groundfish

  • Dae-Kyum Kim
    • 수산경영론집
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    • 제16권2호
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    • pp.75-87
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    • 1985
  • In 1977, the United States enacted the Magnuson Fishery Conservation and Management Act (MFCMA), which established U.S. Fisheries Conservation Zone (FCZ). The MFCMA grants preference to U.S. harvesters over foreign fleets in the U.S. FCZ. At present, the large stocks of groundfish in the U.S. FCZ off the Alaska coast have been under-utilized in the U.S. domestic market and the fisheries for these groundfish are dominated by foreign fleets. Hence, expected benefits from replacing foreign fisheries by domestic fleets will accrue to the U.S. fishery only by exporting the increased U.S. products to foreign countries. U.S. exports may be dependent on the price levels in the foreign markets raised by the reduced foreign catch from U,S. waters. In this paper, Japanese demand models for Alaska groundfish were estimated. The derived coefficient from the estimated models suggest that a decrease in the Japanese landings from the U.S. FCZ by a thousand metric tons will increase pollock price by 0.017 Yen/kg, cod price by 0.351 Yen/kg, flatfish by 1.074 Yen/kg, and ocean perch by 1.347 Yen/kg in the Japanese market. These results based on percentage would increase 19 percent for pollock price, 11 percent for cod price, 40 percent for flatfish, and 2 percent for ocean perch price.

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NFRC 201 실험방법에 의한 내부 차양장치가 적용된 창호의 일사획득계수 평가 (Evaluation on the Solar Heat Gain Coefficient of Glazing System installed in internal shading device by experiments according to the NFRC 201)

  • 임재한;송승영
    • 한국태양에너지학회 논문집
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    • 제30권3호
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    • pp.47-54
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    • 2010
  • Recently the researchers has been interested in the development of the high performance windows such as solar control window using automatic shading devices, air-flow window, selective coating window. In order to assess the energy performance of total fenestration system, the net energy gains or losses through the glazings and windows should be evaluated. It depends on the thermal transmittance (U-value) and the total solar energy transmittance (SHGC, g-value). This study aims to measure the solar heat gain coefficient according to the NFRC 201 standard test method. In results, we could find the result of different SHGC of the glazing system with a different slat angles. The SHGC in case of $90^{\circ}$ of internal slat angle with regard to the window surface is about 0.56, that in case of $45^{\circ}$ is about 0.49 and that in case of $0^{\circ}$ is about 0.33. Significant dependence on the solar radiation intensity and incident angle was found in comparison of the measured and simulated SHGC.

A comparison of the performance characteristics of large 2 MW and 3 MW wind turbines on existing onshore wind farms

  • Bilgili, Mehmet;Ekinci, Firat;Demirdelen, Tugce
    • Wind and Structures
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    • 제32권2호
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    • pp.81-87
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    • 2021
  • The aim of the current study is to compare the performance of large 2 MW and 3 MW wind turbines operating on existing onshore wind farms using Blade Element Momentum (BEM) theory and Angular Momentum (AM) theory and illustrate the performance characteristic curves of the turbines as a function of wind speed (U∞). To achieve this, the measurement data obtained from two different Wind Energy Power Plants (WEPPs) located in the Hatay region of Turkey was used. Two different horizontal-axis wind turbines with capacities of 2 MW and 3 MW were selected for evaluation and comparison. The hub-height wind speed (UD), turbine power output (P), atmospheric air temperature (Tatm) and turbine rotational speed (Ω) data were used in the evaluation of the turbine performance characteristics. Curves of turbine power output (P), axial flow induction factor (a), turbine rotational speed (Ω), turbine power coefficient (CP), blade tip speed ratio (λ), thrust force coefficient (CT) and thrust force (T) as a function of U∞ were obtained for the 2 MW and 3 MW wind turbines and these characteristic curves were compared. Results revealed that, for the same wind speed conditions, the higher-capacity wind turbine (3 MW) was operating at higher turbine power coefficient rates, while rotating at lower rotational speed ratios than the lower-capacity wind turbine (2 MW).

인천국제공항 부지 해성 점토에 대한 피에조콘과 딜라토미터 시험 결과 비교 (Comparison of Piezocone and Dilatometer Test Results on Inchon International Airport Marine Clay)

  • 김주형;김영웅;김명모
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2000년도 봄 학술발표회 논문집
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    • pp.677-684
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    • 2000
  • Piezocone test as well as Dilatometer tests are used worldwide to evaluate the engineering properties of clay soils. The common strong point of the two tests is that they can estimate, by the identical test equipment, various properties of soils, which are the unit weight of soils of OCR, K$\sub$o/, undrained shear strength(s$\sub$u/), coefficient of consolidation(c$\sub$h/) and soil classification etc,. A series of the two types of field tests are performed in this study on marine clays with low plasticity at Inchon International Airport construction site to estimate various properties of the soils such as s$\sub$u/, OCR, and c$\sub$h/, which are then compared each other as well as with the results of reference tests. The comparisons show that the way of interpretation is the most critical factor in obtaining confidential results for a certain engineering property for both tests.

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SUFFICIENT CONDITIONS FOR UNIVALENCE AND STUDY OF A CLASS OF MEROMORPHIC UNIVALENT FUNCTIONS

  • Bhowmik, Bappaditya;Parveen, Firdoshi
    • 대한수학회보
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    • 제55권3호
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    • pp.999-1006
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    • 2018
  • In this article we consider the class ${\mathcal{A}}(p)$ which consists of functions that are meromorphic in the unit disc $\mathbb{D}$ having a simple pole at $z=p{\in}(0,1)$ with the normalization $f(0)=0=f^{\prime}(0)-1$. First we prove some sufficient conditions for univalence of such functions in $\mathbb{D}$. One of these conditions enable us to consider the class ${\mathcal{A}}_p({\lambda})$ that consists of functions satisfying certain differential inequality which forces univalence of such functions. Next we establish that ${\mathcal{U}}_p({\lambda}){\subsetneq}{\mathcal{A}}_p({\lambda})$, where ${\mathcal{U}}_p({\lambda})$ was introduced and studied in [2]. Finally, we discuss some coefficient problems for ${\mathcal{A}}_p({\lambda})$ and end the article with a coefficient conjecture.

A Semi-empirical Equation for Activity Coefficients of Ions with One Parameter

  • Lee, Jai-Yeop;Han, Ihnsup
    • Bulletin of the Korean Chemical Society
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    • 제34권12호
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    • pp.3709-3714
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    • 2013
  • Based on the Debye-H$\ddot{u}$ckel equation, a semi-empirical equation for activity coefficients was derived through empirical and theoretical trial and error efforts. The obtained equation included two parameters: the proportional factor and the effective radius of an ionic sphere. These parameters were used in the empirical and regression parameter fitting of the calculated values to the experimental results. The activity coefficients calculated from the equation agreed with the data. Transforming to a semi-empirical form, the equation was expressed with one parameter, the ion radius. The ion radius, ${\alpha}$, was divided into three parameters, ${\alpha}_{cation}$, ${\alpha}_{anion}$ and ${\delta}_{cation}$, representing parameters for the cation, anion and combination, respectively. The advantage of this equation is the ability to propose a semi-empirical equation that can easily determine the activity coefficient with just one parameter, so the equation is expected to be used more widely in actual industry applications.

Parameterization of Along-Wind Dispersion Coefficients based on Field and Wind Tunnel Data

  • Kang, Sung-Dae
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제10권S_1호
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    • pp.11-22
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    • 2001
  • Observations related to the along-wind dispersion of puffs were collected from 12 field sites and from a wind tunnel experiment and used to test simple similarity relations. Because most of the date made use of concentration time series observation from fixed monitors, the basic observation was t, the standard deviation of the concentration time series. This data also allowed the travel time, t, from the source to the receptor to be estimated, from which the puff advective speed ue, could be determined. The along-wind dispersion coefficient, x, was then assumed to equal tue. The data, which extended over four orders of magnitude, supported the similarity relations t=0.1 t and x=1.8 $u^*$t, where t is the travel time and $u^*$ is the friction velocity. About 50% of the observations were within a factor of two of the predictions based on the similarity relations.

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A Method of Evaluating Korean Articulation Quality for Rehabilitation of Articulation Disorder in Children

  • Lee, Keonsoo;Nam, Yunyoung
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제14권8호
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    • pp.3257-3269
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    • 2020
  • Articulation disorders are characterized by an inability to achieve clear pronunciation due to misuse of the articulators. In this paper, a method of detecting such disorders by comparing to the standard pronunciations is proposed. This method defines the standard pronunciations from the speeches of normal children by clustering them with three features which are the Linear Predictive Cepstral Coefficient (LPCC), the Mel-Frequency Cepstral Coefficient (MFCC), and the Relative Spectral Analysis Perceptual Linear Prediction (RASTA-PLP). By calculating the distance between the centroid of the standard pronunciation and the inputted pronunciation, disordered speech whose features locates outside the cluster is detected. 89 children (58 of normal children and 31 of children with disorders) were recruited. 35 U-TAP test words were selected and each word's standard pronunciation is made from normal children and compared to each pronunciation of children with disorders. In the experiments, the pronunciations with disorders were successfully distinguished from the standard pronunciations.

다짐 화강풍화토의 균등계수 변화에 따른 함수특성곡선에 관한 연구 (A Study on the Soil Water Characteristic Curve with Change of Coefficient of Uniform in Compacted Granitic Soils)

  • 유건선;김덕경;유남재
    • 산업기술연구
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    • 제29권A호
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    • pp.145-153
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    • 2009
  • In this study, to determine characteristics of compaction and the soil water characteristic curve(SWCC) in decomposed granitic soils, compaction tests and SWCC tests were carried out for samples having various contents of coefficient of uniform($c_u$), By compacting their samples with standard Proctor density test, the effects of binder contents on maximum dry density and optimum moisture content were investigated and compared. Samples compacted with the maximum dry density and the optimum moisture content were tested by means of the SWCC, to determine their SWCC parameters, such as Brooks & Corey(${\lambda}$, ${\Psi}_b$), Van Genuchten (${\alpha}$, n, m), Fredlund & Xing(a, n, m).

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Behaviour of geocell reinforced soft clay bed subjected to incremental cyclic loading

  • Hegde, A.;Sitharam, T.G.
    • Geomechanics and Engineering
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    • 제10권4호
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    • pp.405-422
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    • 2016
  • The paper deals with the results of the laboratory cyclic plate load tests performed on the reinforced soft clay beds. The performances of the clay bed reinforced with geocells and geocells with additional basal geogrid cases are compared with the performance of the unreinforced clay beds. From the cyclic plate load test results, the coefficient of elastic uniform compression ($C_u$) was calculated for the different cases. The $C_u$ value was found to increase in the presence of geocell reinforcement. The maximum increase in the $C_u$ value was observed in the case of the clay bed reinforced with the combination of geocell and geogrid. In addition, 3 times increase in the strain modulus, 10 times increase in the bearing capacity, 8 times increase in the stiffness and 90% reduction in the settlement was observed in the presence of the geocell and geogrid. Based on the laboratory test results, a hypothetical case of a prototype foundation subjected to cyclic load was analyzed. The results revealed that the natural frequency of the foundation-soil system increases by 4 times and the amplitude of the vibration reduces by 92% in the presence of the geocells and the geogrids.