• Title/Summary/Keyword: modelling studies

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THE STRUCTURE, STRATIGRAPHY AND PETROLEUM GEOLOGY OF THE MURZUK BASIN, SOUTHWEST LIBYA

  • JHO Jhoon Soo
    • 한국석유지질학회:학술대회논문집
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    • autumn
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    • pp.57-72
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    • 2000
  • The Murzuk Basin covers an area in excess of $350,000{\cal}km^2$, and is one of several intra-cratonic sag basins located on the Saharan Platform of North Africa. Compared with some of these basins, the Murzuk Basin has a relatively simple structure and stratigraphy, probably as a result of it's location on a the East Saharan Craton. The basin contains a sedimentary fill which reaches a thickness of about $4,000{\cal}m$ in the basin centre. This fill can be divided into a predominantly marine Paleozoic section, and a continental Mesozoic section. The principal hydrocarbon play consists of a glacial-marine sandstone reservoir of Cambro-Ordovician age, sourced and sealed by overlying Silurian shales. The present day borders of the basin are defined by tectonic uplifts, each of multi-phase generation, and the present day basin geometry bears little relation to the more extensive Early Palaeozoic sedimentary basin within which the reservoir and source rocks were deposited. The key to the understanding of the Cambro-Ordovician play is the relative timing of oil generation compared to the Cretaceous and Tertiary inversion tectonics which influenced source burial depth, reactivated faults and reorganised migration pathways. At the present day only a limited area of the basin centre remains within the oil generating window. Modelling of the timing and distribution of source rock maturity uses input data from AFTA and fluid inclusion studies to define palaeo temperatures, shale velocity work to estimate maximum burial depth and source rock geochemistry to define kinetics and pseudo-Ro. Migration pathways are investigated through structural analysis. The majority of the discovered fields and identified exploration prospects in the Murzuk Basin involve traps associated with high angle reverse faults. Extensional faulting occurred in the Cambro-Ordovician and this was followed by repeated compressional movements during Late Silurian, Late Carboniferous, Mid Cretaceous and Tertiary, each associated with regional uplift and erosion.

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The Marshall-Olkin generalized gamma distribution

  • Barriga, Gladys D.C.;Cordeiro, Gauss M.;Dey, Dipak K.;Cancho, Vicente G.;Louzada, Francisco;Suzuki, Adriano K.
    • Communications for Statistical Applications and Methods
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    • v.25 no.3
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    • pp.245-261
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    • 2018
  • Attempts have been made to define new classes of distributions that provide more flexibility for modelling skewed data in practice. In this work we define a new extension of the generalized gamma distribution (Stacy, The Annals of Mathematical Statistics, 33, 1187-1192, 1962) for Marshall-Olkin generalized gamma (MOGG) distribution, based on the generator pioneered by Marshall and Olkin (Biometrika, 84, 641-652, 1997). This new lifetime model is very flexible including twenty one special models. The main advantage of the new family relies on the fact that practitioners will have a quite flexible distribution to fit real data from several fields, such as engineering, hydrology and survival analysis. Further, we also define a MOGG mixture model, a modification of the MOGG distribution for analyzing lifetime data in presence of cure fraction. This proposed model can be seen as a model of competing causes, where the parameter associated with the Marshall-Olkin distribution controls the activation mechanism of the latent risks (Cooner et al., Statistical Methods in Medical Research, 15, 307-324, 2006). The asymptotic properties of the maximum likelihood estimation approach of the parameters of the model are evaluated by means of simulation studies. The proposed distribution is fitted to two real data sets, one arising from measuring the strength of fibers and the other on melanoma data.

Studies on the Laboratory Animal Modelling of Atherosclerosis and the Preventive Mechanisms of Dietary Fiber against Atherosclerosis (동맥경화증의 실험동물 모델화와 식이섬유의 동맥경화 방어기전에 관한 연구)

  • Kim, Hyoung-ook;Lee, Yong-soon;Lee, Heung-shik S;Shin, Kwang-soon;Lim, Chang-hyeong
    • Korean Journal of Veterinary Research
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    • v.33 no.3
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    • pp.513-524
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    • 1993
  • mechanisms for the hypocholesterolemic effects of $\beta$-glucan remain unclear. Rats were divided into 3 groups ; normal control group, atherogenic group(oral administration of cholesterol 40 mg/kg/day plus vit. $D_2$ 320,000 IU/kg/day), $\beta$-glucan treatment group(atherogenic treatment plus $\beta$-glucan 0.135 g/kg/day). The $\beta$-glucan treatment group showed moderate increases of serum lipids concentration compared with atherogenic group. In histopathological examination, aortas showed no critical lesions. The total fecal neutral sterols and bile acids excreted for 6 days was increased compared with both normal and atherogenic group. To compare effects of soluble fiber and insoluble fiber extracted from barley on postprandial lipemia, 5 healthy male adults ingested on separate days a low-fiber(total dietary fiber 2.61g) control meal or dietary fiber-enriched(12.61g) meals. Fasting and postprandial blood samples were obtained for 6.5h and serum lipids were analyzed. The serum total lipids, total cholesterols, LDL & VLDL-cholesterol were markedly reduced with soluble fiber-enriched meals, but no decrease with insoluble fiber-enriched meals. These results suggest that mechanisms for the hypocholesterolemic effect of $\beta$-glucan on rats were due to the inhibition of cholesterol absorption in the intestinal lumen and acceleration of cholesterol catabolism in the liver. And the soluble dietary fiber($\beta$-glucan) has the hypocholesterolemic effect by dropping serum LDL & VLDL-cholesterol in the clinical study.

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Assessment of Blast-induced Vibration Using Dynamic Distinct Element Analysis (불연속체 동해석 기법을 이용한 발파진동 영향평가)

  • Park, Byung-Ki;Jeon, Seokwon;Park, Gwang-Jun;Do, Deog-Soo;Kim, Tae-Hoon;Jung, Du-Seop
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.12 s.105
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    • pp.1389-1397
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    • 2005
  • Since blast-induced vibration may cause serious problem to the rock mass as well as the nearby structures, the prediction of blast-induced nitration and the stability evaluation must be performed before blasting activities. Dynamic analysis has been increased recently in order to analyze the effect of the blast-Induced vibration. Most of the previous studies, however, were based on the continuum analysis unable to consider rock joints which significantly affect the wave propagation and attenuation characteristics. They also adopted pressure corves estimated tv theoretical or empirical equations as input detonation load, thus there were very difficult to reflect the characteristics of propagating media. In this study, therefore, we suggested a dynamic distinct element analysis technique which uses velocity waveform obtained from a test blast as an input detonation load. A distinct element program, UDEC was used to consider the effect of rock joints. In order to verify the validity of proposed method, the test blast was simulated. The predicted results from the proposed method showed a good agreement with the measured vibration data from the test blast. Through the dynamic numerical modelling on the planned road tunnel and slope, we evaluated the effect of blast-induced nitration and the stability of rock slope.

A Occupant Load Density and Computer Modelling of Evacuation time in Office Buildings (사무소 건물의 거주밀도 분포와 피난시간 예측)

  • Kim, Un-Hyeong;Rui, Hu;Kim, Hong
    • Fire Science and Engineering
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    • v.13 no.3
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    • pp.35-42
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    • 1999
  • A occupant load density of contemporary office buildings were surveyed by a building w walk through procedure in Korea. The survey results of ten office buildings are range from 1 2 2 2 213.14 m !person 041.4 ft !person) to 22.69 m /person (244.34 ft !person) with 95% confidence l level and the mean occupant load density is 17.92 m2/person 092.87 ft2/야rson). The impacts of occupant load on evacuation flow time was analyzed by applying time-based egress m model, SIMULEX with various occupant load densities from previous studies. I In order to demonstrate the validation of egress modeling method, fire evacuation exercise a and computer simulation were used to simulate the actual evacuation plan for a high-rise office building. An analysis and comparison of the results of these approaches was made to i illustrate the influence of model limitations on the result of prediction The result of the study shows that the introduction of occupant load concept in building c code of Korea is essential to achieving resonable building life safety design in future.

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Dynamic Analysis of Structure-Fluid-Soil Interaction Problem of a Bridge Subjected to Seismic-Load Using Finite Element Method (유한요소법을 이용한 지진하중을 받는 교량의 구조물-유체-지반 동적 상호작용해석)

  • You, Hee-Yong;Park, Young-Tack;Lee, Jae-Young
    • Journal of The Korean Society of Agricultural Engineers
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    • v.50 no.4
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    • pp.67-75
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    • 2008
  • In construction facilities such as bridges, the fluid boundary layer(or water film) is formed at the structure-soil interface by the inflow into the system due to rainfall or/and rising ground-water. As a result, the structure-soil interaction(SSI) state changes into the structure-fluid-soil interaction(SFSI) state. In general, construction facilities may be endangered by the inflow of water into the soil foundation. Thus, it is important to predict the dynamic SFSI responses accurately so that the facilities may be properly designed against such dangers. It is desired to have the robust tools of attaining such a purpose. However, there has not been any report of a method for the SFSI analyses. The objective of this study is to propose an efficient method of finite element modelling using the new interface element named hybrid interface element capable of giving reasonable predictions of the dynamic SFSI response. This element enables the simulation of the limited normal tensile resistance and the tangential hydro-plane behaviour, which has not been preceded in the previous studies. The hybrid interface element was tested numerically for its validity and employed in the analysis of SFSI responses of the continuous bridge subjected to seismic load under rainfall or/and rising ground-water condition. It showed that dynamic responses of the continuous bridge resting on direct foundation may be amplified under rainfall condition and consequently lead to significant variation of stresses.

Multi-alternative Retrofit Modelling and its Application to Korean Generation Capacity Expansion Planning (발전설비확장계획에서 다중대안 리트로핏 모형화 방안 및 사례연구)

  • Chung, Yong Joo
    • The Journal of Information Systems
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    • v.29 no.1
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    • pp.75-91
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    • 2020
  • Purpose Retrofit, defined to be addition of new technologies or features to the old system to increase efficiency or to abate GHG emissions, is considered as an important alternative for the old coal-fired power plant. The purpose of this study is to propose mathematical method to model multiple alternative retrofit in Generation Capacity Expansion Planning(GCEP) problem, and to get insight to the retrofit patterns from realistic case studies. Design/methodology/approach This study made a multi-alternative retrofit GECP model by adopting some new variables and equations to the existing GECP model. Added variables and equations are to ensure the retrofit feature that the life time of retrofitted plant is the remaining life time of the old power plant. We formulated such that multiple retrofit alternatives are simultaneously compared and the best retrofit alternative can be selected. And we found that old approach to model retrofit has a problem that old plant with long remaining life time is retrofitted earlier than the one with short remaining life time, fixed the problem by some constraints with some binary variables. Therefore, the proposed model is formulated into a mixed binary programming problem, and coded and run using the GAMS/cplex. Findings According to the empirical analysis result, we found that approach to model the multiple alternative retrofit proposed in this study is comparing simultaneously multiple retrofit alternatives and select the best retrofit satisfying the retrofit features related to the life time. And we found that retrofit order problem is cleared. In addition, the model is expected to be very useful in evaluating and developing the national policies concerning coal-fired power plant retrofit.

Estimation of Dynamic Characteristics of Core Zone of Rockfill Dam by Multi-channel Analysis of Surface Waves (MASW 조사를 통한 사력댐 코어존 동적물성의 평가)

  • Lee, Jong-Wook;Ha, Ik-Soo;Oh, Byung-Hyun
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.860-868
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    • 2008
  • Seismic safety analysis of rockfill dams are consist of the stability analysis as an simplifed method and the dynamic analysis as an detailed method. When high risk dams such as Multi-purpose dams were often applied detailed method by dynamic analysis, dynamic properties of dam materials such as shear modulus are considered as most important factor. Dynamic material properties such as shear modulus had to be investigated by cyclic triaxial test et al. during design and construction stage but these were not conducted because of the condition of domestic seismic design technique. MASW and SASW methods had been applied as a non destructive method to investigate dynamic material properties of existing rockfill dam, has no problems in dam safety at present. These methods were usually performed under the assumptions that the subsurface can be described horizontally homogeneous and isotropic layers. Recent studies(Marwin, 1993, Kim, 2001) showed that surface waves generated through inclined structures have different characteristics from those through a horizontally homogeneous layered model. further Kim et al(2005) and Min and Kim(2006) showed that central core type rockfill dam overestimated the shear wave velocities as increasing the depth through the 3D numerical modelling dut to the effect of outer rockfill and geometrical reasons In this study the results of shear wave velocities of seven rockfill dams form comprehensive facility review, was carried out from 2003 to 2007, were collected and analysed to establish the shear wave velocity distribution characteristics in increasing confining stress in rockfill dams and surface wave velocity ranges in rockfill dam through MASW and the limitation in application are discussed to be utilized as an reference value for dynamic analysis.

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Evaluating the Relationship between Place Attachment, Residential Evaluations and Satisfaction in a Medium-sized Romanian City (루마니아 도시에서의 장소애착, 거주성 평가, 만족도 간에 상관성 연구)

  • Dumitru, Adina;Garcia Mira, Ricardo;Maricutoiu, Laurentiu;Ilin, Corina
    • Journal of the Korean housing association
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    • v.25 no.4
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    • pp.31-38
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    • 2014
  • The present research aimed at researching the relationships among place attachment, residential evaluations and satisfaction in a medium-sized post-communist Romanian city. Studies on post-communist cities are scarce and this research tried to fill that gap. This research is part of a government project that intended to significantly reform three medium-sized cities in the Western part of Romania and transform the urban space. Since the three of them are relatively small-sized and close spatially, the project intends to undertake massive reforms of the communications and services of the three cities. In this article, we report findings on the city of Hunedoara. A representative random sample was selected, and a total of 384 people were interviewed, with an overall reliability of the sample of 95%. The instruments used to gather the data were the Neighbourhood Perceived Environmental Quality Scale and a composite measure of place attachment was also included. The structure of each scale was checked using exploratory factor analysis. We tested alternative causal models using structural equations modelling. Our model showed a good fit to the data and explains satisfaction in the city adequately. Results show that satisfaction is directly predicted by the general evaluation of the city and by residential privacy. Residential noise and place attachment influence satisfaction indirectly. The results are discussed and some policy recommendations are formulated.

Hydraulic Analysis of Urban Water-Supply Networks in Marivan

  • Tavosi, Mohammad Ghareb;Siosemarde, Maaroof
    • Industrial Engineering and Management Systems
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    • v.15 no.4
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    • pp.396-402
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    • 2016
  • In this study, hydraulic analysis of water-supply networks in Marivan was performed by modeling. WATERGEMS was used for modeling and it was calibrated using existing rules and regulations. The purpose of this research is modeling urban water network and its analysis based on hydraulic criteria and meeting pressure conditions at the nodes and complying the economic speed. To achieve this goal, first the pipelines of city streets was designed in AutoCAD on a map of the city. It should be mentioned that it was tried to prevent from creating additional loops in the network and the optimal network was designed by a combination of annular and branch loops. In the next step, the pipes were called in WATERGEMS and then we continue the operation by the allocation of elevation digits to the pipes. Since the topography of this city is very specific and unique, the number of pressure zones was increased. Three zones created only covers about 20% of the population in the city. In this dissertation, the design was performed on the city's main zone with the largest density in the Figures 1,320-1,340. In the next step, the network triangulation was conducted. Finally, the Debiw as allocated based on the triangulation conducted and considering the density of the city for year of horizon. Ultimately, the network of Marivan was designed and calibrated according to hydraulic criteria and pressure zoning. The output of this model can be used in water-supply projects, improvement and reform of the existing net-work in the city, and various other studies. Numerous and various graphs obtained in different parts of a network modelled can be used in the analysis of critical situation, leakage.