• Title/Summary/Keyword: Extreme Points

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Soil Loss Vulnerability Assessment in the Mekong River Basin

  • Thuy, Hoang Thu;Lee, Giha
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.1
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    • pp.37-47
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    • 2017
  • The Mekong River plays an extremely important role in Southeast Asia. Flowing through six countries, including China, Myanmar, Thailand, Laos PDR, Cambodia, and Vietnam, it is a site of great biological and ecological diversity and the habitat of numerous species of fish. It also supports a very large population that lives along the river basin. Therefore, much attention has been focused on the giant Mekong River Basin, particularly, its soil erosion and sedimentation problems. In fact, many methods have been used to calculate and simulate these problems. However, in the case of the Mekong River Basin, the available data is limited because of the extreme size of the area (about $795,000km^2$) and lack of equipment systems in the countries through which the Mekong River flows. In this study, we applied the Universal Soil Loss Equation (USLE) model in a GIS (Geographic Information System) framework to calculate the amount of soil erosion and sediment load during the selected period, from 1951 to 2007. The result points out dangerous areas, such as the Upper Mekong River Basin and 3S Basin (containing the Sekong, Sesan, and Srepok Rivers) that are suffering the serious consequences of soil erosion problems. Moreover, the present model is also useful for supporting river basin management in the implementation of sustainable management practices in the Mekong River Basin and other basins.

Spatial Distribution of Air Temperature during an Extreme Heat Period in Daegu Metropolitan Area in 2016 (2016년 여름철 폭염 시기 대구의 기온공간분포 특성)

  • Kim, Ji-Hye;Kim, Hae-Dong
    • Journal of Environmental Science International
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    • v.26 no.9
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    • pp.1023-1029
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    • 2017
  • We studied the distribution of air temperature using the high density urban climate observation network data of Daegu. The observation system was established in February 2013. We used a total of 38 air temperature observation points (23 thermometers and 18 AWSs). From the distribution of monthly averaged air temperatures, air temperatures at the center of Daegu were higher than in the suburbs. The daily minimum air temperature was more than or equal to $25^{\circ}C$ and the daily maximum air temperature was more than or equal to $35^{\circ}C$ at the elementary school near the center of Daegu. Also, we compared the time elements, which are characterized by the diurnal variation of surface air temperature. The warming and cooling rates in rural areas were faster than in urban areas. This is mainly due to the difference in surface heat capacity. These results indicate the influence of urbanization on the formation of the daily minimum temperature in Daegu.

Impact of Climate Change on Runoff Analysis in the Geum River Basin (금강 유역에서의 기후변화에 대한 유출 영향 분석)

  • Ahn, Jung-Min;Jung, Kang-Young;Kim, Gyeonghoon;Kwon, Heongak;Yang, Duk-Seok;Shin, Dongseok
    • Journal of Environmental Science International
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    • v.26 no.5
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    • pp.549-561
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    • 2017
  • Recently IPCC (International Panel on Climate Change, 2007) pointed out that global warming is a certain ongoing process on the earth, due to which water resources management is becoming one of the most difficult tasks with the frequent occurrences of extreme floods and droughts. In this study we made runoff predictions for several control points in the Geum River by using the watershed runoff model, SSARR (Streamflow Synthesis and Reservoir Regulation Model), with daily RCP 4.5 and RCP 8.5 scenarios for 100 year from 1st Jan 2006 to 31st Dec 2100 at the resolution of 1 km given by Climate Change Information Center. As a result of, the Geum River Basin is predicted to be a constant flow increases, and it showed a variation in the water circulation system. Thus, it was found that the different seasonality occurred.

A Study on the Expression of Optical lIIusion in Textile Design (텍스타일 디자인에 있어서 옵 . 아트의 착시표현 연구)

  • 이혜주;채지영
    • Journal of the Korean Society of Clothing and Textiles
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    • v.19 no.2
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    • pp.190-202
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    • 1995
  • The Optical Art is based on the principle of visual perception of the illusionary effects which induce psychological responses. It has influenced greatly on the Texile Design in that unique iJlusionary creativity of pattern simulates the visual sense of special movement; the dynamic psylosophy of vitalism. The Optical pattern has become a highly valued item due to its innovative effect in aesthetic direction. According to Vitor Vasarely the pioneer in this area, the integration and the inseparability of form and color which he calls 'Plastic Unity' provides the basis for the composition of infinite variety. The composition of infinite variety. The composition reveals the complex interaction between the space and form relating to order, repetition, combination and permutation. It is not simple to create optical patterns due to the extreme complexity composed by the multi-dimension and the infusion of form and color giving immensely varied movement. The purposes of this study are as follows; 1) to classify the complex processes of optical pattern on the basis of formative method. 2) to develop creative ideas for progressive contemporary textile design In this study, the analysis of applied methods is concentrated, which is based 1) on the gradual modification and on the transformation of the basic plastic elements which depend on thle direction of visual points involVing contradictory perspectives 2) on the composition varied special situations by repeating, overlapping and converging a series of idetUical units or by means of irrdiation, radiation and etc.

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Re-conceptualization of Business Model for Marketing Nowadays: Theory and Implications

  • FIRMAN, Ahmad;PUTRA, Aditya Halim Perdana Kusuma;MUSTAPA, Zainuddin;ILYAS, Gunawan Bata;KARIM, Kasnaeny
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.7
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    • pp.279-291
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    • 2020
  • This study aims to develop the concept of innovation models with the marketing channel construct approach, marketing innovation, product segmentation, and customer insight; as well as improvements to the theory of resource-based combined with the method of service-dominant logic. This study approach is based on quantitative descriptive conducted with three stages of testing scenarios. The first test is the mapping of the innovation model construct through testing the validity and reliability with the moderation of customer orientation variables. The second scenario examines the relationship of influence between the independent variables on the dependent variable of 29 hypothetical analysis equation modeling. The unit of analysis was conducted on 497 SMEs involved in the food and beverage sectors, with the criteria being SMEs must have a rating of 4-5 points on the Go-Food applications software. The results shown that: 1) the construct used to develop an innovative model both directly and via moderation is positive and significant; 2) Through a complicated relationship that involves all components of the variable, it outlines a positive and significant effect except for the path of analysis (μ5). The theoretical and managerial implications state that the service-dominant logic approach and resource-based view theory have extreme reliability and interrelations.

Hydro-structural issues in the design of ultra large container ships

  • Malenica, Sime;Derbanne, Quentin
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.4
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    • pp.983-999
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    • 2014
  • The structural design of the ships includes two main issues which should be checked carefully, namely the extreme structural response (yielding & buckling) and the fatigue structural response. Even if the corresponding failure modes are fundamentally different, the overall methodologies for their evaluation have many common points. Both issues require application of two main steps: deterministic calculations of hydro-structure interactions for given operating conditions on one side and the statistical post-processing in order to take into account the lifetime operational profile, on the other side. In the case of ultra large ships such as the container ships and in addition to the classical quasi-static type of structural responses the hydroelastic structural response becomes important. This is due to several reasons among which the following are the most important: the increase of the flexibility due to their large dimensions (Lpp close to 400 m) which leads to the lower structural natural frequencies, very large operational speed (> 20 knots) and large bow flare (increased slamming loads). The correct modeling of the hydroelastic ship structural response, and its inclusion into the overall design procedure, is significantly more complex than the evaluation of the quasi static structural response. The present paper gives an overview of the different tools and methods which are used in nowadays practice.

Optimization of Cooked Brown Rice by Controlling the Ratio of Grain Cereal Blends to Improve Palatability (현미밥의 식미 향상을 위한 곡류 혼합비의 최적화)

  • Han, Gyusang;Chung, Hae-Jung;Yoon, Jihyun;Baek, Man-Kee
    • Journal of the East Asian Society of Dietary Life
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    • v.22 no.6
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    • pp.782-794
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    • 2012
  • The objective of this study was to determine the optimal conditions for preparation of cooked brown rice by blending brown rice, white rice and glutinous rice to improve the palatability. Formulations composed of brown rice (10~100%), white rice (0~90%) and glutinous rice (0~90%) were generated from an extreme-vertices of mixture experimental design, which showed ten experimental points for brown rice, with white rice and glutinous rice as the independent variables. The sensory evaluation, color, and texture profile analysis (TPA) of cooked brown rice and pasting characteristics of blending cereals flour were measured as response variables. Regression analysis showed that all responsible variables fit linear, quadratic or special cubic models (p<0.1), except for the cohesiveness of TPA. The goals of optimization of the blending ratio of brown rice, white rice and glutinous rice were given as appearance, flavor, texture and overall acceptability (lower: 5.50, target: 6.62). The optimal conditions were determined to be 34.55% brown rice, 42.71% white rice and 22.74% glutinous rice.

An algorithm to simulate the nonlinear behavior of RC 1D structural members under monotonic or cyclic combined loading

  • Nouban, Fatemeh;Sadeghi, Kabir
    • Structural Engineering and Mechanics
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    • v.66 no.3
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    • pp.305-315
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    • 2018
  • Interaction of lateral loading, combined with axial force needs to be determined with care in reinforced concrete (RC) one-dimensional structural members (1D SMs) such as beam-columns (BCs) and columns. RC 1D SMs under heavy axial loading are known to fail by brittle mode and small lateral displacements. In this paper, a macro element-based algorithm is proposed to analyze the RC 1D SMs under monotonic or cyclic combined loading. The 1D SMs are discretized into macro-elements (MEs) located between the critical sections and the inflection points. The critical sections are discretized into fixed rectangular finite elements (FRFE). The nonlinear behavior of confined and unconfined concretes and steel elements are considered in the proposed algorithm. The proposed algorithm has been validated by the results of experimental tests carried out on full-scale RC structural members. The evolution of ultimate strain at extreme compression fiber of a rectangular RC section for different orientations of lateral loading shows that the ultimate strain decreases with increasing the axial force. In the examined cases, this ultimate strain ranges from 0.0024 to 0.0038. Therefore, the 0.003 value given by ACI-318 code for ultimate strain, is not conservative and valid for the combined load cases with significant values of axial force (i.e. for the axial forces heavier than 70% of the ultimate axial force).

Numerical optimization of Wells turbine for wave energy extraction

  • Halder, Paresh;Rhee, Shin Hyung;Samad, Abdus
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.9 no.1
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    • pp.11-24
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    • 2017
  • The present work focuses multi-objective optimization of blade sweep for a Wells turbine. The blade-sweep parameters at the mid and the tip sections are selected as design variables. The peak-torque coefficient and the corresponding efficiency are the objective functions, which are maximized. The numerical analysis has been carried out by solving 3D RANS equations based on k-w SST turbulence model. Nine design points are selected within a design space and the simulations are run. Based on the computational results, surrogate-based weighted average models are constructed and the population based multi-objective evolutionary algorithm gave Pareto optimal solutions. The peak-torque coefficient and the corresponding efficiency are enhanced, and the results are analysed using CFD simulations. Two extreme designs in the Pareto solutions show that the peak-torque-coefficient is increased by 28.28% and the corresponding efficiency is decreased by 13.5%. A detailed flow analysis shows the separation phenomena change the turbine performance.

Accuracy of incidental dynamic analysis of mobile elevating work platforms

  • Jovanovic, Miomir L.J.;Radoicic, Goran N.;Stojanovic, Vladimir S.
    • Structural Engineering and Mechanics
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    • v.71 no.5
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    • pp.553-562
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    • 2019
  • This paper presents the results of a study into the dynamic behaviour of a support structure of a mobile elevating work platform. The vibrations of the mechanical system of the observed structure are examined analytically, numerically, and experimentally. Within the analytical examination, a simple mathematical model is developed to describe free and forced vibrations. The dynamic analysis of the mechanical system is conducted using a discrete dynamic model with a reduced number of vibrational degrees of freedom. On the basis of the expression for the system energy, and by applying Lagrange's equations of the second kind, differential equations are derived for system vibrations, frequencies are determined, and the laws of forced platform vibration are established. At the same time, a nonlinear FEM model is developed and the laws of free and forced vibration are determined. The experimental and numerical part of the study deal with the examination of the real structure in extreme conditions, taking into account: the lowest eigenfrequency, forced actions that could endanger the general stability, the maximal amplitudes, and the acceleration of the work platform. The obtained analytical and numerical results are compared with the experiments. The experimental verification points to the adverse behaviour of the platform in excitation cases - swaying. In such a situation, even a relatively small physical force can lead to unacceptably high amplitudes of displacement and acceleration - exceeding the usual work values.