• Title/Summary/Keyword: Evolution of research area

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The effect of the new stopping criterion on the genetic algorithm performance

  • Kaya, Mustafa;Genc, Asim
    • Computers and Concrete
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    • v.27 no.1
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    • pp.63-71
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    • 2021
  • In this study, a new stopping criterion, called "backward controlled stopping criterion" (BCSC), was proposed to be used in Genetic Algorithms. In the study, the available stopping citeria; adaptive stopping citerion, evolution time, fitness threshold, fitness convergence, population convergence, gene convergence, and developed stopping criterion were applied to the following four comparison problems; high strength concrete mix design, pre-stressed precast concrete beam, travelling salesman and reinforced concrete deep beam problems. When completed the analysis, the developed stopping criterion was found to be more accomplished than available criteria, and was able to research a much larger area in the space design supplying higher fitness values.

Direct simulations on 2D mold-filling processes of particle-filled fluids

  • Hwang, Wook-Ryol;Kim, Worl-Yong;Kang, Shin-Hyun;Kim, See-Jo
    • Korea-Australia Rheology Journal
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    • v.21 no.3
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    • pp.193-200
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    • 2009
  • We present a direct simulation technique for two-dimensional mold-filling simulations of fluids filled with a large number of circular disk-like rigid particles. It is a direct simulation in that the hydrodynamic interaction between particles and fluid is fully considered. We employ a pseudo-concentration method for the evolution of the flow front and the DLM (distributed Lagrangian multipliers)-like fictitious domain method for the implicit treatment of the hydrodynamic interaction. Both methods allow the use of a fixed regular discretization during the entire computation. The discontinuous Galerkin method has been used to solve the concentration evolution equation and the rigid-ring description has been introduced for freely suspended particles. A buffer zone, the gate region of a finite area subject to the uniform velocity profile, has been introduced to put discrete particles into the computational domain avoiding any artificial discontinuity. From example problems of 450 particles, we investigated the particle motion and effects of particles on the flow for both Newtonian and shear-thinning fluid media. We report the prolonged particle movement toward the wall in case of a shear-thinning fluid, which has been interpreted with the shear rate distribution.

Electrochemical Characterization of Electrospun LaCoO3 Perovskite Nanofibers Prepared at Different Temperature for Oxygen Reduction and Evolution in Alkaline Solution (다양한 온도에서 합성한 전기방사 LaCoO3 페롭스카이트 나노섬유의 알칼리용액에서 산소환원 및 발생반응에 대한 전기화학 특성)

  • Lopez, Kareen J.;Sun, Ho-Jung;Park, Gyungse;Eom, Seungwook;Shim, Joongpyo
    • Journal of Hydrogen and New Energy
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    • v.26 no.2
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    • pp.148-155
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    • 2015
  • Electrospun $LaCoO_3$ perovskite nanofibers were produced for the air electrode in Zn-air rechargeable batteries using electrospinning technique with sequential calcination. The final calcination temperature was varied from 500 to $800^{\circ}C$ in order to determine its effect on the physical and electrochemical properties of the prepared $LaCoO_3$ perovskite nanofibers. The surface area of the electrospun $LaCoO_3$ perovskite nanofibers were observed to decrease with increasing final calcination temperature. Electrospun $LaCoO_3$ perovskite nanofibers calcined with final calcination temperature of $700^{\circ}C$ had the best electrocatalytic activity among the prepared perovskite nanofibers.

Evolution of trauma care and the trauma registry in the West Australian health system

  • Iddagoda, Mayura Thilanka;Burrell, Maxine;Rao, Sudhakar;Flicker, Leon
    • Journal of Trauma and Injury
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    • v.35 no.2
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    • pp.71-75
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    • 2022
  • Trauma care is evolving throughout the world to meet the demand resulting from rapidly increasing rates of mortality and morbidity related to external injuries. The State Major Trauma Service was designated to Royal Perth Hospital in 2004 to provide comprehensive care for trauma patients in Western Australia (WA), which is the largest state by area in the country. The State Major Trauma Unit, which was established in 2008, functions as a level I center and admits over 1,000 major trauma patients per year, making it the second busiest trauma center in Australia. The importance of recording data related to trauma was identified by the trauma service in WA to inspire higher standards of patient care and injury prevention. In 1994, the service established a trauma registry, which has undergone significant changes over the last two decades. The current State Trauma Registry is linked to a statewide database called the Data Linkage System. The linked data are available for policy development, quality assurance, and research. This article discusses the evolution of the trauma service and the registry database in the WA health system. The State Trauma Registry has enormous potential to contribute to research and quality improvement studies along with its ability to link with other databases.

Study on the water bursting law and spatial distribution of fractures of mining overlying strata in weakly cemented strata in West China

  • Li, Yangyang;Zhang, Shichuan;Yang, Yingming;Chen, Hairui;Li, Zongkai;Ma, Qiang
    • Geomechanics and Engineering
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    • v.28 no.6
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    • pp.613-624
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    • 2022
  • A study of the evolution of overburden fractures under the solid-fluid coupling state was conducted based on the geological and mining characteristics of the coal seam depth, weak strata cementation, and high-intensity mining in the mining areas of West China. These mining characteristics are key to achieving water conservation during mining or establishing groundwater reservoirs in coal mines. Based on the engineering background of the Daliuta Coal Mine, a non-hydrophilic simulation material suitable for simulating the weakly cemented rock masses in this area was developed, and a physical simulation test was carried out using a water-sand gushing test system. The study explored the spatial distribution and dynamic evolution of the fractured zone in the mining overburden under the coupling of stress and seepage. The experimental results show that the mining overburden can be vertically divided into the overall migration zone, the fracture extension zone and the collapse zone; additionally, in the horizontal direction, the mining overburden can be divided into the primary fracture zone, periodic fracture zone, and stop-fracture zone. The scope of groundwater flow in the overburden gradually expands with the mining of coal seams. When a stable water inrush channel is formed, other areas no longer generate new channels, and the unstable water inrush channels gradually close. Finally, the primary fracture area becomes the main water inrush channel for coal mines. The numerical simulation results indicate that the overlying rock breaking above the middle of the mined-out area allows the formation of the water-conducting channel. The water body will flow into the fracture extension zone with the shortest path, resulting in the occurrence of water bursting accidents in the mining face. The experimental research results provide a theoretical basis for the implementation of water conservation mining or the establishment of groundwater reservoirs in western mining areas, and this theoretical basis has considerable application and promotion value.

The domestication event of the Tibetan pig revealed to be in the upstream region of the Yellow River based on the mtDNA D-loop

  • Ge, Qianyun;Gao, Caixia;Cai, Yuan;Jiao, Ting;Quan, Jinqiang;Guo, Yongbo;Zheng, Wangshan;Zhao, Shengguo
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.4
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    • pp.531-538
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    • 2020
  • Objective: Evidence from previous reports indicates that pig domestication in East Asia mainly occurred in the Mekong region and the middle and downstream regions of the Yangtze River. Further research identified two new origin centers for domestic pigs in the Tibetan Plateau and the islands of Southeast Asia. However, due to the small sample size of Tibetan pigs, details of the origin and spread of Tibetan pigs has not yet been established. Methods: We analyzed mitochondrial DNA control region (D-loop) variation in 1,201 individuals from nine Tibetan pig populations across five provinces. Comprehensive Tibetan pig samples were taken to perform the most detailed analysis of Tibetan pigs to date. Results: The result indicate that Rkaze pigs had the lowest level of diversity, while Changdu pigs had the highest diversity. Interestingly, these two populations were both in the Tibetan Plateau area. If we calculate diversity in terms of each province, the Tibetan Plateau area had the lowest diversity, while the Chinese province of Gansu had the highest diversity. Diversity gradient analysis of major haplotypes suggested three domestication centers of Tibetan pigs in the Tibetan Plateau and the Chinese provinces of Gansu and Yunnan. Conclusion: We found two new domestication centers for Tibetan pigs. One is in the Chinese province of Gansu, which lies in the upstream region of the Yellow River, and the other is in the Chinese province of Yunnan.

Mammalian Status of Mt. Cheomchalsan in Jindo, Korea

  • Shin, Hwa-Yong;Lee, Hwa-Jin;Kim, Woo-Yeol;Yoon, Hee-Nam;Lee, Jung-Hyo;Ha, Jeong-Wook
    • Animal Systematics, Evolution and Diversity
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    • no.spc9
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    • pp.80-83
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    • 2016
  • In order to analyze a status of animal in an area where has been became a land cause of Jindo Grand Bridge established on Jindo island area, mammal status in the biggest mountain in Jindo province, Mt. Cheomchalsan has been investigated for four times from May to October of 2016. According to the investigation, 5 orders, 9 families and 15 species of inhabitation was confirmed, and water deer (Hydropotes inermis), raccoon (Nyctereutes procyonoides), cat (Felis catus), and etcetera were dominant. Biodiversity and evenness index were likely to be high as 2.24 and 0.83, respectively and it is considered that favorable condition of natural ecosystem for inhabitation of mammalian is established. Meanwhile, since the cat designated as control species is confirmed as a dominant species, it is supposed that continuous management is necessary.

Frameworks and Directions in AIS Research : An Analysis of AIS Doctoral Dissertations (회계정보시스템연구의 구조틀과 방향 : 1980년부터 1990년까지의 미국 회계학 박사학위논문 분석을 통하여)

  • Im, Hak-Bin;Sim, Jeong-Pil
    • Asia pacific journal of information systems
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    • v.4 no.1
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    • pp.32-46
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    • 1994
  • The present study addresses the research frameworks and directions in the area of accounting information systems (AIS) by conducting a comprehensive survey of 76 A/S doctoral dissertations published between 1980 and 1990. The central research task is to identify the distinctive features of A/S that distinguish it from other disciplines. The procedure of the survey analysis is as follows. First, the A/S dissertations are categorized according to information systems (IS) and accounting. Then, some representative A/S research areas are documented, based on the IS/accounting domain combinations. The paper also attempts to discover the topical trends, supporting bases, and qualitative aspects of the A/S research. The survey reveals a : 1) the existence of economics as a supporting discipline, 2) the topical trend consistent with the evolution of IS, but restricted by the specific combinations of its parent domains, and 3) the need for intellectual rigor in the A/S research.

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Ship information system: overview and research trends

  • Liu, Sheng;Xing, Bowen;Li, Bing;Gu, Mingming
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.3
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    • pp.670-684
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    • 2014
  • Ship Information Systems (SISs) have been one of the main research focuses in ship design and become a multidisciplinary area. With these growing research trends, it is important to consolidate the latest knowledge and information to keep up with the research needs. In this paper, the SIS and its different forms are introduced and discussed. The beginning of this paper discusses the history and evolution of SIS. The next part of this paper focuses on different fields and research areas such as networking technology, information fusion, information decision, message display, ship control in real-time SISs. A Semi-Physical Simulation Platform (SPSIM) designed for SIS research and its running effect through a new Fuzzy-PID fusion algorithm are introduced in this paper then. A brief literature survey and possible future direction concerning each topic is included.

Design and Synthesis of Multi Functional Noble Metal Based Ternary Nitride Thin Film Resistors

  • Kwack, Won-Sub;Choi, Hyun-Jin;Lee, Woo-Jae;Jang, Seung-Il;Kwon, Se-Hun
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.93-93
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    • 2013
  • In recent years, multifunctional ternary nitride thin films have received extenstive attention due to its versatility in many applications. In particular, noble metal based ternary nitride thin films showed a promising properties in the application of Multifunctional heating resistor films because its good electrical properties and excellent resistance against oxidation and corrosion. In this study, we prepared multifunctional noble metal based ternary nitride thin films by atomic layer deposition (ALD) and plasma-enhanced ALD (PEALD) method. ALD and PEALD techniques were used due to their inherent merits such as a precise composition control and large area uniformity, which is very attractive for preparing multicomponent thin films on large area substrate. Here, we will demonstrate the design concept of multifunctional noble metal based ternary thin films. And, the relationship between microstructural evolution and electrical resistivity in noble metal based ternary thin films will be systemically presented. The useful properties of noble metal based ternary thin films including anti-corrosion and anti-oxidation will be discussed in terms of hybrid functionality.

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