• Ocean and Polar Research
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• v.34 no.3
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• pp.275-286
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• 2012

Over the last 20 years there have been more than 3000 peer-reviewed papers relating to climate change and biodiversity published, and still the numbers are increasing. However, most studies focused on the impacts of climate change at population or community levels, and the results invariably reveal that there has been, or will be, a negative effect on the structure and pattern of biodiversity. Moreover, the climate change models and statistical analyses used to test the impacts are only newly developed, and the analyses or predictions can often be misled. In this review, I ask why an individual's life history is considered in the study how climate change affects biodiversity, and what ecological factors are impacted by climate change. Using evidence from a range of species, I demonstrate that diverse life history traits, such as early growth rate, migration/foraging behaviour and lifespan, can be shifted by climate change at individual level. Particularly I discuss that the optimal decision under unknown circumstance (climate change) would be the reduction of the ecological fitness at individual level, and hence, a shift in the balance of the ecosystem could be affected without having a critical impact on any one species. To conclude, I summarize the links between climate changes, ecological decision in life history, the revised consequence at individual level, and discuss how the finely-balanced relationship affects biodiversity and population structure.

• Journal of the Korean Society for Heat Treatment
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• v.6 no.1
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• pp.9-16
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• 1993

To investigate the properties of diffusion bonding of 7050 Al alloy, the diffusion bonding joints have been produced in self-made diffusion bonding hot-press which admits a defined application of the bonding pressure during the heating phase and also rapid cooling after the bonding process with various bonding condition. The strength of the bond increases with increasing the bonding time and temperature. Shear test at toom temperature showed that high strength up to 70% that of parent metal (320 MPa), 220 MPa for the specimen bonded 14 hr at $560^{\circ}C$, with 3 MPa. In this case, however, there is large deformation more than 20% reduction in thickness. The results were correlated with joint characteristics found by optical microstructure and by fractography by SEM. When the strengths of the bonds are more than 50% that of parent metal, a great deal of dimples stretched along the direction of shear stress are observed over the fractured surface of the bond. On the microstructure of the bond line, initial mophology of the bond line disapeared for the grain boundary migration with increasing the bonding time.

• Journal of the Korea Institute of Building Construction
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• v.11 no.4
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• pp.379-386
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• 2011

Durability of concrete is an important issue, and one of the most critical aspects affecting durability is chloride diffusivity. Factors such as water.cement ratio, degree of hydration, volume of the aggregates and their particle size distribution have a significant effect on chloride diffusivity in concrete. The use of polypropylene fibers(particularly very fine and well dispersed micro fibers) or mineral additives has been shown to cause a reduction in concrete's permeability. The main objective of this study is to evaluate the manner in which the inclusion of fiber(in terms of volume and size) and blast furnace slag(BFS) (in terms of volume replacement of cement) influence the chloride diffusivity in concrete by applying 3D computer modeling for the composite structure and performing a simulation of the chloride penetration. The modeled parameters, i.e. chloride diffusivity in concrete, are compared to the experimental data obtained in a parallel chloride migration test experiment with the same concrete mixtures. A good agreement of the same order is found between multi.scale microstructure model, and through this chloride diffusivity in concrete was predicted with results similar to those experimentally measured.

• Fire Science and Engineering
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• v.23 no.5
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• pp.17-23
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• 2009

Moisture evaporates, when concrete is exposed to fire, not only at concrete surface but also at inside the concrete to adjust the equilibrium and transfer properties of moisture. The equilibrium properties of moisture are described by means of water vapor sorption isotherms, which illustrate the hysteretical behavior of materials. In this paper, the prediction method of the moisture distribution inside the concrete members at fire is presented. Finite element method is employed to facilitate the moisture diffusion analysis for any position of member. And the moisture diffusivity model of high strength concrete by high temperature is proposed. To demonstrate the validity of this numerical procedure, the prediction by the proposed algorithm is compared with the test result of other researcher. The proposed algorithm shows a good agreement with the experimental results including the vaporization effect inside the concrete.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.2
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• pp.110-114
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• 2006

The study has been performed on the improvement of bonding process and bond strength of HTPB propellant and liner using a polymeric curative. In case of liner using polymeric curative prepared from reaction of HTPB and TDI, migration of curative was decreased at bond interface. So EPDM insulation sanding and Desmodur RE coating process could be omitted in motor case preparation and bond strengths between the HTPB propellant and liner were increased. Also deterioration phenomena of bond strength could not be observed in accelerated aging test.

• Journal of the Korea Society of Computer and Information
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• v.22 no.11
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• pp.89-96
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• 2017

This study analyzed how mental health affects stress in adolescents. The subjects of the study were data of about 60,000 middle and high school students living in the country, using cross-tabulation data and chi - square test to analyze the relationship between stress and mental health of adolescents. As a result of the research, it was found that the adolescents exposed to the excessive stress showed a poor correlation with the recovery of the fatigue, while the adolescents with relatively low stress showed the good recovery of fatigue. In the case of mental illness, depression or despair, the students who answered that they were stressed showed a lot of experience. In the case of suicide ideation, suicide attempt, and suicide attempt, the number of attempts to commit suicide was high when the level of perceived stress was high similar to the result of previous analysis. This finding confirms that stress is an important factor in the quality of life in adolescent mental health. It can be used as a strategy and business to prevent the problem of youth suicide in modern society in advance by stress management.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.3
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• pp.60-70
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• 2001

The study of compatible liner with ADP-505 propellant based PCP was performed. HTPB/DDl was chosen as a binder of liner in order to prohibit migration of nitroester plasticizer from propellant. The possible formulations for liner were screened by peel test of EPDM insulation/liner, propellant/liner and insulation/liner/propellant. Also, the adhesion tests including tension and shear were conducted. The adhesion of liner and propellant fumed out to be very good. The peel value was shown 1.5∼1.8 daN/cm, tensile force was 5.5∼6.0bar and shear force was 4.2∼5.0bar. In the samples of insulation/liner/propellant, they also have shown good adhesion properties. The peel, tensile and shear strength were 1.8 daN/cm, 5.0∼6.0bar and 4.5∼5.0bar, respectively.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.4787-4807
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• 2016

Although the dense interconnection datacenter networks (DCNs) (e.g. FatTree) provide multiple paths and high bisection bandwidth for each server pair, the single-path TCP (SPT) and ECMP which are widely used currently neither achieve high bandwidth utilization nor have good load balancing. Due to only one available transmission path, SPT cannot make full use of all available bandwidth, while ECMP's random hashing results in many collisions. In this paper, we present OFPT, an OpenFlow based Parallel Transport framework, which integrates precise routing and scheduling for better load balancing and higher network throughput. By adopting OpenFlow based centralized control mechanism, OFPT computes the optimal path and bandwidth provision for each flow according to the global network view. To guarantee high throughput, OFPT dynamically schedules flows with Seamless Flow Migration Mechanism (SFMM), which can avoid packet loss in flow rerouting. Finally, we test OFPT on Mininet and implement it in a real testbed. The experimental results show that the average network throughput in OFPT is up to 97.5% of bisection bandwidth, which is higher than ECMP by 36%. Besides, OFPT decreases the average flow completion time (AFCT) and achieves better scalability.

• The Journal of Korean Society for Neurotherapy
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• v.22 no.3
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• pp.43-48
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• 2018

Purpose The purpose of this study is to identify the prevalence, risk factors, characteristics, and interventions of hip joint problems in children with cerebral palsy, and to be able to serve as leverage for early detection, prevention, and function recovery. Method The electronic journal site was searched by the search terms "cerebral palsy", "hip joint", "hip joint dislocation", we analyzed and descript the cited articles from domestic and foreign papers in Pubmed 9, Science Direct 7, and K RISS analysis and analysis. Results Children with cerebral palsy showed the different prevalence according to their disability type, severity, and functional level, and we knew that abnormal neuromuscular control, stiffness, and biomechanical changes could be risk factors. Migration Index, Acetabolum Index, Neck shaft angle using by radiography and passive ROM test, special tests were available for the diagnosis and evaluation of the hip joint. Combination of physical therapy and orthopedic surgery was very important intervention, and complementary alternative therapy, orthosis, and postural assistant are effective. Conclusion We suggested that early detection and prevention is the most important periodic examination and that a multidisciplinary approach is a major factor in intervention.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.11
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• pp.5357-5381
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• 2018

Cloud computing offers a wide range of on-demand resources over the internet. Utility-based resource allocation in cloud data centers significantly increases the number of cloud users. Heavy usage of cloud data center encounters many problems such as sacrificing system performance, increasing operational cost and high-energy consumption. Therefore, the result of the system damages the environment extremely due to heavy carbon (CO2) emission. However, dynamic allocation of energy-efficient resources in cloud data centers overcomes these problems. In this paper, we have proposed Energy and Service Level Agreement (SLA) Aware Resource Allocation Heuristic Algorithms. These algorithms are essential for reducing power consumption and SLA violation without diminishing the performance and Quality-of-Service (QoS) in cloud data centers. Our proposed model is organized as follows: a) SLA violation detection model is used to prevent Virtual Machines (VMs) from overloaded and underloaded host usage; b) for reducing power consumption of VMs, we have introduced Enhanced minPower and maxUtilization (EMPMU) VM migration policy; and c) efficient utilization of cloud resources and VM placement are achieved using SLA-aware Modified Best Fit Decreasing (MBFD) algorithm. We have validated our test results using CloudSim toolkit 3.0.3. Finally, experimental results have shown better resource utilization, reduced energy consumption and SLA violation in heterogeneous dynamic cloud environment.