• Journal of Ecology and Environment
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• v.37 no.3
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• pp.123-129
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• 2014

Ant communities are well suited for monitoring changes in ecosystems. Although numerous studies have examined the responses of ant communities to environmental disturbance, relatively few long-term studies on ant communities have been undertaken in urban environments. We examined species richness in nine urban parks in Hiroshima, Japan, and compared the survey results with data collected at the same sites by using the same methods in 1999. In both surveys, total of 25 species was recorded: 23 species in 1999 and 20 species in 2012. Non-metric multidimensional scaling analysis revealed that the ant communities consisted of two distinct groups, which could in turn be characterized by three patterns of ant community changes in between the two groups. The first of these community change patterns was characterized by a shift within group 1, but the number of species remained constant (approx. 10 species). The second pattern was characterized by a shift within group 2, but the number of species remained low (approx. 4 species). The third pattern was characterized by a shift from group 1 to group 2 as the abundance of Linepithema humile (Mayr) increased over time. Unlike the first and second patterns, the number of ant species in communities of the third type decreased significantly. These findings suggest that L. humile has a marked effect on the species diversity of indigenous ant communities in urban environments.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.57
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• pp.3-34
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• 2013

In the international sales contract, long-term contracts often face hardship in fulfilling the original contract terms by relevant parties due to rapid change and uncertainty of political and economic circumstance. In this case, party who faces hardship of fulfillment terminates contract or demands adaptation to contract condition but if opponent doesn't accept this, it proceeds to commercial dispute needing legal interpretation. Generally it is wise to set forth governing law in contract between parties in the case of international contract, for legal stability. One of universal governing law which relevant parties select by agreement to solve economical hardship of fulfillment is PICC. PICC defines the hardship in detail for renegotiation on following hardship of fulfillment unexpected. In the case of failing renegotiation, Court(arbitral tribunal) conducts termination to contract or adaptation to contract condition through arbitration or mediation. In conclusion, when signing international long-term contract, it is desirous to handle dispute effectively by inserting provisions which can deal with economical hardship in contract or defining PICC as governing law in the case of hardship incurred. It is because it is realistic to handle dispute smoothly to the extent that both parties can be satisfied in the case of hardship incurred, though international contract should be fulfilled.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.12 no.1
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• pp.41-48
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• 2016

To investigate the effect of long-term thermal aging on the microstructural and mechanical characteristics of weldment made of nickel base alloy and its weld metal, an accelerated heat treatment was applied to simulate the process of long-term thermal aging in the operating condition of nuclear power plant. A representative nickel-based weldment with Alloy 600 and Alloy 182 was fabricated and heat-treated at $400^{\circ}C$ for 1,713 h and 3,427 h to simulate the thermal aging for the period equivalent to 15 and 30 years in operating pressurized water reactors, respectively. The microstructural and mechanical characteristics were analyzed by using optical microscopy, scanning electron microscopy and Vickers microhardness measurement. Changes were observed in precipitation behavior and microhardness of each specimen, and these changes were mainly attributed to the change in precipitated morphology and residual stress across the weld during the thermal aging process.

• The Korean Journal of Food And Nutrition
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• v.13 no.1
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• pp.21-27
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• 2000

In order to investigate the changes of rice qualities during 4 years storage of paddy in warehouse of normal temperature condition. As storage period go by, head ratio was deduced and broken rice was increased according as a change of temperature during the long term storage. A color of rice was became more dark gray than that of entering time as L value was decreased from 64.07 to 61.62 a 4 years late. As a results of studies on the cooking quality of milled rice, water uptake ratio and expanded volume were increased in proporation to storage period, wherease total solids and iodine blue value were decreased. In the characteristic of texture of cooked rice, viscosity/hardness ratio(-H/H) had a decreasing tendency, while adhesiveness and cohesiveness increased with increased storage time. The qualities of cooked milled rice studied were sensory attributies of odor, taste, stickiness and appearance which were evaluvated by multiple comparsion method. The sensory results showed that all of descriptions were deterirated with a increased storage period. The taste and stickiness were changed from good score to bad score a 2 years later.

• International Journal of Concrete Structures and Materials
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• v.2 no.2
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• pp.91-98
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• 2008

Curved bridges are important components of a highway transportation network for connecting local roads and highways, but very few data have been collected in terms of their field performance. This paper presents two-years monitoring and system identification results of a curved concrete box-girder bridge, the West St. On-Ramp, under ambient traffic excitations. The authors permanently installed accelerometers on the bridge from the beginning of the bridge life. From the ambient vibration data sets collected over the two years, the element stiffness correction factors for the columns, the girder, and boundary springs were identified using the back-propagation neural network. The results showed that the element stiffness values were nearly 10% different from the initial design values. It was also observed that the traffic conditions heavily influence the dynamic characteristics of this curved bridge. Furthermore, a probability distribution model of the element stiffness was established for long-term monitoring and analysis of the bridge stiffness change.

• Spatial Information Research
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• v.21 no.5
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• pp.1-6
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• 2013

Trying to estimate variations of the riverbed is basic and important for river management. When new dam constructed in upstream and a structure were planned, impact of the riverbed changes in downstream should be considered for stably maintained and sustained rivers in the future. In this study, long-term riverbed changes analyzed using aerial photographs in Naeseongcheon. Also applying one-dimensional numerical model, GSTARS analyzed the effects of bed deformation in critical points. Based on Changing Patterns of long-term riverbed, it is possible that after the dam was built, to explore how to manage Naeseongcheon.

• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.122-128
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• 1999

The cholesterol-lowering effect of a fermented milk was studied for long-term period (56 weeks) in 206 Korean adults (106 normal cholesterol group and 100 hypercholesterol group) 300 $m\ell$ of the fermented milk was taken daily to all subjects for 10 weeks. 24 subjects drinking the fermented milk for 56 weeks and 42 subjects no-drinking for 40 weeks and then re-drinking from 50 th week for 6 weeks were followed up. Paired t-test, Duncan's multiple range test, and GLM repeated measure were used for statistical analysis. The level of total blood cholesterol and LDL after drinking the fermented milk for 10 weeks were decreased significantly in both group and affected by total cholesterol level at baseline, BMI, smoking and drinking. there is no significant change in triglyceride, HDL, and LDL/HDL ratio by drinking the fermented milk. The fermented milk intake for long-term period (56 weeks) did not show any more effect after 10 week on the level of TC, TG, HDL, LDL.

• Transactions of the Korean hydrogen and new energy society
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• v.18 no.2
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• pp.207-215
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• 2007

The rapid changes of energy environment such as high oil price, united nations framework convention on climate change, and the hydrogen economy have been happening to provide national energy security in the 21st century, we need to build strategic approach for coping with energy environment. From a long-term viewpoint of energy technology development, it's time to develop energy technology with selection and specification. In this study, we build energy technology roadmap for establishing the hydrogen economy with a long-term strategy. We analyze economic spin-offs and commercial potential for establishing energy technology roadmap of energy technology development for establishing the hydrogen economy.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.195-196
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• 2022

Insulation material absorption rate is closely related to thermal conductivity. In Korea, there is no study on the change of insulation material in a long-term continuous exposure environment. In this study, basic data on the long-term durability of insulation materials were obtained by measuring the absorption rate of insulation materials over time. For the purpose of providing, as a result of the measurement, PIR class2 No.2 and PIR noncombustible show similar absorption rate trends, which is thought to be due to the fact that both are made of rigid urethane foam, and flame retardant EPS has the highest absorption rate except for PF. This is thought to be because there is a space for absorption between the beads and the beads. In the case of XPS, it is thought that the reason for showing the lowest absorption rate is that because it is produced by extrusion, it has a high density and thus has less space for moisture to penetrate.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.322-325
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• 2006

The research project evaluates different infrastructure project delivery methods used internationally. The goal is to define the main benefits, deficiencies, and requirements of the project delivery systems for both the short term and long term perspectives. Also, the research attempts to determine alternatives to modify and to promote change in the current infrastructure project delivery methods in order to make the processes more efficient with value added benefits to all participants.