• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.7089-7097
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• 2015

Bed changes in the Nakdong River were analyzed with long-term monitoring data for analyzing riverbed change patterns after Four Major Rivers Restoration Project (FMRRP). Also, possible long-term bed changes were predicted using one-dimensional numerical model for the section where the largest change was observed after FMRRP. The sensitive analysis was performed with different incoming sediment discharge conditions and sediment transport equations. The numerical model was calibrated by comparing short-term monitoring data and simulated results, and was applied for predicting bed change after 10 years. As a result of monitoring data analysis, the largest change in bed elevation occurred at the section between the Changnyeong-Haman and Hapcheon-Changnyeong weirs. The result of one-dimensional numerical modeling for 10 years indicated that maximum depositions of 2.07 m and 3.26 m were produced in this section.

• The Journal of Fisheries Business Administration
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• v.52 no.2
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• pp.55-67
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• 2021

Global warming affects critical natural resources, one of which is the oceans that occupy 70% of the total cover of the earth. In other words, ocean warming is a subset of global warming which needs to be addressed urgently. Purple laver (pyropia spp.) is one of the most vulnerable items to climate change although it is a major export product of Korean fisheries. The purpose of this study is to analyze the causality of how climate change caused by global warming affects the increase or decrease of PLP (purple laver production). The target area for analysis was set to Maro-hae between Jindo-gun and Haenam-gun. We selected marine environmental factors and meteorologic factors that could affect PLP as variables, as well as co-integration tests to determine long-term balance, and the Granger causticity tests. As a result, PLP and marine environmental factors WT (water temperature), pH, and DO confirmed that long-term equilibrium relationships were established, respectively. However, there is only causality with WT and it is confirmed that there is only a correlation between pH and DO (dissolved oxygen). There was no long-term equilibrium relationship between PLP and HDD (heating degree days) and there is a causal effect that HDD affects PLP; however, it was less clear than that of WT. The relationship between PLP and RF (rainfall), WS (wind speed), SS (percentage of sunshine), and FF (farm facilities) was all balanced in the long term, and causality exists. Based on the results of the analysis, policy proposals were made.

• Atmosphere
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• v.31 no.5
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• pp.553-562
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• 2021

The long-term trend of surface wind speed in Korea is estimated by correcting wind measurements at 29 KMA weather stations from 1985 to 2019 with physical and statistical homogenization. The anemometer height changes at each station are first adjusted by applying physical homogenization using the power-law wind profile. The statistical homogenization is then applied to the adjusted data. A standard normal homogeneity test (SNHT) is particularly utilized. Approximately 40% of inhomogeneities detected by the SNHT match with the sea-level-height change of each station, indicating that an SNHT is an effective technique for reconciling data inhomogeneity. The long-term trends are compared with homogenized data. Statistically significant negative trends are observed along the coast, while insignificant trends are dominant inland. The mean trend, averaged over all stations, is -0.03 ± 0.07 m s^-1 decade^-1. This insignificant trend is due to a trend change across 2001. A decreasing trend of -0.10 m s^-1 decade^-1 reverses to an increasing trend of 0.03 m s^-1 decade^-1 from 2001. This trend change is consistent with mid-latitude wind change in the Northern hemisphere, indicating that the long-term trend of surface wind speed in Korea is partly determined by large-scale atmospheric circulation.

• 한국노년학
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• v.31 no.4
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• pp.999-1014
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• 2011

The purpose of this study is to examine the effects of long-term care insurance(macro-system) on family relationship(micro-system)s' change based on ecosystems theory. Data come from the second(2007) and the fourth(2009) Korean Welfare Panel Study(KWPS). Experimental group is the beneficiary using long-term care insurance and the member of household in their households, and control group is the non-beneficiary not using long-term care insurance and the member of household in their households. The main findings of difference-in-difference model analysis are as follows. First, the ecosystems theory is a theory examining the correlation between long-term care insurance and family relationship. Second, the effects of long-term care insurance is not income effect but independent effect. This result shows that the meaning of family has faded away and family relationship has been weaken and that long-term care insurance has not complete characteristics as a social insurance. Thus, system reforms of long-term care insurance is highly needed for system comprehensiveness, coverage, adequacy, and service accessibility and is changed into family-friendly social policy.

• Journal of Environmental Policy
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• v.14 no.3
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• pp.21-40
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• 2015

Heat waves are not new, but due to climate change, the probability of occurrence and severity of heat waves increases, which results in more adverse impacts and damages on local community. Accordingly, the need to tackle heat waves in a more comprehensive and precautionary manner increases. Our study therefore lays emphasis on 1) a long-term plan which not only includes short-term plans in response to the observed damages, but also incorporates relevant sectors to deal with potential impacts in longer term perspective; and 2) a mechanism to manage and adjust the plan in a sustainable manner. In doing so, it examines the impacts of heatwaves and existing plans to tackle them. Based on that, two key conceptual frameworks, namely policy integration and adaptive management, are applied to provide strategies for the development and management of a long-term adapting heatwave plan addressing climate change.

• Journal of the Korean Society of Tobacco Science
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• v.14 no.1
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• pp.57-65
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• 1992

The quality of cut tobacco will be deteriorated due to weather conditions such as temperature and relative humidity, when shipping and long term storaging. The change of equilibrium moisture contents in cut tobacco were under influence of relative humidity and temperature but not humectants. Therefore internal packing materials are necessary for cut tobacco to maintain initial quality, including taste, flavour and musty smell during shipping or storaging. When packing cut tobacco for shipping or long term storaging, desiralbe packing density was 200/$m^2$, For the long term storage under R.H 90% and 3$0^{\circ}C$, polyethylene film thickness suitable for packing material are above 100$\mu$, which resulted in 42days of shelf life.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.320-320
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• 2010

The dye-sensitized solar cells (DSSCs) have achieved so far the highest validated efficiency over 11%. However, the cells with the best performance utilize volatile solvent as a electrolyte, which can cause some practical limitations for the long-term operation. This is one of the most substantial problems to be resolved for the commercialization of DSSCs. In order to improve the long-term stability, many research groups have reported new electrolyte system, to replace the liquid type electrolyte by non-volatile ones. In this work, we studied long-term stability of the DSSCs with various types of electrolytes such as (PVDF HFP) based polymer, eutectic melts of ionic liquids, and liquid based solvent. The cells with various electrolytes have been exposed to the condition under thermal stress and illumination over 1000 hours. We will report the change of photovoltaic properties with time and investigate the degradation mechanism with the impedance spectroscopic analysis.

• Journal of Ocean Engineering and Technology
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• v.21 no.4
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• pp.15-20
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• 2007

The harbor siltation by longshore sediment transports has become a serious problem on the East Coast of Korea. A reasonable prediction of the longshore sediment rate is important to approach the siltation problem effectively. In the recently developed 1-line model, the empirical constants of the sediment transport formula, which include the absolute quantity of sediment transport rate and the spatial distribution of breaking wave height by wave deformation, are treated as calibration parameters. Since these constants should be determined by the very long-term shoreline data, the longshore sediment rates are much more reasonable values. The method was applied to Hupo Beach, which has experienced heavy siltation. The authors also discuss long-term shoreline change using aerial photos and the observed wave-induced current patterns. According to the result, the SW-direction sediment transport rate was $146,892m^3/year$, and the NE direction was $2,694,450m^3/year$ at Hupo Beach for the last 11 years. The siltation in Hupo Harbor might be affected by the NE-direction sediment transport from Hupo Beach.

• The Korean Journal of Health Service Management
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• v.5 no.3
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• pp.13-23
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• 2011

This paper investigated the operating environment for the representative of each agency and the facility workers on the basis of analytical result of recognition changes of the operating environment changes under the operating the long-term care insurance. It was described plans to take positive effect on the operating as follows. The first, on the result of regression analysis, the service administrative range takes the biggest effect on the general recognition of executing the long-term care insurance off and on. The affirmative recognition of the service administrative range had the general recognition on the system be positive effect. But the operator of facility asserts that the care manager's professionalism related quality of service be strengthened. The second, on the result of regression analysis, in the financial accounting administrative it is revealed the more positive recognition it is, the more positive effects it has. From the difference verification of an operation size from operation subject, the small operation size and personal facility recognize the long term care insurance positively. On the other side the facilities where the operation size is big recognize the system negatively. The long-term care facility should rearrange a support program newly and the government needs to promote the donation activity, because it is needed to reduce the financial burden of facilities.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.9
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• pp.1581-1586
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• 2010

Korea Power Exchange has successfully performed the Long-term Electricity Demand Forecasting. Recently there is a lot of change in electricity industry sector; the national master-plan for green gas emission reducing, rise of smart-grid, and new trend of electricity consumption, and it is becoming painful challenging for demand forecasting. In new circumstance the demand forecasting is required more flexible and more accurate.