• Korean Journal of Remote Sensing
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• v.33 no.6_1
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• pp.947-960
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• 2017

Soil moisture plays an important role to affect the Earth's radiative energy balance and water cycle. In general, satellite observations are useful for estimating the soil moisture content. Passive microwave satellites have an advantage of direct sensitivity on surface soil moisture. However, their coarse spatial resolutions (10-36 km) are not suitable for regional-scale hydrological applications. Meanwhile, in-situ ground observations of point-based soil moisture content have the disadvantage of spatially discontinuous information. This paper presents an experimental soil moisture retrieval using Sentinel-1 SAR (Synthetic Aperture Radar) with 10m spatial resolution for cropland in South Korea. We developed a soil moisture retrieval algorithm based on the technique of linear regression and SVR (support vector regression) using the ground observations at five in-situ sites and Sentinel-1 SAR data from April to October in 2015-2017 period. Our results showed the polarization dependency on the different soil sensitivities at backscattered signals, but no polarization dependence on the accuracies. No particular seasonal characteristics of the soil moisture retrieval imply that soil moisture is generally more affected by hydro-meteorology and land surface characteristics than by phenological factors. At the narrower range of incidence angles, the relationship between the backscattered signal and soil moisture content was more distinct because the decreasing surface interference increased the retrieval accuracies under the condition of evenly distributed soil moisture (during the raining period or on the paddy field). We had an overall error estimate of RMSE (root mean square error) of approximately 6.5%. Our soil moisture retrieval algorithm will be improved if the effects of surface roughness, geomorphology, and soil properties would be considered in the future works.

• Korean Journal of Plant Resources
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• v.22 no.4
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• pp.323-329
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• 2009

In order to find out superior corn line which has a strong antioxidant activity in the corn silk, antioxidant compounds and antioxidant activity were measured from various inbred and F1 lines. As a result, the contents of phenolic and flavonoid compounds range from 532 mg/100 g to 3,274 mg/100 g and from 980 mg/100 g to 2,420 mg/100 g respectively. Absorbance at 517 nm for contents of anthocyanins ranges from 0.05 to 0.76. Correlation coefficients between antioxidant compounds and various antioxidant assays such as DPPH, ABTS and FRAP were analyzed. Correlation coefficients between antioxidant activity and phenolic compounds and anthocyanin were significantly high in ABTS and FRAP assays. Considering acidic extraction condition and intervention between anthocyanins and DPPH solution, ABTS assay and FRAP assay are more suitable methods to evaluate antioxidant activity of corn silks. Especially, ABTS assay is thought to be the best method among three assays because the antioxidant activity in ABTS assay showed high correlation with phenol, flavonoid and anthocyanin compounds respectively. Among the samples, S15 which showed the highest contents of total phenolic compounds and the most potent antioxidant activity in ABTS and FRAP assay will be a good source for functional material.

• Journal of Advanced Navigation Technology
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• v.6 no.3
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• pp.195-202
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• 2002

Recently, as the range of mobile communication services is extended, the interference between adjacent base-stations is increased. Nowdays, one of the important factors causing interference is IMD (Inter-Modulation Distortion) problems. Not only active IMD but also passive IMD effects must be considered to design a CDMA system. In this study, we design and implement 7/16" DIN connectors which have a various intensity of surface illumination, thickness and quality of plating material to analyze the effects of PIMD. And propose the methods for improving the PIMD characteristics: First, it is more profitable to use the metal which has good intensity of surface illumination where most of all electric currents passes through it. Secondly, we should plate metals more than $5{\mu}m$ for RF energy enough to propagate in a medium. Thirdly, it is necessary to select a metal having high conductivity and specific heat to protect the aging phenomenon of plate material. And it is required to develop a new plating material to replace the current materials, such as the alloy of three components for cost reduction. We have to know that the plate which has intensity of surface illumination 6 S and the thickness of plating material $5{\mu}m$ satisfy the domestic PIMD specification (KTF) -150 dBc, regardless of the plate material in case of 7/16" DIN connector.

• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.149-159
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• 2011

Bentazone is benzothiadiazole group herbicide, and used to foliage treatment. This herbicide have already been widely used for cereals and vegetables planting in worldwide. This experiment was conducted to establish a determination method for bentazone residue in crops using HPLC-UVD/MS. Bentazone residue was extracted with acetone (adjusted pH 1 with phosphoric acid) from representative samples of five raw products which comprised hulled rice, soybean, apple, green pepper, and Chinese cabbage. The extract was diluted with saline water, and dichloromethane partition was followed to recover bentazone from the aqueous phase. Florisil column chromatography was additionally employed for final clean up of the extract. The bentazone was quantitated by HPLC with UVD, using a YMC ODS AM 303 ($4.6{\times}250$ mm) column. The crops were fortified with bentazone at 3 levels per crop. Mean recovery ratio were ranged from 82.0% for a 0.2 mg/kg in apple to 97.9% for a 0.02 mg/kg in Chinese cabbage. The coefficients of variation were ranged from 0.5% for a 0.02 mg/kg in soybean to 9.7% for a 0.02 mg/kg in Chinese cabbage. Quantitative limit of bentazone was 0.02 mg/kg in representative five crop samples. A LC/MS with selected-ion monitoring was also provided to confirm the suspected residue. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of bentazone in agricultural commodities.

• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.125-133
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• 2011

Ametryn is used in USA, China, and Japan, but not introduced in Korea yet. So, MRL (Maximum Residue Level), and analytical method of ametryn were not establishment in Korea. Therefore, this experiment was conducted to establish a determination method for ametryn residue in crops using HPLC-UVD/MS. Ametryn residue was extracted with acetone from representative samples of five raw products which comprised hulled rice, soybean, apple, green pepper, and Chinese cabbage. The extract was diluted with saline water, and dichloromethane partition was followed to recover ametryn from the aqueous phase. Florisil column chromatography was additionally employed for final clean up of the extract. The ametryn was quantitated by HPLC with UVD, using a Tosoh ODS 120T ($4.6{\times}250$ mm) column. The crops were fortified with ametryn at 2 levels per crop. Mean recovery ratio were ranged from 83.7% for a 0.2 mg/kg in soybean to 91.1% for a 1.0 mg/kg in hulled rice. The coefficients of variation were ranged from 1.2% for a 1.0 mg/kg in hulled rice to 3.6% for a 1.0 mg/kg in soybean. Quantitative limit of amatryn was 0.02 mg/kg in representative 5 crop samples. A LC/MS with selected-ion monitoring was also provided to confirm the suspected residue. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of ametryne in agricultural commodities.

• Journal of The Korean Association of Information Education
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• v.10 no.1
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• pp.47-57
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• 2006

As teenagers' Internet use increases and Internet takes an important part in their everyday lives, many people become concerned with Internet addiction. In this study, I attempt to analyze the current status of teenagers' Internet addiction using an evaluation tool developed for students, and to compare elementary students' Internet addiction level with secondary students. Also I analyze factors affecting Internet addiction. For the analysis, 18 variables are selected from the areas such as demographic background, the experience of Internet use, family-related traits and social activities. A survey was conducted to 1,155 elementary students and 1,822 secondary students selected from nationwide schools. The main finding of this study is that among the elementary students 5.0% of the sample students are in the stage of serious addiction, and 19.7% in the stage of early addiction. In addition, the level of elementary students' Internet addiction is significantly higher than the level of secondary students. Also, the degree of elementary students' Internet addiction is significantly affected by some factors such as gender, surfing time, surfing purpose, satisfaction with parental relationship, parents' interference in Internet use, conversation frequency among family members, and satisfaction with school life.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.43 no.1 s.307
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• pp.45-54
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• 2006

This paper proposed color matching technique, including display characterization, chromatic adaptation model, and gamut mapping and extension, to generate consistent colors for the same input signal in each display device. It is necessary to characterize the relationship between input and output colors for display device, to apply chromatic adaptation model considering the difference of reference white, and to compensate for the gamut which display devices can represent for reproducing consistent colors on DTV display devices. In this paper, 9 channel-independent GOG model, which is improved from conventional 3 channel GOG(gain, offset gamma) model, is used to consider channel interaction and enhance the modeling accuracy. Then, the input images have to be adjusted to compensate for the limited gamut of each display device. We proposed the gamut mapping and extension method, preserving lightness and hue of an original image and enhancing the saturation of an original image in xy chromaticity diagram. Since the hmm visual system is more sensitive to lightness and hue, these values are maintained as the values of input signal, and the enhancement of saturation is changed to the ratio of input and output gamut. Also the xy chromaticity diagram is effective to reduce the complexity of establishing gamut boundary and the process of reproducing moving-pictures in DTV display devices. As a result, reproducing accurate colors can be implemented when the proposed method is applied to LCD and PDP display devices

• Journal of Korean Society of Forest Science
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• v.105 no.2
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• pp.238-246
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• 2016

The study aims to examine Japan's National REDD+ Strategies prepared for Post-2020 and the status of its implementation by organizations in Japan, and then to suggest the potential REDD+ countermeasures against Joint Credit Mechanism (JCM) for Republic of Korea and their implications. As for the technical limitations of the guidelines of REDD+ under the JCM, it is pointed out that forests located at the place with less potential safeguard intervention tend to be selected as the target area for a project and that, as reference emission trend changes depending on the basic year of the baseline, differences could occur among the amounts of greenhouse gas emission. In addition, it is pointed out that the result of the calculation of the displacement of emissions, or leakeage, in REDD+, can have an uncertainty, since the calculation is done by just multiplying leakage area by certain coefficients, without considering the size of the leakage area. Furthermore, the lack of implementation guideline or methodologies for a project level is also pointed out as a limitation, considering that there are only some national and sub-national monitoring guidelines at present. Finally, internationally accepted guidelines for safeguard and its sub-items needed to be prepared, as current safeguard policy only includes lists without detailed items. Such things mentioned above are all related to, and can lead to the problem of double counting of items in Nested Approach etc., as well as of the distribution of credits. Therefore, Republic of Korea should take these into consideration when implementing its REDD+ projects.

• Korean Journal of Social Welfare
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• v.67 no.3
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• pp.203-225
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• 2015

Social care service has grown much with the introduction of Long-Term Care Insurance, but it remains difficult to answer in the affirmative to the question: are we providing sufficiently good care? This study has its purpose in figuring out what conditions are necessary to realize good care in our society. The study has used focus group interview (FGI) as a way to acquire realistic knowledge on the conditions that create good care and its deterring factors. The focus group interview, which targeted long-term care workers and facility heads, was conducted three times from January through March 2014, with each session taking about 3 hours. The analysis showed that the components of good care were mutual understanding and recognition through active interaction, making a good relationship based on mutual trust and respect, professionalism of care worker with flexible judgment that provides customized services, professionalism of center manager with appropriate intermediation, and the tripartite partnership among family, elderly, and care worker. Meanwhile, the deterring factors of good care were identified as devaluation of care labor, ambiguous job description and abuse, unprofessionalism of care worker and manager, inappropriate interference and indifference of family, and the structural constraints on long-term care environment.

• Korean Journal of Environment and Ecology
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• v.1 no.1
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• pp.46-65
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• 1987

This study was excuted to measure the user's impact area of the Bukhan Mountain National Park. Eighteen sites of the campsite and the picnic area were sample to measure the impact rating of soil and vegetation. And three belt transects were sampled to analyze soil properties and vegetational change by the user's impact. Also user's psychology was investigated through questionnaires with the visitor and 726 answers were collected from May to June in 1987. The regression equation was significant between the distance and the soil hardness. individual number per 100$m^2$, herb coverage and similarity index from the center of picnic area to the non-use site. The tolerant tree against user's impact are Lespedza maximowiczii. Stephanandra insica, Actinidia arguta Symplocos chinensis for. pilosa and the sensitive trees were Fraxinus rhy chophylla Sorbus alnifolia. and Rhodadendron mucronulatun. The facilities factor and social factor are the most affecting factors to User's psychology by the varimax rotated factor analysis. The carrying capacity of the picnic area was 25$m^2$ per man by the degree of psychological satisfaction.