• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.886-894
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• 2012

Well-designed housing systems are important from the viewpoint of animal welfare and improvement of meat production. In this study, we investigated the effects of outdoor housing of pigs on their behavior, cortisol levels, and meat characteristics. Two groups that were born and raised in a spacious outdoor pen ($4{\times}10$ m for every two sows) or a minimum-sized standard pen in a piggery ($1.9{\times}2.2$ m for every sow) were studied. When their behaviors at the age of 2 to 3 wk were observed, the number of rooting episodes tended to be larger (p = 0.0509) and the total time of rooting tended to be longer (p = 0.0640) in the outdoor-housed piglets although the difference was not significant. Basal salivary cortisol levels of the outdoor piglets at the age of 4 wk were significantly lower than those of the indoor piglets ($5.0{\pm}0.59$ ng/ml vs. $11.6{\pm}0.91$ ng/ml, 30 min after treatment), although their plasma cortisol levels were similar ($53.3{\pm}3.54$ ng/ml vs. $59.9{\pm}4.84$ ng/ml, 30 min after treatment). When the ears were pierced at weaning, plasma and salivary cortisol levels were increased in both groups, even at 15 min after piercing. However, the increase in the outdoor-housed group was significantly less than that in the indoor-housed group. Throughout their lives, body weight and daily gain of the pigs were not significantly different between the two groups. In a meat taste preference test taken by 20 panelists, saltiness, flavor, and color of the outdoor-housed pork were found to be more acceptable. Moreover, when an electronic taste-sensing device was utilized, the C00 and CPA-C00 outputs ($3.78{\pm}0.07$ and $-0.20{\pm}0.023$), which correspond to compounds of bitterness and smells, respectively, were significantly lower in the outdoor-housed pork ($5.03{\pm}0.16$ and $-0.13{\pm}0.009$). Our results demonstrate that the outdoor housing system for piglets induces natural behaviors such as rooting and suppresses the strongest stress reaction of piglets, which could be important for animal welfare. Moreover, the outdoor housing system might change muscle characteristics and improve pork bitterness, flavor, and color. These changes may be preferred by consumers, increasing the sale of these meats.

• Korean Journal of Remote Sensing
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• v.14 no.1
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• pp.37-52
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• 1998

The NSCAT(NASA Scatterometer) carried by the japanese Advanced Earth Observing Satellite(ADEOS) was the first high resolution(25 km) device for the direct wind measurement over the ocean. Even it was ceased to operate in lune of 1977 because of the power failure, it gave the first opportunity to the marine meteorologists to study the direct measured ocean wind during its 9 months of operation, especially around Korea. This study is to show monthly mean ocean wind and wind stress curl fields around Korea from January, 1997 to June, 1997. Mean ocean winds in January are predominantly northwesterly and the strongest wind(12 m/s) is found near Vladivostok. The winds in the western East Sea are strongly inf1uenced by the mountain range in Korea and these topographically influenced winds make about five times larger wind stress curl fields than previous estimates based on the weather maps. The calculation of Sverdrup transport in the East Sea shows the possibility of the directional change of the East Korean Cold Current from southward to northward direction caused by the winter wind. The downwelling area near North Korea has maximum estimated speed of 45 m in january and this wind induced downwelling makes good condition for the formation of Intermediate East Sea Water together with vigorous mixing by the strong wind.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1559-1572
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• 2021

The response of vegetation under the crop stress condition was evaluated using structural, biochemical, and physiological vegetation indices based on unmanned aerial vehicle (UAV) images and field-spectrometer data. A high concentration of herbicide was sprayed at the different growth stages of garlic to process crop stress, the above ground dry matter of garlic at experimental area (EA) decreased about 46.2~84.5% compared to that at control area. The structural vegetation indices clearly responded to these crop damages. Spectral reflectance at near-infrared wavelength consistently decreased at EA. Most biochemical vegetation indices reflected the crop stress conditions, but the meaning of physiological vegetation indices is not clear due to the effect of vinyl mulching. The difference of the decreasing ratio of vegetation indices after the herbicide spray was 2.3% averagely in the case of structural vegetation indices and 1.3~4.1% in the case of normalization-based vegetation indices. These results meant that appropriate vegetation indices should be utilized depending on the types of crop stress and the cultivation environment and the normalization-based vegetation indices measured from the different spatial scale has the minimized difference.

• Journal of Adhesion and Interface
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• v.10 no.2
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• pp.90-97
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• 2009

Dispersion and self-sensing evaluation for single-carbon fiber reinforced in three different acid-treated CNT-epoxy nanocomposites were investigated by electro-micromechanical techniques and wettability tests. Self-sensing based on contact resistivity exhibited more noise for single carbon fiber/acid-treated CNT-epoxy composites than it did for untreated CNT. However, the apparent modulus was higher the acid treated case than the untreated case which is attributed to better stress transfer. The interfacial shear strength (IFSS) between carbon fibers and the CNT-epoxy was lower than that between carbon fiber and neat epoxy due to the increased viscosity associated with the addition of the CNT. The CNT-epoxy nanocomposite exhibited more hydrophobicity than did neat epoxy. Change in the thermodynamic work of adhesion was consistent with changes in the IFSS but disproportional to that of the apparent modulus. The optimum condition of acid treatment on the need can be obtained instead of the maximum condition.

• Composites Research
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• v.30 no.2
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• pp.138-144
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• 2017

Damage sensing of polymer composite films consisting of poly(dicyclopentadiene) p-DCPD and carbon nanotube (CNT) was studied experimentally. Only up to 1st ring-opening polymerization occurred with the addition of CNT, which made the modified film electrically conductive, while interfering with polymerization. The interfacial adhesion of composite films with varying CNT concentration was evaluated by measuring the wettability using the static contact angle method. 0.5 wt% CNT/p-DCPD was determined to be the optimal condition via electrical dispersion method and tensile test. Dynamic fatigue test was conducted to evaluate the durability of the films by measuring the change in electrical resistance. For the initial three cycles, the change in electrical resistance pattern was similar to the tensile stress-strain curve. The CNT/p-DCPD film was attached to an epoxy matrix to demonstrate its utilization as a sensor for fracture behavior. At the onset of epoxy fracture, electrical resistance showed a drastic increase, which indicated adhesive fracture between sensor and matrix. It leads to prediction of crack and fracture of matrix.

• Journal of Life Science
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• v.31 no.1
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• pp.100-108
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• 2021

In the oral cavity, there are hundreds of microbial species that exist as planktonic cells or are incorporated into biofilms. The accumulation and proliferation of pathogenic bacteria in the oral biofilm can lead to caries and periodontitis, which are typical oral diseases. The oral bacteria in the biofilm not only can resist environmental stress inside the oral cavity, but also have a 1,000 times higher resistance to antibiotics than planktonic cells by genes exchange through the interaction between cells in the oral biofilm. Therefore, if the formation of oral biofilm is suppressed or removed, oral diseases caused by bacterial infection can be more effectively prevented or treated. In particular, since oral biofilms have the characteristic of forming a biofilm by gathering several bacteria, quorum sensing, a signaling system between cells, can be a target for controlling the oral biofilm. In addition, a method of inhibiting biofilm formation by using arginine, an alkali-producing substrate of oral bacteria, is used to convert the distribution of oral microorganisms into an environment similar to that of healthy teeth or inhibit the secretion of glucosyltransferase by S. mutans to inhibit the formation of non-soluble glucans. It can be a target to control oral biofilm. This method of inhibiting or removing the oral biofilm formation rather than inducing the death of pathogenic bacteria in the oral cavity will be a new strategy that can selectively prevent or therapeutic avenues for oral diseases including dental caries.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.637-648
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• 2021

In order to support the establishment of a farming plan, it is important to preemptively evaluate crop changes and to provide precise information. Therefore, it is necessary to provide customized information suitable for decision-making by farming stage through scientific and continuous monitoring using drones. This study was carried out to support the establishment of the farming plan for ground vegetable. The cultivation management map of each information was obtained from preliminary study. Three cultivation management maps include 'field emergence map', 'stress map' and 'productivity map' reflected spatial variation in the plantation by providing information in units of plants based on 3-dimensions. Application fields of the cultivation management map can be summarized as follows: detect miss-planted, replanting decision, fertilization, weeding, pest control, irrigation schedule, market quality evaluation, harvest schedule, etc.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1101-1107
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• 2022

The leaf temperature is principally regulated by the opening and closing of stomata that is sensitive to various kinds of plant physiological stress. Thus, the analysis of thermal imagery, one of remote sensing technique, will be useful to detect crop physiological condition on smart farm system and phenomics platform. However, there are few case studies using a thermal imaging camera on the agricultural application. In this study, three cases are presented: the effect of lime fertilizer on the rice, the different physiological properties of soybean under shading condition, and the screening of soybean breeds for salinity tolerance characteristic. The leaf temperature measured by thermal imaging camera on the three cases was used effectively to the physiological change and characteristics. However, the thermal imagery analysis requires considering the accuracy of measured temperature and the weather conditions that affects to the leaf temperature.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1231-1244
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• 2022

The frequency of exposure of field crops to stress situations is increasing due to abnormal weather conditions. In South Korea, large-scale diseases in representative paddy rice cultivation area were happened. There are limits to field investigation on the crop damage due to large-scale. Satellite-based remote sensing techniques are useful for monitoring crops in cities and counties, but the sensitivity of vegetation index measured from satellite under abnormal growth of crop should be evaluated. The goal is to evaluate satellite-based normalized difference vegetation index (NDVI) retrieved from different spatial scales using drone imagery. In this study, Sentinel-2 and Landsat-8 satellites were used and they have spatial resolution of 10 and 30 m. Drone-based NDVI, which was resampled to the scale of satellite data, had correlation of 0.867-0.940 with Sentinel-2 NDVI and of 0.813-0.934 with Landsat-8 NDVI. When the effects of bias were minimized, Sentinel-2 NDVI had a normalized root mean square error of 0.2 to 2.8% less than that of the drone NDVI compared to Landsat-8 NDVI. In addition, Sentinel-2 NDVI had the constant error values regardless of diseases damage. On the other hand, Landsat-8 NDVI had different error values depending on degree of diseases. Considering the large error at the boundary of agricultural field, high spatial resolution data is more effective in monitoring crops.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1141-1180
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• 2022

The application of satellite imageries has increased in the field of hydrology and water resources in recent years. However, challenges have been encountered on obtaining accurate evapotranspiration and soil moisture. Therefore, present researches have emphasized the necessity to obtain estimations of satellite-based evapotranspiration and soil moisture with related development researches. In this study, we presented the research status in Korea by investigating the current trends and methodologies for evapotranspiration and soil moisture. As a result of examining the detailed methodologies, we have ascertained that, in general, evapotranspiration is estimated using Energy balance models, such as Surface Energy Balance Algorithm for Land (SEBAL) and Mapping Evapotranspiration with Internalized Calibration (METRIC). In addition, Penman-Monteith and Priestley-Taylor equations are also used to estimate evapotranspiration. In the case of soil moisture, in general, active (AMSR-E, AMSR2, MIRAS, and SMAP) and passive (ASCAT and SAR)sensors are used for estimation. In terms of statistics, deep learning, as well as linear regression equations and artificial neural networks, are used for estimating these parameters. There were a number of research cases in which various indices were calculated using satellite-based data and applied to the characterization of drought. In some cases, hydrological cycle factors of evapotranspiration and soil moisture were calculated based on the Land Surface Model (LSM). Through this process, by comparing, reviewing, and presenting major detailed methodologies, we intend to use these references in related research, and lay the foundation for the advancement of researches on the calculation of satellite-based hydrological cycle data in the future.