• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.195-201
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• 2020

A forest operation is considered as one of the riskiest environments for the development of musculoskeletal disorders because operators are exposed to harmful environmental conditions such as rough terrain, inclement weather, and poor working postures. In weed and kudzu removal operations, manual application is still common in Korea. In this study, we evaluated the ergonomic conditions of weed and kudzu removal in regeneration forests and the associated risk of musculoskeletal disorders. The risk of musculoskeletal disorders was evaluated using the Ovako Working Posture Analysis System and postural risk index. Postural risk was significantly higher for kudzu compared with weed removal operations. This suggests that kudzu removal operations must be improved to decrease postural risk.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.4
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• pp.401-408
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• 2005

Presently many constructions establish in underwater, but approaching to underwater constructions are difficult, for comparing with ground, underwater environment is different in media. Usually measurement methods for underwater constructions are using tapes, using depth gauges, using acoustic positioning systems. But, tapes are hard to measure the correct distance, for applying a right tension is not easy in underwater. Depth gauges have a weakness in settling, for it takes long time to do it. Acoustic positioning systems don't work well in confined spaces and cost a lot. Hence, the purpose of this study is, at first, to understand rays path in multimedia like water, glass and air. The second thing is to perform a camera calibration at the field to compare with the interior orientation parameter. And the third thing is to find out whether photogrammetry is applied for underwater object in using cube for accuracy examination. The last thing is to perform underwater photogrammetry about underwater object, which is pier model and riverbed. We came to the conclusion through this experiment that the applying underwater photogrammerty for underwater constructions and underwater ground is possible.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.3
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• pp.263-272
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• 2001

For a high resolution real-time kinematic GPS surveying using carrier phase, positioning accuracy according to the OTF initialization was better than 1 cm with more than 5-minute initialization within 20 km baseline. Also, it is recommended that measurements be carried out when PDOP and RDOP can be kept less than 4.0 since the geometrical layout of satellites has a great influence on the positioning accuracy. After considering the initial conditions and measuring time zone for real-time kinematic GPS. post-processed continuous kinematic GPS and real-time kinematic GPS measurements have been carried out. A new system has been proposed to store measured data by using a program developed to store GPS data in real time and to monitor the satellite condition through controller at the time of measurement. As a result, it has been revealed that possible noise in surveying could be corrected and the accuracy could be improved.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.2
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• pp.111-116
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• 2008

The study installed non metric camera which was a 10 Mega Pixel camera in RC Helicopter. And the study controlled images hotographed in air on land, considering their overlap. The study could express DEM by abstracting TIN from the acquired images through image registration. Also, the study compared and examined accuracy between reference point and check point observed by Total Station which was a conventional type of survey. As the results, the study could get errors of $-0.194{\sim}0.224\;m$ on X axis, $-0.088{\sim}0.180\;m$ on Y axis and $-0.286{\sim}0.285\;m$ on Z axis. Expressing an error's RMSE in the checkpoint, the study could get of 0.021388 m on X axis, 0.015285 m on Y axis and 0.041872 m on Z axis. It is judged that the above photographing and analyzing technique are better than the existing Total Station to acquire more terrain elevation data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.1
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• pp.1-9
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• 2011

The objective of this paper is to improve the accuracy of the 3D geopositioning extracted from Rational Polynomial Coefficient(RPC) provide in the KOMPSAT-2 metadata files. In this paper, we developed the algorithm to adjust a RFM(Rational Functional Model), and could improve the accuracy of a RFM with this algorithm. Furthermore, when a RFM was adjusted with this algorithm, the effects of the number of GCPs on the accuracy of the adjusted RFM was tested. For accuracy assessment using adjusted RFM, 9 ground control points(GCPs) and 24 check points could be used. Results indicated that the root mean squared errors(RMSEs) of horizontal residual errors calculated 24 check points were 2.20(m). The achieved accuracy of three dimensional object-point determination was 1.72(m) in the X-dimension and 1.37(m) in the Y-dimension and 2.20(m) in the Z-dimension.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.5
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• pp.515-525
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• 2014

Recently, because of increasing in downpour and typhoon, which are caused by climate changes, those sedimentation disasters, such as landslide and debris flow, have become frequent. Those sedimentation disasters take place in natural slope. In order to predict debris flow damage range within wide area, the response model is more appropriate than numerical analysis. However, to make a prediction using Random Walk Model, the regional parameters is needed to be decided, since the regional environments conditions are not always same. This random Walk Model is a probability model with easy calculation method, and simplified slope factor. The objective of this study is to calculate the optimal parameters of Random Walk Model for Umyeon mountain in Seoul, where the large debris flow has occurred in 2011. Debris flow initiation zones and sedimentation zones were extracted through field survey, aerial photograph and visual reading of debris flow before and after its occurrence via LiDAR DEM.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.4
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• pp.300-304
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• 1993

This experiment was carried out to increase the utility and productivity of forage crop as to investigate the rotation system which is suitable to cultivat at the alpine area. The treatments were 9 crops combinations including corn - rye treatment. The results obtained were as follows: 1. Rye can be cultivated satisfactorily at cold and high altitude areas such as Tae Kwan Ryong. 2. Corn, to be raised as a second crop after rye in the same year, does not have to be early (short) or medium maturity varieties in the high alpine area. 3. It is possible to increase the harvest by 30% in terms of dry melter or green crop yield through raising two crops, rye and corn, in the same year. 4. Maturity period or growth conditions of corn. as a tropical crop and the best forage crop, can improve or worsen acording to the external circumstance, such as low temperature resulting from high atitude.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.1
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• pp.48-58
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• 2014

It is very important to investigate air pollutants emissions emitted from open burning in order to control nonpoint sources effectively. In this study, we utilized incineration simulator proposed by U.S EPA and investigated emissions of CO, OC/EC, from household waste and biomass burning to estimate pollutant emissions by illegal incineration of biomass wastes. Emission factor of OC was estimated as 17.1 g/kg for rice strew, 23.5 g/kg for barley, 10.3 g/kg for corn stover, 4.3 g/kg for unseasoned wood, respectively. In case of EC, it was calculated as 1.6 g/kg for rice strew, 4.3 g/kg for barley, 1.4 g/kg for corn stover, 0.6 g/kg for unseasoned wood, respectively. Most of the pollutants emissions were emitted at the stage 1 and 2. In the stage 3, the pollutants concentration decreased gradually. To estimate emissions and build inventory for biomass burning, we need to know accurate activity data. We, therefore, used activity data of both survey results of previous study and statistical data of National Statistical Office. However, we need to perform additional experiments in the future to obtain more accurate activity data for various cases.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.2
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• pp.181-190
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• 2011

The air pollutants from vehicle exhaust gas are affected by many factors including fuel qualities, engine and vehicle technologies, driving patterns. In particular, fuel qualities and after-treatment devices could directly affect the emission level of pollutants. The pollutant reduction characteristics that caused by enforced fuel quality standard were analyzed. Three types of test fuel were selected in accordance with Korean automotive fuel standard in 2006, 2009, 2012 and used for vehicle emission test in chassis dynamometer. European COPERT correction equation of fuel impact was considered as reference information to quantify the vehicle emission test results. The contribution rates of exhaust emission by COPERT correction equation showed that aromatic compounds and oxygen contents in gasoline fuel was most important. In case of diesel fuel, cetane index and polycyclic aromatic compounds accounted for the greater part. The exhaust emission effects by COPERT correction equation revealed that CO and VOC was increased 0.86%, 1.57% respectively in after 2009 gasoline when compared to before 2009 gasoline fuel. In case of light-duty diesel vehicle CO, VOC and PM were decreased in range of 3~7%. The result from this study could be provided for developing future fuel standards and be used to fundamental information for Korean clean air act.

• Journal of Animal Environmental Science
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• v.12 no.1
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• pp.41-44
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• 2006

Broiler manure has much nutrient that can be used as the organic fertilizer to enhance the fertility of soil. However, if it is used directly without biodegradation of organic materials and destruction of weed seed and harmful bacteria, it can produce the generation of weed and disease of plant. Composting of manure is a biodegradation of organic materials into inorganic materials and humus. To proceed biodegradation of manure effectively and enhance the composting performance, optimum environmental condition for microbial growing should be maintained. Environmental variables which can influence the growing activity of microbes are moisture content, pH, porosity, C/N of the composting materials and oxygen supply quantity. Oxygen and porosity are usually supplied by aeration or mixing of materials. This study was intended to investigate the effect of mixing frequency on the composting performance. Mixing of composting materials was performed by turning the bioreactor up and down by hand without any mechanical energy. The broiler manure was captured from the greenhouse type broiler ham as the compounds of broiler manure and rice-hulls, which were used as the base materials. To compost the compounds of broiler manure and rice-hulls, dairy manure was mixed to get appropriate characteristics of composting material. Composting temperature over $55^{\circ}C$ for killing pathogen and weed seed was maintained for longer period with increase of mixing frequency.