• Korean Journal of Organic Agriculture
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• v.30 no.4
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• pp.485-497
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• 2022

Agricultural environmental policies to reduce negative externalities and expand positive externalities became common around the world. However, literature regarding the efficient and effective implementation of agricultural environmental policies, such as optional direct payment, is limited. This study, thus, analyzes the relative importance for target selecting-criteria in order to enhance the cost-effectiveness of the Agricultural Environment Conservation Program in Korea. In this context, we conducted survey to 15 experts who are related in agricultural environment policies and analyzed survey results based on ANP method which can consider correlation between selecting criteria. The results show that, in the case field, "soil", "water", and "ecology" field have relative high importance than the other fields. Also, the relative importance for 'improving rural landscape', 'giving nutrient input moderately', and 'conserving agricultural heritage' activities is higher than the other activities. Furthermore, the relative importance among fields and activities of ANP is different from those of AHP. This result implies that it is necessary to consider the correlation between selecting criteria in order to design effectively. Finally, we suggest that in order to enhance the effectiveness of the program, it would be appropriate to assign differential points according to the importance of each activity when identifying appropriate farms.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.387-396
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• 2020

Wearable biosensors have the potential to non-invasively and continuously monitor seniors' stress in their daily interaction with the urban environment, thereby enabling to address the stress and ultimately advance their outdoor mobility. However, current wearable biosensor-based stress detection methods have several drawbacks in field application due to their dependence on batch-learning algorithms. First, these methods train a single classifier, which might not account for multiple subjects' different physiological reactivity to stress. Second, they require a great deal of computational power to store and reuse all previous data for updating the signle classifier. To address this issue, we tested the feasibility of online multi-task learning (OMTL) algorithms to identify multiple seniors' stress from electrodermal activity (EDA) collected by a wristband-type biosensor in a daily trip setting. As a result, OMTL algorithms showed the higher test accuracy (75.7%, 76.2%, and 71.2%) than a batch-learning algorithm (64.8%). This finding demonstrates that the OMTL algorithms can strengthen the field applicability of the wearable biosensor-based stress detection, thereby contributing to better understanding the seniors' stress in the urban environment and ultimately advancing their mobility.

• Journal of Soil and Groundwater Environment
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• v.18 no.3
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• pp.93-108
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• 2013

This study is aimed to prepare the effective detail survey methods(Phase II) of abandoned metal mines through the contamination assessment for mine types and facilities in the abandoned metal mine areas. The study sites of 12 abandoned mines are located in Gyeonggi-do and Gangwon-do and those were chosen among 310 sites that the Phase II survey was conducted from 2007 to 2009 after considering the results of Phase I for abandoned mines scattered all over the country. 12 study sites were classified into four types; Type I sites only have pit mouth. Type II sites have pit mouth and mine-waste field. Type III sites have pit mouth and tailing sorting field. Type IV sites have pit mouth, tailing sorting field and concentrator(s). In forest land, paddy soil and farm land of Type I, As and Cd were showed average concentration, and Cu and Pb were high on the pit mouth area in one mines where the pit mouth was developed within 500 m. In the mines of Type II, Cu and Pb were showed average concentration too, but As and Cd were slightly high in pit mouth and mine-waste field. The mines of Type III which had grinding particle process through physical separation milling or hitting showed similar tendency with Type II. However, mines of Type IV pit mouth, mine-waste field and showed various results depending on defining the contamination sources. For example, if contamination source was pit mouth, the mixed results of Type I, II, II were showed. In tailing sorting field which was regarded as the most important source and having high mobility, however, if there were no facilities or it was difficult to access directly, field sampling was missed occasionally during phase I and phase II survey. For that reason, the assessment for tailing sorting field is missed and it leads to completely different results. In the areas of Type I mines, the concentration of heavy metals exceeded precautionary standards of soil contamination or not within 1,000 meters of pit mouth. Nickel(Ni) was the largest factor of the heavy metal contamination in this type. The heavy metals except Arsenic(As) were shown high levels of concentration in Type II areas, where pit mouth and mine-waste field were operated for making powder in upriver region; therefore, to the areas in the vicinity of midstream and downstream, the high content of heavy metals were shown. The tendency of high level of heavy metals and toxic materials contained in flotation agent used during sorting process were found in soil around sorting and tailing field. In the abandoned-pit-mouth area, drygrinding area and tailing sorting field area, the content of Cupper(Cu) and Zinc(Zn) were higher than other areas. Also, the contaminated area were larger than mine reclamation area(2,000 m) and the location of tailing sorting field was one of the important factors to estimate contaminated area.

• Journal of Navigation and Port Research
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• v.43 no.3
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• pp.172-178
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• 2019

Although the needs for providing resilient PNT information are increasing, threats due to the intentional RFI or space weather change are challenging to resolve. eLoran, which is a terrestrial navigation system that use a high-power signal is considered as a best back-up navigation system. Depending on the user's environment in the eLoran system, the user may use one of E-field or H-field antennas. H-field antenna, which has no restriction on setting stable ground and is relatively resistant to noise of general electronic equipment, is composed of two loops, and shows anisotropic gain pattern due to the different measurement at the two loops. Therefore, the H-field antenna's phase estimation value of signal varies depending on its direction even at the static environment. The error due to the direction of the signal should be eliminated if the user want to estimate the own position more precisely. In this paper, a method to compensate the error according to the geometric distribution between the H-field antenna and the transmitting station is proposed. A model was developed to compensate the directional error of H-field antenna based on the signal generated from the eLoran signal simulator. The model is then used to the survey measurement performed in the land area and verify its performance.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.12
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• pp.2343-2352
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• 2015

In this paper, we propose novel motion field estimation method using U-disparity map and forward-backward error removal in vehicles environment. Generally, in an image obtained from a camera attached in a vehicle, a motion vector occurs according to the movement of the vehicle. but this motion vector is less accurate by effect of surrounding environment. In particular, it is difficult to extract an accurate motion vector because of adjacent pixels which are similar each other on the road surface. Therefore, proposed method removes road surface by using U-disparity map and performs optical flow about remaining portion. forward-backward error removal method is used to improve the accuracy of the motion vector. Finally, we predict motion of the vehicle by applying RANSAC(RANdom SAmple Consensus) from acquired motion vector and then generate motion field. Through experimental results, we show that the proposed algorithm performs better than old schemes.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.4
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• pp.363-371
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• 2008

The aim of this study is to compare the numerical results obtained by 2-D and 3-D models which are used to examine the wave field around a permeable submerged breakwater. At first, the numerical model, which is able to consider the flow through a porous medium with inertial, laminar and turbulent resistance terms and determine the eddy viscosity with LES turbulent model, is used and validated by comparing with existing experimental data. And then, the numerical test on the wave field around a permeable submerged breakwater is performed. It is revealed from the numerical results that, at the onshore side of the submerged breakwater, the wave height by 2-D analysis is higher than that by 3-D analysis. Also, the time-averaged mean flow around a submerged breakwater is discussed in detail.

• Journal of Soil and Groundwater Environment
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• v.15 no.1
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• pp.57-65
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• 2010

Currently, the pursuit of industrialization for rapid economic growth has led to serious environmental damage and related problems because of comtamination with chemicals. Over time, this contaminaion is getting worse and worse. Most developing countries have tried to pursue their economic development and growth, however without preparation for the control and disposal of hazardous wastes. Permitting hazardous waste to be abandoned and disposed in appropriately causes soil pollution, groundwater contamination, and surface water contamination, which are all extremely serious. In particular, when hazardous wastes which include toxic chemicals are distributed around the living environment even in small amounts, concentration can occur in the food chain through ecological systems, which can therefore affect human. Chromium(VI) has contaminated soil in China. We experimented to test the immobilization, chemical reduction, and soil washing methods in order to make our experiment efficient in the purification of soil contaminated with Chromium(VI), and to prove the theoretical models by experiments testing the field applications. The field experiment showed that result of experiment satisfied with the standards of China. The result of multi-stage continuous remediation reduce the Chromium(VI) concentration to 11.95 mg/kg and 14.83 mg/kg that were equivalent to 98% and 97% removal rates. This result implied we could apply multi-stage process of Chromium(VI) contaminated soil to meet the regulatory limit of Chromium(VI).

• Journal of Soil and Groundwater Environment
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• v.18 no.7
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• pp.54-62
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• 2013

Fine suspended solids and soluble heavy metals generated from mine drainage could destroy environment as the aesthetic landscapes, and depreciate water quality. Therefore, this research is focused on process development applied the actual field for controlling fine suspended solids and heavy metals, and so that bench-scale tests were performed for field application based on advanced researches. The field of mine drainage in this research was in H mine located Taebaek-si, Gangwon-do. The inclination plates were mounted 2 kinds of arrangement (octagon and radial types) in circle type settling basin. The inclination plates could be helped to settle of suspended solids; decreased 34% of suspended solids and 50% of turbidity in effluent. Radial type of inclination plates showed the results that is more efficient to settle of suspended solids (average to 3.45 mg/L) compared to octagon type. In the experiments to decrease retention time of mine drainage in settling basin from 6 hrs to 1.5 hrs, suspended solid concentration was exceeded to 30 mg/L as the standard for suspended solid at 10 days after the operation under tha retention time of 3hrs and 1.5hrs. In the tests for filtration, granular activated carbons were indicated the better effective to filtering and absorption of fine suspended solid and soluble heavy metals than anthracite.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.1
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• pp.29-37
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• 2011

PIV measurements of the velocity field, pressure field, vorticity, and turbulent intensity in the rear of curved section of an oil fence with current speed showed that the flow directions in the rear of flow boundary area were similar to those in the front of it. As the current speed increased, the patterns of pressure distribution were changed, and the turbulent flow became more irregular. CFD simulations under the same conditions as the PIV tests showed that the flow patterns of the wake were similar to those by PIV tests in speed of 0.3 m/s and less, but were distinctively deviated from those in 0.4 m/s due to the flexibility of the oil fence, which was not properly taken care of in CFD modeling.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.3
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• pp.53-59
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• 2018

This study analyzed the field applicability through the combination of environment-friendly grid-typed reinforcements and pre-mixed fiber with filler. The film of the grid-typed reinforcement is made by recycled PE resin. And, Ascon fiber is obtained the dispersion by pre-mixing of filler. To be able to recognize in advance the various circumstances that could arise in the construction of the road pavement layer, we conducted a basic field application test of the (Mock Up) pavement layer. As a result, it was found that the pavement with environment-friendly grid-typed reinforcement and dispersive fiber construction had improved strength, stress, and rutting resistance. It is consistent with the strength and stress results of the actual test of the mock up specimen. It is expected to perform an effective role in the safety as well as the use of environment-friendly fibers in actual construction.