• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.4
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• pp.43-61
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• 2017

The wetlands are facing environmental changes such as desiccation that occurs with the passage of time and reduced ecosystem services from wetlands in the city. In order to maintain the ecosystem services provided by wetlands in urban areas, a system thinking about the trade-off phenomenon of ecosystem services occurring as the wetlands undergo environmental changes is needed. Therefore, the purpose of this study is to develop strategies for wetland design using system thinking approach to enhance the resilience of ecosystem services degraded by the desiccation of wetlands and other disturbances. The objectives of this study include the system boundary and variables. Second, analyzing the dynamics of wetland design strategy. Third, it analyzes the trade-off phenomenon of ecosystem services in terms of the hydrology, hydric soil, and plants strategies to mitigate these effects. Fourth, wetland basic design to improve the resilience of ecosystem services. A wetland in Abuk-Mountain Neighborhood Park, Miryang-si, Gyeongsangnam-do, has been selected as a case study. Causal loop diagrams(CLDs) are used to analyze feedback in the wetland regime. In summary, hydrology, hydric soil, and plants is suggested as system boundaries to design plan. Design strategies for the wetland focused on robustness, redundancy, rapidity, and resourcefulness as a result of CLD analysis are first proposed in order to effectively maintain the wetland regime over the long term. Secondly, in a section related to hydrology, the CLD results show the trade-offs between provisioning-cultural services and regulating services. In order to control these services, a "water cycling system" has been implemented due to its strength in terms of robustness. The CLDs for hydric soil showed the trade-offs between regulating services and supporting services. An "installation of storm drainage for maintaining water levels" was selected due to the strength offered in terms of redundancy and rapidity. The CLDs for plants showed the trade-offs between provisioning - cultural services and regulating services. In order to control the strategic points, the "planting of indigenous vegetation" was suggested given the strength in terms of redundancy. In this study, a wetland design method is proposed that can improve the resilience of wetland ecosystem services by analyzing the dynamics overtime. The results of this research can theoretically be applied to help restore ecosystem services in wetlands using ecological landscape design. In addition, this study will contribute to reducing maintenance costs by improving wetland resilience.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.4
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• pp.1-10
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• 2018

Use of de-icing salts results in accumulation of high concentrations of ions on roadside soils and tree. The purpose of this study isto determine translocation of seasonal impact of exchangeable cations originating from de-icing salt on roadside surface soil-plant influenced by the intensity of foliar damage (NY = 0-25%, SY = 26-50%, CY = 51-75%) of trees. This paper investigated the concentration of four exchangeable cations ($K^+$, $Ca^{2+}$, $Na^+$, and $Mg^{2+}$) on the roadside surface soil. The tree (Ginko biloba) samples were collected from the Konkuk and Judeok intersections in Chung-ju city. The sequential extraction procedure was applied to 120 soil samples of the soilsurface and 30 tree samples. Four cation exchange ions were determined by ICP-OES. The content of four exchangeable cations present on roadside soil was found to be the lowest in NY but highest in CY from tree pits in the order of NY < SY < CY. Especially, the results were apparent during spring time compared to other seasons. Soil collected from tree pits had the highest concentration of $Ca^{2+}$ possibly due to a higher volume of traffic on those streetsresulting in splashing of more calcium chloride ($CaCl_2$). The analysis of three exchangeable cations ($K^+$, $Mg^{2+}$, and $Na^+$) in the tree leaves revealed higher levels than roadside surface soil when foliar damage ratio increased in the order of NY < SY < CY in summer. In addition, a strong positive linear relationship was observed between the concentration of exchangeable cations in soil and trees. It is hypothesized that the results of this study can be a valuable baseline for managing de-icing salt on roadside soil and trees, in order to mitigate the salt stress that can damage the roadside soil and trees.

• Agribusiness and Information Management
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• v.11 no.1
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• pp.27-39
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• 2019

Agricultural risks are exacerbated by a variety of factors ranging from climatevariability and change, frequent natural disasters, uncertainties in yields and prices, weakrural infrastructure, imperfect markets and lack of financial services including limited spanand design of risk mitigation instruments such as credit and insurance. Indian agriculture has little more than half (53%) of its area still rainfed and this makes it highly sensitive to vagaries of climate causing unstable output. Besides adverse climatic factors, there are man-made disasters such as fire, sale of spurious seeds, adulteration of pesticides and fertilizers etc., and all these severely affect farmers through loss in production and farm income, and are beyond the control of farmers. Hence, crop insurance' is considered to be the promising tool to insulate the farmers from risks faced by them and to sustain them in the agri-business. This paper critically evaluates the performance of recent crop insurance scheme viz., Pradhan Mantri Fasal Bhima Yojana (PMFBY) and its comparative performance with earlier agricultural insurance schemes implemented in the country. It is heartening that, the comparative performance of PMFBY with earlier schemes revealed that, the Government has definitely taken a leap forward in covering more number of farmers and bringing more area under crop insurance with the execution of this new scheme and on this front, it deserves the appreciation in fulfilling the objective for bringing more number of farmers under insurance cover. The use of mobile based technology, reduced number of Crop Cutting Experiments (CCEs) and smart CCEs, digitization of land record and linking them to farmers' account for faster assessment/settlement of claims are some of the steps that contributed for effective implementation of this new crop insurance scheme. However, inadequate claim payments, errors in loss/yield assessment, delayed claim payment, no direct linkage between insurance companies and farmers are the major shortcomings of this scheme. This calls for revamping the crop insurance program in India from time to time in tune with the dynamic changes in climatic factors on one hand and to provide a safety-net for farmers to mitigate losses arising from climatic shocks on the other. The future research avenues include: insuring the revenue of the farmer (Price × Yield) as in USA and more and more tenant farmers should be brought under insurance by doling out discounts for group coverage of farmers like in Philippines where 20 per cent discount in premium is given for a group of 5-10 farmers, 30 per cent for a group of 10-20 and 40 per cent for a group of >20 farmers.

• Journal of KIISE:Software and Applications
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• v.29 no.4
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• pp.211-224
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• 2002

As system become larger and more complex, it is important to correctly analyze and specify user's requirements. Use case modeling is widely used in Object-Oriented Analysis and Design(OOAD) and Component-Based Development(CBD). It is useful to mitigate the complexity of the requirements analysis. However, use cases are difficult to be structured, to explicitly represent non-functional requirements, and to analyze what is affected by changes of use cases. To alleviate these problems, we propose scenario-based goal-oriented approach for use case modeling. The approach is to apply goal-oriented analysis method to use case model. Since goal-oriented analysis method is not systematic and heuristics is considerably involved, we adopted scenarios as the basis for the goal extraction. The proposed method is applied to City Bus Information Subsystem(CBIS) in Intelligent Transport Systems(ITS) domain. The proposed approach helps software engineer to analyze what is affected by use case's changes and represent non-functional requirements.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.5
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• pp.498-509
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• 2001

Collaborative systems allow users, who may be far removed from each other geographically, to do collaborative work such as 3D animation, computer game, and industrial design in a single virtual space. This paper describes our experience to develop a collaborative system framework that aims at expanding the some functions of a stand-alone visual modeling tool, called 3D Studio Max, into those of the distributed collaborative working environments. The paper mainly deals with design and implementation of a 3D shared-object Plug-In with respect to the 3D Studio Max Plug-In Software Development Kit in the distributed collaborative system developed by the authors. There are two major functions of the proposed scheme; one is to write 3D object-information to the shared memory after extracting it from the 3D Studio Max, the other is to create 3D objects after retrieving them from the shared memory. Also, the proposed scheme provides a simple way of storing 3D objects that have variable size, by means of shared memory which located in between the collaborative system clients and 3D studio Max. One of the remarkable virtures of the Plug-In is to reduce a considerable amount of shared object data which in consequence can mitigate the network overhead. This can be achieved by the fact that the system is able to extract a minimum amount of 3D objects that are required to transmit. Also, using the proposed scheme, user can facilitate 3D Studio Max into distributed collaborative working environments. This, in consequence give many benefits such as saving time as well as eliminating space constraints in the course of 3D modeling when we are under industrial design process.

• Economic and Environmental Geology
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• v.29 no.3
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• pp.315-323
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• 1996

An apatite drain was constructed on September 30, 1994 at the Green Valley Abandoned Coal Mine site near Terre Haute in west central Indiana. The primary objective of this experiment is to evaluate the long-term ability of the apatite drain to mitigate acid mine drainage (AMD) under field conditions. The drain 9 m long, 3.3 m wide, and 0.75 m deep, contain 95 rum to No. 30 mesh-size apatite ore (francolite) and receive AMD seepage from reclaimed gob piles, and designed according to the laboratory testing. The apatite drain was covered with limestone riprap and filter fabric to protect the drainage system from stormwater and siltation. The drain consists of about 50 metric tons of apatite ore obtained from a phosphate mine in Florida. A gabion structure was constructed downstream of the apatite drain to create a settling pond to collect precipitates. Apatite effectively removed iron up to 4,200 mg/l, aluminum up to 830 mg/l and sulfate up to 13,430 mg/l. The pH was nearly constant for the influent and effluent, ranging between 3.1 and 4.3. Flow rate measured at the gabion structure ranged from 3 to 4.5 l/m. Precipitates of iron and aluminum phosphate (yellow and white suspendid solids) continued to accumulate in the settling pond.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.6
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• pp.185-195
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• 2017

In recent years, unexpected bridge fire accidents have increased because of augmenting the number of traffic volumes and hazardous materials by the increment in traffics and distribution business. Furthermore, in accordance with the effort of using the under space of bridges, the ratio of occupied by combustible materials like oil tanker or lorry has been increased. As a result, the occurrence of bridge fire has been growing drastically. In order to mitigate the accident of bridge fire, risk assessment of bridge fire has been studied, however, practical risk models considering safety from users' viewpoints were scarce. This study represented quantitative risk assessment model applicable to national road bridges in Korea. The primary factors with significant impacts on bridge fire accidents was chosen such as clearance height, materials of bridges, arrival time of fire truck and fire intensity. The selected factors were used for Fire Dynamics Simulation (FDS) and the peak temperature calculated by FDS in accordance with the fire duration and fire intensity. The risk assessment model in bridge fire reflected the FDS analysis results, the fire damage criteria, and the grade of fire truck arrival time was established. Response plans for bridge fire accidents according to the risk assessment output has been discussed. Lastly, distances between bridges and fire stations were calculated by GIS network analysis. Based on the suggested assessment model and methodology, sample bridges were selected and graded for the risk assessment.

• The Journal of the Korea Contents Association
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• v.15 no.3
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• pp.467-476
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• 2015

This study aims to verify mediating effect of ego-resilience and mental health between psychological home environment and adaptation to school of early adolescents in schools with Educational Welfare Priority Project(EWPP). For this purpose, multiple regression analysis and hierarchical regression analysis were conducted on the relationship between psychological home environment and adaptation to school, ego-resilience and metal health of 310 male and female students in fifth and sixth grade in four elementary schools on EWPP located in Busan area. As the result of analysis, three major variables affecting adaptation to school life turned out to be in the order of ego-resilience, home environment and mental health and both ego-resilience and mental health were confirmed to play partial mediating role in the relationship between home environment and adaptation to school life. Since home environment as a psychological variable of adolescents from poor families have an effect on adaptation to school in connection with ego-resilience and mental health as personal variables, this study can be used as base materials for the development of programs to strengthen psychological home environment, ego-resilience, and mental health. In addition, in terms of practical implications, educational welfare policies for alienated class can be practical policy alternative to mitigate social polarization.

• Journal of Hydrogen and New Energy
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• v.9 no.1
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• pp.8-15
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• 1998

The catalytic hydrogenation of carbon dioxide has been studied for the fixation of carbon dioxide to mitigate global warming problems, but it needed hydrogen, which the price is still high. Recently, the electrochemical reduction of carbon dioxide has been drawn attractions because carbon dioxide could be converted to the valuable chemicals such as methane, ethane and alcohols electrochemically in the electrolyte solution using a catalytic electrode. This system is simple because the water electrolysis and hydrogenation take place at the same time using the surplus electricity at midnight. In this work, a continuous electrochemical reduction system was fabricated, which was composed of the reduction electrode (copper or perovskite type, $2{\times}2cm^2$), reference electrode(platinum, $2{\times}6cm^2$), standard electrode(Ag/AgCl), and potassium bicarbonate electrolyte solution saturated with carbon dioxide. The quality and quantity of the products and reduction current were analyzed, according to the electrolyte concentration and electrode type.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4A
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• pp.421-430
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• 2006

In this paper, we propose a practical implementation of network-adaptive HD(high definition) MPEG-2 video streaming with a cross-layered channel monitoring(CLM) over the IEEE 802.11a WLAN(wireless local area network). For wireless channel monitoring, AP(access point) periodically measures the MAC(medium access control) layer transmission information and sends the monitoring information to a streaming server. This makes that the streaming server reacts more quickly as well as efficiently to the fluctuated wireless channel than that of the end-to-end monitoring(E2EM) scheme for the video adaptation. The streaming sewer dynamically performs the priority-based frame dropping to adjust the video sending rate according to the measured wireless channel condition. For this purpose, our streaming system nicely provides frame-based prioritized packetization by using a real-time stream parsing module. Various evaluation results over an IEEE 802.11a WLAM testbed are provided to verify the intended QoS adaptation capability The experimental results show that the proposed system can effectively mitigate the quality degradation of video streaming caused by the fluctuations of time-varying wireless channel condition.