• Journal of Wetlands Research
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• v.15 no.2
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• pp.223-231
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• 2013

Excessive precipitation, drought, heat waves, strong typhoons and rising sea levels are just some of the common indicators of climate change. In the Philippines, excessive precipitation never failed to devastate and drown the streets of Metro Manila, a highly urbanized and flood-prone area; such problems are expected to occur frequently. Moreover, the water supply of Metro Manila is dependent only to Angat Reservoir. Rainwater harvesting can serve as an alternative source of raw water and it can mitigate the effects of flooding. The harvested rainwater can be used for: potable consumption if filtered and disinfected; and non-potable consumptions (e.g., irrigation, flushing toilets, carwash, gardening, etc.) if used untreated. The rainfall data were gathered from all 5 rainfall stations located in Metro Manila namely: Science Garden, Port Area, Polo, Nangka and Napindan rain gauge stations. To be able to determine the potential volume of rainwater harvested and the potentiality of rainwater harvesting system as an alternate source of raw water; in this study, three different climatic conditions were considered, the dry, median and wet rainfall years. The frequent occurrence of cyclonic events in the Philippines brought significant amount of rainwater that causes flooding in the highly urbanized region of Metro Manila. Based from the results of this study, the utilization of rainwater harvesting system can serve as an alternative source of non-potable water for the community; and could also reduce the amount of surface runoff that could result to extreme flooding.

• Journal of Korea Water Resources Association
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• v.43 no.12
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• pp.1011-1027
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• 2010

In hydrologic modeling, prediction uncertainty generally stems from various uncertainty sources associated with model structure, data, and parameters, etc. This study aims to assess the parameter uncertainty effect on hydrologic prediction results. For this objective, a distributed rainfall-sediment yield-runoff model, which consists of rainfall-runoff module for simulation of surface and subsurface flows and sediment yield module based on unit stream power theory, was applied to the mesoscale mountainous area (Cheoncheon catchment; 289.9 $km^2$). For parameter uncertainty evaluation, the model was calibrated by a multi-objective optimization algorithm (MOSCEM) with two different objective functions (RMSE and HMLE) and Pareto optimal solutions of each case were then estimated. In Case I, the rainfall-runoff module was calibrated to investigate the effect of parameter uncertainty on hydrograph reproduction whereas in Case II, sediment yield module was calibrated to show the propagation of parameter uncertainty into sedigraph estimation. Additionally, in Case III, all parameters of both modules were simultaneously calibrated in order to take account of prediction uncertainty in rainfall-sediment yield-runoff modeling. The results showed that hydrograph prediction uncertainty of Case I was observed over the low-flow periods while the sedigraph of high-flow periods was sensitive to uncertainty of the sediment yield module parameters in Case II. In Case III, prediction uncertainty ranges of both hydrograph and sedigraph were larger than the other cases. Furthermore, prediction uncertainty in terms of spatial distribution of erosion and deposition drastically varied with the applied model parameters for all cases.

• Journal of the Korea Concrete Institute
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• v.28 no.5
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• pp.535-544
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• 2016

This paper aims at examining the effects of sustained load and elevated temperature on the time-dependent deformation of a carbon fiber reinforced polymer (CFRP) sheets bonded to concrete as well as the pull-off strength of single-lap shear specimens after the sustained loading period using digital images. Elevated temperature during the sustained loading period resulted in increased slip of the CFRP composites, whereas increased curing time of the polymer resin prior to the sustained loading period resulted in reduced slip. Pull-off tests conducted after sustained loading period showed that the presence of sustained load resulted in increased pull-off strength and interfacial fracture energy. This beneficial effect decreased with increased creep duration. Based on analysis of digital images, results on strain distributions and fracture surfaces indicated that stress relaxation of the epoxy occurred in the 30 mm closest to the loaded end of the CFRP composites during sustained loading, which increased the pull-off strength provided the failure locus remained mostly in the concrete. For longer sustained loading duration, the failure mode of concrete-CFRP bond region can change from a cohesive failure in the concrete to an interfacial failure along the concrete/epoxy interface, which diminished part of the strength increase due to the stress relaxation of the adhesive.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.312-321
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• 2018

The Korean DR market proposes suppression of peak demand under reliability crisis caused a natural disaster or unexpected power plant accidents as well as saving power plant construction costs and expanding amount of reserve as utility's perspective. End-user is notified a DR event signal DR execution before one hour, and executes DR based on requested amount of load reduction. This paper proposes a DR energy management algorithm that can be scheduled the optimal operations of chiller system and ESS in the next day considering the TOU tariff and DR scheme. In this DR algorithm is divided into two scheduling's; day-ahead operation scheduling with temperature forecasting error and operation rescheduling on DR operation. In day-ahead operation scheduling, the operations of DR resources are scheduled based on the finite number of ambient temperature scenarios, which have been generated based on the historical ambient temperature data. As well as, the uncertainties in DR event including requested amount of load reduction and specified DR duration are also considered as scenarios. Also, operation rescheduling on DR operation day is proposed to ensure thermal comfort and the benefit of a COB owner. The proposed method minimizes the expected energy cost by a mixed integer linear programming (MILP).

• Journal of Korean Tunnelling and Underground Space Association
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• v.17 no.3
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• pp.249-256
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• 2015

Quantitative Mokpo-Jeju undersea tunnel is currently on the basis plan for reviewing validation. As for the cross section shape for express boat of 105 km line, sing track two tube is being reviewed as the Euro tunnel equipped with service tunnel. Also, 10 carriage trains have been planned to operate 76 times for one way a day. So, in this study, quantitative risk assessment method is settled, which is intended to review the optimal space between evacuation connection hall of tunnel by quantitative risk analysis method. In addition to this, optimal evacuation connection hall space is calculated by the types of cross section, which are Type 3 (double track single tube), Type 1 (sing track two tube), and Type 2 (separating double track on tube with partition). As a result, cross section of Type 2 is most efficient for securing evacuation safety, and the evacuation connection space is required for 350 m in Type 1, 400 m in Type 2, and 1,500 m in Type3 to satisfy current domestic social risk assessment standard.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.795-810
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• 2019

In this paper, The study was conducted on the method to roughly determine the area and length of the multi-utility tunnel before the planning and design phase of the multi-utility tunnel construction. For this purpose, four feasibility indexes were used: traffic density, population density, disaster prevention index (number of workers), and urbanization rate, which reflect the regional characteristics. The installation criteria were set in consideration of the average value and minimum value of the feasibility indexes for the tunnel type among areas that can be installed in the multi-utility tunnel of Seoul. The analysis area included 200 areas based on 14 zones. The results of the analysis based on the minimum value of feasibility indexes indicated that the tunnel type of multi-utility tunnel is suitable for 39 areas with high traffic volume and population. On the other hand, the 'gun' area, etc., has a wider population than the 'si' and 'gu', suggesting that it is not suitable to install multi-utility tunnel. In addition, it can be seen that the larger the index value centered on the minimum value of each index, the smaller the tunnel type of multi-utility tunnel installation area.

• The Journal of the Korea Contents Association
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• v.16 no.6
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• pp.507-515
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• 2016

In South Korea, there are a large number of tunnels because of the mountainous terrain, and to overcome this characteristics, lengths of tunnels are more longer than existing tunnels. The need to improvement current tunnel management contents is giving rise for accidents in tunnel section is continuously increased although lots of efforts to reduce the accidents. Conventionally, disaster prevention have been focused on the Tunnel Management Systems, tunnel operators generally tend to depend on CCTV images for most contents of detailed traffic flow managing. In this paper, investigation about current Tunnel Management Systems contents using IPA survey was conducted, and Priority Improvement Contents(Accident Situation Management Support, 2nd Accident Management Support, Traffic Flow Monitoring), which importance are high, but satisfaction are low, are deducted. Also, CCTV images, lack intuitive understanding, are judged as a main cause of low satisfaction of those contents. To overcome those limitations of the existing Tunnel Management Systems, this study sought to develop a technology for the synthesis of road images to derive traffic information from synthesis images, and the contents improvement stragegy is established. Tunnel operators-oriented satisfaction survey on new contents was carried out, and scored 4.2 on a 5-point scale. This has confirmed that the availability of new contents and at this stage, with pushing ahead of long-tunnels and undersea tunnels construction, politic applications are expected.

• Journal of Korean Society of Archives and Records Management
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• v.15 no.3
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• pp.169-191
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• 2015

The purpose of this study is to examine the driving forces and main contents of the reform of the records and archives management system in Japan from the 2009 enactment of the Public Records and Archives Management Act. The key essentials of the reform can be explained in two ways. First is through the legal system, a multilayer structure of the law and guidelines to the institutional documents management regulations for an effective application to each administrative institution. The other is the Public Records and Archives Management Commission, a deliberative body that guarantees the rigorous application and enforcement of the rules and regulations. One of the remarkable outcomes from the reform is the compulsory creation of minutes of the countermeasure meetings in government agencies related to the Great East Japan Earthquake Disaster, as well as the various significant cabinet meetings through a revision of the Guidelines for Public Administrative Records Management. In addition, the new construction of the National Archives of Japan and its meaning have been examined. It is being pushed ahead, with the active support of the ruling party members, through activities such as research and review meetings for improving the functions and facilities of the National Archives of Japan.

• Journal of Korea Water Resources Association
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• v.47 no.4
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• pp.357-370
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• 2014

This study aims to develop a rainfall field tracking method for depth-area-duration (DAD) analysis and assess whether the proposed tracking methods are able to properly estimate the maximum average areal rainfall (MAAR) within the study area during a rainfall period. We proposed three different rainfall field tracking algorithms (Box-tracking, Point-tracking, Advanced point-tracking) and then applied them to the virtual rainfall field with 1hr duration and also compared DAD curves of each method. In addition, we applied the three tracking methods and a traditional GIS-based tool to the typhoon 'Nari' rainfall event of the Yongdam-Dam watershed and then assess applicability of the proposed methods for DAD analysis. The results showed that Box-tracking was much faster than the other two tracking methods in terms of searching for the MAAR but it was impossible to describe rainfall spatial pattern during its tracking processes. On the other hand, both Point-tracking and Advanced point-tracking provided the MAAR by considering the spatial distribution of rainfall fields. In particular, Advanced point-tracking estimated the MAAR more accurately than Point-tracking in the virtual rainfall field, which has two rainfall centers with similar depths. The proposed automatic rainfall field tracking methods can be used as effective tools to analyze DAD relationship and also calculate areal reduction factor.

• Journal of Korea Water Resources Association
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• v.47 no.10
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• pp.891-906
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• 2014

This study suggests the hedging rule of MIP (Mixed Integer Programing) in counting the risk evaluation criteria of the objective function and constraints in order to provide the optimum operating rule in reservoir system as constraining water shortage as much as possible which may happen in the downstream control point of water supply in the aspect of water system management. The proposed model is applied to the Han-river reservoir system for two testing periods (Case I: Jan. 1993~Dec. 1997, Case II: Jan. 1999~Dec. 2003). The model based on the hedging rule with trigger volume, estimated in this study shows that in Case I, the monthly minimum discharge was $310.6{\times}10^6m^3$ in the single operation, $56.3{\times}10^6m^3$ in the joint operation, and $317.5{\times}10^6m^3$ in the hedging rule and also, in Case II, the monthly minimum discharge was found to be $204.2{\times}10^6m^3$ in the single operation, $111.2{\times}10^6m^3$ in the joint operation, and $243.7{\times}10^6m^3$ in the hedging rule. In conclusion, the hedging rule, proposed in this study can decrease vulnerability while guarantees reliability and resiliency.