• Journal of the Society of Disaster Information
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• v.9 no.1
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• pp.1-10
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• 2013

The main objective of this research is to develop the Mechanistic-Empirical (M-E) guidelines for evaluating the capacity of existing highways to sustain route overweight truck traffic over a specified performance period due to a growing concern on the impact of increasing overweight truck loads on highways. In this study, a two-stage framework was developed for this purpose. Level I procedure involves the use of pavement evaluation charts to identify the best possible route from among the alternatives considered and to determine what additional tests and analyses are needed as a screening tool. Level II involves the application of the Overweight Truck Route Analysis (OTRA) program to evaluate the structural adequacy of an existing route to carry routine overweight truck traffic over the specified performance period along with estimating asphalt concrete overlay thickness, if necessary.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.74-79
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• 2016

The Seoul Metropolitan Subway, which started operating in 1974, plays a major role in transporting 7,289 thousands passengers daily. This trend of a steadily increase in passengers from 2012 has increased the congestion rate because of the limited capacity and time. To solve this problem, Seoul city is consistently working on improving the subway facilities, such as the construction of a detour path. This project, however, has only a slight effect on improving the congestion rate and is too expensive to construct the facilities. Hence, this study suggests The Congestion Standardization System based on the IoT for improving the subway congestion rate. Based on the system, the expected effect analysis was performed, which resulted in a decrease in ride passengers from 34 to 20. In addition, this expected effect analysis shows that the number of subway vehicles can increase from 20 to 24. The suggested system will have a significant effect on the efficiency of the management system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.10
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• pp.6322-6328
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• 2014

Finite element analyses were performed to find out the load bearing behavior of three kinds of shallow foundations. The analysis results for strip footing showed that local shear failure mode could be observed for a zero dilatancy angle and general shear failure mode could be seen for non-zero dilatancy angles. The ultimate bearing loads for non-zero dilatancy angles were approximately 1.5 times higher than that of a zero dilatancy angle. General shear failure mode was observed for circular footing and square footing regardless of the dilatancy angle. The ultimate bearing loads for a non-zero dilatancy angle were slightly greater than that for a zero dilatancy angle. A comparison of the load-settlement curves for three kinds of footing showed that the load bearing capacities for non-zero dilatancy angle were greater than those for a zero-dilatancy angle.

• Journal of Advanced Navigation Technology
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• v.22 no.4
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• pp.302-310
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• 2018

To realize the self-driving technology, there have been various system designs based on the related V2X standards, especially the IEEE 802.11p and WAVE standard supporting the WLAN V2X communication. On the other hand, the new standard IEEE 802.11ba defining supplementary wake-up radio operation is now under standardization targeting the low power operation, and it includes the V2P operation in use cases. However, if IEEE 802.11ba is used with the IEEE 802.11ba for V2X operation, the additional transmission procedure of wake-up frame in IEEE 802.11ba may cause the congestion problem and fails to meet the delay requirement. In this paper, the system structure of the combination of IEEE 802.11ba with the 802.11p is studied. In addition, based on the analysis and simulation, the considerations and improvements for effective low-power V2P communication in future self-driving technology using IEEE 802.11ba are proposed.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.5
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• pp.529-536
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• 2019

Recently, various efforts have been tried in the construction industry to improve productivity by applying the fourth industrial revolution technology. Among the various technologies, researches for the automation and digitization of earthworks are being carried out steadily. As the interest in the benefits of digitalization of the earthwork field has increased, there have been more cases of technology development and application for digitalization of the earthwork field. However, there is not enough case study to present the analysis results of application cases. The purpose of this study is to verify the feasibility of applying the digitization technology of the earthwork in actual worksite. In order to digitize the worksite terrain, it is required the process of field measurement, measurement data registration, earthwork information input, and analysis cell generation. Particularly, it is possible to achieve information-enabled digitization rather than digitalizing only the shape through the input of the earthwork information and the analysis cell generation. By using the digital information of the earthwork field, it is possible to visually recognize the change of the earthwork field, so that it is expected to enhance the worker 's understanding and to be highly applicable to the management work. It is expected that the digital technology of earthwork site will be able to know the precise amount of volume change of the earthwork numerically, and it will be highly applicable to construction management.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.468-479
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• 2016

In order to supply power to online monitoring systems that are attached to high voltage catenary or overhead wires, a wireless power transfer system is required that is able to transmit power over the insulation gap. Such wireless power transfer systems have transmitter and receiver coils that have diameters of over 10cm. This paper focused on an investigation of the sources of loss in the coils when the coils are fabricated using printed circuit board technology. Using finite element simulation results, it has been shown that the dielectric loss in the substrate was the dominant source of the total loss. It has been demonstrated that the selection of a proper dielectric material was the most critical factor in reducing the loss. For further reduction of the loss, the distributed tuning capacitor method and the slotting of the inter-turn spaces have been proposed. For the evaluation of the proposed methods, four coils have been fabricated and their equivalent series resistances and quality factors were measured. Measured quality factors were greater than 300, which means that these devices will be helpful in achieving high coil-to-coil efficiency.

• Journal of Korean Society on Water Environment
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• v.37 no.2
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• pp.128-136
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• 2021

It is generally known that a wastewater treatment plant (WWTP) consumes immense energy even if it can produce energy. With an aim to increase the energy independence rate of WWTP from 3.5% in 2010 to 50% in 2030, the Korean government has invested enormous research funds. In this study, cost-effective operating alternatives were investigated by analyzing the energy efficiency and economic feasibility for biogas and power generation using new and renewable energy. Based on the US EPA Energy Conservation Measures and Korea ESCO projects, energy production and independence rate were also analyzed. The main energy consumption equipment in WWTP is the blower for aeration, discharge pump for effluent, and pump for influent. Considering the processes of WWTP, the specific energy consumption rate of the process using media and MBR was the lowest (0.549 kWh/㎥) and the highest (1.427 kWh/㎥), respectively. Energy-saving by enhancing anaerobic digester efficiency was turned out to be efficient when in conjunction with stable wastewater treatment. The result of economic analysis (B/C ratio) was 2.5 for digestive gas power generation, 0.86 for small hydropower, 0.49 for solar energy, and 0.15 for wind energy, respectively. Furthermore, it was observed that the energy independence rate could be enhanced by installing energy production facilities such as solar and small hydropower and reducing energy consumption via the replacement of high-efficiency operating.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.4
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• pp.251-258
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• 2019

The physical treatment such as chemical precipitation or adsorption was usually added after biological treatment in wastewater treatment process since it was enforced to reduce the concentration of phosphate for wastewater effluent to 0.2 mg/L as P which was well known as one of main nutrient causing eutrophication in waterbody. Therefore, the new material functioned for both adsorption and disinfection was prepared with Fe and Cu, and $TiO_2$, respectively, by changing the ratio of concentration referred to tri-metal (TM). According to SEM-EDS, $TiO_2$ was 30~40% composition for any TM regardless of any synthesis condition. However, the ratio of composition for Fe and Cu was dependent on the initial Fe and Cu concentration, respectively. The removal efficiency of phosphate was obtained to 15% at low initial concentration and the maximum uptake (Q) was calculated to ~11 mg/g through Langmuir isotherm model using TM1 which was synthesized at 1000 mg/L, 1000 mg/L, and 2 g (10 g/L) for $Fe(NO_3)_3$, $Cu(NO_3)_2$, $TiO_2$, respectively. In disinfection test, the efficiency of virus removal using TM was increased with increase of dosage of TM and can be reached 98% at 0.2 g.

• The Korean Journal of Applied Statistics
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• v.32 no.1
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• pp.139-148
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• 2019

This study proposed a multiple intervention time series model to predict KTX passenger demand. In order to revise the research of Kim and Kim (Korean Society for Railway, 14, 470-476, 2011) considering only the intervention of the second phase of Gyeong-bu before November of 2011, we adopted multiple intervention seasonal ARIMA models to model the time series data with additional interventions which occurred after November of 2011. Through the data analysis, it was confirmed that the effects of various interventions such as Gyeong-bu and Ho-nam 2 phase, outbreak of MERS and national holidays, which affected the KTX transportation demand, are successfully explained and the prediction accuracy could be quite improved significantly.

• Journal of the Korean Institute of Rural Architecture
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• v.21 no.2
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• pp.27-34
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• 2019

This study explores the emergence of a modern form of Cheongju-eup townscape in the late 1930s by re-examining the 1960s restoration model of Seongan-dong and Jungang-dong in Cheongju, one of the historic cities in South Korea. According to the acquired data from the restoration model, it is found that the construction of a new urban area during the late 1930 was resulted from the following events: the development of a railroad station located outside of the north gate of Cheongju-eup since 1921, the completion of Musimcheon embankment outside the south gate in 1932, and the construction of Chungcheongbuk provincial office outside the eastern gate in 1937. In this period of development, which the author named 'Cheongju-eup period', the streets in the old castle, consisting only of two-story financial buildings, had been expanded from the existing area at the Seongan-gil intersection to the outside the east gate of Cheongju-eup. In addition, public government buildings, which were mainly located in both Seongan-gil and Yulgok-ro in the east-west direction, were newly constructed during the late 1930s in Seokgyo-dong, a new area in which a large number of commercial buildings including department stores, clothing stores, shoes shops, and watch stores were also built along the streets. Moreover, the modern form of Cheongju-eup was to be formed by several construction projects in the area of Jungang-ro in the late 1930s. Until the 1920s, the townscape outside the northern gate of Cheongju-eup, were composed of primary, agricultural, and female schools built on a largest site of Gyoseo-ro and Daeseong-ro as well as a transportation warehouse and a railway office near the Cheongju station. Then, entering the 1930s, new school buildings and domestic industrial shops and factories were built around the area of Jungang-ro ranging from the railway outside the northern gate to Bangadari. As a result, the expansion of townscape with newly constructed buildings in the late 1930s marked the emergence of a modern form of Cheongju-eup.