• Journal of Internet of Things and Convergence
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• v.7 no.3
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• pp.9-14
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• 2021

This paper discovers the energy loss factors through the insulation diagnosis of houses or buildings, and proposes directions for energy efficiency improvement. The energy efficiency factor of a building consists of insulation diagnosis, thermal bridge diagnosis, window diagnosis, airtight diagnosis, and equipment diagnosis. Among the residents and facilities in the energy welfare blind spot, an energy efficiency diagnosis was conducted for one senior citizen building located in Naju-si, Jeollanam-do, and energy efficiency diagnosis was conducted after insulation was installed. Energy measurement, diagnosis and analysis were performed using the IoT-based integrated wired/wireless energy diagnosis platform, Energy Finder. As a result of comparison, an overall energy saving rate of 16.38% was achieved. Annual heating energy consumption per unit area decreased from 333.51kWh before construction to 277.35kWh after construction, and annual cooling energy consumption per unit area decreased from 5.51kWh before construction to 5.22kWh after construction. The annual primary energy consumption per unit area decreased from 464.52kWh before construction to 403.69kWh after construction, and the annual energy cost was reduced from 3,063,307.14 won before construction to 2,641,072.49 won after construction. The additional improvement work is needed on the standards affecting energy efficiency other than insulation.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.41-50
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• 2021

This study was conducted to see the differences of park users by classifying them with their park use frequency in terms of park use, management policy and perception, using the same survey results conducted in 2014 and 2020. Research was conducted on urban parks in Yangju, South Korea, and 740 in 2014 and 431 in 2000 survey results were used. After classifying the high-use and low-use groups according to park use frequency, this study compared the demographic differences and park use method differences according to the group, the recognition differences for the future park management direction between the two groups were analyzed and compared using statistical analysis by year. The results showed that the park's quantitative expansion and accessibility improvements were the most important issues in 2014, while the importance of park management, such as checking and improving aging facilities, providing various programs, and creating a themed neighborhood park that could reveal the identity of the area, was increased in 2020. Despite recognizing the importance of persistent management in the case of high-use groups, the results showed that they were less willing to participate in park management programs compared to less-use groups, which showed the need for a discussion of how to involve high-use groups for long term park management. This study contribute the body of literature that it seeks to understand differences of park user in terms of their park use frequency. However, in future studies, analyzing the differences of park users through a short-term study is required.

• Journal of the Korean Institute of Landscape Architecture
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• v.49 no.2
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• pp.113-127
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• 2021

Although planning techniques linking parks, green areas, and waterways have become common, there are frequent disruptions in the operation and management of landscape-use artificial channels (LuAC). Therefore, this study examined a design to promote the sustainable management and operation of a LuAC using rainwater for the streamlets of the Jeonju-Wanju Innovative City. In order to accomplish the purpose of this study, scenarios were set up by dividing the design into waterhead and waterway portions. First, the scenario regarding the waterhead was analyzed to calculate the water supply and storage required for the waterway and waterhead. The analysis showed that the waterway requires a water supply of 676.8 tons/months, 3,018 tons to 5,512 tons of storage space, and a water depth of 0.75 m to 1.37 m considering the ecological and landscape aspects. The second scenario is to select an effective system of facilities for the operation and management of the LuAC. To accomplish this, a single-circulation system (SCS), which transports water to a highland location was compared to a multi-circulation system (MCS), which supplied water separately to each water space and operated independently. The results showed that the MCS, which was operated independently by small power units, was more effective owing to the vast difference in water supply operation times.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.129-134
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• 2021

Recently, the demand for electricity is gradually increasing due to the rapid industrial development and the improvement of living standards. In the case of Korea, which is highly dependent on fossil fuels due to such a surge in electricity demand, reduction and freezing of greenhouse gas emissions due to international environmental regulations will immediately lead to a contraction in industrial activities. Accordingly, there are many difficulties in competition with advanced countries that want to link the environment with the country's industrial production activities, and the development of alternative energy as a countermeasure is of great interest around the world. Among these new power generation methods, small-scale power generation facilities with relatively small capacity include photovoltaic generation, wind power generation, and fuel cell generation. Among them, the fuel cell attracts the most attention in consideration of continuous operation, high power generation efficiency, and long-term durability, which are important factors for practical use. Therefore, in this paper, the fuel cell power generation system was researched and constructed by designing the power conversion circuit necessary to finally obtain the AC power used in our daily life by using the DC power generated from the fuel cell as an input.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.4
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• pp.12-19
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• 2021

Recently, with frequent earthquakes around the world, research on seismic design and seismic reinforcement of reinforced concrete facilities has been actively conducted from earthquakes. In particular, columns, which are compressed members of reinforced concrete structures, are vulnerable to lateral forces caused by earthquakes, so an appropriate seismic reinforcement method is required. Therefore, this study intended to develop Velcro seismic reinforcement method that is quick and easy to construct. For the development of Velcro seismic reinforcement, the adhesion and tensile strength of the existing industrial velcro was improved. A direct tensile test was also conducted to compare the tensile performance of the newly-developed velcro seismic reinforcement to industrial one. In addition, numerical analysis was performed to predict the seismic performance of RC columns reinforced by industrial and newly-developed velcro. Based on the analysis results, the strength and ductility of the non-seismic and velcro-reinforced RC column were reviewed. The analysis confirmed that both the strength and ductility of non-seismic RC columns reinforced by industrial and newly-developed velcro increased, but the seismic performance of the newly-developed Velcro reinforcement is better than that of industrial velcro.

• Ocean policy research
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• v.33 no.2
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• pp.83-119
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• 2018

Under the Korean Marine Environment Management Act (hereunder, the KMEMA), the duty to arrange spill clean-up equipments, including spill clean-up vessels, required by the article 67 of the KMEMA is in essence the provision of public goods since it is a precautionary or preventive measure for the efficient performance of oil spill cleaning up. Also the obligation to control marine pollution and the duty to arrange of anti-pollution measures imposed on polluters is the obligation imposed by the public law in accordance with "the Polluter-Pays Principle". Therefore, the execution of such obligations shall be accompanied by the minimum legal and institutional arrangements. On the other hand, judging whether to form the roles of the public and private sectors in providing public goods is basically a matter of policy decision. However, even if the private sector is allowed to participate in the provision of public goods, it is imperative that a minimum requirement be provided to secure the public interest. Although major countries allows polluters to conclude a preliminary contract with a civil anti-pollution management company, these civilian institutions are in principle constituted by the owners of oil storage facilities. Additionally it is worth noting that it operates as a non-profit organization. In particular, if the practitioner performs pollution control for commercial purposes, their profitability may depend on the size of the pollution, the period spent on pollution control, the size of the equipment and manpower mobilized in the pollution control, and so on. Considering the above problems, caution should be taken to allow marine environmental management companies to be un-limitedly entrusted with the responsibility of arranging measures such as pollution control. In order to allow the marine environmental management contractor to be entrusted for the assignment of duty to protect the marine environment, the marine environment management business should be expanded so that the marine pollutant management capacity satisfies the statutory control capacity. For this purpose, it is necessary to manage and supervise the maintenance and improvement of the control capability of the marine environment management business. It is also necessary to discuss the introduction of the grading system for the control ability of the civil control companies alike in major countries.

• Journal of Navigation and Port Research
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• v.42 no.6
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• pp.478-485
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• 2018

Aids to Navigation (AtoN) is one of the marine traffic safety facilities that promotes the safety of maritime traffic and enhance ship's operational efficiency. However, functional failure of AtoN due to ship's collision or bad weather conditions leads to inconvenience or navigational risk to various users such as the ship operators. For insstance, the largest container port in Korea, Busan Port has experienced a total of 400 AtoN accidents in the past 12 years (2006-2017).Therefore, an average of 20.6 days of recovery time is required, which increases the maritime safety anxiety for AtoN users. is the objective of this study was to present the quantitative support of the users for the prevention of AtoN accidents and the improvement of the feasibility of implementing more efficient management in Korea. A survey was conducted on the users of Busan port areas to investigate general perception of AtoN in general and the accidents that have happened, and to estimate the economic value of navigational risk reduction by implementing effective AtoN management measure. Using the representative non-market valuation method for environmental or public goods known as contingent valuation method (CVM), the economic value granted to users for the AtoN services in Busan port was estimated to at least 16 billion won. Therefore, these finding could be used by AtoN managers and/or policy makers as a valuable data to identify the users' need of various AtoN services including Busan Port and to establish and implement more efficient management plan.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.6
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• pp.917-930
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• 2018

A quantitative risk assessment method for quantitatively evaluating the fire risk in designing a road tunnel disaster prevention facilities has been introduced to evaluate the appropriateness of a disaster prevention facility in a large tunnel through which all vehicle types pass. However, since the quantitative risk assessment method of the developed can be applied only to the large sectional area tunnels (large tunnels), it is necessary to develop a quantitative risk assessment method for road tunnels passing only small cars which has recently been constructed or planned. In this study, fire accidents scenarios and quantitative risk assesment method for small road tunnels through small cars only which is based on the methods for existing road tunnels (large tunnels). And the risk according to the distance between cross passage is evaluated. As a result, in order to satisfy the societal risk assessment criteria, the distance of the appropriate distance between cross passages was estimated to be 200 m, and the effect of the ventilation system of the large port exhaust ventilation system was quantitatively analyzed by comparing the longitudinal ventilation system.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.649-656
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• 2019

Flux cored arc welding (FCAW), which is used widely in many fields, such as shipyards, bridge structures, construction machinery, and plant industry, is an alternative to shielded metal arc welding (SMAW). FCAW is used largely in the welding of carbon and alloy steel because it can be welded in all poses and obtain excellent quality in the field under a range of working conditions. In this study, the mechanical properties of welded parts were analyzed after different welding of SS400 and SM490A using FCAW. The following conclusions were drawn. The tensile test results satisfied the KS standard tensile strength in the range of 400~510 N/mm2 in all welding positions. The bending test confirmed that most of the specimens did not show surface breakage or other defects during bending and exhibited sufficient toughness, even after plastic deformation. The hardness test results were lower than the standard value of 350 Hv of KS B 0893. Similar to the hardness test, were greater than the KS reference value. The macro test revealed no internal flaws, non-metallic inclusions, bubbles or impurities on the entire cross section of the weld, and there were no concerns regarding lamination.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.6
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• pp.142-149
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• 2019

In this study, the past erosion history and current status in the CHUNG-UI beach of Eulwang-dong, Jung-gu, Incheon-Si, South Korea were investigated and analyzed the wave with wave-induced current to investigate the causes of coastal erosion. As a result, the significant wave height ($H_{1/3}$) was in the range of 0.07~1.57 m and the mean value was 0.21 m. The maximum wave height ($H_{max}$) was in the range of 0.02-4.76m and the mean value was 0.27m. The vertical wave height and cycles were estimated through numerical model experiments of wave transformation. The 50-year frequency design wave height ranged from 0.82m to 3.75m. As a result of the experiment of wave-induced current, wave-induced current in the CHUNG-UI beach was decreased after the installation of the Detached breakwater and the Jetty. On the other hand, when the crest elevation was increased up to 5 m, there was no significant change, but when the crest elevation was increased to 8m, strong wave-induced current occurred around the submerged breakwaters due to lowered depth of water. In addition, the main erosion of the CHUNG-UI beach is due to the intensive invasion of the wave characteristics coming from the outer sea into the white sandy beach. The deformation of the wave centered on the front of the sandy beach caused additional longshore currents flowing parallel to the sandy beach and rip currents in the transverse direction, thus confirming that the longshore sediment was moved out of the front and out of the sea. The results of this study can be used as preliminary data for the recovery of the sand and the selection of efficient erosion prevention facilities.