• Journal of Wetlands Research
• /
• v.23 no.2
• /
• pp.154-162
• /
• 2021

The naturally opened Han river estuary is a place where the flows of the Han river, Imjin river, Yaesung river meet with West Sea of Korea, so the hydrodynamic mechanism(Impact-Response) structure of Han river estuary is complex. Continuous observation and measurement due to the morphological characteristics at the estuary are required to maintain the estuary environment and river management facilities. However, the Sannam wetland(the study area) is in the military operation area. Therefore, Sannam wetland has the limited access under the control from military office. In 2020, there had a natural disaster due to flooding in August and COVID-19, and it made a survey hard. The noncontact survey technique, the analysis of LANDSAT images at Sannam wetland, was applied to analyze riverbed fluctuation and morphological transformation around Sannam wetland. LANDSAT images obtained from EarthExplorer, USGS and analyzed by QGIS. The analysis was performed based on the area and the distance near Sannam wetland. As a result, an erosion was happened on the downstream of the study area, and the upstream of the study area did not have any serious sediment transport. Considering the resolution of LANDSAT images, this noncontect survey technique is applicable to manage the study area. From the analysis of LANDSAT images, it is assumed that the tidal effect is greater than the inflow from the upstream. The pattern change of tidal response causes the damage of the river facilities near the Hangang river estuary.

• Environmental and Resource Economics Review
• /
• v.31 no.4
• /
• pp.801-824
• /
• 2022

Recently, United Nations found that 38% of global carbon emissions are generated in the building sector, surpassing other industries (32%) and transportation (23%), and ESG is actively used as a way to reduce carbon emissions in the building sector, led by overseas advanced countries. In Korea, as the National Pension Service announced "Consider ESG with more than 50% of investment assets" this year, the move to introduce ESG in the building sector is accelerating, centering on construction companies and asset management companies. However, as the domestic ESG evaluation system is still mainly focused on corporate governance and social responsibility, interest in the environmental sector is lagging behind that of advanced countries. As ESG in the building sector is expected to grow rapidly over the next 10 years, I would like to suggest the following development directions. The first is the expansion of the incentive system. In order for the government to successfully implement policies related to ESG in the building sector, incentive system such as tax reduction and building standards should be expanded further than now in addition to negative systems such as rent restrictions and punishment taxes due to regulatory violations. Second, standardized ESG standards are established. Rather than creating an independent Korean ESG standard that is far from global standards, it is necessary to organize the common parts of global standards and evaluation methods and create and provide guidelines in the form of standard textbooks that can be used equally by all stakeholders. Third, it is an effort to link ESG in the building sector with Digital Transformation(DX). This is because actual energy savings and carbon emission reduction can be realized only when the operation method of the building sector, which is operated mainly by manpower, is digitalized and converted to an intelligent way.

• The Journal of Bigdata
• /
• v.8 no.1
• /
• pp.83-97
• /
• 2023

Project evaluation is the process of evaluating the progress and results of a project. Smart city projects can be divided into system components (infrastructure, services, platforms), or projects can run simultaneously for multiple services. In addition, services are developed and expanded through additional projects. In order to ensure that the smart city, which is composed of various projects, proceeds in accordance with the goals and strategies, periodic project evaluation is required during the project implementation process. The smart city project evaluation system proposed in this paper is designed to provide comprehensive and objective indicators by reflecting various factors that must be considered for projects occurring in all stages of planning, design, construction, and operation of smart cities. The indicators derived from the evaluation system can be used by decision makers to determine the direction of smart city project development. In addition, it is designed so that the performance of the project can be evaluated interim before the end of the project and the feedback obtained from it can be reflected. To introduce the application method of the smart city project evaluation system proposed in this study, the evaluation system developed in this study was applied to the smart city project case of Incheon Free Economic Zone (IFEZ). Based on the evaluation results, items that can maximize the improvement effect of each smart city project item were presented, and the direction of smart city project implementation was suggested. By utilizing a smart city project evaluation system that reflects the characteristics of smart city projects that are composed of multiple projects, comprehensive planning and management of smart city projects will be possible, and this study will serve as a reference for identifying priority improvement factors for projects.

• Journal of Internet of Things and Convergence
• /
• v.9 no.6
• /
• pp.93-98
• /
• 2023

In paddy rice farming, water management is a critical task. To suppress weed emergence during the early stages of growth, fields are deeply flooded, and after transplantation, the water level is reduced to promote rooting and stimulate stem generation. Later, water is drained to prevent the production of sterile tillers. The adequacy of water supply is influenced by various factors such as field location, irrigation channels, soil conditions, and weather, requiring farmers to frequently check water levels and control the ingress and egress of water. This effort increases if the fields are scattered in remote locations. Automated irrigation systems have been considered to reduce labor and improve productivity. However, the net income from rice production in 2022 was about KRW 320,000/10a on average, making it financially unfeasible to implement high-cost devices or construct new infrastructure. This study focused on developing an IoT-Based irrigation valve that can be easily integrated into existing agricultural infrastructure without additional construction. The research was carried out in three main areas: Firstly, an irrigation valve was designed for quick and easy installation on existing agricultural pipes. Secondly, a power circuit was developed to connect a low-power Cat M1 communication modem with an Arduino Nano board for remote operation. Thirdly, a cloud-based platform was used to set up a server and database environment and create a web interface that users can easily access.

• Journal of Advanced Navigation Technology
• /
• v.25 no.6
• /
• pp.510-516
• /
• 2021

Recently, the range of utilization and demand for unmanned aerial vehicle (UAV) has been continuously increasing, and research on the construction of a separate operating system for low-altitude UAV is underway through the development of a management system separate from manned aircraft. Since low-altitude UAVs also fly in the airspace, it is essential to establish technical standards and certification systems necessary for the operation of the aircraft, and research on this is also in progress. If the operating standards and certification requirements of the aircraft are presented, a test method to confirm this should also be presented. In particular, the accuracy of small UAV's navigation required during flight is required to be more precise than that of a manned aircraft or a large UAV. It was necessary to calculate a separate navigation error. In this study, we presented a test method for deriving navigation errors that can be applied to UAVs that have difficulty in acquiring long-term operational data, which is different from existing manned aircraft, and conducted verification tests.

• Korean Journal of Child Education & Care
• /
• v.17 no.4
• /
• pp.1-30
• /
• 2017

The purpose of this study is to investigate the awareness of daycare teachers by the nursery school operation performance of the National Competency Standards(NCS). For this purpose, 35 public and private daycare center, home daycare centers and corporation daycare center teachers were randomly sampled in Busan Metropolitan City. We conducted a questionnaire consisting of 230 sub-elements based on 45 sub-competency unit elements extracted from 12 areas of job ability of the national competence standards. Final questionnaires were collected from 117 questionnaires of 28 national daycare teachers, 30 private daycare teachers, 30 home daycare teachers, and 29 corporation daycare teachers. As a result, there was a difference in the awareness of importance among the four groups in all 12 performance capability units. For the 12 job performance units, the importance was recognized in the order of corporate daycare center, national daycare center, home daycare center, and private daycare center. Among them, "Establishment of Child Care Center Management Policy", "Construction of Child Care Service", "Child Care Activity Management", "Infant and Child Playing Guide", "Body and Art Activity Guidance", "Language, Nutritional guidance" there were no differences in the awareness of the importance of corporate daycare teachers and national daycare teachers, and there was no difference between national daycare teachers and home daycare teachers. However, there was a difference between corporate daycare teachers and home daycare teachers.. There is also a difference in the awareness of importance between home daycare teachers and private daycare teachers. In the remaining five job competence units, "Child Care Assessment", "Support for Infant and Toddler Development", "Cooperation with the Home and Community", "Child Care Management", and "Child Care Research", corporation daycare centers, national daycare centers. There was no statistically significant difference in the awareness of importance, but there was a significant difference from the private daycare teachers. Also this tendency was consistently observed in 45 sub-capacity unit elements.

• Journal of The Korean Association For Science Education
• /
• v.33 no.7
• /
• pp.1431-1449
• /
• 2013

This study is based on the assertion that science museums should consider visitors' views and expectations as they are not satisfied in many cases. In this study, we investigated 31 scientifically gifted students and 177 science high school students about their image of science museums. Using the questionnaire, it was found that only 51% of students visited science museums; however, the average number of visits was 4.2. This means that students tended to re-visit after the first visit of the science museum. Students had a 'good' image of science museums when they incurred hands-on experiences and observed new, interesting, curious and funny exhibits. And students had a 'bad' image of science museums due to the following aspects: lack of new and interesting exhibits, information and guide, diverse contents, and hands-on experience; deficiencies in environment; and inadequacy of the management, operation and composition of exhibits. Therefore, they hoped that science museums will provide more hands-on experiences and experiments, new and interesting exhibits, systematic management and composition of exhibits, information and guides, and a good environment. So science museums need to pay special attention to aspects like management, information guides and environment for the first-time visitors. Based on the above results, we suggested "Directions for a good science museum based on students' views". While asking students what topics they wanted to know and learn in a science museum, each student was given the choice of four topics; eventually, 2.9 answers overlapped for each topic. When classifying students' topics into four main themes for the Gwangju National Science Museum, the order from the most popular theme to the least one was 'science in everyday life', 'ocean/space/future science', 'light and science', and 'culture, art and science'. Among the topics mentioned by students, only 37% are exhibited in Seoul, Gwacheon, Daejeon, or Gwangju science museums. We hope that the results and research methods will be used for evaluation, re-construction, and reinvigorated presentation of science museums.

• Journal of Energy Engineering
• /
• v.28 no.3
• /
• pp.65-79
• /
• 2019

The study attempted to estimate the optimal facility capacity by combining renewable energy sources that can be connected with gas CHP in industrial complexes. In particular, we reviewed industrial complexes subject to energy use plan from 2013 to 2016. Although the regional designation was excluded, Sejong industrial complex, which has a fuel usage of 38 thousand TOE annually and a high heat density of $92.6Gcal/km^2{\cdot}h$, was selected for research. And we analyzed the optimal operation model of CHP Hybrid System linking fuel cell and photovoltaic power generation using HOMER Pro, a renewable energy hybrid system economic analysis program. In addition, in order to improve the reliability of the research by analyzing not only the heat demand but also the heat demand patterns for the dominant sectors in the thermal energy, the main supply energy source of CHP, the economic benefits were added to compare the relative benefits. As a result, the total indirect heat demand of Sejong industrial complex under construction was 378,282 Gcal per year, of which paper industry accounted for 77.7%, which is 293,754 Gcal per year. For the entire industrial complex indirect heat demand, a single CHP has an optimal capacity of 30,000 kW. In this case, CHP shares 275,707 Gcal and 72.8% of heat production, while peak load boiler PLB shares 103,240 Gcal and 27.2%. In the CHP, fuel cell, and photovoltaic combinations, the optimum capacity is 30,000 kW, 5,000 kW, and 1,980 kW, respectively. At this time, CHP shared 275,940 Gcal, 72.8%, fuel cell 12,390 Gcal, 3.3%, and PLB 90,620 Gcal, 23.9%. The CHP capacity was not reduced because an uneconomical alternative was found that required excessive operation of the PLB for insufficient heat production resulting from the CHP capacity reduction. On the other hand, in terms of indirect heat demand for the paper industry, which is the dominant industry, the optimal capacity of CHP, fuel cell, and photovoltaic combination is 25,000 kW, 5,000 kW, and 2,000 kW. The heat production was analyzed to be CHP 225,053 Gcal, 76.5%, fuel cell 11,215 Gcal, 3.8%, PLB 58,012 Gcal, 19.7%. However, the economic analysis results of the current electricity market and gas market confirm that the return on investment is impossible. However, we confirmed that the CHP Hybrid System, which combines CHP, fuel cell, and solar power, can improve management conditions of about KRW 9.3 billion annually for a single CHP system.

• Journal of Korea Water Resources Association
• /
• v.56 no.11
• /
• pp.775-784
• /
• 2023

With the increasing trend of extreme rainfall that exceeds the design frequency of man-made structures due to extreme weather, it is necessary to review the safety of agricultural reservoirs designed in the past. However, there are no local government-managed reservoirs (13,685) that can be discharged in an emergency, except for reservoirs over a certain size under the jurisdiction of the Korea Rural Affairs Corporation. In this case, it is important to quickly deploy a mobile siphon to the site for preliminary discharge, and this study evaluated the applicability of a mobile siphon with a diameter of 200 mm, a minimum water level difference of 6 m, 420 (m²/h), and 10,000 (m²/day), which can perform both preliminary and emergency discharge functions, to the Yugum Reservoir in Gyeongju City. The test bed, Yugum Reservoir, is a facility that was completed in 1945 and has been in use for about 78 years. According to the hydrological stability analysis, the lowest height of the current dam crest section is 27.15 (EL.m), which is 0.29m lower than the reviewed flood level of 27.44 (EL.m), indicating that there is a possibility of lunar flow through the embankment, and the headroom is insufficient by 1.72 m, so it was reviewed as not securing hydrological safety. The water level-volume curve was arbitrarily derived because it was difficult to clearly establish the water level-flow relationship curve of the reservoir since the water level-flow measurement was not carried out regularly, and based on the derived curve, the algorithm for operating small and medium-sized old reservoirs was developed to consider the pre-discharge time, the amount of spillway discharge, and to predict the reservoir lunar flow time according to the flood volume by frequency, thereby securing evacuation time in advance and reducing the risk of collapse. Based on one row of 200 mm diameter mobile siphons, the optimal pre-discharge time to secure evacuation time (about 1 hour) while maintaining 80% of the upper limit water level (about 30,000 m²) during a 30-year flood was analyzed to be 12 hours earlier. If the pre-discharge technology utilizing siphons for small and medium-sized old reservoirs and the algorithm for reservoir operation are implemented in advance in case of abnormal weather and the decision-making of managers is supported, it is possible to secure the safety of residents in the risk area of reservoir collapse, resolve the anxiety of residents through the establishment of a support system for evacuating residents, and reduce risk factors by providing risk avoidance measures in the event of a reservoir risk situation.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.51 no.1
• /
• pp.13-28
• /
• 2023

This study examines the process of project promotion in Busan, which introduced the private participation-type consultative body for the first time in the country in the promotion stage of the private-initiated park development project, and introduced flexible application of the system and differentiated policy elements in the implementation process, and examines the operational characteristics and we tried to analyze performance, etc. As a result of the analysis, first, the preferred bidder was selected by introducing a mixed method in the project method, which is an independent project method that cannot be seen in other local governments. Second, by specifying guidelines considering the characteristics of each park and detailed guidelines such as the location, area, and maximum height of non-park facilities, criteria for establishing a rational development plan utilizing regional identity and the basis of evaluation standards were laid. Third, in the project process, transparency was secured through the delegation-type roundtable, in which the private sector performs the functions and roles of key actors, thereby preventing disputes such as suspicion of preferential treatment. Fourth, in order to improve the quality of park facilities to be donated and to secure design adequacy, after approval of the implementation plan, a general planner was introduced and construction project management (design stage) services were performed to promote efficient implementation and specialization of luxury parks in the region. As a result, the city of Busan carried out the project efficiently by conserving 5 parks from sunset, a park area of 2.25km², and reducing land compensation and park construction costs by KRW 740 billion. Reinforcement of the public nature of the private-initiated park development project was suggested. However, due to the application of these systems and verification procedures, the project period is prolonged, and park services are delayed along with the financial burden on private operators.