• Journal of Korean Society of Water and Wastewater
• /
• v.32 no.6
• /
• pp.487-497
• /
• 2018

Water quality improvement processes for stagnant area consist mainly of technologies applying vegetation and artificial water circulation, and these existing technologies have some limits to handle pollution loads effectively. To improve the purification efficiency, eco-friendly technologies should be developed that can reinforce self-purification functions. In this study, a multi-functional floating island combined with physical chemical biological functions ((1) flotation and oxidization using microbubbles, (2) vegetation purification and (3) bio-filtration with improved adsorption capacity) has been developed and basic experiments were performed to determine the optimal combination conditions for each unit process. It has been shown that it is desirable to operate the microbubble unit process under conditions greater than $3.5kgf/cm^2$. In vegetation purification unit process, Yellow Iris (Iris pseudacorus) was suggested to be suitable considering water quality, landscape improvement and maintenance. When granular red-mud was applied to the bio-filtration unit process, it was found that T-P removal efficiency was good and its value was also stable for various linear velocity conditions. The appropriate thickness of filter media was suggested between 30 and 45 cm. In this study, the optimal design and operating parameters of the multi-functional floating island have been presented based on the results of the basic experiments of each unit process.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.22 no.3
• /
• pp.15-30
• /
• 2019

Changpo Lake was created as a part of a land reclamation for refugee self-helping projects. It shows characteristics of a fresh water lake, and still retains the early appearance of reclamation that surrounding regions have not been developed into farm lands. Shallow wetland has formed around the lake, which provides great conditions for diverse lives, and surrounding earthiness is favorable for growth of vegetation and restoration of the ecosystem. However, as facilities of the Muan International Airport nearby Changpo Lake are expanding and barns are being constructed, artificialness is gradually increasing. Particularly, since pollution sources such as sport facilities, farm lands and barns are scattered around Changpo Lake, pollutants are flowing in constantly. Accordingly, the results for setting up management areas according to the spatial characteristics and creating natural ecological spaces near Changpo Lake, Taebongcheon stream and Hakgyecheon stream are as follows. First, the creation of a natural eco-friendly waterfront space should be promoted by securing the health of the aquatic ecosystem and restoring species and the ecosystem. In addition, a consultative body needs to be formed to lead local residents to participating in river investigation and monitoring, maintenance, and management through role sharing. Second, the basic direction of the spatial management plan is to keep the unique charm of Changpo Lake, maintain harmony with nature, create diverse waterfront areas, and secure the continuity of Changpo Lake and inflow streams. Moreover, the area should be divided into three zones such as a conservation zone, a restoration zone and a waterfront zone, and for each zone, the preservation of vegetation, the creation of ecological wetlands and restoration of the ecotone and ecological nature need to be promoted. Third, facilities and activity programs for each space of Changpo Lake should be operated for efficient management of protected areas. In order to suit the status of each space, biological habitats, water purification spaces, experiential and learning spaces, and convenience and rest spaces should be organized and designated as research, monitoring, education, and tourism areas. Accordingly, points of interest should be set up within the corresponding area. In this study, there are many parts that need to be supplemented for immediate implementation since the detailed plans and project costs for the promotion of programs by area are not calculated. Therefore, it is necessary to make detailed project plans and consider related projects such as water quality, restoration of habitats, nature learning and observation, and experience of ecological environments based on the categories such as research, monitoring, education and tourism in the future.

• Journal of the Korea Society of Computer and Information
• /
• v.26 no.3
• /
• pp.99-109
• /
• 2021

In recent machine learning studies, in order to consider the quality and completeness of data, derivation of non-functional requirements for data has been proposed from the viewpoint of requirements engineering. In particular, requirements engineers have defined data requirements in machine learning. In this study, data requirements were derived at the data acquisition (DAQ) stage, where data is collected and stored before data preprocessing. Through this, it is possible to express the requirements of all data required in the existing DAQ system, the presence of tasks (functions) satisfying them, and the relationship between the requirements and functions. In addition, it is possible to elicit requirements and to define the relationship, so that a software design document can be produced, and a systematic approach and direction can be established in terms of software design and maintenance. This research using existing DAQ system cases, scenarios and use cases for requirements engineering approach are created, and data requirements for each case are extracted based on them, and the relationship between requirements, functions, and goals is illustrated through goal modeling. Through the research results, it was possible to extract the non-functional requirements of the system, especially the data requirements, from the DAQ system using requirements engineering.

• Journal of the Korean Institute of Rural Architecture
• /
• v.24 no.3
• /
• pp.23-30
• /
• 2022

In this study, in order to grasp the current situation of indoor environmental pollution and indoor ventilation in one-room around the university in the post-corona era, we analyzed the experimental data and conducted a questionnaire survey on university students. By analyzing the content, the effects of formaldehyde, dust and other pollution on the human body, which are usually not easily detectable, are digitized and more easily taken into account. Among the experimental results, the concentration of VOC and HCHO, gas pollutants among indoor pollutants, exceeded the recommended criteria of the Ministry of Environment in most studio apartments. Overall, the average CO₂ concentration was lower than the Ministry of Environment's maintenance standard (1000ppm), but it was relatively high in summer and winter, and it is believed to be caused by cooling and heating in an enclosed space. The levels of PM2.5 and PM10, particulate pollutants, increased in November and December, and it is believed that ventilation defects due to degradation in external temperature. There was no clear difference between the two types, and there was a very high correlation between PM2.5 and PM10, HCHO and VOC. It was found that temperature was closely correlated with all sources except CO₂, and humidity was closely correlated with all sources except PM2.5 and PM10. Health risk assessment was conducted for formaldehyde. The average ECR of studio R2 in May was 3.91E^-4, and the ECR figure in September was 3.65E^-4, which was very high compared to other residential spaces. The R2 level was calculated as 4 people per 10,000 people in the lifetime risk of cancer of residents, exceeding the allowable risk. R8 also showed higher ECR results than other spaces after R2, especially in October, 2.01E^-4, six times higher than R7 measured in October, and 1.87E^-4 in July, four times higher than R9.

• Analytical Science and Technology
• /
• v.35 no.5
• /
• pp.205-211
• /
• 2022

Deuterium (D) is an isotope with one more neutron number than hydrogen (H). Heavy elements rarely change their chemical properties with little effect even if the number of neutrons increases, but low-mass elements change their vibration energy, diffusion rate, and reaction rate because the effect cannot be ignored, which is called an isotope effect. Recently, in the semiconductor and display industries, there is a trend to replace hydrogen gas (H₂) with deuterium gas (D₂) in order to improve process stability and product quality by using the isotope effect. In addition, as the demand for D₂ in industries increases, domestic gas producers are making efforts to produce and supply D₂ on their own. In the case of high purity D₂, most of them are produced by electrolysis of heavy water (D₂O), and among D₂, hydrogen deuteride (HD) molecules are present as isotope impurities. Therefore, in order to maximize the isotope effect of hydrogen in the electronic industry, HD, which is an isotope impurity of D₂ used in the process, should be small amount. To this end, purity analysis of D₂ for industrial processing is essential. In this study, HD quantitative analysis of D₂ for high purity D₂ purity analysis was established and hydrogen isotope RM (Reference material) was developed. Since hydrogen isotopes are difficult to analyze with general gas analysis instrument, they were analyzed using a high-precision mass spectrometer (Gas/MS, Finnigan MAT271). High purity HD gas was injected into Gas/MS, sensitivity was determined by a signal according to pressure, and HD concentrations in two bottles of D₂ were quantified using the corresponding sensitivity. The amount fraction of HD in each D₂ was (4518 ± 275) μmol/mol, (2282 ± 144) μmol/mol. D₂, which quantifies HD amount using the developed quantitative analysis method, will be manufactured with hydrogen isotope RM and distributed for quality management and maintenance of electronic industries and gas producers in the future.

• Journal of the Korea Institute of Building Construction
• /
• v.21 no.3
• /
• pp.231-239
• /
• 2021

Entering the era of the fourth industrial revolution, information and communication technologies such as CCTV, home network systems and equipment are being used in the construction industry. In particular, in order to increase the autonomy of information and communication technologies in apartments, the government has announced an administrative revision of information and communication-related laws, and companies are focusing on developing technologies such as smart home services. In addition, most domestic and foreign studies on the information and communication work were mainly conducted on technology and management. However there is a lack of research on physical defects affecting the quality of ICT. Therefore, this study collected the defect data registered in the project management system of three domestic construction companies and classified them according to the standards of the Enforcement Decree of the Apartment House Management Act. According to the analysis of the frequency of defects work type, 88.10% of defects occurred in home network equipment work. In addition, analysis of defects type in the four detailed works showed the highest number of operation error. The cause was analyzed and prevention measures and countermeasures were presented in parts of design, construction, and maintenance. The results of this study will improve the quality of apartment housing and be used as basic data for future research on practical defect minimization and prevention measures.

• Journal of Marine Life Science
• /
• v.5 no.2
• /
• pp.51-57
• /
• 2020

Disinfection and maintenance of rearing water in aquaculture is an essential element for the prevention of fish diseases. This is especially important in recirculating aquaculture systems (RAS) in which fish are reared at high density using recycled water. In this study, tilapia was reared in two different RAS (one with plasma generator - PW system, another without plasma generator - No PW system). In plasma treated group, UVT% of water was improved clearly, and the number of heterotrophic bacteria decreased significantly after 40 days. Total weight gain of tilapia in PW system was significantly higher, and other growth indicators were also relatively higher although not statistically significant. In addition, the fish in PW system had a 100% survival rate, and there were no histological differences between fish from both systems. Fish did not seem to be affected by the toxicity of ROS. In conclusion, it is expected that plasma water can effectively deactivate fish pathogens and improve the quality of rearing water.

• Journal of Korea Entertainment Industry Association
• /
• v.15 no.7
• /
• pp.145-158
• /
• 2021

This study is aimed at identifying the important factors required by customers through importance-satisfaction analysis of how they choose skin care shops on the basis of certain factors and attributes at this time when there is an urgent need to improve the level of quality that meets their expectations and demands in combination with the quantitative expansion of skin care shops. To achieve this, a survey was carried out to 217 people over the age of 20 in Gwangju and Jeonnam area with experience in using skin care shop services. The SPSS v. 21.0 program was used to analyze the collected data. The results are summarized as follows. IPA grid analysis of the difference in importance-satisfaction of sub-factors for skin care shop choice showed that the items corresponding to the upper-left side of maintenance and strengthening, the upper-right side of stainability, and the lower-left side of gradual improvement were the 'sanitary control of tools and products', 'basic situation(legal compliance)', and 'workers' sanitary control', 'internal control of skin care shops', 'professionalism and skills of workers'and 'quality of services', respectively. Consequently, the results of this study will be based on the efficient operation of skin care shops, and further more the utilization of them is expected to expand the quantitative and qualitative base of the skin care industry.

• Therapeutic Science for Rehabilitation
• /
• v.10 no.4
• /
• pp.7-24
• /
• 2021

Objective : This study examined the characteristics of the literature involving a single-subject research design among positive behavior support intervention studies to improve problem behavior in children with autism spectrum disorders and assess the quality level. Methods : This is a literature study, and the targets of analysis were nine single-subject research papers published between 2011 and 2020. The subject papers were analyzed by dividing them into general characteristics and the qualitative levels according to the content of the research method. Results : Analysis of analyzing the contents of the study showed that the subjects were preschool and elementary school-age children at the same ratio. Furthermore, the study design involved mostly the middle and multiple baseline designs among the behaviors. All papers presented social validity, intervention fidelity, and observer reliability. Problem behaviors included self-injury and aggression behaviors, disturbing behaviors, and seat break-away behaviors, while the most dependent variables were measured through partial interval recording. As a result of confirming the intervention effect, the effect was confirmed in intervention, maintenance, and generalization. All analysis studies showed high-quality levels. Conclusion : This study confirmed the content and qualitative level of the thesis that applied the single-subject research design among positive behavior support intervention studies for problem behaviors of children with autism spectrum disorders. Positive behavior support intervention, an evidence-based intervention for children with autism spectrum disorders, was confirmed an effective intervention for autism spectrum disorders.

• Membrane Journal
• /
• v.32 no.4
• /
• pp.253-263
• /
• 2022

This study suggests a guideline for designing unit process of wastewater reuse in terms of a maintenance of the process based on critical parameters to draw a high quality performance of RO unit. Defining the parameters was done by applying membrane integrity test (MIT) in pretreatment process utilizing lab-scale MF. SDI is utilized for judging whether permeate is suitable to RO unit. However, result said TOC concentration matching with particle count analysis is better for judging the permeate condition. When membrane test pressure (P_test) was measured to derive log removal value in PDT, virgin state of membrane fiber was used to measure dynamic contact angle utilizing surface tension of the membrane fiber. Actually, foulant affects to the state of membrane surface, and it decreases the P_test value along with time elapsed. Consequently, LRV_DIT is also affected by P_test value. Thus, sensitivity of direct integrity test descends with result of P_test value change, so P_test value should be considered not the virgin state of the membrane but its current state. Overall, this study focuses on defining design parameters suitable to MF pretreatment for RO process in wastewater reuse by assessing its impact. Therefore, utilities can acknowledge that the membrane surface condition must be considered when users conduct the direct integrity test so that P_test and other relative parameter used to calculate LRV_DIT are adequately measured.