• Journal of Korea Society of Industrial Information Systems
• /
• v.13 no.3
• /
• pp.16-22
• /
• 2008

In recent years, embedded applications have emerged at a fast rate and used in every field of one can think of ranging from household products such as microwaves, to automotive products such as air bags sensing and control, to industrial robots. In this paper, a wireless ordering system is developed using Bluetooth communications. The features of this system is the order is performed by the customers rather than the waiters. It can save time to wait until the attenders to take order. Also, the unintended ordering mistakes through waiters can be prevented. The developed system is connected to the kitchen and the counter for automatic checkout.

• Journal of Korea Society of Industrial Information Systems
• /
• v.25 no.2
• /
• pp.1-9
• /
• 2020

A smart factory is a key industrial application introduced by the 4^th industrial revolution. The automatic guided vehicle (AGV) is one of the technology realizing smart factory, but the development cost is high due to its early stage of technology. Although developing a low-cost AGV requires a lot of data, it has limited data acquisition capability because of the limited storage and the AGV movement. Hence, we propose a development environment using Bluetooth to collect data and design a lane detector. The proposed lane detector shows a high lane detection ratio regardless of light variation and a shade.

• Journal of Environmental Science International
• /
• v.28 no.8
• /
• pp.669-676
• /
• 2019

The purpose of this study was to evaluate the effects of different Hydraulic Retention Times (HRTs) on the contaminant removal efficiency using Aerobic Granular Sludge (AGS). A laboratory-scale experiment was performed using a sequencing batch reactor, and the Chemical Oxygen Demand (COD), nitrogen, orthophosphate removal efficiency, AGS/MLSS ratio, and precipitability in accordance with the HRT were evaluated. As a result, the COD removal efficiency was not significantly different with the reduction in HRT, and at a HRT of 6 h, the removal rate was slightly increased owing to the increase in organic loading rate. The nitrogen removal efficiency was improved by injection of influent division at a HRT of 6 h. As the HRT decreased, the MLSS and AGS tended to increase, and the sludge volume index finally decreased to 50 mL/g. In addition, the size of the AGS gradually increased to about 1.0 mm. Therefore, the control of HRT provides favorable conditions for the stable formation of AGS, and is expected to improve the contaminant removal efficiency with the selection of a proper operation strategy.

• Journal of Environmental Science International
• /
• v.28 no.8
• /
• pp.677-687
• /
• 2019

This study evaluated the biosorption properties of calcium ion using Aerobic Granular Sludge (AGS). A sequencing batch reactor was used to induce the production of Extracellular Polymeric Substances (EPS) through salinity injection, and the calcium ion adsorption efficiency was analyzed by a batch test. The EPS contents showed significant changes (104-136 mg/g MLVSS) at different salinity concentrations. The calcium ion adsorption efficiency was highest for AGS collected at 5.0% salinity, and it was confirmed that the biosorption efficiency of AGS was increased owing to the increase in EPS content. The results of the Freundlich isotherms showed that the ion binding strength (1/n) was 0.3941-0.7242 and the adsorption capacity ($K_f$) was 2.4082-3.3312. The specific surface area and the pore size of the AGS were $586.1m^2/g$ and 0.7547 nm, respectively, which were not significantly different from each other. It was confirmed that the influence of biological properties, such as EPS content, was relatively large among the factors affecting calcium ion adsorption.

• Journal of Environmental Science International
• /
• v.28 no.9
• /
• pp.719-727
• /
• 2019

In this study, the effect on the stability of Aerobic Granular Sludge (AGS) with different Carbon/Nitrogen (C/N) ratios was investigated. The C/N ratios were controlled to 10.0, 7.5, 5.0, and 2.5 using the sequencing batch reactor, and the results showed that the removal efficiency of organic matter and total nitrogen decreased simultaneously with the decrease of C/N ratio. The removal efficiency of organic matter and total nitrogen at C/N ratio of 2.5 was 70.7% and 52.3% respectively. In addition, the AGS/mixed liquor suspended solids (MLSS) ratio showed a tendency to decrease from 85.7% to 73.7%, while the sludge volume index showed a tendency to increase from 82 mL/g to 102 mL/g as the C/N ratio decreased. At the same time, the apparent deviation of polysaccharide (PS) content in extracellular polymeric substances was observed, and polysaccharides/protein (PS/PN) ratio decreased from 0.62 to 0.31 as the C/N ratio decreased. Optical microscope observations showed that the reduction in C/N ratio caused the growth of filamentous bacteria and significantly affected the stability of AGS.

• Journal of Environmental Science International
• /
• v.28 no.7
• /
• pp.607-615
• /
• 2019

The purpose of this study is to biological treatment of high salinity wastewater using Aerobic Granular Sludge (AGS). In laboratory scale's experiments research was performed using a sequencing batch reactor, and evaluation of the denitrification reaction in accordance with the injection condition of salinity concentration, surface properties of microorganisms, and sludge precipitability was performed. The results showed that the salinity concentration increased up to 1.5%, and there was no significant difference in the nitrogen removal efficiency; however, it showed a tendency to decrease gradually from 2.0% onward. The specific denitrification rate (SDNR) was 0.052 - 0.134 mg $NO_3{^-}-N/mg$ MLVSS (mixed liquor volatile suspended solid)${\cdot}day$. The MLVSS/MLSS (mixed liquor suspended solid) ratio decreased to 76.2%, and sludge volume index ($SVI_{30}$) was finally lowered to 57 mL/g. Using an optical microscope, it was also observed that the initial size of the sludge was 0.2 mm, and finally it was formed to 0.8-1.0 mm. Therefore, salinity injection provides favorable conditions for the formation of an AGS, and it was possible to maintain stable granular sludge during long-term operation of the biological treatment system.

• Journal of Environmental Science International
• /
• v.28 no.7
• /
• pp.629-637
• /
• 2019

The purpose of this study was to evaluate the effect of high-salinity wastewater on the microbial activity of Aerobic Granule Sludge (AGS). Laboratory-scale experiments were performed using a sequencing batch reactor, and the Chemical Oxygen Demand (COD), nitrogen removal efficiency, sludge precipitability, and microbial activity were evaluated under various salinity injection. The COD removal efficiency was found to decrease gradually to 3.0% salinity injection, and it tended to recover slightly from 4.0%. The specific nitrification rate was 0.043 - 0.139 mg $NH_4{^+}-N/mg$ $MLVSS{\cdot}day$. The specific denitrification rate was 0.069 - 0.108 mg $NO_3{^-}-N/mg$ $MLVSS{\cdot}day$. The sludge volume index ($SVI_{30}$) ultimately decreased to 46 mL/g. The specific oxygen uptake rate decreased from an initial value 120.3 to a final value 70.7 mg $O_2/g$ $MLVSS{\cdot}hr$. Therefore, salinity injection affects the activity of AGS, causing degradation of the COD and nitrogen removal efficiency. It can be used as an indicator to objectively determine the effect of salinity on microbial activity.

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.12
• /
• pp.17-23
• /
• 2020

As the number of households with companion animals increases, the demand to monitor the health of companion animals in remote locations far away is increasing. We are going to put a wearable device on a companion animal so that it can monitor the heart beat signal from a remote location. However, the monitoring method using Bluetooth has some disadvantages. it can be accessed only in a short distances. In case of WiFi, large power consumption is the problem. To overcome these issues, we propose a system to reduce power consumption by indirectly receiving a user's request using Bluetooth at a time when the user does not need it, and sending sensor data through WiFi when the user makes a monitoring request.

• 한국벤처창업학회:학술대회논문집
• /
• 2020.11a
• /
• pp.33-37
• /
• 2020

최근 농업은 6차산업을 넘어 국민의 건강회복 및 유지증진을 도모하기 위하여 이용되는 다양한 농업·농촌자원의 활용과 이와 관련한 활동을 통해 사회적 또 는 경제적 부가가치를 창출하는 산업으로 치유농업을 들 수 있다. 현 코로나19로 인한 고립과 단절, 앞날을 예측하기 어려운 상황이 길어지면서 우울감을 느끼는 '코로나 블루(Blue)'를 넘어 우울과 불안 감정이 분노로 폭발하는 '코로나 레드(Red)'를 호소하는 이들마저 있다고 한다. 최근 한국건강증진개발원이 한국갤럽에 의뢰해 전국 만 성인 남녀대상으로 '코로나19로 인한 건강 상태'를 조사한 결과에 따르면 응답자의 40.7%가 코로나 블루를 "경험했다"고 답했는데 특히 여성(50.7%)의 경험 비율이 남성(34.2%)보다 높았다고 한다. 이에 따라 실내에서 반려동물이나 반려식물을 키우는 이가 급증하고 노년층은 실버 텃밭 정원프로그램을 통해 우울증이 크게 감소됐다. 이와 같이 치유농업은 자연친화적인 환경을 조성해 주고, 도시민의 농업에 대한 이해를 높이며 도시와 농촌이 상생하는데 이바지할 수 있기 때문에 지속적으로 발전시켜 나갈 필요가 있다. 본 연구에서는 치유농업시설의 이용의도를 가진 자를 대상으로 치유농업시설 선택속성에 주관적규범과 주도성향이 치유농업시설 이용의도에 미치는 영향을 살펴보고자 한다. 본 연구를 통해 치유농업시설을 이용하는 데에 있어 선택속성의 요소들에 대하여 파악하고 주관적규범과 주도성향에 따른 영향도 확인하여 치유농업시설 선택속성을 제공하고자 할 때 우선시해야 할 시사점을 파악하고자 한다.

• Journal of Environmental Science International
• /
• v.32 no.6
• /
• pp.465-475
• /
• 2023

In this study, we evaluated the treatment efficiency of livestock wastewater by altering the current density using boron-doped diamond (BDD) electrodes. As the current density was adjusted from 10 to 35 mA/cm2, the removal efficiency of organic matter increased from 22.2 to 71.5%. Similar to that of organic matter, the removal efficiency of color increased with increasing current density up to 85.7%, indicating a higher removal efficiency for color than that of organic matter. The removal efficiency of ammonia nitrogen increased from 14.6 to 53.3% as the current density increased, but it was lower than that of organic matter. In addition, the removal of organic matter, color, and ammonia nitrogen followed first-order reactions, according to the reaction rate analysis. The energy consumption ranged from 4.87 to 8.33 kWh/kg COD, and it was found that the organic matter removal efficiency was more efficient at high current densities. Based on various analyses, the optimal current density was 20 mA/cm2, and the corresponding energy consumption was 6.824 kWh/kg COD.