• Journal of Korea Water Resources Association
• /
• v.55 no.2
• /
• pp.111-120
• /
• 2022

The concept of soil moisture memory was used as a method for quantifying the function of soil to control water flow, which evaluates the average residence time of precipitation. In order to characterize the soil moisture memory, a new measurement index called stored precipitation fraction (F_p(f)) was used by tracking the increments in soil moisture by the precipitation event. In this study, the temporal and spatial distribution of soil moisture memory was evaluated along with the slope and soil characteristics of the surface (0~5 cm) soil by using satellite- and model-based precipitation and soil moisture in the Korean peninsula, from 2019 to 2020. The spatial deviation of the soil moisture memory was large as the stored precipitation fraction in the soil decreased preferentially along the mountain range at the beginning (after 3 hours), and the deviation decreased overall after 24 hours. The stored precipitation fraction in the soil clearly decreased as the slope increased, and the effect of drainage of water in the soil according to the composition ratio of the soil particle size was also shown. In addition, average soil moisture contributed to the increase and decrease of hydraulic conductivity, and the rate of rainfall transfer to the depths affected the stored precipitation fraction. It is expected that the results of this study will greatly contribute in clarifying the relationship between soil moisture memory and surface characteristics (slope, soil characteristics) and understanding spatio-temporal variation of soil moisture.

• Journal of the Korean Institute of Gas
• /
• v.26 no.6
• /
• pp.24-29
• /
• 2022

This paper is a purpose to Analyze and study the failure examples for a engine oil leakage of camshaft bearing seal, poor contact by computer connector fin damage and vaporizer inferiority on LPG automotive. The first example, when the researcher disassembled the cylinder head of engine to establish the cause for oil leakage, he confirmed the engine oil leakage by damaged between the engine intake camshaft bearing and seal part. The second example, the connector fin of power source line that control the starting of a car supplied with engine computer. As a result, it found the fact that the engine operation stopped because of cutting of the power source by connector fin damage. The third example, it verified the engine incongruity phe cutting of the power source by connector fin damage. The third example, it verified the engine incongruity phenomenon as thd gas didn't flow the vaporizer by foreign substance deposit. Finally, it supplied a small quantity gas from vaporizer to mix. As the computer controlling mix opening condition supplied a air as opening signal, the air and fuel became rarefied state. it knew that the engine didn't produce prpper power. Therefore, a car have to throughtly inspect not in order to arise the failure symptoms.

• Korean Journal of Environmental Agriculture
• /
• v.40 no.4
• /
• pp.313-321
• /
• 2021

BACKGROUND: Ammonia is a causative substance for the fine particulate matters (PM_2.5) and generates dust through atmospheric reactions. Agricultural sector accounts for 79.3% of ammonia emissions in Korea. Urea and composted organic fertilizer (COF) are used in the soil for the purpose of supplying nutrients in grapevine orchards. This study was conducted to investigate estimates of ammonia emission and examine fruit quality from the rain proof cultivation of the 'Beni Balad', applied by urea and COF to the soil. METHODS AND RESULTS: Urea, COF1, and COF2 were applied at the rates of 119, 135, and 271 kg ha^-1 respectively. Ammonia emissionwas measured using a dynamic flow-through method. CONCLUSION(S): Ammonia emissions by urea and COF treatments to 'Beni Balad' soils under rain proof cultivation were calculated to be 2.63, 12.95, 2.05, and 3.97 kg NH₃-N ha^-1 day^-1, respectively for the control, urea, COF1, and COF2. Urea soil application increased soluble solids, firmness, and anthocyanin content in fruits at harvest, and COF1 application increased the soluble solids and anthocyanin content. For all the treatments, acidity increased in the harvested fruits.

• Particle and aerosol research
• /
• v.18 no.3
• /
• pp.51-59
• /
• 2022

In this work, virion concentration and its dose changes by HVAC and air cleaners were estimated in a subway station platform to control airborne infection of SARS-CoV-2. Collection efficiencies with particle size were measured for the air filter equipped in a HVAC in one subway station in Daejeon. Indoor PM_2.5 changes according to outdoor PM_2.5 with time were also measured to estimate air infiltration rate in the subway station platform. When infected persons generate virions by 10⁴, 10⁵, 10⁶, 3 × 10⁶ and 5 × 10⁶ h^-1 in a 2,400 m³ volume platform, the concentration and dose were estimated as 9, 92, 275 and 458 virions/m³ and 4, 43, 130 and 217 virions after 1 hour exposure, respectively. The concentration and dose were reduced by 70%, and 64%, respectively by operations of both HVAC (with a flow rate of 16,000 m³/h, MERV 11) and ten air cleaners(with total CADR 10,740 m³/h) compared to those without operation of both HVAC and air cleaners. However, virion dose in the platform was estimated to be too low at the general conditions due to a large space, a high air infiltration (3 h^-1) and a short residence time (usually < 10 mins) in the platform irrespective of the operations of HVAC or air cleaners. HVAC with filters and air cleaners would be more necessary in the concourse or shopping areas in the subway stations to reduce the infection dose from a few hundred to several tens virions in a hour.

• Therapeutic Science for Rehabilitation
• /
• v.11 no.3
• /
• pp.7-22
• /
• 2022

Objectives : This study was a systematic review of tongue movements in stroke patients with dysphagia. This study aimed to provide a basis for verifying the effects of tongue movement and identifying the tendency of tongue movement. Methods : A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist and flow chart. PubMed, MEDLINE, CINAHL, RISS, and e-articles databases were searched. A total of six documents were investigated, and the PEDro scale was used to evaluate the quality of the papers. Results : Three intervention methods were included in the six papers analyzed. Regarding the type of tongue exercise, three TPRT (Tongue to Palate Resistance Trainings) and two TSAT (Tongue Strength and Accuracy Training) were mediated through the IOPI (Iowa Oral Performance Instrument), and only one study applied TSE (Tongue Stretching Exercise). The treatment effects for each intervention implemented in the literature were confirmed to be effective. However, generalizability of findings is difficult because of the small sample size. Further, no significant difference was found between the experimental and control groups. Conclusions : This study can help occupational therapists provide efficient swallowing rehabilitation treatment by applying tongue exercises to stroke patients with dysphagia. More research should be conducted to determine the effects of tongue exercise.

• Journal of Life Science
• /
• v.33 no.5
• /
• pp.397-405
• /
• 2023

Although glutathione (GSH) has been shown to play an important role in the prevention of oxidative damage as an antioxidant, studies on immune regulation by it have not been properly conducted. In this study, we investigated whether luthione^®, a reduced GSH, has an immune enhancing effect in murine macrophage RAW 264.7 cells. The results of flow cytometry and immunofluorescence experiments indicated that luthione increased phagocytic activity, a representative function of macrophages, compared to the control cells. According to the results of the cytokine array, the expression of interleukin (IL)-5, IL-1β, and IL-27 was significantly increased in the luthione-treated cells. Luthione also enhanced the production of tumor necrosis factor-α and IL-1β through increased expression of their proteins, and increased release of the immune mediators such as nitric oxide (NO) and prostaglandin E₂ was associated with increased expression of inducible NO synthase and cyclooxygenase-2. In addition, the expression of cluster of differentiation 86, an M1 macrophage marker, was dramatically enhanced in RAW 264.7 cells treated with luthione. Furthermore, as a result of heat map analysis, we found that cytokine signaling 1/3-mediated signal transducer and activator of transcription/Janus tyrosine kinase signaling pathway was involved in the immunomodulatory effect by luthione. In conclusion, our data suggested that luthione could act as a molecular regulator in M1 macrophage polarization and enhance immune capacity by promoting macrophage phagocytic function.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2023.05a
• /
• pp.371-371
• /
• 2023

담양 및 화순 홍수조절지는 홍수 시 본류에 계획방류량만 흘러가도록 제수문을 운영하고, 계획방류량을 초과하는 홍수량은 하도 및 조절지 내에 저류하여 홍수를 지체시킨 후 저류된 홍수량은 첨두홍수가 지나간 이후 방류하는 방법으로 영산강 유역의 홍수를 방어하기 위해 '12년 건설되었다. 그러나 홍수조절지는 200년 빈도의 홍수량을 저감 시키도록 설계됨에 따라 준공 이후 10년간 '20년 8월 홍수 등 3회만 홍수방어용으로 활용되었다. 영산강은 오염부하량 대비 유출량 부족 등으로 수질관리에 취약하고 하천유지용수를 공급하는 다목적댐이 없는 등 수자원 확보가 어려우므로, 비홍수기 홍수조절지에 환경대응용수를 담수 및 방류하여 영산강의 유량확보 및 수질개선 등 활용 다변화 방안을 모색하고자 한다. 이와 관련하여 '16년 및 '19년에 시범담수를 실시하였으나, 담수 수질 관리의 어려움, 방류 전후 강우 등 제한적 여건으로 인해 하류 유량증가 및 수질 개선 효과의 확인은 어려웠으며, 제방 물비침 등을 발견하여 시설 안정성 확보가 필요한 것으로 확인되었다. '21년 안정성 확보를 위한 보강 그라우팅을 시행했으며, '19년부터 '21년 2월까지 「홍수조절지를 활용한 영산강 수질개선 방안」연구용역을 실시하여, 비홍수기 활용방안을 수립하였다. '21년 4/4분기 댐과 보 등의 연계운영협의회에 '시범담수 계획' 안건 상정 및 의결을 거쳤고, '22년 3월 25~26일까지 담양 74mm, 화순 61mm 비가 내려 담양 63만m³, 화순 151만m³를 담수하고 18~19일간 저류 후 담양은 평균 3.0m³/초로 25시간 동안, 화순은 평균 5.0m³/초로 32시간 동안 하류로 방류하였다. 방류 후 담양·화순 모두 가까운 하류 수위국 수위 상승을 확인했으며, 화순의 경우 하류 수질에 일부 영향이 있음을 확인하였다. 다만, 초기유출수 배제 등을 고려하지 않아 담수의 수질이 본류보다 좋지 않았으며, 이에 따라 수질 영향의 인과관계 확인이 어려웠다. 기존 연구용역에서 제시한 비홍수기 활용방안의 검증·보완을 위한 연구용역이 '22.5월부터 '23.12월까지 진행될 예정이며, 초기유출수 배제를 위한 조건 재수립, 수질 모니터링지점 확대 등 보완된 '시범담수 계획'을 '23.3월 댐과 보 등의 연계운영협의회에 보고하였다. 연말까지 연구용역과 연계한 시범담수·방류 시행 및 모니터링·효과분석을 통해 비홍수기 홍수조절지 최적운영방안을 마련할 계획이다.

• Journal of the Korea Society for Simulation
• /
• v.19 no.2
• /
• pp.73-80
• /
• 2010

A wireless sensor network which is deployed in hostile environment can be easily compromised by attackers. The selective forwarding attack can jam the packet or drop a sensitive packet such as the movement of the enemy on data flow path through the compromised node. Xiao, Yu and Gao proposed the checkpoint-based multi-hop acknowledgement scheme(CHEMAS). In CHEMAS, each path node enable to be the checkpoint node according to the pre-defined probability and then can detect the area where the selective forwarding attacks is generated through the checkpoint nodes. In this scheme, the number of hops is very important because this parameter may trade off between energy conservation and detection capacity. In this paper, we used the fuzzy rule system to determine adaptive threshold value which is the number of hops for the ACK packets. In every period, the base station determines threshold value while using fuzzy logic. The energy level, the number of compromised node, and the distance to each node from base station are used to determine threshold value in fuzzy logic.

• Journal of Korea Entertainment Industry Association
• /
• v.13 no.2
• /
• pp.253-259
• /
• 2019

Prostate cancer(PrCa) is a leading cause of cancer-related death in man. Medicinal plants are exploited for many drugs to treat various ailments. The drugs derived from the plants promote health, augmented the resistance of the body against disease. Pueraia lobata(wild) Ohwi(P. Lobata), kudzu, which is a twining perennial woody herb native to China, Korea, Japan, India, and the United States. Plants such as Moringa oleifera, have hypoglycemic properties and other beneficial properties. The objective of the study was to analyze the effects of kadzu and moringa, natural plant products on antioxidant activity and proliferation of the hormone-sensitive prostate cancer LNCaP cells. MTT assay, flow cytometry analysis were employed to investigate the anticancer mechanism and DPPH assay was determined to the antioxidant activity to scavenge free radicals in extract of these. All two extracts showed significantly antioxidant activity at 10 and 50mg/ml of concentration. kadzu and moringa reduced LNCaP cell viability in a dose dependent manner. Specially moringa extract was more potent cytotoxic than kadzu extract. Statistical analyses revealed kadzu and moringa exhibited significantly higher (P < 0.05) cytotoxicity and antioxidant activity in LNCaP. The finding of this study provides a scientific basis for using kadzu and moringa in future development of chemotherapeutic drugs against hormone-sensitive prostate cancer.

• Journal of Korea Water Resources Association
• /
• v.55 no.spc1
• /
• pp.1283-1293
• /
• 2022

The purpose of this study is to predict residual chlorine in order to maintain stable residual chlorine concentration in sedimentation basin by using artificial intelligence algorithms in water treatment process employing pre-chlorination. Available water quantity and quality data are collected and analyzed statistically to apply into mathematical multiple regression and artificial intelligence models including multi-layer perceptron neural network, random forest, long short term memory (LSTM) algorithms. Water temperature, turbidity, pH, conductivity, flow rate, alkalinity and pre-chlorination dosage data are used as the input parameters to develop prediction models. As results, it is presented that the random forest algorithm shows the most moderate prediction result among four cases, which are long short term memory, multi-layer perceptron, multiple regression including random forest. Especially, it is result that the multiple regression model can not represent the residual chlorine with the input parameters which varies independently with seasonal change, numerical scale and dimension difference between quantity and quality. For this reason, random forest model is more appropriate for predict water qualities than other algorithms, which is classified into decision tree type algorithm. Also, it is expected that real time prediction by artificial intelligence models can play role of the stable operation of residual chlorine in water treatment plant including pre-chlorination process.