• Nuclear Engineering and Technology
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• v.56 no.2
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• pp.389-401
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• 2024

In recent decades, numerous instances of blockages have been reported in coastal nuclear power plants globally, leading to serious safety accidents such as power reduction, manual or automatic power loss, or shutdown of nuclear power units. Loss or shortage of cooling water may compromise the reliability of the cooling water system, thus threatening the operational safety of power plants and resulting in revenue reduction. This study provides a comprehensive review of the current state of cooling water system safety in coastal nuclear power plants worldwide and the common challenges they face, as well as the relevant research on cooling water system safety issues. The research overview and progress in investigation methods, outbreak mechanisms, prevention and control measures, and practical cases of blockages were summarized. Despite existing research, there are still many shortcomings regarding the pertinence, comprehensiveness and prospects of related research, and many problems urgently need to be solved. The most fundamental concern involves understanding the list of potential risks of blockages and their spatially distributed effects in surrounding waters. Furthermore, knowledge of the biological cycles and ecological habits of key organisms is essential for implementing risk prevention and control and for building a scientific and effective monitoring system.

• Journal of Information Science Theory and Practice
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• v.12 no.3
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• pp.49-62
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• 2024

Strategy monitoring is essential for business management and for administrators, including managers and executives, to build a data-driven organization. Having a tool that is able to visualize strategic data is significant for business intelligence. Unfortunately, there are gaps between business users and information technology departments or business intelligence experts that need to be filled to meet user requirements. For example, business users want to be self-reliant when using business intelligence systems, but they are too inexperienced to deal with the technical difficulties of the business intelligence systems. This research aims to create an automatic matching framework between the key performance indicators (KPI) formula and the data in database systems, based on ontology concepts, in the case study of Prince of Songkla University. The mapping data schema with ontology (MapDSOnto) framework is created through knowledge adaptation from the literature review and is evaluated using sample data from the case study. String similarity methods are compared to find the best fit for this framework. The research results reveal that the "fuzz.token_set_ratio" method is suitable for this study, with a 91.50 similarity score. The two main algorithms, database schema mapping and domain schema mapping, present the process of the MapDS-Onto framework using the "fuzz.token_set_ratio" method and database structure ontology to match the correct data of each factor in the KPI formula. The MapDS-Onto framework contributes to increasing self-reliance by reducing the amount of database knowledge that business users need to use semantic business intelligence.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.272-279
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• 2021

A pump-type eDNA filtering system that can control voltage and hydraulic pressure respectively has been developed, and applied a filter case that can filter out without damaging the filter. The filtering performance of the developed system was evaluated by comparing the eDNA concentration with the conventional vacuum-pressured filtering method at the catchment conduit intake reservoir. The developed system was divided into a voltage control (manual pump system) method and a pressure control (automatic pump system) method, and the pressure was measured during filtering and the pressure change of each system was compared. The voltage control method started with 65 [KPa] at the beginning of the filtering, and as the filtering time elapsed, the amount of filtrate accumulated in the filter increased, so the pressure gradually increased. As a result of controlling the pressure control method to maintain a constant pressure according to the designed algorithm, there was a difference in the width of the hydraulic pressure fluctuation during the filtering process according to the feedback time of the hydraulic pressure sensor, and it was confirmed that the pressure was converged to the target pressure. The filtering performance of the developed system was confirmed by measuring the eDNA concentration and comparing the voltage control method and the hydraulic control method with the control group. The voltage control method obtained similar results to the control group, but the hydraulic control method showed lower results than the control group. It is considered that the low eDNA concentration in the hydraulic control method is due to the large pressure deviation during filtering and maintaining a constant pressure during the filtering process. Therefore, rather than maintaining a constant pressure during filtering, it was confirmed that a voltage control method in which the pressure is gradually increased as the filtrate increases with the lapse of filtering time is suitable for collecting eDNA. As a result of comparing the average concentration of eDNA in lentic zone and lotic zone as a control group, it was found to be 96.2 [ng µL^-1] and 88.4 [ng µL^-1l], respectively. The result of comparing the average concentration of eDNA by the pump method was also high in the lentic zone sample as 90.7 [ng µL^-1] and 74.8 [ng µL^-1] in the lentic zone and the lotic zone, respectively. The high eDNA concentration in the lentic zone is thought to be due to the influence of microorganisms including the remaining eDNA.

• Korean Journal of Remote Sensing
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• v.23 no.4
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• pp.323-334
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• 2007

We analyzed the ocean environmental data from water sample and automatic measurement instruments with the Incheon-Jeju passenger ship for 18 times during 4 years from 2001 to 2004. The objectives of this study are to monitor the spatial and temporal variations of ocean environmental parameters in coastal waters of the Yellow Sea using water sample analysis, and to compare and analyze the reliability of automatic measurement sensors for chlorophyll and turbidity using in situ measurements. The chlorophyll concentration showed the ranges between 0.1 to $6.0mg/m^3$. High concentrations occurred in the Gyeonggi Bay through all the cruises. The maximum value of chlorophyll concentration was $16.5mg/m^3$ in this area during September 2004. The absorption coefficients of dissolve organic matter at 400 nm showed below $0.5m^{-1}$ except those in August 2001 During 2002-2003, it did not distinctly change the seasonal variations with the ranges 0.1 to $0.4m^{-1}$. In the case of suspended sediment (SS) concentration, most of the area showed below $20g/m^3$ through all seasons except the Gyeonggi Bay and around Mokpo area. In general SS concentration of autumn and winter season was higher than that of summer. The central area of the Yellow Sea appeared to have lower value $10g/m^3$. The YSI fluorometer for chlorophyll concentration had a very low reliability and turbidity sensor had a $R^2$ value of 0.77 through the 4 times measurements comparing with water sampling method. For the automatic measurement using instruments for chlorphlyll and suspended sediment concentration, McVan and Choses sensor was greater than YSI multisensor. The SeaWiFS SS distribution map was well spatially matched with in situ measurement, however, there was a little difference in quantitative concentration.

• Korean Journal of Agricultural and Forest Meteorology
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• v.26 no.3
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• pp.161-173
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• 2024

In South Korea, 50-65% of the annual precipitation is concentrated during the summer monsoon season, which is called Changma. In 2023, extreme precipitation was observed during Changma period, and was recorded the highest amount in southern part of Korea. Extreme precipitation in forest region is one of significant factors related to the landslide. Therefore, accurate monitoring and understanding of precipitation patterns are crucial for preventing the landslide disasters in Changma period. This study investigated the precipitation patterns including precipitation intensity, duration, and total amount in mountainous and non-mountainous regions during the Changma period using dataset observed from the Korea Forest Service's Automatic Mountain Meteorology Observation Station (AMOS) and the Korea Meteorological Administration (KMA). Precipitation map produced from the Modified Korean-Parameter elevation Regressions an Independent Slopes Model (MK-PRISM) was also used to verify precipitation patterns in areas affected by landslides in Gyeongsangbuk-do province. The results used from precipitation observations revealed that the total amount of precipitation was greater at elevations such as mountainous regions. In particular, extreme precipitation events such as precipitation duration exceeding 50 hours with amount of over 300 mm and heavy rainfalls of over 30 mm/hr occurred at landslide areas including Mungyeong, Bonghwa, and Yeongju in Gyeongsangbuk-do province. Total amount of precipitation produced by MK-PRISM in these areas during Changma period were more than double compared with 30 years mean values obtained from KMA. The results conducted in this study indicate that it is essential to establish the thresolds considering recent precipitation patterns to effectively prepare and prevent for landslide disasters.

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1615-1633
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• 2023

Sargassum horneri is one of the floating algae in the sea, which breeds in large quantities in the Yellow Sea and East China Sea and then flows into the coast of Republic of Korea, causing various problems such as destroying the environment and damaging fish farms. In order to effectively prevent damage and preserve the coastal environment, the development of Sargassum horneri detection algorithms using satellite-based remote sensing technology has been actively developed. However, incorrect detection information causes an increase in the moving distance of ships collecting Sargassum horneri and confusion in the response of related local governments or institutions,so it is very important to minimize false detections when producing Sargassum horneri spatial information. This study applied technology to automatically remove false detection results using the GOCI-II-based Sargassum horneri detection algorithm of the National Ocean Satellite Center (NOSC) of the Korea Hydrographic and Oceanography Agency (KHOA). Based on the results of analyzing the causes of major false detection results, it includes a process of removing linear and sporadic false detections and green algae that occurs in large quantities along the coast of China in spring and summer by considering them as false detections. The technology to automatically remove false detection was applied to the dates when Sargassum horneri occurred from February 24 to June 25, 2022. Visual assessment results were generated using mid-resolution satellite images, qualitative and quantitative evaluations were performed. Linear false detection results were completely removed, and most of the sporadic and green algae false detection results that affected the distribution were removed. Even after the automatic false detection removal process, it was possible to confirm the distribution area of Sargassum horneri compared to the visual assessment results, and the accuracy and precision calculated using the binary classification model averaged 97.73% and 95.4%, respectively. Recall value was very low at 29.03%, which is presumed to be due to the effect of Sargassum horneri movement due to the observation time discrepancy between GOCI-II and mid-resolution satellite images, differences in spatial resolution, location deviation by orthocorrection, and cloud masking. The results of this study's removal of false detections of Sargassum horneri can determine the spatial distribution status in near real-time, but there are limitations in accurately estimating biomass. Therefore, continuous research on upgrading the Sargassum horneri monitoring system must be conducted to use it as data for establishing future Sargassum horneri response plans.

• Journal of Soil and Groundwater Environment
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• v.13 no.1
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• pp.43-51
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• 2008

Periodic fluctuation of water levels were analyzed for their causes and effects on groundwater movement. Groundwater levels were monitored from two shallow monitoring wells, G1 and G4, located at a headwater catchment in the Gwangneung Ecohydrological Research Site using pressure transducers with automatic data-loggers by five-minute interval from February to October, 2006. The water table fluctuates on a daily basis with a clear diurnal variation, and the fluctuation amplitude increases with time from the winter to the summer. Results from spectral analysis of water-level data show periodic variations in 24.38 hour and in 12.19 hour, indicating $P_1$ diurnal and $L_2$ semidiurnal tidal components, respectively. The diurnal component of the water level in summer has greater power than that in winter, implying that the water table is affected not only by earth tides, but also by evapotranspiration. Right after rain stops, the power of diurnal component of the water level decreases, indicating that evapotranspiration influences significantly diurnal periodicity. The effects of diurnal and semidiurnal components of the water level range from 0.4 to 4.2 cm and from 0.2 to 0.7 cm, respectively.

• Journal of Veterinary Clinics
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• v.32 no.5
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• pp.399-403
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• 2015

Peritoneal dialysis (PD) is a treatment for renal failure and acute poisoning, and uses the patient's peritoneum in the abdomen as a membrane across which fluids and dissolved substances are exchanged from the blood. In this study, we evaluated the therapeutic efficacy and complications of automated peritoneal dialyzer (APD) in dogs with renal failure. PD was performed in 10 dogs using a swan neck catheter (Neonatal, Coviden) and automatic APD. The efficacy for each dog was assessed by calculating urea reduction ratio (URR) and creatinine reduction ratio (CRR). Mean concentrations of pre-dialysis creatinine and blood urea (BUN) were $7.09{\pm}3.84$ and $145.8{\pm}48.5$, respectively. The mean number of peritoneal dialysis cycles applied was $6{\pm}1$ cycles. Peritoneal dialysis resulted in a significant decrease in BUN concentration in 7/10 dogs, while a significant decrease in creatinine concentration in 9/10 dogs. The mean of URR was higher than that of CRR ($0.39{\pm}0.16$ vs $0.38{\pm}0.13$). The mean CRR and URR per dialysis cycles were $0.064{\pm}0.023$ and $0.065{\pm}0.023$, respectively. Complications found in this study were catheter occlusion, subcutaneous dialysate leakage, septic peritonitis, hypoalbuminemia and overhydration. This study found PD using a swan neck catheter and APD machine showed acceptable efficacy for successful peritoneal dialysis in dogs. However, close monitoring is required to minimize the risk of complication.

• Korean Journal of Cognitive Science
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• v.22 no.2
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• pp.145-172
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• 2011

Prospective memory (PM) is memory for activities to be performed in the future, such as remembering to purchase a piece of fruit on the way home or remembering to give someone a telephone message. Theoretically, PM retrieval can be accomplished either by controlled monitoring of intended action or by a more automatic process that spontaneously responds to the presence of intended event. The present study examined the effect of meta-cognitive awareness in PM retrieval process. In Experiment 1, we manipulated PM condition with a salient cue to stimulate participants' meta-cognitive awareness. Results showed the salient cue condition spontaneously triggered remembering to perform an intended action. In Experiment 2, we manipulated participants' meta-cognitive awareness about PM task difficulty and about the degree to which cognitive capacity is required to realize the PM task. Results showed that PM retrieval process varied with meta-cognitive awareness (i.e., more resources were allocated if the PM task was expected to be difficult). These results imply that participants' meta-cognitive awareness play an important role in PM retrieval process.

• Journal of Astronomy and Space Sciences
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• v.24 no.4
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• pp.367-378
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• 2007

We present a software which we developed for the multi-purpose CCD camera. This software can be used on the all 3 types of CCD - KAF-0401E ($768{\times}512$), KAF-1602E ($1536{\times}1024$), KAF-3200E ($2184{\times}1472$) made in KODAK Co.. For the efficient CCD camera control, the software is operated with two independent processes of the CCD control program and the temperature/shutter operation program. This software is designed to fully automatic operation as well as manually operation under LINUX system, and is controled by LINUX user signal procedure. We plan to use this software for all sky survey system and also night sky monitoring and sky observation. As our results, the read-out time of each CCD are about 15sec, 64sec, 134sec for KAF-0401E, KAF-1602E, KAF-3200E., because these time are limited by the data transmission speed of parallel port. For larger format CCD, the data transmission is required more high speed. we are considering this control software to one using USB port for high speed data transmission.