• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.25-34
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• 2015

In this research, we applied a procedure of quality control (QC) to the agro-meteorological data measured at the Suwon weather station of Korea Meteorological Administration (KMA). The QC was conducted through six steps based on the KMA Real-time Quality control system for Meteorological Observation Data (RQMOD) and four steps based on the International Soil Moisture Network (ISMN) QC modules. In addition, we set up our own empirical method to remove erroneous data which could not be filtered by the RQMOD and ISMN methods. After all these QC procedures, a well-refined agro-meteorological dataset was complied at both air and soil temperatures. Our research suggests that soil moisture requires more detailed and reliable grounds to remove doubtful data, especially in winter with its abnormal variations. The raw data and the data after QC are now available at the NCAM website (http://ncam.kr/page/req/agri_weather.php).

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.1
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• pp.13-34
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• 2022

Soil moisture data have been collected at 11 agrometeorological stations operated by The Korea Meteorological Administration (KMA). This study aimed to verify the accuracy of soil moisture data of KMA and develop a correction formula to be applied to improve their quality. The soil of the observation field was sampled to analyze its physical properties that affect soil water content. Soil texture was classified to be sandy loam and loamy sand at most sites. The bulk density of the soil samples was about 1.5 g/cm³ on average. The content of silt and clay was also closely related to bulk density and water holding capacity. The EnviroSCAN model, which was used as a reference sensor, was calibrated using the self-manufactured "reference soil moisture observation system". Comparison between the calibrated reference sensor and the field sensor of KMA was conducted at least three times at each of the 11 sites. Overall, the trend of fluctuations over time in the measured values of the two sensors appeared similar. Still, there were sites where the latter had relatively lower soil moisture values than the former. A linear correction formula was derived for each site and depth using the range and average of the observed data for the given period. This correction formula resulted in an improvement in agreement between sensor values at the Suwon site. In addition, the detailed approach was developed to estimate the correction value for the period in which a correction formula was not calculated. In summary, the correction of soil moisture data at a regular time interval, e.g., twice a year, would be recommended for all observation sites to improve the quality of soil moisture observation data.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.114-115
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• 2003

양식 생물에게 있어 용존산소는 호흡에 필수적이며, 양식 시설 내에서 적절한 용존 산소량을 유지하는 것은 생산량을 좌우하는 가장 중요한 요인이며, 어종, 수온, 광주기, 나이와 크기, 어류의 행동과 먹이 공급 및 환경 조건에 따라 달라진다. 이 중 같은 종 내에서 선발육종된 개체와 일반 양식 종 그리고 이들 계통간 잡종에 대한 대사 효율 즉, 용존산소 소비율의 차이에 관한 연구는 거의 없다. 따라서 본 실험에서는 한국해양연구원에서 선발육종 해 온 참돔과 일본 양식산 참돔 및 이들의 교배 자손들을 대상으로 수온과 광주기 변화에 따른 용존산소 소비율을 조사하였다. 실험어는 일본 양식산인 TPN 교배구 자손과 한국해양연구원 선발육종산인 KORDI F4 교배구 자손, JPN♀×KORDI F4♂ 그리고 KORDI F4♀×JPN♂ 교배구 자손을 대상으로 실시하였다. 체중이 각각 52.0±0.6 g(JPN 교배구; 그룹 1), 52.3±0.7 g(JPN♀×KORDI F4♂; 그룹 2), 51.7±0.4 g(KORDI F4♀ × KORDI F4♂; 그룹 3) 그리고 52.1±0.7 g(KORDI F4♀ × JPN♂; 그룹 4)인 참돔 치어를 각각 5마리씩 3반복 수용하여 실험에 이용하였다. 실험기간 동안 사육수의 pH는 8.1±0.1, 염분도는 34.0±0.5‰로 유지하였으며, 실험 장치는 김(1999)이 고안한 순환 시스템을 이용하였다. 수온은 각각 15℃, 20℃ 및 25℃로 변화시켰으며 각 수온 조건에서 광주기를 24L:0D, 12L:12D 그리고 0L:24D로 변화시켜 매 조건마다 용존 산소 소비량을 측정하였다. JPN 교배구인 그룹 1의 경우, 수온 15℃일 때 산소 소비량은 170.35∼266.29 mg O₂/kg fish/hr의 범위를 보였으며 수온 20℃와 25℃일 때 각각 236.76∼307.37 mg O₂/kg fish/hr와 346.96∼459.30 mg O₂/kg fish/hr 범위를 보여 수온 상승에 따라 산소 소비량 역시 증가하는 것으로 나타났다. 그룹 2의 경우, 수온 15℃일 때 산소 소비량은 162.01∼279.51 mg O₂/kg fish/hr의 범위를 보였으며 수온 20℃와 25℃일 때 각각 303.48∼342.72 mg O₂/kg fish/hr와 447.18∼528.45 mg O₂/kg fish/hr 범위를 보여 그룹 1과 마찬가지로 수온 상승에 따라 산소 소비량 역시 증가하는 것으로 나타났다. 그룹 3의 경우, 수온 15℃일 때 산소 소비량은 170.11∼220.98 mg O₂/kg fish/hr의 범위를 보였으며 수온 20℃와 25℃일 때 각각 262.62∼282.27 mg O₂/kg fish/hr와 302.24∼415.73 mg O₂/kg fish/hr 범위를 보여 그룹 1, 2와 유사한 경향을 보였다. 그룹 4의 경우, 수온 15℃일 때 산소 소비량은 156.03∼214.49 mg O₂/kg fish/hr의 범위를 보였으며 수온 20℃와 25℃일 때 각각 238.40∼274.28 mg O₂/kg fish/hr와 379.93∼430.97 mg O₂/kg fish/hr 범위를 보여 수온 상승에 따라 산소 소비량 역시 증가하는 것으로 나타나, 그룹 1, 2와 유사한 경향을 보였다. 모든 실험구에서 수온 상승과 함께 산소 소비량이 증가하는 것으로 나타났으며 가장 높은 산소 소비량은 그룹 2에서 관찰되었다. 실험 결과 JPN 계통의 암컷을 사용하여 생산된 그룹 1과 2의 산소 소비량이 KORDI F4 계통의 암컷을 사용한 그룹 3, 4보다 대체적으로 높은 것으로 나타났다. 연속적인 명기 조건인 24L:0D에서 수온 15℃의 경우 그룹 1, 2, 3 그리고 4의 시간당 산소 소비량은 각각 266.29 mg O₂/kg fish/hr,279.51 mg O₂/kg fish/hr, 220.98 mg O₂/kg fish/hr 그리고 214.49 mg O₂/kg fish/hr으로 나타났고, 명기와 암기가 동일한 조건인 12L:12D에서는 각각 192.20 mg O₂/kg fish/hr, 258.03 mg O₂/kg fish/hr, 192.76 mg O₂/kg fish/hr 그리고 170.40 mg O₂/kg fish/hr로 나타났다. 또한 연속적인 암기 조건인 OL:24D 조건에서는 각각 170.35 mg O₂/kg fish/hr, 162.01 mg O₂/kg fish/hr, 170.11 mg O₂/kg fish/hr 그리고 156.03 mg O₂,/kg fish/hr로 나타났다. 그리고 수온 20℃와 25℃에서도 그룹간의 변화는 이와 비슷한 경향을 보였다. 연속 명기 조건인 24L:0D에서의 산소 소비량이 명기와 암기가 동일한 조건인 12L:12D와 연속 암기 조건인 0L:24D에서의 산소 소비량 보다 대체적으로 높은 것으로 나타났으며, 그룹 2의 연속 명기 조건에서 528.45 mg O₂/kg fish/hr으로 가장 높게 나타났다. 그룹 4에서는 대사량이 점점 더 높아지는 수온 상승과 함께 연속 명기 조건과 더불어 12L:12D 조건에서의 산소 소비량이 크게 증가하는 것으로 나타났다.

• Journal of KIISE:Information Networking
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• v.29 no.3
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• pp.286-298
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• 2002

The Remote Procedure Call(RPC) has been traditionally used for Inter Process Communication(IPC) among precesses in distributed computing environment. As distributed applications have been complicated more and more, the Mobile Agent paradigm for IPC is emerged. Because there are some paradigms for IPC, researches to evaluate and compare the performance of each paradigm are issued recently. But the performance models used in the previous research did not reflect real distributed computing environment correctly, because they did not consider the evacuation elements for providing security services. Since real distributed environment is open, it is very vulnerable to a variety of attacks. In order to execute applications securely in distributed computing environment, security services which protect applications and information against the attacks must be considered. In this paper, we evaluate and compare the performance of the Remote Procedure Call with that of the Mobile Agent in IPC paradigms. We examine security services to execute applications securely, and propose new performance models considering those services. We design performance models, which describe information retrieval system through N database services, using Petri Net. We compare the performance of two paradigms by assigning numerical values to parameters and measuring the execution time of two paradigms. In this paper, the comparison of two performance models with security services for secure communication shows the results that the execution time of the Remote Procedure Call performance model is sharply increased because of many communications with the high cryptography mechanism between hosts, and that the execution time of the Mobile Agent model is gradually increased because the Mobile Agent paradigm can reduce the quantity of the communications between hosts.

• 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.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.531-546
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• 2018

Air quality forecasting system with Asian dust emissions was developed in East Asia, and $PM_{10}$ forecasting performance of chemical transport model with Asian dust emissions was validated and evaluated. The chemical transport model (CTM) with Asian dust emission was found to supplement $PM_{10}$ concentrations that had been under-estimated in China regions and improved statistics for performance of CTM, although the model were overestimated during some periods in China. In Korea, the prediction model adequately simulated inflow of Asian dust events on February 22~24 and March 16~17, but the model is found to be overestimated during no Asian dust event periods on April. However, the model supplemented $PM_{10}$ concentrations, which was underestimated in most regions in Korea and the statistics for performance of the models were improved. The $PM_{10}$ forecasting performance of air quality forecasting model with Asian dust emissions tends to improve POD (Probability of Detection) compared to basic model without Asian dust emissions, but A (Accuracy) has shown similar or decreased, and FAR (False Alarms) have increased during 2017.Therefore, the developed air quality forecasting model with Asian dust emission was not proposed as a representative $PM_{10}$ forecast model in South Korea.

• Journal of Nutrition and Health
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• v.51 no.4
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• pp.275-286
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• 2018

Purpose: Our previous study demonstrated that persimmon (Diospyros kaki Thumb.) at different stages of ripening provided different protective effects against high-fat/cholesterol diet (HFD)-induced dyslipidemia in rats. In this study, we compared the metabolites profile and gene expressions related to triglyceride (TG)/cholesterol metabolism in vitro and in vivo after treating with persimmon water extracts (PWE) or tannin-enriched persimmon concentrate (TEP). Methods: Primary and secondary metabolites in test materials were determined by GC-TOF/MS, UHPLC-LTQ-ESI-IT-MS/MS, and UPLC-Q-TOF-MS. The expression of genes related to TG and cholesterol metabolism were determined by RT-PCR both in HepG2 cells stimulated by oleic acid/palmitic acid and in liver tissues obtained from Wistar rats fed with HFD and PWE at 0, 150, 300, and 600 mg/d (experiment I) or TEP at 0, 7, 14, and 28 mg/d (experiment II) by oral gavage for 9 weeks. Results: PLS-DA analysis and heatmap analysis demonstrated significantly differential profiling of metabolites of PWE and TEP according to processing of persimmon powder. In vitro, TEP showed similar hypolipidemic effects as PWE, but significantly enhanced hypocholesterolemic effects compared to PWE in sterol regulatory element-binding protein 2 (SREBP2), HMG-CoA reductase (HMGCR), proprotein convertase subtilisin/kexin type 9 (PCSK9), cholesterol $7{\alpha}-hydroxylase$ (CYP7A1), and low density lipoprotein receptor (LDLR) gene expression. Consistently, TEP and PWE showed similar hypolipidemic capacity in vivo, but significantly enhanced hypocholesterolemic capacity in terms of SREBP2, HMGCR, and bile salt export pump (BSEP) gene expression. Conclusion: These results suggest that column extraction after hot water extraction may be a good strategy to enhance tannins and long-chain fatty acid amides, which might cause stimulation of hypocholesterolemic actions through downregulation of cholesterol biosynthesis gene expression and upregulation of LDL receptor gene expression.

• Journal of Environmental Impact Assessment
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• v.26 no.2
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• pp.93-104
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• 2017

CCS (Carbon Capture and Storage) is a technical process to capture $CO_2$ from industrial and energy-based sources, to transfer and sequestrate impressed $CO_2$ in geological formations, oceans, or mineral carbonates. However, potential $CO_2$ leakage exists and causes environmental problems. Thus, this study was conducted to analyze the spatial and temporal variations of $CO_2$ fluxes and concentrations after artificial $CO_2$ release. The Environmental Impact Evaluation Test Facility (EIT) was built in Eumseong, Korea in 2015. Approximately 34kg $CO_2$ /day/zone were injected at Zones 2, 3, and 4 among the total of 5 zones from October 26 to 30, 2015. $CO_2$ fluxes were measured every 30 minutes at the surface at 0m, 1.5m, 2.5m, and 10m from the $CO_2$ releasing well using LI-8100A until November 13, 2015, and $CO_2$ concentrations were measured once a day at 15cm, 30cm, and 60cm depths at every 0m, 1.5m, 2.5m, 5m, and 10m from the well using GA5000 until November 28, 2015. $CO_2$ flux at 0m from the well started increasing on the fifth day after $CO_2$ release started, and continued to increase until November 13 even though the artificial $CO_2$ release stopped. $CO_2$ fluxes measured at 2.5m, 5.0m, and 10m from the well were not significantly different with each other. On the other hand, soil $CO_2$ concentration was shown as 38.4% at 60cm depth at 0m from the well in Zone 3 on the next day after $CO_2$ release started. Soil $CO_2$ was horizontally spreaded overtime, and detected up to 5m away from the well in all zones until $CO_2$ release stopped. Also, soil $CO_2$ concentrations at 30cm and 60cm depths at 0m from the well were measured similarly as $50.6{\pm}25.4%$ and $55.3{\pm}25.6%$, respectively, followed by 30cm depth ($31.3{\pm}17.2%$) which was significantly lower than those measured at the other depths on the final day of $CO_2$ release period. Soil $CO_2$ concentrations at all depths in all zones were gradually decreased for about 1 month after $CO_2$ release stopped, but still higher than those of the first day after $CO_2$ release stared. In conclusion, the closer the distance from the well and the deeper the depth, the higher $CO_2$ fluxes and concentrations occurred. Also, long-term monitoring should be required because the leaked $CO_2$ gas can remains in the soil for a long time even if the leakage stopped.

• Journal of Intelligence and Information Systems
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• v.24 no.1
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• pp.183-203
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• 2018

News articles are the most suitable medium for examining the events occurring at home and abroad. Especially, as the development of information and communication technology has brought various kinds of online news media, the news about the events occurring in society has increased greatly. So automatically summarizing key events from massive amounts of news data will help users to look at many of the events at a glance. In addition, if we build and provide an event network based on the relevance of events, it will be able to greatly help the reader in understanding the current events. In this study, we propose a method for extracting event networks from large news text data. To this end, we first collected Korean political and social articles from March 2016 to March 2017, and integrated the synonyms by leaving only meaningful words through preprocessing using NPMI and Word2Vec. Latent Dirichlet allocation (LDA) topic modeling was used to calculate the subject distribution by date and to find the peak of the subject distribution and to detect the event. A total of 32 topics were extracted from the topic modeling, and the point of occurrence of the event was deduced by looking at the point at which each subject distribution surged. As a result, a total of 85 events were detected, but the final 16 events were filtered and presented using the Gaussian smoothing technique. We also calculated the relevance score between events detected to construct the event network. Using the cosine coefficient between the co-occurred events, we calculated the relevance between the events and connected the events to construct the event network. Finally, we set up the event network by setting each event to each vertex and the relevance score between events to the vertices connecting the vertices. The event network constructed in our methods helped us to sort out major events in the political and social fields in Korea that occurred in the last one year in chronological order and at the same time identify which events are related to certain events. Our approach differs from existing event detection methods in that LDA topic modeling makes it possible to easily analyze large amounts of data and to identify the relevance of events that were difficult to detect in existing event detection. We applied various text mining techniques and Word2vec technique in the text preprocessing to improve the accuracy of the extraction of proper nouns and synthetic nouns, which have been difficult in analyzing existing Korean texts, can be found. In this study, the detection and network configuration techniques of the event have the following advantages in practical application. First, LDA topic modeling, which is unsupervised learning, can easily analyze subject and topic words and distribution from huge amount of data. Also, by using the date information of the collected news articles, it is possible to express the distribution by topic in a time series. Second, we can find out the connection of events in the form of present and summarized form by calculating relevance score and constructing event network by using simultaneous occurrence of topics that are difficult to grasp in existing event detection. It can be seen from the fact that the inter-event relevance-based event network proposed in this study was actually constructed in order of occurrence time. It is also possible to identify what happened as a starting point for a series of events through the event network. The limitation of this study is that the characteristics of LDA topic modeling have different results according to the initial parameters and the number of subjects, and the subject and event name of the analysis result should be given by the subjective judgment of the researcher. Also, since each topic is assumed to be exclusive and independent, it does not take into account the relevance between themes. Subsequent studies need to calculate the relevance between events that are not covered in this study or those that belong to the same subject.

• Journal of Biomedical Engineering Research
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• v.19 no.1
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• pp.59-68
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• 1998

Digital hearing aids offer many advantages over conventional analog hearing aids. With the advent of high speed digital signal processing chips, new digital techniques have been introduced to digital hearing aids. In addition, the evaluation of new ideas in hearing aids is necessarily accompanied by intensive subject-based clinical tests which requires much time and cost. In this paper, we present an objective method to evaluate and predict the performance of hearing aid systems without the help of such subject-based tests. In the hearing impairment simulation(HIS) algorithm, a sensorineural hearing impairment medel is established from auditory test data of the impaired subject being simulated. Also, the nonlinear behavior of the loudness recruitment is defined using hearing loss functions generated from the measurements. To transform the natural input sound into the impaired one, a frequency sampling filter is designed. The filter is continuously refreshed with the level-dependent frequency response function provided by the impairment model. To assess the performance, the HIS algorithm was implemented in real-time using a floating-point DSP. Signals processed with the real-time system were presented to normal subjects and their auditory data modified by the system was measured. The sensorineural hearing impairment was simulated and tested. The threshold of hearing and the speech discrimination tests exhibited the efficiency of the system in its use for the hearing impairment simulation. Using the HIS system we evaluated three typical hearing aid algorithms.