• Title/Summary/Keyword: time trends

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Recent Trends of Advanced Biosensors for Mycotoxin Analysis

  • Shim, Won-Bo
    • 한국균학회소식:학술대회논문집
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    • 2016.05a
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    • pp.35-35
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    • 2016
  • A mycotoxin is a toxic secondary metabolite produced by organisms of the fungus kingdom, commonly known as molds and has been widely contaminated in agricultural products such as grains and cereals. Many methods including high performance liquid chromatography (HPLC) and gas chromatography (GC) have already been proposed and reviewed for mycotoxins. These methods are either expensive or time-consuming due to the complication of sample preparation and pre-concentration before determination. In addition, both methods are unsuitable for the routine screening of large sample numbers. A biosensor is a fictive analytical device that combines a biological component with a physicochemical detector for the detection of an analyte. Biosensors represent a rapidly expanding field, at the present time, with an estimated 60% annual growth rate; the major impetus coming from the health-care industry but with some pressure from other areas, such as food safety and environmental monitoring. Antibodies and aptamers are bioreceptors which have been used in the development of biosensors. There are many kinds of antibodies and aptamers specific to mycotoxin, and antibody (or aptamer)-based biosensors have been successfully developed for the detection of mycotoxin. The biosensors permit the rapid, sensitive, simple, and on-site detection of a range of mycotoxins and can be an alternative method to traditional methods such as HPLC and GC. This presentation provides the development trends of biosensors to mycotoxins and their application to food and agricultural products.

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A Survey of the Harmonics Level on a Typical Household Loads by Field Measurements (현장 측정에 의한 일반 가정집 부하의 고조파 수준 조사)

  • Kim, Kyung-Chul;Oh, Kyung-Hoon;Choi, Hyoung-Bumb;Hong, Sa-Guen
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.5
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    • pp.95-102
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    • 2008
  • Typical household loads have nonlinear loads including a personal computer, video, refrigerator, microwave oven, TV, and audio set. These nonlinear loads generate harmonic currents and create distortions on the sinusoidal voltage of the power system. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. A cumulative probablistic approach is the most commonly used method to solve time varying harmonics. This paper provides in depth analysis on harmonics field measurement of the typical household loads for one year period and the survey is conducted with the objectives to identify the trends of harmonic distortion level present and indentify the future trends of metering in the presence of nonsinusoidal current and voltage waveforms in the system.

esearch Trend Analysis Focused on Thesis Key Words: in the Fields of Korean Language and Literature, Korean Language Education, and Korean Language Education as a Foreign Language (학위논문 주제어 중심 연구동향 분석 -국어국문학, 국어교육학, 한국어교육학 분야를 중심으로-)

  • Kim, Eunsil;Kang, Seunghae
    • Journal of Korean language education
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    • v.29 no.2
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    • pp.25-48
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    • 2018
  • The aim of this study was to analyze research trends in the fields of Korean Language and Literature, Korean Language Education, and Korean Language Education as a Foreign Language. To this end, key words were extracted from 29,470 academic theses published between 2000 and 2017. The results of the analysis are as follows. First, in the field of Korean Language and Literature, there is greater quantity in studies about Korean language than about literature, and starting from 2010, there was an increase in studies similar to those from the field of Korean Language Education as a Foreign Language. Next, in comparison to the other fields, the field of Korean Language Education has greater variance in its research theme-in particular, numerous studies related to the site of education. Finally, the field of Korean Language Education has the following trends: a) there are copious studies focused on Korean language learners in comparison to other fields, b) there are a greater number of studies focused on culture, and c) the key words change by time period which suggest that research demands transformed over time. Overall, a total of 64 highest frequency key words from the three academic fields were investigated. Of these, 22 were common key words and 42 were differential key words. In this way, it was possible to illuminate the identity of each field.

Trend analysis of aridity index for southeast of Korea

  • Ghafouri-Azar, Mona;Bae, Deg-Hyo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2017.05a
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    • pp.193-193
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    • 2017
  • Trend analysis can enhance our knowledge of the dominant processes in the area and contribute to the analysis of future climate projections. The results of previous studies in South Korea showed that southeast regions of Korea had the highest value of evapotranspiration. Thereby, it is of interest to determine the trend analysis in hydrological variables in this area. In this study, the recent 35 year trends of precipitation, reference evapotranspiration, and aridity index in monthly and annual time scale will be analyzed over three stations (Pohang, Daegu, and Pusan) of southeast Korea. After removing the significant Lag-1 serial correlation effect by pre-whitening, non-parametric statistical Mann-Kendall test was used to detect the trends. Also, the slope of trend of the Mann-Kendall test was determined by using Theil-Sen's estimator. The results of the trend analysis of reference evapotranspiration on the annual scale showed the increasing trend for the three mentioned stations, with significant increasing trend for Pusan station. The results obtained from this research can guide development if water management practices and cropping systems in the area that rely on this weather stations. The approaches use and the models fitted in this study can serve as a demonstration of how a time series trend can be analyzed.

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Trace Element in the Indian Ocean: Current Research Trends and Future Needs (인도양에서 미량원소 연구 동향 및 향후 연구 방향)

  • Kim, Intae
    • Ocean and Polar Research
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    • v.43 no.4
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    • pp.335-352
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    • 2021
  • Trace elements in the ocean have been known as essential micronutrients for the primary production of phytoplankton and the growth of marine organisms. The GEOTRACES program beginning in the mid-2000 provided a new understanding of the distribution, origin and behavior of trace elements in the ocean, together with the establishment of both clean seawater sampling and trace element analysis techniques. The Indian Ocean, one of the major oceans, is relatively the least explored area, despite playing an important role in global climate variability. Although trace element observations have recently been conducted in the Indian Ocean by Japanese-and Indian scientists, relatively not much study has been done compared to the Atlantic, Pacific and Polar Regions. Recently, together with the launch of R/V Isabu, a 5,000-ton grade large- and comprehensive research vessel, the observations of trace elements has been conducted in the Indian Ocean for the first time in Korea since 2018. In this paper, we introduce the key results of currently conducted GEOTRACES expedition in the Indian Ocean to present future trace element research directions in the Indian Ocean, and also reviewed the preliminary results in the Indian Ocean studies from Korea. In the 2020s, new Indian Ocean GEOTRACES projects are planned around European countries, and it is time for Korea to prepare for the next phase of the trace element study in the Indian Ocean in line with these international trends.

Topic Analysis of Scholarly Communication Research

  • Ji, Hyun;Cha, Mikyeong
    • Journal of Information Science Theory and Practice
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    • v.9 no.2
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    • pp.47-65
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    • 2021
  • This study aims to identify specific topics, trends, and structural characteristics of scholarly communication research, based on 1,435 articles published from 1970 to 2018 in the Scopus database through Latent Dirichlet Allocation topic modeling, serial analysis, and network analysis. Topic modeling, time series analysis, and network analysis were used to analyze specific topics, trends, and structures, respectively. The results were summarized into three sets as follows. First, the specific topics of scholarly communication research were nineteen in number, including research resource management and research data, and their research proportion is even. Second, as a result of the time series analysis, there are three upward trending topics: Topic 6: Open Access Publishing, Topic 7: Green Open Access, Topic 19: Informal Communication, and two downward trending topics: Topic 11: Researcher Network and Topic 12: Electronic Journal. Third, the network analysis results indicated that high mean profile association topics were related to the institution, and topics with high triangle betweenness centrality, such as Topic 14: Research Resource Management, shared the citation context. Also, through cluster analysis using parallel nearest neighbor clustering, six clusters connected with different concepts were identified.

Study of age specific lung cancer mortality trends in the US using functional data analysis

  • Tharu, Bhikhari;Pokhrel, Keshav;Aryal, Gokarna;Kafle, Ram C.;Khanal, Netra
    • Communications for Statistical Applications and Methods
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    • v.28 no.2
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    • pp.119-134
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    • 2021
  • Lung cancer is one of the leading causes of cancer deaths in the world. Investigation of mortality rates is pivotal to adequately understand the determinants causing this disease, allocate public health resources, and apply different control measures. Our study aims to analyze and forecast age-specific US lung cancer mortality trends. We report functions of mortality rates for different age groups by incorporating functional principal component analysis to understand the underlying mortality trend with respect to time. The mortality rates of lung cancer have been higher in men than in women. These rates have been decreasing for all age groups since 1990 in men. The same pattern is observed for women since 2000 except for the age group 85 and above. No significant changes in mortality rates in lower age groups have been reported for both gender. Lung cancer mortality rates for males are relatively higher than females. Ten-year predictions of mortality rates depict a continuous decline for both gender with no apparent change for lower age groups (below 40).

Numerical Study on the Erosion Tendency of Centrifugal Slurry Pump Impeller for Thermal Power Plants (화력발전소용 원심 슬러리 펌프 임펠러의 침식경향 해석적 연구)

  • Cheon, Min-Woo;Lee, Chul-Hee
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.2
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    • pp.101-108
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    • 2022
  • Centrifugal pumps are typically used in many slurry industries to transport solid materials. Solid particles in the slurry frequently shock the walls inside the pump, significantly abrading the flow path. Wear damage causes replacement of the pump components, which wastes manpower and time. Therefore, previous studies have been conducted on factors to improve efficiency and life time. This study identifies trends in pumps supplying lime to desulfurized devices from thermal power plants. The shear stress transport(SST) model is used to determine the erosion trend of the centrifugal pump that transfers lime slurry. The purpose of this study is to identify efficiency and erosion trends by selecting three of the various impeller design elements. The three impeller blade design variables mentioned above represent the inlet draft angle and blade angle of leading edge(L.E) and trailing edge(T.E). The maximum value of the erosion density rate tends to be similar to the Input power.

A Study on Consumer Sentiment Index Analysis and Prediction Using ARMA Model (ARMA모형을 이용한 소비자 심리지수 분석과 예측에 관한 연구)

  • Kim, Dongha
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.18 no.3
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    • pp.75-82
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    • 2022
  • The purpose of the Consumer sentiment index survey is to determine the consumer's economic situation and consumption spending plan, and it is used as basic data for diagnosing economic phenomena and forecasting the future economic direction. The purpose of this paper is to analyze and predict the future Consumer sentiment index using the ARMA model based on the past consumer index. Consumer sentiment index is determined according to consumer trends, so it can reflect consumer realities. The consumer sentiment index is greatly influenced by economic indicators such as the base interest rate and consumer price index, as well as various external economic factors. If the consumer sentiment index, which fluctuates greatly due to consumer economic conditions, can be predicted, it will be useful information for households, businesses, and policy authorities. This study predicted the Consumer sentiment index for the next 3 years (36 months in total) by using time series analysis using the ARMA model. As a result of the analysis, it shows a characteristic of repeating an increase or a decrease every month according to the consumer trend. This study provides empirical results of prediction of Consumer sentiment index through statistical techniques, and has a contribution to raising the need for policy authorities to prepare flexible operating policies in line with economic trends.

Comparing Separate and Statically-Partitioned Caches for Time-Predictable Multicore Processors

  • Wu, Lan;Ding, Yiqiang;Zhang, Wei
    • Journal of Computing Science and Engineering
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    • v.8 no.1
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    • pp.25-33
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    • 2014
  • In this paper, we quantitatively compare two different time-predictable multicore cache architectures, separate and statically-partitioned caches, through extensive simulation. Current research trends primarily focus on partitioned-cache architectures in order to achieve time predictability for hard real-time multicore based systems, and our experiments reveal that separate caches actually lead to much better performance and energy efficiency when compared to statically-partitioned caches, and both of them are adequate for timing analysis for real-time multicore applications.