• Proceedings of the Korea Concrete Institute Conference
• /
• 2001.05a
• /
• pp.991-996
• /
• 2001

The long-term durability characteristics of high-early-strength concrete were assessed. The effect of long-term durability characteristics of high-early-strength concrete were investigated. In experiment, two different types of fiber were adopted for improvement of durability. High-early-strength fiber reinforced concretes using regulated-set cements are compared with high-early-strength concrete without fiber. The durability performance of the laboratory-cured high-early-strength concrete specimens was determined by conducting an accelerated chloride permeability, abrasion resistance, freeze-thaw, surface deicer salt scaling and wet-dry repetition test. The results indicated that incorporation of fibers enhance durability performance.

• Asia-Pacific Journal of Business
• /
• v.13 no.1
• /
• pp.167-183
• /
• 2022

Purpose - The purpose of this study is to show the need to use the past long-term returns for investment decisions in U.S. equity funds and to suggest an investment strategy using long-term returns. Design/methodology/approach - This study solves the problem of high return volatility in long-term returns and proposes new investment portfolios based on the behavior of fund investors according to past returns. For the investment portfolio of this study, 60 months are divided into several periods and the average of the performance ranks for each period is used. Findings - First, funds with high average returns over multiple periods have lower future outflows and higher future returns than funds with high 60-month cumulative returns. Second, funds with low average returns over multiple periods have lower future inflows and lower future returns than funds with low 60-month cumulative returns. The findings mean that when making decisions based on past long-term returns, it is a smarter investment choice to buy funds with high average returns over multiple periods and sell funds with low average returns over multiple periods. Research implications or Originality - This study shows that it is necessary to use long-term returns in fund investment by analyzing the characteristics of the portfolio based on past returns. In addition, the study is meaningful in that it suggests a way to use long-term returns more efficiently based on the behavior of fund investors and shows that such investments lead to higher returns in the future.

• Korean Management Science Review
• /
• v.24 no.1
• /
• pp.45-62
• /
• 2007

We aim to explain the role of corporate's 'long-term orientation' and 'asset specificity' in the process of SCM(Supply Chain Management) practices' effect on SCM performances, with empirical study about 167 manufacturing companies ail over the country. With confirmatory factor analysis and structural equation model using AMOS program, we conclude long-term orientation and asset specificity act as 'infra-structural role', rather than 'Intermediate role', in the process of SCM practice's effect on SCM performances.

• ETRI Journal
• /
• v.43 no.2
• /
• pp.288-298
• /
• 2021

Abstractive text summarization is a process of making a summary of a given text by paraphrasing the facts of the text while keeping the meaning intact. The manmade summary generation process is laborious and time-consuming. We present here a summary generation model that is based on multilayered attentional peephole convolutional long short-term memory (MAPCoL; LSTM) in order to extract abstractive summaries of large text in an automated manner. We added the concept of attention in a peephole convolutional LSTM to improve the overall quality of a summary by giving weights to important parts of the source text during training. We evaluated the performance with regard to semantic coherence of our MAPCoL model over a popular dataset named CNN/Daily Mail, and found that MAPCoL outperformed other traditional LSTM-based models. We found improvements in the performance of MAPCoL in different internal settings when compared to state-of-the-art models of abstractive text summarization.

• The Plant Pathology Journal
• /
• v.38 no.4
• /
• pp.395-402
• /
• 2022

To predict rice blast, many machine learning methods have been proposed. As the quality and quantity of input data are essential for machine learning techniques, this study develops three artificial neural network (ANN)-based rice blast prediction models by combining two ANN models, the feed-forward neural network (FFNN) and long short-term memory, with diverse input datasets, and compares their performance. The Blast_Weathe long short-term memory r_FFNN model had the highest recall score (66.3%) for rice blast prediction. This model requires two types of input data: blast occurrence data for the last 3 years and weather data (daily maximum temperature, relative humidity, and precipitation) between January and July of the prediction year. This study showed that the performance of an ANN-based disease prediction model was improved by applying suitable machine learning techniques together with the optimization of hyperparameter tuning involving input data. Moreover, we highlight the importance of the systematic collection of long-term disease data.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.3
• /
• pp.691-698
• /
• 2015

In the area of high traffic volume, such as expressway across large cities, the amount of nitrogen oxides (NOx) emitted into the atmosphere as air pollution can be significant since NOx gases are the major cause of smog and acid rain. Recently, the importance of NOx removal has arisen in the world. Titanium dioxide ($TiO_2$), that is one of photocatalytic reaction material, is very efficient for removing NOx. Therefore, application of $TiO_2$ concrete is a good alternative in order to remove NOx which is a main cause of air pollution. This experimental study aimed to evaluate the long-term performance of $TiO_2$ concrete such as NOx removal efficiency due to performance period and environmental resistance for application of road structures. It was found that the $TiO_2$ is reasonable applicable on the road structure because $TiO_2$ concrete has a long-term performance.

• Journal of Digital Convergence
• /
• v.17 no.9
• /
• pp.231-240
• /
• 2019

The purpose of this study was to explore and describe the relationship of the perception of patient safety culture, knowledge of standard precaution and performance of standard precaution among long-term care hospital nurses. Participants were 134 nurse in long-term hospital. Data were collected with structured questionnaires from January 2 to June 4, 2018. Data were analyzed by SPSS/WIN 21.0 program for descriptive statistics t-test, ANOVA, Scheffe's test and Pearson's correlation coefficient. The perception of patient safety culture were significantly correlated with knowledge of standard precaution(r=.192, p=.027), performance of standard precaution(r=211, p=.014). Therefore, in order to enhance the perception of patient safety culture and performance of standard precaution of long-term care hospital nurses, it would be necessary to enable health-care associated infections by themselves by cultivating standard precaution knowledge through systemic education and by enabling the establishment of affirmative patient safety culture.

• Korean small business review
• /
• v.39 no.1
• /
• pp.59-87
• /
• 2017

There is growing concern of the international community for the environmental issues including climate change. Scholars have examined various issues regrading Green Supply Chain Management (GSCM) but they mainly have focused on why firms introduce and implement GSCM from the persecutive of manufacturers. In particular, there has been few studies of green supply chain management in Korea. We investigate the effects of long-term relationships on green supply chain management and the relationship between GSCM and environmental performance. We also examine the relationship between long-term relationships and green information sharing, the effects of green information sharing on the GSCM. The data for this study were collected through a questionnaire survey on firms that participated in the Green Partnership Program of Korea Institute of Industrial Technology. Based on the responses of 155 firms the research model is empirically tested through a structural equation model. We found that long-term relationships facilitate GSCM significantly as it was expected. Green purchase and green product design also appears to improve environmental performance. Long-term relationship appears to affect positively green information sharing. Green information sharing does not have a statistically significant effect on environmental performance but show positive effect on GSCM including green purchase and green product design.

• Nuclear Engineering and Technology
• /
• v.38 no.6
• /
• pp.459-482
• /
• 2006

A geochemical approach to the long-term safety of waste disposal is discussed in connection with the significance of actinides, which shall deliver the major radioactivity inventory subsequent to the relatively short-term decay of fission products. Every power reactor generates transuranic (TRU) elements: plutonium and minor actinides (Np, Am, Cm), which consist chiefly of long-lived nuclides emitting alpha radiation. The amount of TRU actinides generated in a fuel life period is found to be relatively small (about 1 wt% or less in spent fuel) but their radioactivity persists many hundred thousands years. Geological confinement of waste containing TRU actinides demands, as a result, fundamental knowledge on the geochemical behavior of actinides in the repository environment for a long period of time. Appraisal of the scientific progress in this subject area is the main objective of the present paper. Following the introductory discussion on natural radioactivities, the nuclear fuel cycle is briefly brought up with reference to actinide generation and waste disposal. As the long-term disposal safety concerns inevitably with actinides, the significance of the aquatic actinide chemistry is summarized in two parts: the fundamental properties relevant to their aquatic behavior and the geochemical reactions in nanoscopic scale. The constrained space of writing allows discussion on some examples only, for which topics of the primary concern are selected, e.g. apparent solubility and colloid generation, colloid-facilitated migration, notable speciation of such processes, etc. Discussion is summed up to end with how to make a geochemical approach available for the long-term disposal safety of nuclear waste or for the performance assessment (PA) as known generally.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.320-320
• /
• 2010

The dye-sensitized solar cells (DSSCs) have achieved so far the highest validated efficiency over 11%. However, the cells with the best performance utilize volatile solvent as a electrolyte, which can cause some practical limitations for the long-term operation. This is one of the most substantial problems to be resolved for the commercialization of DSSCs. In order to improve the long-term stability, many research groups have reported new electrolyte system, to replace the liquid type electrolyte by non-volatile ones. In this work, we studied long-term stability of the DSSCs with various types of electrolytes such as (PVDF HFP) based polymer, eutectic melts of ionic liquids, and liquid based solvent. The cells with various electrolytes have been exposed to the condition under thermal stress and illumination over 1000 hours. We will report the change of photovoltaic properties with time and investigate the degradation mechanism with the impedance spectroscopic analysis.