1,411 research outputs found
Accounting Conservatism, Changes In Real Investment, And Analysts Earnings Forecasts
This study examines whether sell-side analysts fully incorporate into their earnings forecasts the joint effects between accounting conservatism and changes in real investment on the quality of current earnings. Our results indicate that sell-side analysts do not fully incorporate such effects when they forecast future earnings so that they overestimate (underestimate) future earnings when current earnings are inflated (depressed) by those effects. Thus, we conclude that sell-side analysts do not recognize fully the joint effects between accounting conservatism and real activity on the earnings quality and that they need to mitigate their bias to enhance market efficiency by providing investors with a good benchmark for their earnings expectation
Development Of River Recreation Index Model Reflecting Fuzziness In Water Quality Data
Recreational activities in rivers are gaining popularities in Korea due to increase of household income and rehabilitation of riverside. As a lot of people enjoy recreation in water, proper information on the water quality of rivers should be provided to the public in order to secure the safety of publics. In this research, a River Recreation Index (RRI) model was developed based on fuzzy set theory. RRI is the integrated index of important water quality parameters related to recreational activities in rivers and expressed as point from 0 to 100. The fuzzy synthetic evaluation approach was used to reflect the fuzziness of water quality criteria and uncertainty in water quality data. The procedure of the fuzzy synthetic evaluation is divided into four steps: choosing water quality parameters which are integrated into RRI, classifying the range of each water quality parameter, designing appropriate membership function of each parameter, and summarizing all membership value into the RRI. In this study, DO, pH, chlorophyll a and turbidity were chosen as the parameters and the criteria of these four parameters were determined referring domestic and overseas water quality criteria. Membership function in the model was determined as half-triangular shape because it expressed the fuzziness of water quality criteria well. The values of four water quality parameters were converted to membership value by the half-triangular membership function. Then, RRI was calculated by weighted average of the membership values. The proposed model was applied to Sangdong monitoring station in the Nakdong River, Korea. The application result was compared with both the calculation results based on the crisp water quality criteria and real time water quality index (RTWQI) posted by the Ministry of Environment. The simulation results show that RRI with the fuzzy function showed more reasonable changes corresponding to the trend of the water quality parameters
Crack-Growth Behavior in Thermal Barrier Coatings with Cyclic Thermal Exposure
Crack-growth behavior in yttria-stabilized zirconia-based thermal barrier coatings (TBCs) is investigated through a cyclic thermal fatigue (CTF) test to understand TBCs’ failure mechanisms. Initial cracks were introduced on the coatings’ top surface and cross section using the micro-indentation technique. The results show that crack length in the surface-cracked TBCs grew parabolically with the number of cycles in the CTF test. Failure in the surface-cracked TBC was dependent on the initial crack length formed with different loading levels, suggesting the existence of a threshold surface crack length. For the cross section, the horizontal crack length increased in a similar manner as observed in the surface. By contrast, in the vertical direction, the crack did not grow very much with CTF testing. An analytical model is proposed to explain the experimentally-observed crack-growth behavior
Crack-Resistance Behavior of an Encapsulated, Healing Agent Embedded Buffer Layer on Self-Healing Thermal Barrier Coatings
In this work, a novel thermal barrier coating (TBC) system is proposed that embeds silicon particles in coating as a crack-healing agent. The healing agent is encapsulated to avoid unintended reactions and premature oxidation. Thermal durability of the developed TBCs is evaluated through cyclic thermal fatigue and jet engine thermal shock tests. Moreover, artificial cracks are introduced into the buffer layer’s cross section using a microhardness indentation method. Then, the indented TBC specimens are subject to heat treatment to investigate their crack-resisting behavior in detail. The TBC specimens with the embedded healing agents exhibit a relatively better thermal fatigue resistance than the conventional TBCs. The encapsulated healing agent protects rapid large crack openings under thermal shock conditions. Different crack-resisting behaviors and mechanisms are proposed depending on the embedding healing agents
Intelligent CCTV Surveillance Based on Sound Recognition and Sound Localization
CCTV is used for many purposes, especially for surveillance and fortraffic condition monitoring. This paper proposesan intelligent CCTV system that tracks sound events based on sound recognition and sound localization. From the experimental results, it is evident that the proposed method can be successfully used for the intelligent CCTV system of CCTV
The Role of Sphingosine Kinase 1/Sphingosine-1-Phosphate Pathway in the Myogenic Tone of Posterior Cerebral Arteries
AIMS: The goal of the current study was to determine whether the sphingosine kinase 1 (SK1)/sphingosine-1-phosphate (S1P) pathway is involved in myogenic vasoconstriction under normal physiological conditions. In the present study, we assessed whether endogenous S1P generated by pressure participates in myogenic vasoconstriction and which signaling pathways are involved in SK1/S1P-induced myogenic response under normal physiological conditions. METHODS AND RESULTS: We measured pressure-induced myogenic response, Ca(2+) concentration, and 20 kDa myosin light chain phosphorylation (MLC(20)) in rabbit posterior cerebral arteries (PCAs). SK1 was expressed and activated by elevated transmural pressure in rabbit PCAs. Translocation of SK1 by pressure elevation was blocked in the absence of external Ca(2+) and in the presence of mechanosensitive ion channel and voltage-sensitive Ca(2+) channel blockers. Pressure-induced myogenic tone was inhibited in rabbit PCAs treated with sphingosine kinase inhibitor (SKI), but was augmented by treatment with NaF, which is an inhibitor of sphingosine-1-phosphate phosphohydrolase. Exogenous S1P further augmented pressure-induced myogenic responses. Pressure induced an increase in Ca(2+) concentration leading to the development of myogenic tone, which was inhibited by SKI. Exogenous S1P further increased the pressure-induced increased Ca(2+) concentration and myogenic tone, but SKI had no effect. Pressure- and exogenous S1P-induced myogenic tone was inhibited by pre-treatment with the Rho kinase inhibitor and NADPH oxidase inhibitors. Pressure- and exogenous S1P-induced myogenic tone were inhibited by pre-treatment with S1P receptor blockers, W146 (S1P1), JTE013 (S1P2), and CAY10444 (S1P3). MLC(20) phosphorylation was increased when the transmural pressure was raised from 40 to 80 mmHg and exogenous S1P further increased MLC(20) phosphorylation. The pressure-induced increase of MLC(20) phosphorylation was inhibited by pre-treatment of arteries with SKI. CONCLUSIONS: Our results suggest that the SK1/S1P pathway may play an important role in pressure-induced myogenic responses in rabbit PCAs under normal physiological conditions
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