• The Journal of Asian Finance, Economics and Business
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• 제7권11호
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• pp.23-31
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• 2020

This paper investigates the impact of monetary policy independence shock on bond yield by allowing for heterogeneous coefficients in the model based on panel data for 19 developing countries using quarterly data from 1991 to 2016. First, we estimate the model using conventional panel VAR estimation with the assumption of homogeneous coefficients across countries. Second, by performing Chow and Roy-Zellner tests to check the homogeneity assumption, we find that the assumption does not hold in the model. Third, we apply a mean-group estimation for panel VAR as a solution for heterogeneity panel model. The results reveal that central bank independence is effective in reducing bond yield with the maximum at period 6 after the shock. Shock one standard deviation bond yield has a negative effect on consumption and investment. We determine that central bank independence has a contradictory effect on real activity; a negative effect on consumption but a positive influence on investment for the first two years after the shock. Additionally, we split our sample into three groups to make the subgroups pool. Our empirical result shows that monetary policy independence shock reduces bond yield. Meanwhile, the response of economic activity to bond yield varies for all three groups.

• 한국동물위생학회지
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• 제47권1호
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• pp.35-40
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• 2024

Hoof health management plays an important role in dairy farms because lameness can impact productivity via decreased milk yield, reproduction rate, and increased culling rate. Regular hoof trimming can help reduce the incidence of hoof diseases in dairy cows. However, its effects on healthy dairy cows remain unclear. This study investigated the effects of hoof trimming on milk yield, rumination time, and activity in healthy Holstein and Jersey cows. Fourteen cows (7 Holstein and 7 Jersey) without lameness were used in this study. We trimmed the cows and collected data from 3 days prior to 9 days after hoof trimming. Milk yield, rumination time, and activity were measured using automatic milking and health monitoring systems. Milk yield and rumination time decreased, whereas activity level increased on the trimming day compared to the previous days in both breeds, although the difference was not significant. On the days after hoof trimming, milk yield, rumination time, and activity recovered to normal. Especially in Holstein cows, a temporary increase in milk yield was observed compared to that in the pre-trimming period. Hoof trimming did not negatively affect the productivity of dairy cows of either breed. Furthermore, productivity can temporarily increase.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1339-1346
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• 2024

Electrorefining in molten salts is used for purifying actinides. Optimizing electrorefining is key to minimizing processing time and radiological waste. One possible way of improving electrorefining efficiency is using an AC superimposed DC waveform. This waveform has demonstrated potential benefits in aqueous solutions but has never been utilized in a molten metal, molten salt application. This work investigates the effects of using an AC superimposed DC waveform on molten bismuth electrorefining in a molten LiCl-KCl-CaCl2 eutectic. Bismuth has been identified as a potential surrogate for plutonium electrorefining and a potential cathode in electrorefining used nuclear fuel (UNF). All electrorefining runs resulted in a high purity cathode ring and high yield with exception of the run using a low-frequency, high-amplitude superimposed AC waveform, which experienced some contamination and a lower yield. The other three AC superimposed DC runs experienced an average yield 6.7 % higher than the average yield of the DC runs. The electrorefining run using the high-frequency, high-amplitude superimposed AC signal had the highest yield. It is recommended in future studies to investigate the statistical variability of electrorefining yield and current efficiency and the impact of AC superimposed DC waveforms on solidified bismuth anodes.

• 한국주조공학회지
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• 제15권2호
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• pp.146-155
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• 1995

This study was performed to investigate the effect of austempering temperature on the mechanical properties and fracture characteristics of the ductile cast iron with Cu, Mo and Cu, Mo, Ni. The results obtained from this study are summarized as follows; Microstructures of Cu-Mo and Cu-Mo-Ni ductile cast iron by austempering were obtained low bainite with some martensite at $250^{\circ}C$, mixture structure of upper and low bainite obtained at $300^{\circ}C$ and upper bainite obtained at $350^{\circ}C$. Tensile, impact and fracture toughness properties were remarkably controlled by retained austenite. With increasing austempering temperature, tensile and yield strength, hardness decreased, while the elongation and impact absorption energy, fracture toughness increased. With adding Ni, tensile and yield strength increased and elongation, facture toughness and impact absorption energy decreased. Retained austenite increased with increasing austempering temperature and the fracture surface were shown mixture structure of fibrous and dimple.

• 환경영향평가
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• 제8권2호
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• pp.45-51
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• 1999

Emergy concept was used to evaluate the contributions of a dam construction to the real wealth of our economy. A dam that is proposed as a multi-purpose dam was used to illustrate emergy evaluation methodology. Models for emergy evaluation were constructed with energy systems language, a symbolic modeling language which presents network properties of systems holistically. Water supply was the most important contribution in terms of emergy, which reflects that the dam is proposed for stable water supply to a local region. Generation of electricity was the second in emergy benefits of the dam. Emergy costs were more evenly distributed among the costs which would occur as a result of the dam construction. Emergy yield ratio was 1.30 if sediments are not included, and 1.15 if sediments are included, which results in net yield in both cases. The ratio would, however, fall below 1.0 if rare species within the system boundary are lost as a result of the dam construction because of the high emergy value included in biotic species, which means that emergy costs will be greater than emergy benefits. This study illustrated a new methodology in environmental impact assessment to better manage our environments in an age of diminishing resources.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2000년도 추계 학술대회지
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• pp.12-27
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• 2000

During the recent decades, he problem of climate variability and change has been in the forefront of scientific problems. The objective of this study was to assess the impact of climate variability on crop growth and yield. The growth duration was the main impact of climate variability on crop yield. Phyllochronterval was shortened in the global worming situations. A simple model to describe developmental traits was provided from heading data of directly seeded rice cultivars and temperature data. Daily mean development rate could be explained by the average temperature during the growth stage. Simple regression equation between daily mean development rate(x) and the average temperature(y) during the growth period as y = ax + b. It can be simply modified as x = 1/a $\ast$ (y-b). The parameters of the model could depict the thermo sensitivity of the cultivars. On the base of this model, the three doubled CO2 GCM scenarios were assessed. The average of these would suggest a decline in rice production of about 11% if we maintained the current cultivars. Future cultivar's developmental traits could be suggested by the two model parameters.

• 대한금속재료학회지
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• 제56권11호
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• pp.796-804
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• 2018

The Charpy impact toughness of the heat affected zone (HAZ) of electro gas welded 390 MPa yield strength grade steel, manufactured by a thermo mechanically controlled process, was investigated. The effects of added Nb on the toughness of the steel and the factors influencing scatter in toughness are discussed in the present work. It was observed that adding Nb to the steel led to the deterioration of HAZ toughness. The presence of soluble Nb in the HAZ increased its hardenability and resulted in a larger amount of low toughness bainitic microstructure. Microstructural observations in the notch root area revealed the significant role of different microstructures in the area. In the presence of a larger amount of bainitic microstructures, the HAZ exhibited a lower Charpy toughness with a larger scatter in toughness. A softened zone with a lower hardness than the base metal was formed in the HAZ. However, theoretical analysis revealed that the presence of the zone might not be a problem in a real welded joint because of the plastic restraint effect enforced by surrounding materials.

• 한국유기농업학회:학술대회논문집
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• 한국유기농업학회 2001년도 상반기 심포지엄 및 학술발표대회
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• pp.1-24
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• 2001

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.220-225
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• 2007

The mechanical characteristics of AC4C Aluminum Casting Alloy were investigated by tensile test and impact test. Based on the tensile test' s result, we found that the yield strength of a high speed was about 10% higher than that of a low speed test and the maximum rupture strain mostly occurred in low speed tensile test. The impact energy of curved surface specimen was higher than that of plane surface specimen that can be measured in impact test.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.294-298
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• 2015

In the United States, the completion of Construction Work Zone (CWZ) impact assessments for all federally-funded highway infrastructure improvement projects is mandated, yet it is regarded as a daunting task for state transportation agencies, due to a lack of standardized analytical methods for developing sounder Transportation Management Plans (TMPs). To circumvent these issues, this study aims to create a spatiotemporal modeling framework, dubbed "SWAT" (Spatiotemporal Work zone Assessment for TMPs). This study drew a total of 43,795 traffic sensor reading data collected from heavily trafficked highways in U.S. metropolitan areas. A multilevel-cluster-driven analysis characterized traffic patterns, while being verified using a measurement system analysis. An artificial neural networks model was created to predict potential 24/7 traffic demand automatically, and its predictive power was statistically validated. It is proposed that the predicted traffic patterns will be then incorporated into a what-if scenario analysis that evaluates the impact of numerous alternative construction plans. This study will yield a breakthrough in automating CWZ impact assessments with the first view of a systematic estimation method.