• International Area Studies Review
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• v.14 no.3
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• pp.62-84
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• 2010

Accurate forecasting of volatility is of considerable interest in financial volatility research, particularly in regard to portfolio allocation, option pricing and risk management because volatility is equal to market risk. So, we attempted to delineate a model with good ability to forecast and identified stylized features of volatility, with a focus on volatility persistence or long memory in the Australian futures market. In this context, we assessed the long-memory property in the volatility of index futures contracts using three conditional volatility models, namely the GARCH, IGARCH and FIGARCH models. We found that the FIGARCH model better captures the long-memory property than do the GARCH and IGARCH models. Additionally, we found that the FIGARCH model provides superior performance in one-day-ahead volatility forecasts. As discussed in this paper, the FIGARCH model should prove a useful technique in forecasting the long-memory volatility in the Australian index futures market.

• Journal of Climate Change Research
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• v.6 no.3
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• pp.185-191
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• 2015

This study presents an estimate of on-site surface fuel loadings composed of coarse woody debris (CWD) using $5^{th}$ National Forest Inventory (NFI) data in South Korea. We classified CWD data into forest type, region and decay class, and used conversion factors by decay class and tonne of oil equivalent developed in the country. In 2010, the total wildfire fuel load of CWD was estimated as 8.9 million TOE; those of coniferous, deciduous and mixed forests were 3.5 million TOE, 2.8 million TOE and 2.6 million TOE, respectively. Gangwon Province had the highest wildfire fuel load of CWD (2.3 million TOE), whereas Seoul exhibited the lowest wildfire fuel load of CWD (0.02 million TOE). Wildfire fuel loads of CWD were estimated as 2.9 million TOE, 1.9 million TOE, 2.4 million TOE and 1.7 million TOE for decay classes I, II, III and IV, respectively. The total wildfire fuel load of CWD corresponded to the calorific value of 8.2 million tons crude oil, 2.46% of that of living trees. Proportionate to the growing stock, total wildfire fuel load of CWD was in a broad distinction by region, while its TOE $ha^{-1}$ was not. This implies that there is no need to establish different guidelines by region for management of CWD. The results of this work provide a baseline study for scientific policy guidelines on preventing wildfires by proposing CWD as wildfire fuel load.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.9
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• pp.1032-1037
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• 2019

In the existing pharmacy automation system, quantity control was carried out only in the memory without first measuring the quantity of the medicine and during the operation of the facility. As a result, the number of drugs that have already been deducted during operation at the time of a facility error has not been managed. Serious problems are caused by important medicines that need to be managed because of lack of quantity control. In addition, the user had to refill the drug when it was exhausted because the user could not know the amount of the drug outside the facility. When the drug was out of stock, the facility was operating with loss of time to restart and the time to replenish the drug. Thus, in this paper, we designed and applied system to control the quantity of medicines frequently by adding displacement sensors to the robot of the facility.

• Journal of Convergence for Information Technology
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• v.11 no.1
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• pp.128-135
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• 2021

The possibility and effectiveness of cryopreservation was determined to assess survival rates and improve stock management of thawed embryos of Manila clam, Ruditapes philippinarum. The ideal freezing rates were designed and tested to allow cryoprotectants to equilibrate across the membrane during freezing. Survival rates ranging from 0 to 64.3% were obtained using a stepwise freezing protocol compared with 82.3% control rates. Embryos of Ruditapes philippinarum were equilibrated in 2 CPAs plus sea water for 10 min at 25℃ and then cooled at -1℃/min from 20℃ to -12℃. Straws containing more than 100 embryos were held at 12℃ for 5 min allowing equilibration after seeding and slowly cooled at 2℃/min. to -35℃ for 30 min for equilibration before quenching in liquid nitrogen. Dimethyl sulfoxide (DMSO) is the best cryoprotectant indicated for embryos of R. philippinarum with a survival rate of 64.3±3.28% in the presence of 2.0 M DMSO.

• Forest Science and Technology
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• v.14 no.4
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• pp.181-191
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• 2018

This study was carried out in the teaching and research forest of the University of Dschang in Belabo, with the aim of analysing land-cover and land-use changes as well as carbon stocks dynamic. The databases used are composed of three Landsat satellite images (5TM of 1984, 7ETM + of 2000 and 8OLI of 2016), enhanced by field missions. Satellite images were processed using ENVI and ArcGIS software. Interview, focus group discussion methods and participatory mapping were used to identify the activities carried out by the local population. An inventory design consisting of four transects was used to measure dendrometric parameters and to identify land-use types. An estimation of carbon stocks in aboveground and underground woody biomass was made using allometric models based on non-destructive method. Dynamic of land-cover showed that the average annual rate of deforestation is 0.48%. The main activities at the base of this change are agriculture, house built-up and logging. Seven types of land-use were identified; adult secondary forests (64.10%), young secondary forests (7.54%), wetlands (7.39%), fallows (3.63%), savannahs (9.59%), cocoa farms (4.28%) and mixed crop farms (3.47%). Adult secondary forests had the highest amount of carbon ($250.75\;t\;C\;ha^{-1}$). This value has decreased by more than 60% for mixed crop farms ($94.67\;t\;C\;ha^{-1}$), showing the impact of agricultural activities on both forest cover and carbon stocks. Agroforestry systems that allow conservation and introduction of woody species should be encouraged as part of a participatory management strategy of this forest.

• The Journal of the Korea Contents Association
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• v.22 no.4
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• pp.314-323
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• 2022

This study examines the effecs of National Pension Service blockholders on accounting conservatism. The sample consists of 10,117 non-banking firm-years listed in Korea Stock Exchange(KOSPI) during the period 2011 to 2018. The results of this study are as follows. First, it was found that companies in which the National Pension Service as a major shareholder hold more than 5% of the shares are less prone to conservative accounting treatment than those that do not. Second, such a negative relationship between investment by the National Pension Service and conservative accounting was consistently found even when the investment period of the National Pension Service was divided into short-term (less than 1 year) and long-term (more than 3 years). It is expected that the National Pension Service, the largest institutional investor in Korea, will be able to carry out meaningful management control activities on investment companies. As the monitoring function of the National Pension Service works effectively in the capital market, agency costs are reduced, and investors' demands for corporate conservative accounting have decreased.

• Journal of Digital Convergence
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• v.20 no.4
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• pp.119-126
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• 2022

With the rise and rapid development of the "Internet+" economic model, the internet is deeply integrated with the social economy and penetrates every corner of life. Compared with expanding the scale of business operations through internal investment and capital accumulation, e-commerce companies are more inclined to directly gain control of other companies through efficient merger and acquisition (M&A). The purpose of this study is to analyze changes in financial performance before and after M&A of Alibaba, China's largest e-commerce company in the Internet era. To present the impact of M&A events on Alibaba's stock price and shareholder wealth more intuitively, this study selected the market model in the event study method to measure abnormal returns. The results show that an M&A event led to a reduction in Alibaba's shareholder wealth in the short term. This study presents the theoretical basis for the M&A performance of e-commerce companies.

• Fisheries and Aquatic Sciences
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• v.25 no.7
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• pp.380-389
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• 2022

Morphometric relationships, condition factor (CF) and reproductive biology are significant tools in fish stock management, fish biology, physiology, conservation and ecology. Growth and reproductive strategy of Oreochromis niloticus were studied from 343 fish specimens collected from Lake Shala between January and December 2018. Fish samples ranged from 7.7 cm to 33.0 cm in total length (TL) and from 7.80 g to 708.21 g in total weight (TW) were collected using gillnets of 4, 6, 8, 10, and 12 mm mesh sizes. The length-weight relationship of O. niloticus was TW = 0.0104TL^3.19, indicating positive allometric growth of the fish. The sex ratio (0.93:1) was insignificant from the ideal fish distribution of 1:1 (χ² = 0.47, p > 0.05). Mean CF for males, females and combined sexes was 1.04, 1.06 and 1.05, respectively and statistically insignificant (p > 0.05). The spawning peak occurred in July (rainy) and February (dry) periods, as defined by ripe females and the breeding season. Absolute mean fecundity was 806 eggs and correlated positively with TL and TW of the fish (p < 0.05) (F = 0.56TL^2.29, R² = 0.93, p < 0.05; F = 18.83TW^0.67, R² = 0.90, p < 0.05). The study provides the first detailed account of the morphometric relationships and reproductive biology of O. niloticus in Lake Shala, which can be used as baseline information for successive biological-based studies in Soda Lakes of Ethiopia.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.45-52
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• 2021

This study conducted t-test and ANOVA analysis, influence of importance-satisfaction, regression analysis to local food and restaurants to the purchase intention in Busan. The subjects of this study were tourists who visited local restaurants in Busan, and the final 392 copies were used for empirical analysis. As a result of the study, first, there will be a significant difference in the recognition of local foods in Busan according to the visitor's region. In all samples, the recognition was high in the order of pork stock, wheat noodle, sauteed·fired soft eel, grilled·ell sashmi. On the other hand, sansung bulgogi, Dongrae pajeon, and sansung makkŏlli were the lowest. Second, in the difference between importance and satisfaction of local restaurants in Busan, 'there is a different taste compared to other regions' showed high satisfaction and importance. Third, In the relationship between the awareness of local restaurants in Busan and the purchase intention, it was found to be effective in service, facilities, prices and locality and cleanliness were rejected.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.359-364
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• 2021

Recently, research on predictive systems using deep learning and machine learning of artificial intelligence is being actively conducted. Due to the development of artificial intelligence, the role of the investment manager is being replaced by artificial intelligence, and due to the higher rate of return than the investment manager, algorithmic trading using artificial intelligence is becoming more common. Algorithmic trading excludes human emotions and trades mechanically according to conditions, so it comes out higher than human trading yields when approached in the long term. The deep learning technique of artificial intelligence learns past time series data and predicts the future, so it learns like a human and can respond to changing strategies. In particular, the LSTM technique is used to predict the future by increasing the weight of recent data by remembering or forgetting part of past data. fbprophet, an artificial intelligence algorithm recently developed by Facebook, boasts high prediction accuracy and is used to predict stock prices and cryptocurrency prices. Therefore, this study intends to establish a sound investment culture by providing a new algorithm for automatic cryptocurrency trading by analyzing the actual value and difference using fbprophet and presenting conditions for accurate prediction.