• The Journal of Asian Finance, Economics and Business
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• v.7 no.8
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• pp.51-59
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• 2020

The objective of this study is to enrich the literature by investigating the impact of introduction of index future trading on spot market returns and trading volume in Vietnam. Data used in this study mainly consist of daily VN30-Index and market trading volume series during the period from February 6^th, 2012 to December 31^st, 2019. Using OLS, GARCH(1,1) and EGARCH(1,1) models, the empirical findings consistently confirm that the introduction of index future trading has no impact on the spot market returns. In addition, the results of the EGARCH(1,1) model indicate that the leverage effect on the spot market volatility is existence in HOSE. Specifically, bad news has a greater effect on the market volatility than good news of the same size. Moreover, our empirical findings reveal that the introduction of index future contracts has the positive impact on the underlying market trading volume. Specifically, the trading volume of the post-index futures introduction increases by 7.5 percent compared with the pre-index futures introduction. Finally, the results obtained from the Granger causality test for the relationship between the spot market returns and the future trading activity confirm that only uni-directional causality running from the market returns to the future trading activity exists in HOSE.

• Journal of Technology Innovation
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• v.19 no.3
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• pp.85-114
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• 2011

This paper aims at developing a new index that represents the Korean new growth industries, which is named the Korea Future Technology Index(KOFTI). The KOFTI is designed to provide a reliable and econometric index based on which the Korean government searches for new growth engines. The KOFTI is composed of three individual indexes such as the Economic Impact Index, the Future Strategy Index, and the Technological Influence Index. The KOFTI is applied for 62 star brands, which have been promoted by the Korean government for the korean future industrial competitiveness. The top 13 leading industries are drawn from the calculation of the KOFTI for 62 star brands.

• Journal of Soil and Groundwater Environment
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• v.25 no.4
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• pp.14-27
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• 2020

The drought has occurred from the past, and has caused a lot of damage. It is important to analyze the past droughts and predict them in the future. In this study, the temperature and precipitation of the past and the future from climate change RCP 4.5 and 8.5 scenarios were analyzed for Seosan and Boryeong in the western region of Chungnam Province, which is considered as a drought-prone area on the Korean Peninsula. Comparing Standardized Precipitation Index (SPI) and Effective Drought Index (EDI) based on the past droughts, EDI was verified to be more suitable for the drought assessment. According to RCP 4.5, the frequency and intensity of droughts in the early future (2021~2060) were expected to increase and to be stronger. Particularly, severe droughts were predicted for a long time from 2022 to 2026, and from 2032 to 2039. Droughts were expected to decrease in the late future (2061~2100). From RCP 8.5, drought occurrences were predicted to increase, but the intensity of the droughts were expected to decrease in the future. As a result of evaluation of the frequencies of droughts by seasons, the region would be most affected by fall drought in the early future and by spring drought in the late future according to RCP 4.5. In the case of RCP 8.5, the seasonal effects were not clearly distinguished. These results suggest that droughts in the future do not have any tendency, but continue to occurr as in the past. Therefore, the measures and efforts to secure water resources and reinforcement of water supply facilities should be prepared to cope with droughts.

• Journal of Korea Spatial Information System Society
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• v.7 no.1 s.13
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• pp.77-89
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• 2005

Recently, application area on the Location Based System(LBS) is increasing because of development of mobile-communication and GPS technique. Previous studies on the index of moving objects are classified as either index for past trajectories or current/future positions. It is necessary to develop a unified index because many applications need to process queries about both past trajectories and current/future positions at the same time. In this paper, the past trajectories of moving objects are represented as line segments and the current and future positions are represented as the function of time. We propose a new index called PCR-tree(Past, Current R-tree) for unification of past, current and future positions. Nodes of the index have bounding boxes that enclose all position data and entries in the nodes are accessed with only one interface. We implement the proposed index and show a feasibility of processing the queries about temporal-spatial domain with the query tool which we develop.

• Journal of Korea Spatial Information System Society
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• v.9 no.1
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• pp.1-13
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• 2007

The necessity of future index is increasing to predict the future location of moving objects promptly for various location-based services. A representative research topic related to future index is the probability trajectory prediction technique that improves reliability using the past trajectory information of moving objects in the road network environment. However, the prediction performance of this technique is lowered by the heavy load of extensive future trajectory search in long-range future queries, and its index maintenance cost is high due to the frequent update of future trajectory. Thus, this paper proposes the Probability Cell Trajectory-Tree (PCT-Tree), a cell-based future indexing technique for efficient long-range future location prediction. The PCT-Tree reduces the size of index by rebuilding the probability of extensive past trajectories in the unit of cell, and improves the prediction performance of long-range future queries. In addition, it predicts reliable future trajectories using information on past trajectories and, by doing so, minimizes the cost of communication resulting from errors in future trajectory prediction and the cost of index rebuilding for updating future trajectories. Through experiment, we proved the superiority of the PCT-Tree over existing indexing techniques in the performance of long-range future queries.

• Journal of KIISE:Databases
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• v.31 no.6
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• pp.624-640
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• 2004

Recently, with the rapid development of location-based techniques, index structures to efficiently manage moving objects have been required. In this paper, we propose a new spatio-temporal index structure that supports a future position retrieval and minimizes a update cost. The proposed index structure combines an assistant index structure that directly accesses current positions of moving objects with KDB-tree that is a space partitioning access method. The internal node in our proposed index structure keeps time parameters in order to support the future position retrieval and to minimize a update cost. Moreover, we propose new update and split methods to maximize the space utilization and the search performance. We perform various experiments to show that our proposed index structure outperforms the existing index structure.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.3
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• pp.309-319
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• 2023

Recently, the frequency and intensity of meteorological disasters have increased due to climate change. In South Korea, there are regional differences in vulnerability and response capability to cope with climate change because of regional climate characteristics. In particular, drought results from various factors and is linked to extensive meteorological, hydrological, and agricultural impacts. Therefore, in order to effectively cope with drought, it is necessary to use a composite drought index that can take into account various factors, and to evaluate future droughts comprehensively considering climate change. This study evaluated hydrologic risk(${\bar{R}}$) of future drought in the Nakdong River basin based on the Dynamic Naive Bayesian Classification (DNBC)-based composite drought index, which was calculated by applying Standardized Precipitation Index (SPI), Streamflow Drought Index (SDI), Evaporate Stress Index (ESI) and Water Supply Capacity Index (WSCI) to the DNBC. The indices used in the DNBC were calculated using observation data and climate scenario data. A bivariate frequency analysis was performed for the severity and duration of the composite drought. Then using the estimated bivariate return periods, hydrologic risks of drought were calculated for observation and future periods. The overall results indicated that there were the highest risks during the future period (2021-2040) (${\bar{R}}$=0.572), and Miryang River (#2021) had the highest risk (${\bar{R}}$=0.940) on average. The hydrologic risk of the Nakdong River basin will increase highly in the near future (2021-2040). During the far future (2041-2099), the hydrologic risk decreased in the northern basins, and increased in the southern basins.

• Atmosphere
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• v.23 no.2
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• pp.131-141
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• 2013

Many studies have related the recent variations of wildfire regime such as the increasing number of occurrances, their patterns and timing changes, and the severity of their extreme cases with global warming. However, there are only a few numbers of wildfire studies to assess how the future wildfire regime will change in the interactions between land and atmosphere with climate change especially over East Asia. This study was performed to estimate the future changing aspect of wildfire danger with global warming, using Haines Index (HI). Calculated from atmospheric instability and dryness, HI is the potential of an existing fire to become a dangerous wildfire. Using the Weather Research and Forecasting (WRF) model, two separated 5-year simulations of current (1995~1999) and far future (2095~2099) were performed and analyzed. Community Climate System Model 3 (CCSM3) model outputs were utilized for the model inputs for the past and future over East Asia; future prediction was driven under the IPCC A1B scenario. The results indicate changes of the wildfire danger regime, showing overall decreasing the wildfire danger in the future but intensified regional deviations between north and south. The overall changes of the wildfire regime seems to stem from atmospheric dryness which is sensitive to soil moisture variation. In some locations, the future wildfire danger overall decreases in summer but increases in winter or fall when the actual fire occurrence are generally peaked especially in South China.

• The Journal of the Korea Contents Association
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• v.4 no.4
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• pp.141-152
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• 2004

In this paper, we propose the index structure supporting the future position retrievals with efficiently updating continuous positions of moving objects in location based services. For reducing update costs of moving objects, our index structure directly accesses to the leaf node with moving objects using secondary index structure and performs bottom up update when node information is changed. Positions of moving objects are stored in primary index structure. In primary index structure, the split information similar to kd-tree is stored to internal node for increasing node's fanout. And the proposed index structure supports the future position retrievals using velocity of moving objects in the child node.

• STI Policy Review
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• v.1 no.2
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• pp.51-68
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• 2010

This paper compares OECD nations by developing a comprehensive evaluation index that examines the efforts and achievements of countries toward Low-Carbon Green Growth. The input-process-output of a Low-Carbon Society system is in dynamic competition with that of a High-Carbon Society system. The model used in this study of the comprehensive evaluation index for Low-Carbon Green Growth was comprised of Large indices such as Input, Process, and Output. The Input and Output consisted of 'Social-economic' and 'Physical-ecological' Middle indices while the Process was made up of 'Stimulation mechanisms' and 'Participation of stakeholders and Knowledge flow' Middle indices. In order to calculate the comprehensive evaluation index, our model gave a weight to each indicator/index and applied a weighted arithmetic mean. Korea ranked $15^{th}$ out of 30 OECD nations in the comprehensive evaluation that analyzed Input ($14^{th}$), Process ($18^{th}$), and Output ($17^{th}$). The top five nations were Switzerland, Sweden, Denmark, Germany, and France; while Japan was $8^{th}$ and the USA $26^{th}$.