• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.4
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• pp.24-35
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• 2011

This paper demonstrates a methodology of integrated operation and management system for intermodal connectivity center (ICC), which is planning to be build up as a large scale public transit facilities for green growth strategy by the national government. The ICC needs to be capable of providing the integrated location based information for the public transit users in terms of collaborating a variety of transit modes and complex facility in a large scale center. Recently, the upcoming information and communication technologies enable to come up with real time information provision on nomadic and portable devices, i.e. smart phones and/or tablet PCs, as what the users actually need to get on demand. In order to provide the public transit users in ICC with the integrated information on their smart phones for example, the integrated operation and management system plays a key role to collect the data utilizing the wireless communication with real time location tracking and to manage them to be effective and operational sources for applicable personalized services. Thus, this paper defines a type of services, subsystems, and relevant technologies for the system integration so called a "Smart Garatagi Service" and shows a filed test demonstration case in the existing airport terminal, Gimpo Domestic.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.1
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• pp.76-86
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• 2008

This paper estimates the TFP in IT manufacturing (total factor productivity) by employment size of establishment and analyses the determinants of it. And the panel data is consisted of time series and cross section data of 4 employment size of establishment over $1990{\sim}2004$. During the period from 1991 to 1997 TFP increased positively irrespective of the employment size of establishment, but from 1998 to 2004 TFP increase rate turned negative except large size(more than 300) of establishment. TFP assume macro variables and policy variables as the determinants of IT manufacturing TFP. The analysis of whole size of establishment shows that sales growth rate is significantly positive, which makes us conclude that there is a teaming by doing effect and economy of scale. But some variables(i.e. IT capital stock, policy financing, and openness etc.) are significant in only a few models. So there may be different effect by employment size of establishment. In TFP determinants analysis by employment size of establishment, we find that coefficients of policy financing and openness variables are significantly positive. The larger employment size of establishment is, the larger scale economy is. And for large size(more than 300) establishment, IT capital stock helps propel the increase of the productivity.

• Knowledge Management Research
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• v.23 no.1
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• pp.89-109
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• 2022

Due to COVID-19 and soaring participation of individual investors, large-scale transactions exceeding system capacity limits have been reported frequently in the capital market. The capital market IT systems, which the impact of system failure is very critical, have encountered unexpectedly tremendous transactions in 2020, resulting in a sharp increase in system failures. Despite the fact that many companies maintained large-scale system capacity planning policies, recent transaction influx suggests that a new approach to capacity planning is required. Therefore, this study developed capital market IT system capacity planning models using machine learning techniques and analyzed those performances. In addition, the performance of the best proposed model was improved by using sentiment index that can promptly reflect the behavior of investors. The model uses empirical data including the COVID-19 period, and has high performance and stability that can be used in practice. In practical significance, this study maximizes the cost-efficiency of a company, but also presents optimal parameters in consideration of the practical constraints involved in changing the system. Additionally, by proving that the sentiment index can be used as a major variable in system capacity planning, it shows that the sentiment index can be actively used for various other forecasting demands.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.342-343
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• 2009

Paper factories use a large amount of water and same amount of wastewater is generated. It is important to purity and recycle the wastewater because of water shortages and water pollution. The existing water treatment facilities like precipitation process need large-scale equipment and wide space to purity the wastewater of paper factory. High gradient magnetic separation (HGMS) system has the merits to purity rapidly because of large voids at filter and to occupy small space. In this paper, two types of superconducting magnets were used for HGMS systems. Cryo-cooled Bi-2223 superconducting magnet system with 70 mm room temperature bore and 200 mm of height was prepared. Cryo-cooled Nb-Ti superconducting magnet with 100 mm room temperature bore and 600 mm of height was used for magnetic separator. Magnetic filters were designed by the analysis of magnetic field distribution at superconducting magnets. The various magnetic seeding reactions were investigated to increase the reactivity of coagulation. The effects of magnetic separation of wastewater were investigated as variation of magnetic field strength and flow rate of wastewater.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.4
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• pp.408-415
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• 2000

Large scale shared memory multiprocessors have suffered from large access latency to shared memory. The large latency partially stems from a feature of directory-based cache coherence schemes which require a shared memory access to be serviced at a home node of the memory block. The home visit results in three or more hops traversal for a memory read access. The traversal becomes much longer as a system scales up. In this paper, we propose a new cache coherence scheme that reduces read access latency. The proposed scheme exploits ideas of invalid hint. Invalid hint for a cache block means which node has invalidated the cache block before. Thus a read access request can be directly sent to and serviced by the node (called owner) without help of a home node. Execution-driven simulation is employed to evaluate performance of the proposed scheme. The simulation results show that read access latency and execution time are reduced.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.05a
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• pp.4-4
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• 2009

Paper factories use a large amount of water and same amount of wastewater is generated. It is important to recycle the wastewater because of water shortages and water pollution. The existing water treatment facilities like precipitation process need large-scale equipment and wide space to purify the wastewater of paper factory. High gradient magnetic separation (HGMS) system has the merits to purify rapidly because of large voids at filter and to occupy small space. In this paper, two types of superconducting magnets were used for HGMS systems. Cryo-cooled Bi-2223 superconducting magnet system with 70 mm room temperature bore and 200 mm of height was prepared. Cryo-cooled Nb-Ti superconducting magnet with 100 mm room temperature bore and 600 mm of height was used for magnetic separator. Magnetic filters were designed by the analysis of magnetic field distribution at superconducting magnets. The various magnetic seeding reactions were investigated to increase the reactivity of coagulation. The effects of magnetic separation of wastewater were investigated as variation of magnetic field strength and flow rate of wastewater.

• Atmosphere
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• v.26 no.1
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• pp.85-95
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• 2016

In this study, we investigated the variabilities of wind speed of 850 hPa and precipitable water over the East Asia region using the NCEP Final Analysis data from December 2001 to November 2011. A large variance of wind speed was observed in northern and eastern China during the winter period. During summer, the regions of the East China Sea, the South Sea of Japan and the East Sea show large variances in the wind speed caused by an extended North Pacific High and typhoon activities. The large variances in the wind speed in the regions are shown to be correlated with the inter-annual variability of precipitable water over the inland region of windward side of the Korean Peninsula. Based on the investigation, sensitivity tests to the domain size were performed using the WRF model version 3.6 for heavy precipitation events over the Korean Peninsula for 26 and 27 July 2011. Numerical experiments of different domain sizes were set up with 5 km horizontal and 50 levels vertical resolutions for the control and the first experimental run, and 9 km horizontal for the second experimental run. We found that the major rainfalls correspond to shortwave troughs with baroclinic structure over Northeast China and extended North Pacific High. The correlation analysis between the observation and experiments for 1-h precipitation indicated that the second experiment with the largest domain had the best performance with the correlation coefficient of 0.79 due to the synoptic-scale systems such as short-wave troughs and North Pacific High.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.4
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• pp.254-259
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• 2014

In this paper, we describe construction of a wind stabilization demo-site and effects of output power control of wind turbines for suppression of ramp rate using ESS (Energy Storage System). It is difficult to control the output power of distributed generator such as wind turbine which of variation is very large. If the large capacity wind farm be interconnected into power system may cause blackout due to Power Quality. For these reasons, the international standards such as Grid-Code is limited to less than 10 [%/min] of renewable energy ramp rate. The case of Korea, government actively conducts propagating large-scale renewable energy for green growth policy, to interconnecting more renewable energy into power system is necessary for stabilization technology. For these reasons, the POSCO consortium has constructed a wind stabilization demo-site that is configured as 500 [kWh] battery energy storage systems can output up to 3 [C-Rate] and two wind turbines rated 750 [kW]. In POSCO consortium, which implements various methods stabilizing output power of wind turbine such as smoothing, section firming and ramp control, we derive the results of long-term demonstration that can be controlled to satisfy to the international standard about ramp rate [%/kW] of wind turbine output power.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.2
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• pp.263-283
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• 2024

Users' comments after online shopping are critical to product reputation and business improvement. These comments, sometimes known as e-commerce reviews, influence other customers' purchasing decisions. To confront large amounts of e-commerce reviews, automatic analysis based on machine learning and deep learning draws more and more attention. A core task therein is sentiment analysis. However, the e-commerce reviews exhibit the following characteristics: (1) inconsistency between comment content and the star rating; (2) a large number of unlabeled data, i.e., comments without a star rating, and (3) the data imbalance caused by the sparse negative comments. This paper employs Bidirectional Encoder Representation from Transformers (BERT), one of the best natural language processing models, as the base model. According to the above data characteristics, we propose the F_MixBERT framework, to more effectively use inconsistently low-quality and unlabeled data and resolve the problem of data imbalance. In the framework, the proposed MixBERT incorporates the MixMatch approach into BERT's high-dimensional vectors to train the unlabeled and low-quality data with generated pseudo labels. Meanwhile, data imbalance is resolved by Focal loss, which penalizes the contribution of large-scale data and easily-identifiable data to total loss. Comparative experiments demonstrate that the proposed framework outperforms BERT and MixBERT for sentiment analysis of e-commerce comments.

• Journal of the Korean association of regional geographers
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• v.3 no.2
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• pp.121-150
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• 1997

This Study puts the purpose to explicate the regionalities of land-lease farming by a comparative analisis of the five case study areas in Kungpook Province as the agricultural space system of Teagu metropolitan city. For the regional comparative analysis the province was divided into the three zones with the distance from the central city(Teagu): urban fringes, intermediate and remote zone, and then subdivided into the five regions by farming systems : horticulture, rice-farming, and dry-field farming. The data were collected from 77 land-leasing farmers by questionnaire and interview with farm managers in 5 sample villages representing the regionalities of the above five regions respectively. In spite of relatively restricted scope of the research areas, the analytical results appear remarkable regional differences in the characteristics of land-lease farming within a single agricultural space system. In the final analysis the regionalities of the five land-lease farming regions could be described respectively as follows. (1) Koryong-Gun in the inner urban fringe zone : The developing land-lease farming region of commercialized suburban horticulture with medium scale. (2) Songju-Gun in the outer urban fringe zone : The developing land-lease farming region of highly commercialized horticulture with large scale. (3) Uisong-Gun in the intermediate zone : The stagnated land-lease farming region of commercialized rice-farming with large scale. (4) Yongil-Gun in the intermediate zone : The stagnated land-lease farming region of commercializing dry-field farming with medium scale. (5) Ponghwa-Gun in the remote zone : The stagnated and delayed region in commercializing of intermountain dry-field land-lease farming with small scale. These varied regionalities resulted from the diverse spatiality as a complex of spatial orders and localities. The spatial orders in this study are frequently recognizable as a form of distance-decay, and the locality of a region is determined mostly by the its peculiarity of physical and population conditions. In the comparative analysis of the regionalities the degree of commercialization of a region is a most comprehensive and useful frame of reference because it reflects the degree of development of capitalist land-lease farming. Finally these apparent regional differentiations of land-lease farming within a agricultural space system raise the problem of impracticality of the existing uniform logic on the land-lease farming such as "large scale farms share larger part of leased farmland." This problem suggests the urgent need of reappraisal of many aspatial logics and theories on the land-lease farming.