• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.23 no.2
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• pp.121-131
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• 2020

Purpose: To determine the long-term efficacy of the anti-tumor necrosis factor (TNF) agents, infliximab (IFX) and adalimumab (ADA), in pediatric luminal Crohn's disease (CD) by performing a systematic literature review. Methods: An electronic search was performed in Medline, Embase, and the Cochrane Library from inception to September 26, 2019. Eligible studies were cohort studies with observation periods that exceeded 1 year. Studies that reported time-to-event analyses were included. Events were defined as discontinuation of anti-TNF therapy for secondary loss of response. We extracted the probabilities of continuing anti-TNF therapy 1, 2, and 3 years after initiation. Results: In total, 2,464 papers were screened, 94 were selected for full text review, and 13 studies (11 on IFX, 2 on ADA) met our eligibility criteria for inclusion. After 1 year, 83-97% of patients were still receiving IFX therapy. After 2 and 3 years the probability of continuing IFX therapy decreased to 67-91% and 61-85%, respectively. In total, 5 of the 11 studies subgrouped by concomitant medication consistently showed that the probabilities of continuing IFX therapy in patients with prolonged immunomodulator use were higher than those in patients on IFX monotherapy. Conclusion: This review of real-world evidence studies confirms the long-term therapeutic benefit of IFX therapy in diverse cohorts of children with luminal CD. Moreover, it supports the view that combination therapy with an immunomodulator prolongs the durability of IFX therapy in patients who previously failed to recover following first-line therapy. The limited number of time-to-event studies in patients on ADA prevented us from drawing definite conclusions about its long-term efficacy.

• Journal of Radiation Protection and Research
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• v.29 no.3
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• pp.157-163
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• 2004

Atmospheric dispersion modelling has been widely used to predict the fate and transport of radioactive or toxic materials released from nuclear facilities which is an unlikely accidental event. To improve the forecasting performance of the dispersion model, it is required that source rate and dispersion characteristics must be defined appropriately. Generally, source term of the radioactive materials is much uncertain at the early phase of an accidental event. In this study, we computed the source rate with the experimental field data monitored at the Yeoung-Kwang nuclear site and obtained the optimal source rate to minimize the errors between the measured concentrations and the computed ones by the Gaussian plume model. Computed source term showed a good result within 24% of the artificially released source rate.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.9
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• pp.31-37
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• 2020

The purpose of this research study is to examine the stock market's response to terrorist attacks. The study uses data of terrorist attacks in different parts of the country (Pakistan) from June 1, 2014 to May 31, 2017. The event window procedure applies to a 16-day window in which 5 days before and 10 days after the attack. In addition, several event windows have been built to test the response of the Pakistan Stock Exchange. KSE-100 index is taken as proxy of response. The total terrorist attacks are classified into four categories: attacks on law enforcement agencies, attacks on civilians, attacks on special places and attacks on politicians, government employees and bureaucrats. The standard market model is used to estimate the abnormal return of the Pakistan Stock Exchange, which takes 252 business days each year. Furthermore, BMP test is used to check statistical significance of cumulative abnormal rate of return (CAAR). The results of this study reveal that total number of terrorist attacks and attacks on law enforcement agencies show long-term effects on Pakistan stock exchange. However, attacks on civilians, attacks on special places and attacks on politicians, government employees and bureaucrats have little effect on the Pakistan Stock Exchange.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.215-219
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• 2005

A macro spreadsheet model, WEANES (Wet Pond Annual Efficiency Simulation Model), has been developed to predict the long-term or annual removal efficiencies of wet retention/detention basins. The model uses historical, site-specific, multi-year, rainfall data, usually available from a nearby National Oceanic and Atmospheric Administration (NOAA) climatological station to estimate basin efficiencies which are calculated based on annual mass loads. Other required input parameters are: 1) watershed parameters; drainage area, pervious curve number, directly connected impervious area, and ti me of concentration, 2) pond parameters; control and overflow elevations, pond side slopes, surface areas at control elevation and pond bottom; 3) outlet structure parameters; 4) pollutant event mean concentrations; and 5) pond loss rate which is defined as the net loss due to evaporation, infiltration and water reuse. The model offers default options for parameters such as pollutant event mean concentrations and pond loss rate. The model can serve as a design, planning, and permitting tool for consulting engineers, planners and government regulators.

• Journal of Electrical Engineering and Technology
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• v.4 no.4
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• pp.476-484
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• 2009

This paper deals with improvements to the special protection schemes (SPS) which have been applied to the low probability and high impact contingencies in the Korea Electric Power Corporation (KEPCO) system since 2004. Among them, the SPS for voltage instability in the Seoul metropolitan area is considered in this paper, and is a form of event-based undervoltage load shedding with a single-step scheme. Simulation results based upon a recent event that occurred on 765kV lines show that the current setting values of the SPS have to be revised and enhanced. In addition, by applying response-based multi-step undervoltage load shedding (UVLS) schemes to severe contingencies in the system, more effective results than those of the existing single-step SPS can be obtained. Centralized and distributed UVLS schemes are considered in the simulation. ULTC-based load recovery models and over excitation limiters (OXL) for the KEPCO system are also included in the long-term voltage instability studies.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.73-81
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• 1999

Inchon Port is the second largest import-export port of Korea, and has the point ant issue such as the excessive logistics cost because of the limits of handing capacity and the chronic demurrage. There is few research activities on the analysis and improvement of the whole port operation, because Inchon Port not only has the dual dock system and various facilities but also handles a various kind of cargo. The purpose of this paper is to develop the simulation program as a long-term strategic support tool, considering the dual dock system and the TOC(terminal operation company) system executed from March, 1997 in Inchon Port. The basic input parameters such as arrival intervals, cargo tons, service rates are analyzed and the probability density function for this parameters are estimated. The main mechanism of simulation model is the discrete event-driven simulation and the next-event time advancing. The program is executed based on the knowledge base and database, and is constructed using VISUAL BASIC and ACCESS database. From the simulation model, it is possible to estimate the demurrage status through analyzing scenarios such as the variation of cargo ton and cargo handing level, the increase of service rate, and so on, and to establish the long-term port strategic plan.

• Korean Journal of Remote Sensing
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• v.27 no.3
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• pp.259-276
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• 2011

Short-term land cover changes, such as forest fire scar and crop harvesting, can be detected by high temporal resolution satellite imagery like MODIS and AVHRR. Because these optical satellite images are often obscured by clouds, the static cloud-free composite methods (maximum NDVI, minblue, minVZA, etc.) has been used based on non-overlapping composite period (8-day, 16-day, or a month). Due to relatively long time lag between successive images, these methods are not suitable for observing short-term land cover changes in near-real time. In this study, we suggested a new dynamic cloud-free composite algorithm that uses cut-and-patch method of cloud-masked daily MODIS data using MOD35 products. Because this dynamic composite algorithm generates daily cloud-free MODIS images with the most recent information, it can be used to monitor short-term land cover changes in near-real time. The dynamic composite algorithm also provides information on the date of each pixel used in compositing, thereby makes accurately identify the date of short-term event.

• STI Policy Review
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• v.9 no.1
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• pp.55-76
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• 2018

This study analyzed the effect of the government R&D subsidy program on long-term firm survival. In order to estimate the average treatment effect for the treated group, we used the survival analysis and matching method by constituting a comprehensive dataset of more than 90,000 observations. The analysis results show that the government R&D subsidy has a negative impact on long-term firm survival. In particular, not only the subsidy does not have a statistically significant effect on firm survival in the relatively short-term, the survival probability of the subsidized firms is statistically significantly lower than the non-subsidized firms after six years. These results can be seen as weakening the justification of government R&D support. There may be problems in the subsidy policy itself and the process of selection of subsidy awardees; however, the more fundamental problem is that the subsidy policy is concluded as the one-time event. Admittedly, it would be difficult for the government to precisely manage the subsidized projects over a long term period. However, in the case of a project in which short-term performance is detected, it would be necessary to provide a step-by-step support to strengthen the firm's competitiveness through further support and continuous development of performance. Of course, mid- and long-term evaluations of subsidy support policy should be performed in parallel with such phased support.

• Smart Media Journal
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• v.6 no.3
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• pp.41-48
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• 2017

Event detection using social media has been widespread since social network services have been an active communication channel for connecting with others, diffusing news message. Especially, the real-time characteristic of social media has created the opportunity for supporting for real-time applications/systems. Social network such as Twitter is the potential data source to explore useful information by mining messages posted by the user community. This paper proposed a novel system for temporal event detection by analyzing social data. As a result, this information can be used by first responders, decision makers, or news agents to gain insight of the situation. The proposed approach takes advantages of deep learning methods that play core techniques on the main tasks including informative data identifying from a noisy environment and temporal event detection. The former is the responsibility of Convolutional Neural Network model trained from labeled Twitter data. The latter is for event detection supported by Recurrent Neural Network module. We demonstrated our approach and experimental results on the case study of earthquake situations. Our system is more adaptive than other systems used traditional methods since deep learning enables to extract the features of data without spending lots of time constructing feature by hand. This benefit makes our approach adaptive to extend to a new context of practice. Moreover, the proposed system promised to respond to acceptable delay within several minutes that will helpful mean for supporting news channel agents or belief plan in case of disaster events.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.6
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• pp.1229-1236
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• 2015

In this study, flow characteristics and bed changes during a short term flood event were analyzed using the two-dimensional CCHE2D model for a meandering sand-bed river, the Naesung Stream. Flow and bed change simulation was carried along the three sub-reaches with sinuosity of 1.2, 1.6 and 2.2 for the 6-day flood event occurring in June 2011. The simulation results indicated that velocity variation due to flow concentration was larger along the sub-reach with the sinuosity less than 1.5 and bed erosion at the outside of the bend was increased by time. In the sub-reach with the sinuosity less than 1.5, the maximum flood discharge produced the maximum flow velocity over 1.6 m/s to 2 m/s locally.