• Fire Science and Engineering
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• v.33 no.1
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• pp.130-137
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• 2019

In this study, the acoustic characteristics of 13 types of emergency broadcasting speakers were tested under the test set-up of UL 2043 and compared. When the sound pressure level of 1 W speakers was compared with speakers with a 15 W output, the SPL of the 15 W speakers was approximately 20 dB higher in some frequency bands. Loudness analysis showed that people can recognize emergency sound from a 15 W speaker twice as loud as the emergency sound from 1 W speakers. The analysis results on the articulation index (room) had an opposite tendency with loudness results, meaning that small speakers can generate clearer sound. Therefore, it is necessary to improve emergency broadcasting speakers to generate louder and clearer sound. Moreover, a performance evaluation standard is needed based on the reasonable and quantitative measurements and evaluations of the acoustic characteristics of the emergency-broadcasting speakers so that a sufficient and clear sound can be generated in various spaces. In addition, it is necessary to establish standards for the clarity of emergency broadcasting in various spaces.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.8-17
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• 2018

A large urban region in Bangkok, Thailand is often inundated due to shallow water floods along the paved roads that have poor drainage facilities, and that can cause urban flooding. Existing methods, including using sand bags are not effective to prevent flooding in urban areas where the amount of sand is not sufficient. Thus, it is necessary to install artificial flood defense structures. However flooding and overflow defense equipment, which was developed in some advanced nations in Europe and in the USA, is highly expensive and complex construction methods are needed, therefore they are not suitable to be used in Southeast Asia. Thus, it is necessary to develop a flood rapid defense system(FRDS), which is inexpensive and simple to build, but is also highly functional. Thus, this study developed an FRDS that can be applied to Southeast Asia through the careful study of FRDS overviews, an analysis on the development trends in Korea and overseas, and the proposal of development needs and directions of the region. For the system developed, Korean Standards(KS) performance evaluations on leakage ratio deformation tests and impact resistance tests were conducted at the Outdoor Demonstration Test Center(Seosan) in the Korea Conformity Laboratories(KCL) and the system satisfied the standards of KS F 2639(leakage and deformation test) and KS F 2236(impact resistance test). The present study results can not only be applied to urban floods in Southeast Asian nations to cope with flood-related disasters, but also be utilized in flood prone regions and for major facilities in Korea. They can also induce scientific and pro-active responses from major local governments and facility management organizations in relation to urban floods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.430-439
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• 2019

In this study, a nonlinear impact analysis was performed to evaluate the safety and damage of an eco-pillar debris barrier with a hollow cross-section, which was proposed to improve constructability and economic efficiency. The construction of concrete eco-pillar debris barriers has increased recently. However, there are no design standards concerning debris barriers in Korea, and it is difficult to find a study on performance evaluations in extreme environments. Thus, an analysis of an eco-pillar debris barrier was done using the rock impact speed, which was estimated from the debris flow velocity. The diameters of rocks were determined by ETAG 27. The impact position, angles, and rock diameter were considered as variables. A concrete nonlinear material model was applied, and the estimation of damage was done by ABAQUS software. As a result, the damage ratio was found to be less than 1.0 at rock diameters of 0.3 m and 0.5 m, but it was 1.39 when the diameter was 0.7 m. This study could be used as basic data on impact force in the design of the cross section of an eco-pillar debris barrier.

• Journal of Korea Entertainment Industry Association
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• v.14 no.5
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• pp.27-35
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• 2020

In 2020, one after another, musicians started to hold non-contact online concerts as the pop music industry began to shrink due to the unprecedented "Covid-19" incident, in seeking for various channels and alternatives. Taking this into account, this study conducted a survey with BTS' "Bang Bang Con The Live" as the subject that was held June 2020 to see if they were qualified as an alternative format for quarantine-focused non-contact concerts. The survey was carried out with the content analysis of online concert videos participated by music experts and by collecting evaluations and alternative suggestions from the audiences. The study showed that the sample performance video well fulfilled the actual feels of offline concert elements (field visualization, face-to-face interaction, and responsive behavior), satisfaction, and convenience as an alternative concert format as an emergency correspondence. However, it was analyzed that there was a serious lack of empathy and realism with fans. Therefore, the study showed the possibility that BTS' "Bangbangcon The Live" will function as an alternative format for non-contact concerts, but suggests that measures such as supplementing digital communication systems and technology devices must be taken to be recognized as a level of settlement in the global music community as well as in Korea.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.3
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• pp.125-132
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• 2022

Sentence compression is a natural language processing task that generates concise sentences that preserves the important meaning of the original sentence. For grammatically appropriate sentence compression, early studies utilized human-defined linguistic rules. Furthermore, while the sequence-to-sequence models perform well on various natural language processing tasks, such as machine translation, there have been studies that utilize it for sentence compression. However, for the linguistic rule-based studies, all rules have to be defined by human, and for the sequence-to-sequence model based studies require a large amount of parallel data for model training. In order to address these challenges, Deleter, a sentence compression model that leverages a pre-trained language model BERT, is proposed. Because the Deleter utilizes perplexity based score computed over BERT to compress sentences, any linguistic rules and parallel dataset is not required for sentence compression. However, because Deleter compresses sentences only considering perplexity, it does not compress sentences by reflecting the linguistic information of the words in the sentences. Furthermore, since the dataset used for pre-learning BERT are far from compressed sentences, there is a problem that this can lad to incorrect sentence compression. In order to address these problems, this paper proposes a method to quantify the importance of linguistic information and reflect it in perplexity-based sentence scoring. Furthermore, by fine-tuning BERT with a corpus of news articles that often contain proper nouns and often omit the unnecessary modifiers, we allow BERT to measure the perplexity appropriate for sentence compression. The evaluations on the English and Korean dataset confirm that the sentence compression performance of sentence-scoring based models can be improved by utilizing the proposed method.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.2
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• pp.130-137
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• 2023

This study analyzed the effect of mixing order on the flowability, compressive strength, and flexural strength of cement composites reinforced with polyvinyl alcohol(PVA) fibers and multi-walled carbon nanotubes(MWCNTs). The experimental results showed that the addition of CNTs significantly reduced the flowability, and the flowability was considerably affected by the mixing order when CNTs were added. The compressive strength was most effectively improved when water and CNTs solution were mixed first before adding PVA fibers, and the flexural strength was highest when water and CNTs solution were mixed with PVA fibers after dry mixing. However, there was no clear correlation between the flexural toughness and the mixing order. In addition, scanning electron microscopy(SEM) image analysis was conducted to analyze the microstructure. The SEM images showed that CNTs were randomly dispersed through the specimens and contributed to the strength improvement, but the effect of the mixing order was not clearly observed. The main results of this study are expected to be useful for evaluations of workability and material performance of PVA fiber-reinforced cement composites with CNTs.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.1
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• pp.105-122
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• 2022

According to the statistics about the fatal crashes that have occurred on the expressways for the last 5 years, those who died on the shoulders of the road has been as 3 times high as the others who died on the expressways. It suggests that the crashes on the shoulders of the road should be fatal, and that it would be important to prevent the traffic crashes by cracking down on the vehicles intruding the shoulders of the road. Therefore, this study proposed a method to detect a vehicle that violates the shoulder lane by using the Faster R-CNN. The vehicle was detected based on the Faster R-CNN, and an additional reading module was configured to determine whether there was a shoulder violation. For experiments and evaluations, GTAV, a simulation game that can reproduce situations similar to the real world, was used. 1,800 images of training data and 800 evaluation data were processed and generated, and the performance according to the change of the threshold value was measured in ZFNet and VGG16. As a result, the detection rate of ZFNet was 99.2% based on Threshold 0.8 and VGG16 93.9% based on Threshold 0.7, and the average detection speed for each model was 0.0468 seconds for ZFNet and 0.16 seconds for VGG16, so the detection rate of ZFNet was about 7% higher. The speed was also confirmed to be about 3.4 times faster. These results show that even in a relatively uncomplicated network, it is possible to detect a vehicle that violates the shoulder lane at a high speed without pre-processing the input image. It suggests that this algorithm can be used to detect violations of designated lanes if sufficient training datasets based on actual video data are obtained.

• Asia Marketing Journal
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• v.11 no.4
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• pp.49-67
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• 2010

Previous researches have proven that corporate social responsibility(adhere CSR) is positively related to corporate performance. But Most of CSR related researches have several limitations. One of limitations is that those researches treated CSR as unidimensional construct. Almost researchers in the area of CSR concepts insisted that CSR is consist of multi dimensions. Carroll's four dimensions of CSR have been utilized by numerous academicians. Carroll asserted that CSR is composed of four dimensions: economic, legal, ethical, and philanthropic responsibility. But Carroll's dimensions were revised as three dimensions by Schwartz and Carroll, because ethical and philanthropic responsibility are not mutually exclusive. If CSR construct is composed of multiple dimensions, a message related to one of dimensions changes beliefs or evaluations about other dimensions that are not mentioned in the message. This phenomenon is called as "spillover effect". According to Ahluwalia, Unnava, and Burnkrant, negative information spills over to attributes that are associated with the target attributes but not mentioned in the message. Like this, this preponderant effect of negative information over positive information has been termed the "negativity effect". In this paper, authors try to prove the spillover effect and negativity effect among Schwartz and Carroll's three dimensions(economic, legal, and ethical responsibility) of CSR. The results of this study show that messages related to legal and ethical responsibility cause spillover effect and influence consumers' evaluation to other dimensions. Moreover, when negativity effect is added on spillover effect, spillover effect is more increased. It means that negative messages related to legal and ethical responsibility is more harmful to corporate image than negative message related to economic responsibility. The results of this study will help companies to manage corporate image using CSR messages as marketing communication tools. Companies should manage messages related to legal and ethical responsibility for more efficiently managing corporate image. Specially, because negative messages related to legal and ethical responsibility are more harmful to corporate image, companies must take care not to spread out negative message related to legal and ethical responsibility. Finally, we discuss the implications of the findings and limitations.

• Membrane Journal
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• v.33 no.6
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• pp.352-361
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• 2023

Steam methane reforming is currently the most widely used technology for producing hydrogen, a clean fuel. Hydrogen produced by steam methane reforming contains impurities such as carbon monoxide, and it is essential to undergo an appropriate post-purification step for commercial usage, such as fuel cells. Recently, membrane separation technology has been gaining great attention as an effective purification method; in this study, we evaluated the feasibility of using commercial polysulfone membranes for biogas upgrading to separate and recover hydrogen from a hydrogen/carbon monoxide gas mixture. Initially, we examined the physicochemical properties of the commercial membrane used. We then conducted performance evaluations of the commercial membrane module under various conditions using mixed gas, considering factors such as stage-cut and operating pressure. Finally, based on the evaluation results, we carried out simulations for process design. The maximum H₂ permeability and H₂/CO separation factor for the commercial membrane process were recorded at 361 GPU and 20.6, respectively. Additionally, the CO removal efficiency reached up to 94%, and the produced hydrogen concentration achieved a maximum of 99.1%.

• Ecology and Resilient Infrastructure
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• v.10 no.4
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• pp.116-124
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• 2023

As the flood damage on small streams increase due to the increase in frequency of extreme climate events, the need to measure hydraulic data of them has increased for disaster risk management. National Disaster Management Institute, Ministry of Interior and Safety develops CADMT, a CCTV-based automatic discharge measurement technology, and operates pilot small streams to verify its performance and develop disaster risk management technology. The research selects two small streams such as the Neungmac and the Jungsunpil streams to develop the Nomograph by using the 4-Parameter Logistic method using only the observed rainfall data from the Automatic Weather System operated by the Korea Meteorological Agency closest to the small streams and discharge data collected by using the CADMT. To evaluate developed Nomograph, the research forecasts floods discharges in each small stream and compares the result with the observed discharges. As a result of the evaluations, the forecasted value is found to represent the observed value well, so if more accurate observed data are collected and the Nomograph based on it is developed in the future, the high-accuracy flood prediction and warning will be possible.