• Journal of The Geomorphological Association of Korea
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• v.20 no.4
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• pp.1-13
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• 2013

Padori beach is one of the representative composite mixed beach in Korea and shows divert geomorphic landscape change. It belongs to the Taean National Park. The purpose of this study is to clarify movement mechanism of sediments from sediment distribution of Padori beach associated with morphology. In addition, it is to explain morphological landscape change under different wave and tide condition in the composite mixed beach consisting of a dissipative low tide terrace and a reflective beach face with a high tide range of 5 to 7m. The results of this study are: First, the mean grain size of sediments becomes smaller from the south of the beach, where there is a wide wave-cut platform, to the north because gravels are supplied from the wave-cut platform as well as sea-cliff in the south of the beach. A sedimentation pattern of the sandy gravel on the beach face and gravel on the berm, and gradation phenomena of grain size on cross-shore and alongshore direction in the beach can be explained with a pattern of sediment movement, overpassing, in the composite mixed beach. Second, micro-topography on beach face and berm were changed depending on effects of wave height and tide. As a result, in low-wave energy environments, a berm is developed in large size, and beach cusps are formed on the upper beach face, while in high-wave energy environments, a berm is built up in relatively small size, and mixture of sediments occur on the upper beach face.

• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.1
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• pp.13-24
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• 2021

Tunnel boring machine (TBM) is widely used for tunnel excavation in hard rock and soft ground. In the perspective of TBM-based tunneling, one of the main challenges is to drive the machine optimally according to varying geological conditions, which could significantly lead to saving highly expensive costs by reducing the total operation time. Generally, drilling investigations are conducted to survey the geological ground before the TBM tunneling. However, it is difficult to provide the precise ground information over the whole tunnel path to operators because it acquires insufficient samples around the path sparsely and irregularly. To overcome this issue, in this study, we proposed a geological type classification system using the TBM operating data recorded in a 5 s sampling rate. We first categorized the various geological conditions (here, we limit to granite) as three geological types (i.e., rock, soil, and mixed type). Then, we applied the preprocessing methods including outlier rejection, normalization, and extracting input features, etc. We adopted a deep neural network (DNN), which has 6 hidden layers, to classify the geological types based on TBM operating data. We evaluated the classification system using the 10-fold cross-validation. Average classification accuracy presents the 75.4% (here, the total number of data were 388,639 samples). Our experimental results still need to improve accuracy but show that geology information classification technique based on TBM operating data could be utilized in the real environment to complement the sparse ground information.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.3
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• pp.830-860
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• 2022

[Introduction] Nowadays, many companies are shifting their businesses online due to the growing trend among customers to buy and shop online, as people prefer online purchasing products. [Problem] Users share a vast amount of information about products, making it difficult and challenging for the end-users to make certain decisions. [Motivation] Therefore, we need a mechanism to automatically analyze end-user opinions, thoughts, or feelings in the social media platform about the products that might be useful for the customers to make or change their decisions about buying or purchasing specific products. [Proposed Solution] For this purpose, we proposed an automated SentiDecpective approach, which classifies end-user reviews into negative, positive, and neutral sentiments and identifies deceptive crowd-users rating information in the social media platform to help the user in decision-making. [Methodology] For this purpose, we first collected 11781 end-users comments from the Amazon store and Flipkart web application covering distant products, such as watches, mobile, shoes, clothes, and perfumes. Next, we develop a coding guideline used as a base for the comments annotation process. We then applied the content analysis approach and existing VADER library to annotate the end-user comments in the data set with the identified codes, which results in a labelled data set used as an input to the machine learning classifiers. Finally, we applied the sentiment analysis approach to identify the end-users opinions and overcome the deceptive rating information in the social media platforms by first preprocessing the input data to remove the irrelevant (stop words, special characters, etc.) data from the dataset, employing two standard resampling approaches to balance the data set, i-e, oversampling, and under-sampling, extract different features (TF-IDF and BOW) from the textual data in the data set and then train & test the machine learning algorithms by applying a standard cross-validation approach (KFold and Shuffle Split). [Results/Outcomes] Furthermore, to support our research study, we developed an automated tool that automatically analyzes each customer feedback and displays the collective sentiments of customers about a specific product with the help of a graph, which helps customers to make certain decisions. In a nutshell, our proposed sentiments approach produces good results when identifying the customer sentiments from the online user feedbacks, i-e, obtained an average 94.01% precision, 93.69% recall, and 93.81% F-measure value for classifying positive sentiments.

• Analyses & Alternatives
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• v.4 no.1
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• pp.63-87
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• 2020

This article not only theoretically explores the necessity and effect of constructive minilateralism and subregionalism in Northeast Asia, but also delves into a series of practical solutions from viewpoint of seeking common ground while reserving differences in this region. The main contents are as follows: First, the various obstacles that hinder the formation of regionalism, subregionalism and minilateralism in the Northeast Asia are discussed. That is to say, geopolitical realism, My Country First ideology, exclusive nationalism in the socio-historical context, and North Korea's latest provocations, etc. Second, this article explores the philosophy and basic principles of realizing Northeast Asia regionalism and minilateralism. Third, in the 21st century, Northeast Asia becomes the center of the world. It examines the core points, controversial focus and platform for building sub regionalism in the region. Finally, based on the institutional platform such as minilateralism and sub regionalism, the various ideas and practical plans of cross-border cooperation among major countries in Northeast Asia were discussed. Because there are a lot of obstacles, so first of all it is more appropriate to promote economic or functional minilateralism or sub regionalism than multilateral cooperation. In order to promote the formation of regionalism and minilateralism in Northeast Asia, the issues to be considered are as follows: First, for the sake of leading regional solidarity and minilateral economic cooperation, it is advisable for China, as a regional economic power, to implement a stable and responsible diplomacy. Secondly, regional solidarity based on credible politics and security should be promoted for a long time beyond the level of economic cooperation. Third, the primary prerequisite for the realization of Northeast Asian regionalism is that in the process of denuclearization of North Korea, the stability and peace mechanism of the Korean Peninsula should be established. Fourth, with the continued hegemonic competition between the United States and China in Northeast Asia, under the circumstance that countries in the region are pushed into so-called "East Asian Paradox", it is profoundly important for them to consider transition from the hostile relationship as the "Thucydides trap" to the order of "coexistence" in which competition and cooperation run side by side, and the two countries should explore a conversion plan for the foreign policy line. This mutual cooperation and peaceful coexistence of the US-China relationship will create a friendly atmosphere for the formation of regionalism in Northeast Asia. In the future, the cooperation of minilateralism in Northeast Asia will break the existing conflict between the maritime forces and the continental forces in order to promote peace. And along with the philosophy that "peace is economy", recent policies of common prosperity as the framework, such as China's "Belt and Road Initiative", North Korea's "Special Zone and Development Zone Policy", Russia's "New Eastern Policy", Japan's participation in the Belt and Road Initiative and South Korea's The "Korean Peninsula New Economy Map" are organically linked and it should promote the so-called "networked regionalism".

• Journal of the Korean Society for information Management
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• v.33 no.2
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• pp.157-176
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• 2016

Cited-by Linking Service is one of the CrossRef's information services that allows you to discover how your publications are being cited and to incorporate that information into your online publication platform. This study tries to investigate citation patterns in the field of both Natural Science and Engineering using all of DOI assigned articles and Cited-by Linking data which are accumulated and managed by KISTI. The investigating approach is designed to verify the theory of 1) cognitive accessibility, 2) 'perceived quality and significance' and 3) 'subject relativity'. For cognitive accessibility verification the fulltext language portion of Korean and English between "Cited DOI Source Data" and "NOT Cited DOI Source Data" was compared. For perceived quality and significance verification the availability of the "Cited DOI Source Data" and "NOT Cited DOI Source Data" from SCIE and SCOPUS was employed. For subject relativity DOI data were classified and analysed on the basis of OECD subject classification scheme. Findings are that global citability is closely related to the fulltext language of the articles and their quality and significance. And in the natural science field most of citations are from the same subject categories, while relatively more citations are from other subject categories in the engineering field.

• Journal of the Korean Society of Safety
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• v.35 no.5
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• pp.49-58
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• 2020

In domestic construction sites, when installing steel pipe scaffolding and system scaffolding, the guardrails are installed after the installation of the work platforms. This conventional guardrail system (CGS) is always exposed to the risk of falls because the safety railing is installed later. In order to prevent fall disasters during erecting and dismantling scaffolds, it is necessary to introduce the advanced guardrail system (AGS) which installs railings in advance of climbing onto a work platform. For the introduction of the AGS, the structural performance of the system scaffolding applying the CGS and the AGS was compared and evaluated. The structural analysis of the system scaffold (height: 31 m and width: 27.4 m) with AGS confirmed that structural safety was ensured because the maximum stress of each element of the system scaffolding satisfies the allowable stress of each element. As a result of performance comparison of CGS and AGS for each element, the combined stress ratio of vertical posts in AGS was 6.4% lower than that of CGS. In addition, in the case of ledger and transom, the combined stress ratios of AGS and CGS were almost the same. The compression test of the assembled system scaffolding (three-storied, 1 bay) showed that the AGS had better performance than the CGS by 9.7% (8.91 kN). The cross bracing exceeds the limit on slenderness ratio of codes for structural steel design. But the safety factor for the compressive load of the cross bracing was evaluated as meeting the design criteria by securing 3 or more. In actual experiments, it was confirmed that brace buckling did not occur even though the overall scaffold was buckled. Therefore, in the case of temporary structures, it was proposed to revise the standards for limiting on slenderness ratio of secondary or auxiliary elements to recommendations. This study can be used as basic data for the introduction of AGS for installing guardrails in advance at domestic construction sites.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.1
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• pp.73-79
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• 2009

In this paper, the structural analysis and optimization of the door supporting rail structure in the header box located at the top of the aluminum passenger safety door(PSD) at the subway station, which opens and closes regularly, is performed. In case the simple fixed boundary condition is used for the bolt fixture on the supporting rail where the glass door is moving, excessive stresses are obtained. Therefore, more realistic finite element modeling of the bolts is used at the bolt fixture in the whole structure in order to obtain the more physically acceptable FEM results. As a result, fatigue life of twenty years of the structure is obtained to satisfy the design object. Also the optimal design of cross section of the rail part is performed using the response surface method and 15% of weight of the supporting rail part on the door is reduced.

• Nuclear Engineering and Technology
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• v.41 no.5
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• pp.729-738
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• 2009

Given the evolution of High-Temperature Gas-cooled Reactor(HTGR) designs, the source terms for licensing must be developed. There are three potential source terms: fission products, actinides in the fuel and tritium in the coolant. It is necessary to provide first an inventory of the source terms under normal operations. An analysis of source terms has yet to be performed for HTGRs. The previous code, which can estimate the inventory of the source terms for LWRs, cannot be used for HTGRs because the general data of a typical neutron cross-section and flux has not been developed. Thus, this paper uses a combination of the MCNP, ORIGEN, and MONTETEBURNS codes for an estimation of the source terms. A method in which the HTR-10 core is constructed using the unit lattice of a body-centered cubic is developed for core modeling. Based on this modeling method by MCNP, the generation of fission products, actinides and tritium with an increase in the burnup ratio is simulated. The model developed by MCNP appears feasible through a comparison with models developed in previous studies. Continuous fuel management is divided into five periods for the feeding and discharging of fuel pebbles. This discrete fuel management scheme is employed using the MONTEBURNS code. Finally, the work is investigated for 22 isotope fission products of nuclides, 22 actinides in the core, and tritium in the coolant. The activities are mainly distributed within the range of $10^{15}{\sim}10^{17}$ Bq in the equilibrium core of HTR-10. The results appear to be highly probable, and they would be informative when the spent fuel of HTGRs is taken into account. The tritium inventory in the primary coolant is also taken into account without a helium purification system. This article can lay a foundation for future work on analyses of source terms as a platform for safety assessment in HTGRs.

• Geophysics and Geophysical Exploration
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• v.13 no.1
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• pp.109-117
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• 2010

To enable high-performance computing (HPC) for applications with large datasets using a $Sony^{(R)}$ $PLAYSTATION^{(R)}$ 3 ($PS3^{TM}$) video game console, we configured a hybrid system consisting of a $Windows^{(R)}$ PC and a $PS3^{TM}$. To validate this system, we implemented the real-time multiplet identifier (RTMI) application, which identifies multiplets of microearthquakes in terms of the similarity of their waveforms. The cross-correlation computation, which is a core algorithm of the RTMI application, was optimised for the $PS3^{TM}$ platform, while the rest of the computation, including data input and output remained on the PC. With this configuration, the core part of the algorithm ran 69 times faster than the original program, accelerating total computation speed more than five times. As a result, the system processed up to 2100 total microseismic events, whereas the original implementation had a limit of 400 events. These results indicate that this system enables high-performance computing for large datasets using the $PS3^{TM}$, as long as data transfer time is negligible compared with computation time.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.8
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• pp.2814-2832
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• 2014

As information society matures to an even higher level and as information technology becomes a necessity to our everyday lives, the needs to develop, support and satisfy personal and social needs without the limitation of time, space, and location have become a vital point to everyday lives. Smartphone users are increasing at a staggering rate but the research on mobile-Learning model and the implementation of m-Learning scenario are still behind the needs of the users. Therefore, this paper focuses on the design of 'repeatable and short-spanned m-Learning model' to meet the needs of the learners who are on the go and on the move with their smartphones. Smartphone users frequently reach out for their phones but compare to the frequencies, the actual span of time they spend per use are relatively and surprisingly short. One way to understand this phenomenon is that the users tend to immediately replace their smartphones with laptops or desktops whenever they are available. A leaning model was needed to reflect this short and frequent use, a use that is solely based on the smartphone environment. This proposed learning model first defines this particular setting and implements the model to real smartphone users over an 8 week period. To understand whether different learning backgrounds can influence this model, different schools with online and offline learning channels participated in the experiment. User survey was conducted after the experiment to get a better understanding of the smartphone users. Pretest and posttest were conducted before and after the experiment and the data were validated and analyzed using SPSS version 18.0 for PC. Preliminary descriptive statistics, multiple regression and cross validation was conducted for the analysis. The results showed that the proposed English Listening and Comprehension Mobile Digital Textbook (ELCMDT) had a positive effect on the learners in general and was more effective for learners who were already experienced with online learning.