• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.1
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• pp.109-119
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• 2004

A design procedure for velocity-dependent supplemental dampers, such as viscous or viscoelastic dampers, required to meet the desired performance objectives was developed using displacement spectra. The amount of supplemental damping required to satisfy given performance limit state was obtained first from the nonlinear static procedure using displacement spectra, then dampers were appropriately distributed throughout the stories to realize the required damping. The proposed method was applied to multi-story steel frames, and the structures were analyzed by time history analysis to validate the accuracy of the design procedure. According to the analysis results the maximum displacements of the model structures retrofitted by the supplemental dampers turned out to be restrained well within the given target values.

• Structural Engineering and Mechanics
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• v.72 no.2
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• pp.141-153
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• 2019

The effect of galleries on the earthquake behavior of dams should be investigated to obtain more realistic results. Therefore, a roller compacted concrete (RCC) dam with and without galleries are examined under ground motion effects. For this purpose, Cine RCC dam constructed in Aydın, Turkey, is selected in applications. The optimal mesh around galleries is investigated to obtain the most realistic results. Two-dimensional finite element models of Cine RCC dam with and without galleries are prepared by using ANSYS software. Empty and full reservoir conditions were taken into account in the time-history analyses. Hydrodynamic effect of the reservoir water was taken into account considering two-dimensional fluid finite elements based on the Lagrangian approach. It is examined that how principle stresses and displacements change by height and during earthquake. The dam-foundation-reservoir interaction was taken into consideration with contact-target element pairs. The displacements and principle stress components obtained from the linear analyses are compared each other for various cases of reservoir water and galleries. According to numerical analyses, the effect of galleries is clear on the response of RCC dam. Besides, hydrodynamic water effect obviously increases the principle stress components and horizontal displacements of the dam.

• Cross-Cultural Studies
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• v.31
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• pp.415-438
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• 2013

This paper explores how to teach Chinese, using multi-media resources such as Chinese dramas and focusing on one of Jin Yong's dramas, The Return of the Condor Heroes. The purpose of this study is to develop teaching methodologies for university students learning Chinese through drama to integrate language skills: enhancing communicative competence and understanding Chinese cultures. First, the overview of previous studies provides several cases of foreign language education using drama. Teaching Chinese through drama can be an integrative education because students can develop their communicative competence as well as understand the cultures of the target language. In other words, the contexts of drama may offer rich sources of the history of China, Han Chinese ethnocentrism, and knowledge of Chinese literature as well as geography. Second, this study applies the principles of Tomlinson (2010) for materials development in language teaching into the case of Chinese drama. It concentrates on Jin Yong's The Return of the Condor Heroes that the author has used in the Chinese language courses for three years. It examines the characteristics of the drama for developing effective ways of teaching and learning Chinese language and culture. Furthermore, it discusses the impact of using drama on changes in students' pervasive perceptions about unnecessity of Chinese classical literature. Third, this paper presents some sample lessons which may help teachers to develop understanding of how to organize lessons through drama. Finally, it illustrates university students' opinions about using drama to learn Chinese.

• Journal of Korean Neurosurgical Society
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• v.62 no.3
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• pp.361-365
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• 2019

Epilepsy has been known to humankind since antiquity. The surgical treatment of epilepsy began in the early days of neurosurgery and has developed greatly. Many surgical procedures have stood the test of time. However, clinicians treating epilepsy patients are now witnessing a huge tide of change. In 2017, the classification system for seizure and epilepsy types was revised nearly 36 years after the previous scheme was released. The actual difference between these systems may not be large, but there have been many conceptual changes, and clinicians must bid farewell to old terminology. Paradigms in drug discovery are changing, and novel anti-seizure drugs have been introduced for clinical use. In particular, drugs that target genetic changes harbor greater therapeutic potential than previous screening-based compounds. The concept of focal epilepsy has been challenged, and now epilepsy is regarded as a network disorder. With this novel concept, stereotactic electroencephalography (SEEG) is becoming increasingly popular for the evaluation of dysfunctioning neuronal networks. Minimally invasive ablative therapies using SEEG electrodes and neuromodulatory therapies such as deep brain stimulation and vagus nerve stimulation are widely applied to remedy dysfunctional epilepsy networks. The use of responsive neurostimulation is currently off-label in children with intractable epilepsy.

• Earthquakes and Structures
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• v.16 no.4
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• pp.437-453
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• 2019

This study investigates a new optimal placement method for viscous dampers between structures in order to prevent pounding of adjacent structures with different dynamic characteristics under earthquake effects. A relative displacement spectrum is developed in two single degree of freedom system to reveal the critical period ratios for the most risky scenario of collision using El Centro earthquake record (NS). Three different types of viscous damper design, which are classical, stair and X-diagonal model, are considered to prevent pounding on two adjacent building models. The objective function is minimized under the upper and lower limits of the damping coefficient of the damper and a target modal damping ratio. A new algorithm including time history analyses and numerical optimization methods is proposed to find the optimal dampers placement. The proposed design method is tested on two 12-storey adjacent building models. The effects of the type of damper placement on structural models, the critical period ratios of adjacent structures, the permissible relative displacement limit, the mode behavior and the upper limit of damper are investigated in detail. The results of the analyzes show that the proposed method can be used as an effective means of finding the optimum amount and location of the dampers and eliminating the risk of pounding.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.11
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• pp.5344-5356
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• 2018

Nowadays with the help of Location-Based Social Networks (LBSNs), users of Point-of-Interest (POI) recommendation service in LBSNs are able to publish their geo-tagged information and physical locations in the form of sign-ups and share their experiences with friends on POI, which can help users to explore new areas and discover new points-of-interest, and promote advertisers to push mobile ads to target users. POI recommendation service in LBSNs is attracting more and more attention from all over the world. Due to the sparsity of users' activity history data set and the aggregation characteristics of sign-in area, conventional recommendation algorithms usually suffer from low accuracy. To address this problem, this paper proposes a new recommendation algorithm based on a novel Preference-Content-Region Model (PCRM). In this new algorithm, three kinds of information, that is, user's preferences, content of the Point-of-Interest and region of the user's activity are considered, helping users obtain ideal recommendation service everywhere. We demonstrate that our algorithm is more effective than existing algorithms through extensive experiments based on an open Eventbrite data set.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.9
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• pp.3258-3273
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• 2021

Malware is a severe threat to the computing system and there's a long history of the battle between malware detection and anti-detection. Most traditional detection methods are based on static analysis with signature matching and dynamic analysis methods that are focused on sensitive behaviors. However, the usual detections have only limited effect when meeting the development of malware, so that the manual update for feature sets is essential. Besides, most of these methods match target samples with the usual feature database, which ignored the characteristics of the sample itself. In this paper, we propose a new malware detection method that could combine the features of a single sample and the general features of malware. Firstly, a structure of Directed Cyclic Graph (DCG) is adopted to extract features from samples. Then the sensitivity of each API call is computed with Markov Chain. Afterward, the graph is merged with the chain to get the final features. Finally, the detectors based on machine learning or deep learning are devised for identification. To evaluate the effect and robustness of our approach, several experiments were adopted. The results showed that the proposed method had a good performance in most tests, and the approach also had stability with the development and growth of malware.

• Architectural research
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• v.22 no.4
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• pp.135-143
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• 2020

The Netherlands is a human-made country and an extremely well-designed European country as well. The general Dutch spatial planning for the city and environment takes place at a regional level. The local community determines the primary development conditions, and the prospect is included in a legally binding land-use plan. Especially, Rotterdam is a representative port city as the center of world trade and the gateway to western Europe. According to the history of war, the city reconstruction and the movement of the port area have led to a general change in Rotterdam and the regional redevelopment project on the southern port area of Mass river for the expansion of city functions and the balanced development. The research purpose is to understand the spatial development of the Netherlands city-region based on the analysis regarding the Kop van Zuid project, which is a representative implemented case in Rotterdam. The theoretical framework is the five dimensions and twelve indicators of territorial governance from the TANGO research project by the EU. The target case is assessed by planning and social aspect, respectively, and the results are discussed based on the theoretical framework. This research has the possibility to be utilized as advanced research by the European perspective for spatial development in other city-regions with the port area, such as Incheon and Busan in Korea.

• Progress in Medical Physics
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• v.31 no.3
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• pp.63-70
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• 2020

Stereotactic radiosurgery is one of the most sophisticated forms of modern advanced radiation therapy. Unlike conventional fractionated radiotherapy, stereotactic radiosurgery uses a high dose of radiation with steep gradient precisely delivered to target lesions. Lars Leksell presented the principle of radiosurgery in 1951. Gamma Knife^® (GK) is the first radiosurgery device used in clinics, and the first patient was treated in the winter of 1967. The first GK unit had 179 cobalt 60 sources distributed on a hemispherical surface. A patient could move only in a single direction. Treatment planning was performed manually and took more than a day. The latest model, Gamma Knife^® Icon^TM, shares the same principle but has many new dazzling characteristics. In this article, first, a brief history of radiosurgery was described. Then, the physical properties of modern radiosurgery machines and physicists' endeavors to assure the quality of radiosurgery were described. Intrinsic characteristics of modern radiosurgery devices such as small fields, steep dose distribution producing sharp penumbra, and multi-directionality of the beam were reviewed together with the techniques to assess the accuracy of these devices. The reference conditions and principles of GK dosimetry given in the most recent international standard protocol, International Atomic Energy Agency TRS 483, were shortly reviewed, and several points needing careful revisions were highlighted. Understanding the principles and physics of radiosurgery will be helpful for modern medical physicists.

• Steel and Composite Structures
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• v.44 no.2
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• pp.283-294
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• 2022

In this study, a new seismic retrofit scheme of building structures is developed by combining a steel moment frame and steel slit plates to be installed inside of an existing reinforced concrete frame. This device has the energy dissipation capability of slit dampers with slight loss of stiffness compared to the conventional steel frame reinforcement method. In order to investigate the seismic performance of the retrofit system, it was installed inside of a reinforced concrete frame and tested under cyclic loading. Finite element analysis was carried out for validation of the test results, and it was observed that the analysis and the test results match well. An analytical model was developed to apply the retrofit system to a commercial software to be used for seismic retrofit design of an example structure. The effectiveness of the retrofit scheme was investigated through nonlinear time-history response analysis (NLTHA). The cyclic loading test showed that the steel frame with slit dampers provides significant increase in strength and ductility to the bare structure. According to the analysis results of a case study building, the proposed system turned out to be effective in decreasing the seismic response of the model structure below the given target limit state.