• Clinical Pain
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• v.19 no.1
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• pp.23-27
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• 2020

Our objective is to evaluate the applicability of segmental phase angle (PhA) via bioelectrical impedance analysis (BIA) for post-stroke complex regional pain syndrome (CRPS). Due to its noninvasiveness and convenience, various studies have used BIA in clinical conditions. We measured segmental PhA in 4 patients at the time of CRPS diagnosis and repeated 4 weeks after 2 weeks of steroid pulse therapy. In 3 cases, the affected-to-unaffected ratio of the upper limb PhA decreased at the time of diagnosis. In 2 cases with improvement of more than 5 points in the CRPS severity score (CSS), increased ratios were observed. In other 2 cases with improvement of less than 4 points in the CSS, no remarkable changes in the ratios were found. We suggest that the segmental PhA can be helpful in assessment of post-stroke CRPS and its recovery.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.1
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• pp.168-182
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• 2020

Spoofing attacks, especially replay attacks, pose great security challenges to automatic speaker verification (ASV) systems. Current works on replay attacks detection primarily focused on either developing new features or improving classifier performance, ignoring the effects of feature variability, e.g., the channel variability. In this paper, we first establish a mathematical model for replay speech and introduce a method for eliminating the negative interference of the channel. Then a novel feature is proposed to detect the replay attacks. To further boost the detection performance, four post-processing methods using normalization techniques are investigated. We evaluate our proposed method on the ASVspoof 2017 dataset. The experimental results show that our approach outperforms the competing methods in terms of detection accuracy. More interestingly, we find that the proposed normalization strategy could also improve the performance of the existing algorithms.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.5
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• pp.27-37
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• 2020

Structural optimization problems with discrete design variables require more function calculations (or finite element analyses) than those in the continuous design space. In this study, a method to find an optimal solution in the discrete design of the truss structure is presented, reducing the number of function calculations. Because a continuous optimal solution is the Karush-Kuhn-Tucker point that satisfies the optimality condition, it is assumed that the discrete optimal solution is around the continuous optimum. Then, response values such as weight, displacement, and stress are predicted using approximate models-referred to as hybrid metamodels-within specified design ranges. The discrete design method using the hybrid metamodels is used as a post-process of the continuous optimization process. Standard truss design problems of 10-bar, 25-bar, 15-bar, and 52-bar are solved to show the usefulness of this method. The results are compared with those of existing methods.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.4
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• pp.52-57
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• 2020

The frequency of the manufacturing and modification of automotive press dies via overlay welding has recently increased, but the welding quality depends on the operator skills and the working conditions. Therefore, this study presents a way to improve the overlay welding quality regardless of the operator skills. Three welding conditions with different pre- and post-heating treatments were tested on some specimens; the weld surface quality was analyzed by examining the cutting face. The results demonstrated the best quality of the weld surface that was heated before and after the welding.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.7
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• pp.2919-2937
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• 2020

Post-Quantum Cryptography (PQC) is rapidly developing as a stable and reliable quantum-resistant form of cryptography, throughout the industry. Similarly to existing cryptography, however, it does not prevent a third-party from using the secret key when third party obtains the secret key by deception, unauthorized sharing, or unauthorized proxying. The most effective alternative to preventing such illegal use is the utilization of biometrics during the generation of the secret key. In this paper, we propose a biometric-based secret key generation scheme for multivariate quadratic signature schemes, such as Rainbow. This prevents the secret key from being used by an unauthorized third party through biometric recognition. It also generates a shorter secret key by applying Principal Component Analysis (PCA)-based Confidence Interval Analysis (CIA) as a feature extraction method. This scheme's optimized implementation performed well at high speeds.

• Electronics and Telecommunications Trends
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• v.35 no.7
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• pp.3-12
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• 2020

In this paper, we introduce ETRI AI Strategy #1, "Proactively Securing AI Core Technologies." The first goal of this strategy is to innovate artificial intelligence (AI) service technology to overcome the current limitations of AI technologies. Even though we saw a big jump in AI technology development recently due to the rise of deep learning (DL), DL still has technical limitations and problems. This paper introduces the four major parts of the advanced AI technologies that ETRI will secure to overcome the problems of DL and harmonize AI with the human world: post DL technology, human-AI collaboration technology, intelligence for autonomous things, and big data platform technology.

• Advances in Computational Design
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• v.5 no.1
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• pp.91-109
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• 2020

Over the past few decades, the impact of natural, manmade and natech (natural hazard triggering technological disasters) disasters has been devastating, affecting over 4.4 billion people. In spite of recent technological advances, the increasing frequency and intensity of natural disasters and the escalation of manmade threats is presenting a number of challenges that warrant immediate attention. This paper explores the integration of drones or Unmanned Aerial Vehicles (UAV's) into infrastructure monitoring and post-disaster assessment. Through reviewing some of the recent disasters, effectiveness of utilizing UAV's in different stages of disaster life cycle is demonstrated and needed steps for successful integration of UAV's in infrastructure monitoring, hazard mitigation and post-incident assessment applications are discussed. In addition, some of the challenges associated with implementing UAV's in disaster monitoring, together with research needs to overcome associated knowledge gaps, is presented.

• Acta Via Serica
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• v.5 no.1
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• pp.187-198
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• 2020

This paper is devoted to the examination of the identity of the Sogdian descendants and their historical role in the second millennium CE. More specifically, it discusses the Sogdian connection to the later Iranic-speaking peoples of Central Asia, namely, the Sarts and the Tajiks. It then discusses the symbiotic relationship between the Sogdian descendants and the Mongols and the Mongol descendants (Chaghatays and Uzbeks) in Central Asia. In sum, this paper argues that the Sogdians did not perish after the Arab conquest of Central Asia in the eighth century CE. They survived under new exonyms Sart and Tajik. Like the Sogdians in pre-Islamic Central Asia, the Tajiks or Sarts played important historical roles in the Mongol and post-Mongol states of Central Asia, maintaining a symbiotic relationship with the nomad elites.

• International Journal of Advanced Culture Technology
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• v.8 no.4
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• pp.177-182
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• 2020

In the age of technology and information, communicating with people from different cultures is significantly important. Regarding this perspective, communicative competence has been the focus in the EFL educational context. The purpose of this study is to investigate the effectiveness of using movies in a culture-integrated English reading course at the college level. In order to achieve this purpose, pre- and post-reading comprehension tests, pre- and post-surveys and in-depth interviews were conducted. The results of data analysis showed that using movies in the culture-integrated English reading class positively affected students' interest and confidence towards English reading as well as their reading achievement. In this respect, we suggest that cultural teaching through movies in English classes should be learner-centered so that learners can proactively analyze and understand different cultural backgrounds shown in the movies and build schemas which can be used in their learning process.

• Acta Via Serica
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• v.5 no.2
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• pp.51-90
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• 2020

The city of Sumqayit in Azerbaijan was famous in the USSR for its chemical plants, which supplied the whole country with plastics, detergents, and fertilizers. While production increased in the post-WWII period, young people from remote Caucasian villages were attracted as workers to the industrial settlement on the shore of the Caspian Sea and worked together with specialists from all over the USSR. Migration did not stop when the USSR collapsed. To the contrary, mobility increased as Azerbaijani refugees from Armenia and IDPs from Karabakh fled to Sumqayit, which grew to become the second-largest city of Azerbaijan. Although a generation has passed since the ceasefire, IDPs still are separately administered. In the last 20 years, more and more internal migrants have chosen the Greater Baku Region as their destination, mostly finding jobs in the informal labor market. In the post-independence transformative period, informal housing has offered migrants a place to stay in the city. Sumqayit can be regarded as an arrival city, an established urban platform for migrants who prefer internal over transnational migration.