• Korean Journal of Audiology
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• v.18 no.3
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• pp.105-111
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• 2014

Assistive listening devices (ALDs) refer to various types of amplification equipment designed to improve the communication of individuals with hard of hearing to enhance the accessibility to speech signal when individual hearing instruments are not sufficient. There are many types of ALDs to overcome a triangle of speech to noise ratio (SNR) problems, noise, distance, and reverberation. ALDs vary in their internal electronic mechanisms ranging from simple hard-wire microphone-amplifier units to more sophisticated broadcasting systems. They usually use microphones to capture an audio source and broadcast it wirelessly over a frequency modulation (FM), infra-red, induction loop, or other transmission techniques. The seven types of ALDs are introduced including hardwire devices, FM sound system, infra-red sound system, induction loop system, telephone listening devices, television, and alert/alarm system. Further development of digital wireless technology in hearing instruments will make possible direct communication with ALDs without any accessories in the near future. There are two technology solutions for digital wireless hearing instruments improving SNR and convenience. One is near-field magnetic induction combined with Bluetooth radio frequency (RF) transmission or proprietary RF transmission and the other is proprietary RF transmission alone. Recently launched digital wireless hearing aid applying this new technology can communicate from the hearing instrument to personal computer, phones, Wi-Fi, alert systems, and ALDs via iPhone, iPad, and iPod. However, it comes with its own iOS application offering a range of features but there is no option for Android users as of this moment.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.1
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• pp.287-295
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• 2017

Recently, MTC (Machine Type Communication) is known as an important part to support IoT (Internet of Things) applications. MTC provides network connectivities between MTC devices without human intervention. In MTC, a large number of devices try to access over communication resource with a short period of time. Due to the limited communication resource, resource contention becomes severe and it brings about access failures of devices. To solve the problem, it needs to regulate device accesses. In this paper, we present an efficient access management scheme. We measure the number of devices which try to access in a certain time period and predict the change of the number of devices in the next time period. Using the predicted change, we control the number of devices which try to access. To verify our scheme, we conduct experiments in terms of success probability, failure probability, collision probability and access delay.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.2
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• pp.81-88
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• 2016

Machine-to-Machine (M2M) communication provides each component (machine) with access to Internet, evolving into the IoT technology. IoT is a trend where numbers of devices provide the communication service, using the Internet protocol. As spreading the concept of IoT(Internet of Things), various objects become home information sources. According to the wide spread of various devices, it is difficult to access data on the devices with unified manners. Under this environment, security is a critical element to create various types of application and service. In this paper propose the inter-device authentication and Centralized Remote Security Provisioning framework in Open M2M environment. The results of previous studies in this task is carried out by protecting it with the latest information on M2M / IoT and designed to provide the ultimate goal of future M2M / IoT optimized platform that can be integrated M2M / IoT service security and security model presents the information.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.6
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• pp.37-42
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• 2022

Recently, with the development of mobile communication technologies such as 5G, interest in oscilloscope technology based on high bandwidth and user-friendly UI is increasing. In this paper, we proposed a Python-based UI(user interface) SW for a high-bandwidth digital oscilloscope in connection with the study of a 13GHz band digital oscilloscope system. The proposed UI SW is designed not only to be executed integrally with the oscilloscope, but also to be run on a separate PC or laptop cooperating with the instrument through WiFi communication. Functions of the UI SW consists of displaying and analyzing signal data, storing signal data in an external storage device, generating test signal data, and reconfiguring the toolbar. Finally, we have shown that the proposed digital oscilloscope system operates normally by interworking test with the signal generator.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.1
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• pp.55-67
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• 2023

Lightweight face recognition models, as one of the most popular and long-standing topics in the field of computer vision, has achieved vigorous development and has been widely used in many real-world applications due to fewer number of parameters, lower floating-point operations, and smaller model size. However, few surveys reviewed lightweight models and reimplemented these lightweight models by using the same calculating resource and training dataset. In this survey article, we present a comprehensive review about the recent research advances on the end-to-end efficient lightweight face recognition models and reimplement several of the most popular models. To start with, we introduce the overview of face recognition with lightweight models. Then, based on the construction of models, we categorize the lightweight models into: (1) artificially designing lightweight FR models, (2) pruned models to face recognition, (3) efficient automatic neural network architecture design based on neural architecture searching, (4) Knowledge distillation and (5) low-rank decomposition. As an example, we also introduce the SqueezeFaceNet and EfficientFaceNet by pruning SqueezeNet and EfficientNet. Additionally, we reimplement and present a detailed performance comparison of different lightweight models on the nine different test benchmarks. At last, the challenges and future works are provided. There are three main contributions in our survey: firstly, the categorized lightweight models can be conveniently identified so that we can explore new lightweight models for face recognition; secondly, the comprehensive performance comparisons are carried out so that ones can choose models when a state-of-the-art end-to-end face recognition system is deployed on mobile devices; thirdly, the challenges and future trends are stated to inspire our future works.

• KIPS Transactions on Computer and Communication Systems
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• v.12 no.7
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• pp.227-234
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• 2023

Measuring heart rate variability by deep breathing and using this to evaluate the autonomic nervous system is a well-known method widely used in various clinical fields. In hospitals, expensive equipment is installed and managed by experts for this purpose. This paper discusses an app we developed that can easily test the autonomic nervous system by deep breathing anytime, anywhere using a smartphone, and then reviews experiments performed to verify the results. The experiments were conducted in the clinical room of the Department of Neurology at Soonchunhyang University Cheonan Hospital on eight volunteers. We tested the autonomic nervous systems of the volunteers first with an electromyography device installed in the hospital and then with the app under identical conditions. We performed a correlation analysis on the results of these two methods using the Pearson method, and this yielded a very high correlation of 0.98.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.2-5
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• 2022

Human organs in the body have a complex structure, and in particular, the small intestine is about 7m long, so endoscopy is not easy and the risk of endoscopy is high. Currently, the test is performed with a capsule endoscope, and the test time is very long. The doctor connects the removed storage device to the computer to store the patient's capsule endoscope image and reads it using a program, but the capsule endoscope test results in a long image length, which takes a lot of time to read. In addition, in the case of the small intestine, there are many curves due to villi, so the occlusion area or light and shade of the image are clearly visible during the examination, and there may be cases where lesions and abnormal signs are missed during the examination. In this paper, we provide a method of assisting small intestine capsule endoscopic lesion examination using artificial neural networks to shorten the doctor's image reading time and improve diagnostic reliability.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.137-145
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• 2020

Providing safety training to construction workers is essential to reduce safety accidents at the construction site. With the prosperity of visualization technologies, Immersive Virtual Reality (IVR) has been adopted for construction safety training by providing interactive learning experiences in a virtual environment. Previous research efforts on IVR-based training have found that the level of fidelity of interaction between real and virtual worlds is one of the important factors contributing to the sense of presence that would affect training performance. Various interactive devices that link activities between real and virtual worlds have been applied in IVR-based training, ranging from existing computer input devices (e.g., keyboard, mouse, joystick, etc.) to specially designed devices such as high-end VR simulators. However, the need for high-fidelity interactive devices may hinder the applicability of IVR-based training as they would be more expensive than IVR headsets. In this regard, this study aims to understand the impact of the level of fidelity of interactive devices in the sense of presence in a virtual environment and the training performance during IVR-based forklift safety training. We conducted a comparative study by recruiting sixty participants, splitting them into two groups, and then providing different interactive devices such as a keyboard for a low fidelity group and a steering wheel and pedals for a high-fidelity group. The results showed that there was no significant difference between the two groups in terms of the sense of presence and task performance. These results indicate that the use of low-fidelity interactive devices would be acceptable for IVR-based safety training as safety training focuses on delivering safety knowledge, and thus would be different from skill transferring training that may need more realistic interaction between real and virtual worlds.

• Journal of Software Assessment and Valuation
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• v.15 no.1
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• pp.37-42
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• 2019

Many similarity analysis methods, one of the dispute resolution methods for computer programs, have been studied. This paper is about quantitative similarity analysis of MIB (Management Information Base) file. Quantitative similarity means that the source codes of two computers are analyzed and the results are compared with a certain standard. The source code to analyze is a program that provides network device management functions such as configuration management, fault management, and performance management using SNMP protocol for WiMAX CPE devices. Here, WiMAX refers to the IEEE 802.16 wireless network standard protocol and can be classified into fixed WiMAX and mobile WiMAX. WiMAX CPE is a wireless Internet terminal that is fixedly used in a customer's home or office. In this paper, we analyze the similarity between MIB file of company A and company B. We will analyze whether the MIB file leaked from the damaged company is not just a list to describe the product specifications, but whether the property value can be recognized.

• Journal of IKEEE
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• v.27 no.4
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• pp.512-517
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• 2023

In this study, we propose a liquid crystal-based polarization control technology that can control polarization by adjusting the voltage applied to the liquid crystal, and apply it to a Closed-circuit Television (CCTV) to transmit only the desired angle of polarized light. CCTV with conventional polarizing films cannot control polarization because they focus on backlight compensation, so light reflected from the water surface or highlights reflected from vehicles interfere with subject identification. However, the Vertical Alignment mode allows the polarization to be adjusted electrically, so that only the polarized light at the user's desired angle is transmitted, eliminating reflected highlights. The images obtained using this technique are optimized by computer software. Liquid crystal polarization panels, which can electrically control the polarization angle, transmittance, and polarization rate, have been applied to polarized image monitoring device to improve subject identification in conventional CCTV.