• Journal of the Korea Society of Computer and Information
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• v.14 no.4
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• pp.111-117
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• 2009

Improvement of Wireless internet and handheld devices makes it possible that users can use various multimedia services. But, access point devices are needed while using handheld devices, and those devices use virtual network address for networking. For that reason, end-users hardly use the 1:1 voice or video chat, and messenger service that require direct communications between devices. Also, service providers need central server for relaying packets from terminals to others, the traffic and costs of relaying go high, so real-time massive data transmission services are restrictively provided. In this study, we apply TCP/UDP hole punching technique to those applications. And we implement service that supports real-time multimedia direct transmission between equipments that use virtual network addresses.

• International Journal of Computer Science & Network Security
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• v.23 no.10
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• pp.37-43
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• 2023

The hospital situation, timing, and patient restrictions have become obstacles to an optimum therapy session. The crowdedness of the hospital might lead to a tight schedule and a shorter period of therapy. This condition might strike a post-stroke patient in a dilemma where they need regular treatment to recover their nervous system. In this work, we propose an in-house and uncomplex serious game system that can be used for physical therapy. The Kinect camera is used to capture the depth image stream of a human skeleton. Afterwards, the user might use their hand gesture to control the game. Voice recognition is deployed to ease them with play. Users must complete the given challenge to obtain a more significant outcome from this therapy system. Subjects will use their upper limb and hands to capture the 3D objects with different speeds and positions. The more substantial challenge, speed, and location will be increased and random. Each delegated entity will raise the scores. Afterwards, the scores will be further evaluated to correlate with therapy progress. Users are delighted with the system and eager to use it as their daily exercise. The experimental studies show a comparison between score and difficulty that represent characteristics of user and game. Users tend to quickly adapt to easy and medium levels, while high level requires better focus and proper synchronization between hand and eye to capture the 3D objects. The statistical analysis with a confidence rate(α:0.05) of the usability test shows that the proposed gaming is accessible, even without specialized training. It is not only for therapy but also for fitness because it can be used for body exercise. The result of the experiment is very satisfying. Most users enjoy and familiarize themselves quickly. The evaluation study demonstrates user satisfaction and perception during testing. Future work of the proposed serious game might involve haptic devices to stimulate their physical sensation.

• International Journal of Computer Science & Network Security
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• v.24 no.5
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• pp.1-10
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• 2024

Individuals with visual impairments face numerous challenges in their daily lives, with navigating streets and public spaces being particularly daunting. The inability to identify safe crossing locations and assess the feasibility of crossing significantly restricts their mobility and independence. Globally, an estimated 285 million people suffer from visual impairment, with 39 million categorized as blind and 246 million as visually impaired, according to the World Health Organization. In Saudi Arabia alone, there are approximately 159 thousand blind individuals, as per unofficial statistics. The profound impact of visual impairments on daily activities underscores the urgent need for solutions to improve mobility and enhance safety. This study aims to address this pressing issue by leveraging computer vision and deep learning techniques to enhance object detection capabilities. Two models were trained to detect objects: one focused on street crossing obstacles, and the other aimed to search for objects. The first model was trained on a dataset comprising 5283 images of road obstacles and traffic signals, annotated to create a labeled dataset. Subsequently, it was trained using the YOLOv8 and YOLOv5 models, with YOLOv5 achieving a satisfactory accuracy of 84%. The second model was trained on the COCO dataset using YOLOv5, yielding an impressive accuracy of 94%. By improving object detection capabilities through advanced technology, this research seeks to empower individuals with visual impairments, enhancing their mobility, independence, and overall quality of life.

• Information and Communications Magazine
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• v.12 no.8
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• pp.53-64
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• 1995

In this article, criteria and considerations for selecting a domestic Personal Communications Services (PCS) system in Korea are presented and upbanded IS-95 Common Air Interface (CAI) is asserted to be appropriate as a result of evaluation by the criteria. And Shinsegi Telecomm, Inc. (STI) is claimed to be a suitable operator to provide PCS by upbanded IS-95 considering the experiences as the cellular operator adopting IS-95 CDMA technology. The PCS R&D plan and strategies of STI are given and the joint R&D plan with domestic manufacturers to develop PCS systems are explained. The results from R&D so far are mentioned. The PCS network architecture and various services-basic voice service, value-added services and wireless data services-are discussed.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11a
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• pp.898-900
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• 2005

초고속 통신망의 확대 적용으로 인터넷의 빠른 성장과 함께 음성과 비디오 그리고 데이터를 통합하고자 하는 노력이 시도 되고 있다. VoIP(Voice over IP)는 IP를 이용하여 음성과 데이터를 패킷 형태로 통합하여 실시간으로 전송하는 기술이다[1]. 패킷 네트워크에서 VoIP 시그널링 기술을 이용하면 망 자원의 효율적 이용 및 PSTN에 가까운 음질 그리고 인터넷과 연계한 다양한 음성서비스 지원(H.323, SIP, MGCP 등 다양한 신호처리 지원)이 가능하다. 본 논문에서는 VoIP망에서 IP기반 녹취 시스템을 설계 및 구현한다. 녹취 시스템은 고객과 상담원의 통화 내용을 자동으로 녹음하여 보관함으로써 고객의 요구사항을 명확히 파악할 수 있으며 녹취 데이터의 통계 자료 제공으로 효율적인 관리가 지원되고 선택 녹취, 스케줄링 녹취, 상담원의 평가 자료를 제공하여 고객 관리의 질적인 향상을 지원한다. 본 논문의 녹취 시스템은 고객과의 통화 내용을 녹취하여 서버의 녹취 DB에 저장하여 관리하는 녹취 시스템으로 모든 네트워크 환경에서 사용할 수 있으며 CTI와 연동하여 효율적이고 체계적인 녹취 시스템 구국이 가능하다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2393-2398
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• 2014

Because each resource in LTE-Advanced system and network's shapes such as bandwidth, error rate change variably, it is judged that it is impossible to control service continuity with procedural, artificial, and static control method applied to the existing voice service. This research suggests a QoS management mechanism to support the service continuity effectively based on policy control. It means a method in which a subscriber's terminal collects information about its current condition and base station around, and a base station, through the data collected by monitoring inner or adjacent base station, shares related data and converges, controlling service continuity on its own.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2899-2902
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• 2003

Mobile communication is one of the fastest growing industries in the world and especially in Korea, where we have well over 30 million voice subscribers. Mobile communication now offers variety of data communication services such as wireless internet, multimedia messages, and color graphic displays. Handsets also have grown to accommodate such services, thus with functionalities such as programmable virtual machines that users can download and execute their own programs. In this paper, we have demonstrated a PCS handset monitoring system which can monitor biometry signals - in this case ECG over wireless internet and wireless data network (IS95C) based on programmable virtual machine architecture. The remote client handset receives data signals from a centralized server and processes and displays them in human friendly form in real time. Since every single handset on sales in Korea has programmable virtual machine and more than 10 million handsets are in distribution already, proper applications may have substantial impact on the related fields.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.99-104
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• 2015

Service platform which can offer various multimedia communication as the video, audio, voice and data is IMS(IP Multi-Media Subsystem). It is effective in the company is introducing only such convergence IMS services to be required to provide various multimedia services at the lowest cost and existing communication environment while keeping the maximum Therefore, in this study, we had developed IMS 코어 main system that not more than 1,000 employees of companies can effectively establish IMS solutions. This system is located at the middle between IMS terminal and CSCF(Call Session Control Function) in line with IMS services and provides CSCF in response to the IMS terminal and IMS terminal in response to the CSCF. As well, corded telephone and SIP phone which were used as terminal is linked with gateway.

• Phonetics and Speech Sciences
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• v.10 no.1
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• pp.39-48
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• 2018

A typical statistical parametric speech synthesis (text-to-speech, TTS) system consists of separate modules, such as a text analysis module, an acoustic modeling module, and a speech synthesis module. This causes two problems: 1) expert knowledge of each module is required, and 2) errors generated in each module accumulate passing through each module. An end-to-end TTS system could avoid such problems by synthesizing voice signals directly from an input string. In this study, we implemented an end-to-end Korean TTS system using Google's Tacotron, which is an end-to-end TTS system based on a sequence-to-sequence model with attention mechanism. We used 4392 utterances spoken by a Korean female speaker, an amount that corresponds to 37% of the dataset Google used for training Tacotron. Our system obtained mean opinion score (MOS) 2.98 and degradation mean opinion score (DMOS) 3.25. We will discuss the factors which affected training of the system. Experiments demonstrate that the post-processing network needs to be designed considering output language and input characters and that according to the amount of training data, the maximum value of n for n-grams modeled by the encoder should be small enough.

• Journal of Korea Multimedia Society
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• v.15 no.5
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• pp.677-691
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• 2012

Location Based Services using GPS receiver with network enabled smart phone provides various services and many business models. Currently, many context awareness models on smart phone applications are under developing. But most of the services are based on current user position and Point of Interest(POI)s, which are very static. In this paper, we proposed and implemented multimedia tourist guide system using smart phone, which are very dynamic and provides tour guide's voice and audio service on the spot. Also we provides tour experience sharing method which can easily share the videos and pictures for each users.