• International journal of advanced smart convergence
• /
• 제12권3호
• /
• pp.13-18
• /
• 2023

This paper aims to investigate data features for neighbor path selection (NPS) in computer network with regional failures. It is necessary to find an available alternate communication path in advance when regional failures due to earthquakes or forest fires occur simultaneously. We describe previous general heuristics and simulation heuristic to solve the NPS problem in the regional fault network. The data features of general heuristics using proximity and sharing factor and the data features of simulation heuristic using machine learning are explained through examples. Simulation heuristic may be better than general heuristics in terms of communication success. However, additional data features are necessary in order to apply the simulation heuristic to the real environment. We propose novel data features for NPS in computer network with regional failures and Keras modeling for computing the communication success probability of candidate neighbor path.

• 전자공학회논문지
• /
• 제51권8호
• /
• pp.3-10
• /
• 2014

최근 폭증하는 모바일 데이터 트래픽을 수용하기 위하여 밀리미터파 (mmWave)가 큰 관심을 받고 있으며, 4 세대 LTE-A(Long Term Evolution-Advanced) 표준을 기반으로 MMB (Millimeter Mobile Broadband) 시스템의 필요성이 대두되고 있다. 현재 mmWave 통신 채널에 대한 많은 연구가 이루어지고 있으며, MMB 채널 환경에 대한 성능 분석 또한 관심의 대상이다. 본 논문에서는 5세대 이동통신을 위한 MMB 시스템을 설계하고 mmWave의 전파 특성 분석을 통한 채널 모델을 제안한다. 또한 MMB 시스템의 28 GHz 대역에서 MMB 채널 환경에 대한 성능을 비교 분석한다.

• 한국정보통신학회논문지
• /
• 제19권8호
• /
• pp.1825-1830
• /
• 2015

일부 보행자의 경우 보행자 신호등이 적색임에도 불구하고 무단횡단을 하거나 차도에 내려서서 보행 신호를 기다리기도 한다. 이럴 경우 자칫하면 교통사고로 이어질 수 있다. 이에 적외선 센서를 이용하여 보행자가 차도로 진입할 경우 경고 안내 방송을 해주는 방식으로 채택해왔으나, 이 경우 교차로의 곡선형 횡단보도에는 설치가 어렵다. 본 논문에서는 카메라의 영상 검지 방식을 사용하여 보행자를 검지하는 방법에 대해 제안한다. 보행철주 상단에 설치된 카메라를 이용하여 이미지를 획득하고, 획득한 이미지를 이용하여 보행자 검지구간을 설정한다. 또한, 획득한 이미지에 대해 소벨( Sobel) 영상 처리 방식을 이용하여 변환하고 변환한 이미지를 다른 이미지와 비교하여 보행자 검지방법을 선택하였다. 이 영상 검지 방식을 사용하면 곡선형 횡단보도에서 보행자를 검지하는데 효과적이다.

• 한국통신학회:학술대회논문집
• /
• 한국통신학회 2006년도 하계종합학술발표회 논문 초록집
• /
• pp.695-695
• /
• 2006

• 한국IT서비스학회지
• /
• 제11권2호
• /
• pp.339-353
• /
• 2012

Mobile communication technology is advancing forward to deliver more connected devices and richer content and applications. The number of subscriptions continues to grow along with an explosive increase in the mobile data traffic demand. Thereby, it creates a significant network capacity shortage concerns for mobile network operators. In order to address this problem, it is essential to increase the network capacity at a low additional cost. The device-to-device (D2D) communication based proximity service is believed to have a promising future mobile communication technology that is capable to create new mobile service opportunities and offload traffic to the eNB. In addition, it is also required to develop new mobile communication services and its business models not only to accommodate the increasing mobile traffic demand but also to foster profitability of mobile business service providers such as the network providers, contents providers and platform providers. In this article, we first analyze current mobile business eco-system in the context of CPNT based value chain. Then, propose service development framework and business model creation methodologies for the device-to-device communication based services in the beyond LTE/LTE-Advanced systems.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제14권5호
• /
• pp.1984-2002
• /
• 2020

With the appearance of wireless spectrum crisis in traditional cellular network, device-to-device (D2D) communication has been regarded as a promising solution to ease heavy traffic burden by enabling precise content delivery among mobile users. However, due to the channel sharing, the interference between D2D and cellular users can affect the transmission rate and narrow the throughput in the network. In this paper, we firstly present a weighted interference minimization cluster formation model involving both social attribute and physical closeness. The weighted-interference, which is evaluated under the susceptible-infected(SI) model, is utilized to gather user in social and physical proximity. Then, we address the cluster formation problem via spectrum clustering with iterative operation. Finally, we propose the stable matching theory algorithm in order to maximize rate oriented to accomplish the one-to-one resource allocation. Numerical results show that our proposed scheme acquires quite well clustering effect and increases the accumulative transmission rate compared with the other two advanced schemes.

• 한국의류산업학회지
• /
• 제24권5호
• /
• pp.647-654
• /
• 2022

Wearable devices come in a variety of shapes and sizes in numerous fields in numerous fields and are available in various forms. They can be integrated into clothing, gloves, hats, glasses, and bags and used in healthcare, the medical field, and machine interfaces. These devices keep track individuals' biological and behavioral data to help with health communication and are often used for injury prevention. Those with hearing loss or impaired vision find it more difficult to recognize an approaching person or object; these sensing devices are particularly useful for such individuals, as they assist them with injury prevention by alerting them to the presence of people or objects in their immediate vicinity. Despite these obvious preventive benefits to developing Internet of Things based devices for the disabled, the development of these devices has been sluggish thus far. In particular, when compared with people without disabilities, people with hearing impairment have a much higher probability of averting danger when they are able to notice it in advance. However, research and development remain severely underfunded. In this study, we incorporated a wearable detection system, which uses an infrared proximity sensor, into a backpack. This system helps its users recognize when someone is approaching from behind through visual and tactile notification, even if they have difficulty hearing or seeing the objects in their surroundings. Furthermore, this backpack could help prevent accidents for all users, particularly those with visual or hearing impairments.

• 한국융합학회논문지
• /
• 제11권10호
• /
• pp.63-69
• /
• 2020

본 논문에서는 저속으로 불규칙하게 움직이는 인체의 심박신호를 감지하기 할 수 있어 웨어러블 디바이스에 적용 가능한 소형 마이크로파 센서를 제안하였다. 이를 위해 2.4 GHz ISM 대역에서 평형 구조를 갖는 마이크로스트립 방사 패치들과 자체발진 검출회로 및 귀환회로가 구성되었다. 이론 전개와 시뮬레이션을 통해 제안된 구조의 타당성을 확인하였고 제작된 시제품을 측정하였다. 회로의 보드는 65mm × 85㎟의 작은 크기이며, 간단한 고주파 회로구조로 60mW 수준의 작은 전력을 소모한다. 센서와 직선거리 2~30mm, 측면 좌우 거리 ±20mm 범위 내에서 저속(0.5Hz)으로 움직이는 인체로부터 심박신호를 얻을 수 있었다.

• 디지털콘텐츠학회 논문지
• /
• 제16권2호
• /
• pp.257-262
• /
• 2015

최근 무선 네트워크의 확산, 모바일 기기의 성능 향상, 서비스에 대한 수요 증가와 함께 모바일 지리 정보서비스에 대한 관심이 높아지고 있다. 기존의 유선 환경기반의 지리 정보 시스템 솔루션으로 무선 환경에서 서비스를 하기 에는 제한된 통신 속도, 처리 속도, 화면 사이즈 등의 한계점이 존재한다. 본 논문에서는 이와 같은 문제를 해결하기 위하여 클라이언트 측의 캐시 알고리즘을 제안하고자 한다. 제안된 알고리즘은 단위 시간과 공간 근접성의 개념을 이용하여 기존의 연구를 개선한다. 그리고 효율성의 향상 정도를 측정하기 위해 성능 평가를 실시하고 결과를 분석한다. 성능 평가 결과, 공간 데이터의 질의 시에 기존의 알고리즘에 비하여 적중률에 있어서 보다 좋은 성능을 나타내었다.

• International journal of advanced smart convergence
• /
• 제6권3호
• /
• pp.29-37
• /
• 2017

The current behavior recognition system don't match data formats between sensor data measured by user's sensor module or device. Therefore, it is necessary to support data processing, sharing and collaboration services between users and behavior recognition system in order to process sensor data of a large capacity, which is another formats. It is also necessary for real time interaction with users and behavior recognition system. To solve this problem, we propose fog cloud based behavior recognition system for human body sensor data processing. Fog cloud based behavior recognition system solve data standard formats in DbaaS (Database as a System) cloud by servicing fog cloud to solve heterogeneity of sensor data measured in user's sensor module or device. In addition, by placing fog cloud between users and cloud, proximity between users and servers is increased, allowing for real time interaction. Based on this, we propose behavior recognition system for user's behavior recognition and service to observers in collaborative environment. Based on the proposed system, it solves the problem of servers overload due to large sensor data and the inability of real time interaction due to non-proximity between users and servers. This shows the process of delivering behavior recognition services that are consistent and capable of real time interaction.