• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.10a
• /
• pp.422-424
• /
• 2014

IPS 측위는 실내의 특정 위치의 무선 신호 정보를 수집하여 radio map을 구성하고 측위 시점에 구성된 정보와 수집된 무선 정보를 비교하여 현재 위치를 판단한다. 비교방법은 핑거프린트, 삼각 측량법 등의 알고리즘을 활용하며 최근에는 wifi 신호와 다른 신호를 혼합하여 계산하거나 다중 비교 방식을 사용하여 정확도를 높이는 측위 방법도 개발되었다. 앞서 언급한 측위방법은 비교적 정확한 실내 위치를 판단하지만 구축된 radio map정보와 측위 시점에서 수집된 신호 정보가 상이할 경우 측위 정확도는 크게 하락한다. 구축 시점과 측위 시점의 무선 신호에 차이가 발생하는 이유는 신호 발생 기기의 고장, 장애물 발생, 채널 간섭 현상 등이다. 특히 채널 간섭은 구축된 신호 영역 내에 동일 채널 및 인접 채널을 가지는 AP 및 테더링 기기 등이 신규로 설치되었을 때 측위에 영향을 주는 신호잡음 현상이다. 본 논문에서는 앞서 언급한 문제점을 해결하기 위해 신호 잡음에 강인한 IPS용 라디오맵에 대하여 제안한다. 제안하는 radio map 설계 방법은 측위 시점에 신호잡음이 발생하였을 때 이 정보를 수집하여 기존 radio map에 반영하여 정확도를 유지하는 방법이다. 이 방법을 적용할 경우 신호잡음에 능동적으로 대처하여 IPS 측위의 정확도를 높일 수 있을 것으로 사료된다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2013.11a
• /
• pp.1425-1428
• /
• 2013

이 기술은 CCTV의 본연의 목적인 범죄 예방을 좀 더 효과적이고 효율적으로 하기 위해 개발하였다. 먼저 사용 공간에 제약을 줄이기 위해 와이파이 기반의 CCTV를 사용하기로 하였다. 그리고 단순히 영상을 수집하는 것이 아니라 아래와 같은 알고리즘을 영상에 적용하여 범죄 예방을 위한 판단을 좀 더 빠르고 정확하게 할 수 있도록 하였다. 첫 번째로 배경에서 객체들을 분리한 뒤 각각의 객체들을 labeling하여 서로를 구분하였다. 그 후 특징점을 이용해 각 객체들을 추적한 뒤 객체마다 적당한 관심영역을 설정한다. 관심영역에서 색을 이용한 외부인 침입 감지기능과 객체의 속도와 방향을 이용한 폭력적인 행동 감지기능을 적용하였다. 더 나아가 사용자의 편의를 위해 서버/클라이언트 모델을 사용하여 외부인 침입이나 폭력이 감지되면 서버가 클라이언트에게 경고 메시지와 함께 현재 상태를 이미지로 보낼 수 있도록 하였고 클라이언트가 원한다면 언제든지 실시간 영상도 볼 수 있도록 하였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2013.05a
• /
• pp.928-931
• /
• 2013

본 논문에서는 산업공장 내의 생산효율을 높이기 위하여 작업에 대한 지시를 효율적으로 이행하는 시스템을 개발하려고 한다. 모든 공장에서는 자동화와 더불어 안전하고 생산성 높은 시스템을 추구한다. 하지만 대부분의 공장에서는 작업공정이 비체계적이며, 자동화가 이루어지지 않는 실정이다. 제조 공장의 급격한 성장으로 인하여 다양하고 많은 제품이 동시 다발적으로 생산되는 상황에서 적기 생산과 완성도 높은 제품을 위한 작업 제어 관리가 필요한 시점으로 작업에 관련된 데이터를 재정리하는 과정이 필요하다. 이러한 문제를 해결하기 위해서는 작업공정 전체를 시스템으로 포착하여 각 설비(요소)의 안전 및 생산성 향상을 도모하여야 하며, 작업공정 처리 결과를 입력하여 제어할 수 있는 ATmega보드를 모듈화 해야한다. 본 논문은 입력장치 모듈과 ATmega128, WIFI 모듈을 접목하여 작업공정 데이터를 실시간으로 입력하는 작업공정 입력 시스템을 개발하였다. 이로 인하여 현 제조 공장 생산업무의 작업효율을 크게 향상시키고, 경영 개선에 이바지 하고자 한다.

• Journal of Korea Multimedia Society
• /
• v.25 no.2
• /
• pp.280-286
• /
• 2022

In order to efficiently collect data, it is essential to locate the facilities and analyze the movement data. The current technology for location collection can collect data using a GPS sensor, but GPS has a strong straightness and low diffraction and reflectance, making it difficult for indoor positioning. In the case of indoor positioning, the location is determined by using wireless network technologies such as Wifi, but there is a problem with low accuracy as the error range reaches 20 to 30 m. In this paper, using BLE 4.2 built in Raspberry Pi, we implement Bluetooth Smart Ready. In detail, a beacon was produced for Advertise, and an experiment was conducted to support the serial port for data transmission/reception. In addition, advertise mode and connection mode were implemented at the same time, and a 3-count gradual algorithm and a quadrangular positioning algorithm were implemented for Bluetooth RSSI error correction. As a result of the experiment, the average error was improved compared to the first correction, and the error rate was also improved compared to before the correction, confirming that the error rate for position measurement was significantly improved.

• International conference on construction engineering and project management
• /
• 2022.06a
• /
• pp.624-631
• /
• 2022

Highway Rest Areas are envisioned to provide an accessible space for rest and parking for travelers, especially those driving a long distance. In addition, modern highway Rest Areas provide many amenities to highway users, including wifi service, picnic tables, litter barrels, running water, public telephones, and sometimes even free coffee. Various studies were conducted in the domain of Rest Area facility design and their operating costs in different states; however, limited studies were conducted on the maintenance costs of these facilities. Therefore, this study's main objective is to compute the annual maintenance cost of Rest Areas in the state of Nevada. This study also analyzes the main cost categories of the maintenance works. The raw cost data of Nevada Rest Area maintenance from 1990 to 2012 were collected from the Nevada Department of Transportation (NDOT). Results show that the maintenance cost fluctuated over the study period; the maintenance cost decreased from 1991 to 2004 and then increased until 2012. The primary cost categories of maintenance work are labor, equipment, and material costs. Among these, labor cost was the largest category with 56 percent of the total maintenance cost, followed by equipment cost and material cost. The findings of this study may help NDOT and other transportation agencies plan their budget for future Rest Area maintenance activities.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2022.11a
• /
• pp.93-94
• /
• 2022

Although various studies about indoor positioning systems, such as beacon and Wifi, have been conducting for indoor positioning of workers at construction sites, these systems have limitations in terms of accuracy or economics. To overcome these limitations, geomagnetic field sequence-based indoor positioning technology can be a good alternative. However, it is necessary to correct the geomagnetic field near the construction material stocking area since the geomagnetic field can be distorted near construction materials such as rebars. Therefore, this study conducted an experiment for identifying correction range of geomagnetic field near the construction material stocking area. It was analyzed that the geomagnetic field should be corrected up to 60cm in the horizontal direction from the stocking point if the height of stocking area for rebars is 40cm or more. This study can be used for important reference for development of geomagnetic field sequence-based indoor positioning technology suitable for construction sites.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.18 no.5
• /
• pp.809-816
• /
• 2023

The purpose of this study is to implement a device using the Raspberry Pi that can transmit and supervise data between devices and servers using the oneM2M standard platform, Mobius. Operating under the same concept as a Gateway or Router, this device performs the role of forwarding packets sent from end nodes to other networks. Theoretical functionality has been achieved to concurrently connect and supervise up to 65536 devices. The communication methods for end nodes connected to the Gateway include ZigBee and WiFi, and for long-distance communication, tests were conducted using LoRa modules.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.1
• /
• pp.25-28
• /
• 2015

Lifts are used as an essential means of transportation within the building in an emergency situation, when used as a means of escape, so expect a lot of research has been conducted high effect. Number of stories in the Seoul-rise building guidelines underground 7th floor, 53 ground floor, floor area $6,800m^2$, floor area $127,050m^2$, use is cultural and convention facilities and sales facilities, business facilities and accommodation (hotel), the construction of public housing (apartments) hagieneun not efficient to install elevators for evacuation mothada was determined separately in designing the lift is designed according to the standards of passenger lifts installed under a judgment as to use for evacuation. However, this does not include detailed design guidelines so far.[1] We propose the Evacuee Guidance of Elevator System that can be used as entering air equipment, sprinkler and smart phone evacuation system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2010.04a
• /
• pp.143-144
• /
• 2010

Recently, IALA has introduced AIS AtoN and standardized Aids to Navigation communication system and the World-wide IALA-Net has announced plans to build the system. Systematic beacon network may offer opportunities to make infrastructure for information service and upgrade AtoN service performance. This paper proposes Aids to Navigation information service network for e-NAV. Network based on AIS is consist of AIS AtoN channels as Real, Synthetic or Virtual AIS AtoN. And inner network is consist of Wireless networks as AIS, WCDMA, WIFI, WlBRO, USN or VSAT. Introducing of various network systems can lead to combine and design among land, beacon and service network infrastructures.

• Journal of Advanced Marine Engineering and Technology
• /
• v.40 no.1
• /
• pp.55-61
• /
• 2016

As the price-performance ratio of embedded PCs improves, the benefits of the PC-Fi can be maximized by designing an embedded PC-Fi system. In this paper presents the design of an embedded PC-Fi that can be manipulated by a remote controller based on mobile devices such as smart phones or tablets. Additionally, an interactive control system and its GUI, through which the user can select and play music as they like at ease, are presented. The case that a large amount of music is stored in the PC-Fi system requires a function allowing the user to easily select the music they want to listen to. In order to implement this function, a DB containing detailed information of each track can be used to find the location of the desired music with keywords provided by the user. In this proposed system, the embedded PC-Fi system and remote controller are mutually connected via a WiFi network, and more than one user can remotely control the embedded system with their own mobile device.