• Journal of Institute of Control, Robotics and Systems
• /
• v.16 no.12
• /
• pp.1167-1175
• /
• 2010

This paper presents the use of the inertial measurement unit information and the infrared sector information for getting the position of an object. Travel distance is usually calculated from the double integration of the accelerometer output with respect to time; however, the accumulated errors due to the drift are inevitable. The orientation change of the accelerometer also causes error because the gravity is added to the measured acceleration. Unless three axis orientations are completely identified, the accelerometer alone does not provide correct acceleration for estimating the travel distance. We propose a way of minimizing the error due to the change of the orientation. In order to reduce the accumulated error, the infrared sector information is fused with the inertial measurement unit information. Infrared sector information has highly deterministic characteristics, different from RFID. By putting several infrared emitters on the ceiling, the floor is divided into many different sectors and each sector is set to have a unique identification. Infrared light based sector information tells the sector the object is in, but the size of the uncertainty is too large if only the sector information is used. This paper presents an algorithm which combines both the inertial measurement unit information and the sector information so that the size of the uncertainty becomes smaller. It also introduces a framework which can be used with other types of the artificial landmarks. The characteristics of the developed infrared light based sector and the proposed algorithm are verified from the experiments.

• Journal of Korea Port Economic Association
• /
• v.24 no.1
• /
• pp.23-39
• /
• 2008

This paper outlines a plan to promote South Jeonnam region's logistics capability in connection with the regional logistics bases such as Gwangyang Port, Jangseong Integrated Freight Terminal, Mokpo Port and Muan International Airport. The capability of regional innovation bodies, and industrial innovation generally, needs to be improved by establishing a systematic regional innovation plan. Smaller import and export logistics bases, presently scattered in downtown Gwangju and its suburban area, need to be integrated as soon as possible, in advance of the completion of a traffic network connecting all of the triangle logistics bases. Moreover, plans to develop Muan International Airport to the status of a hub airport need to be established, and its function as an air freight terminal should be strengthened. Gwangyang Port and Mokpo Port should be developed as Korea's key harbors with international logistics bases the two ports, presently conducting simple cargo work, should be transformed into general logistics ports conducting logistics, assembling, trading, and international business by developing their surrounding areas.

• Journal of IKEEE
• /
• v.12 no.2
• /
• pp.95-101
• /
• 2008

In this paper, we study an optimum design of search synchronization structure for Baseband Modem to support ISO/IEC 18185-5 and 24730-2 Standard. For DSSS Modem, we design the code acquisition and tracking structure which are important in receiver operation, and examine the parameters to be considered. The data and PN chip transmission rates and processing gain of the proposed modem are 59.7 kbps, 30.521875 Mcps, and 27 dB, respectively. This indicates that the noise immunity of the proposed modem is 17dB better than IEEE 802.11b (Processing gain : 10dB). Therefore, we design the optimum structure for the modem search synchronization which is compatible to the proposed modem standard.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.1438-1447
• /
• 2010

Construction sites are becoming larger and complex with the growth of national economy. Accordingly, It is essential to indentify real-time information about materials, equipments and manpower during construction at job sites. Even though research utilizing cutting-edge sensors has been conducted in architectural engineering field; this area of research is almost nil in civil engineering field. Therefore a feasibility study to find a way to apply cutting-edge sensors to an in-situ tunnel construction site adopting NATM is tried as the first step. After listing all construction materials needed in each activity, the most representative materials were identified so that IT technology can be applied by attaching and monitoring sensors to the selected materials; shotcrete and lining were selected as representative materials. Moreover, a plan to visualize construction process and progress management system using selected representative materials was proposed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.28 no.1
• /
• pp.10-18
• /
• 2017

In this paper, we designed and implemented a visible light identification(VLID) system consisting of a VLID reader and a tag which backscatters incident lights from the reader. A VLID tag sends its ID to the reader by switching an LCD shutter which is located on its surface. The VLID reader consists of six LEDs and a photodiode(PD). The LEDs emit visible light and a PD located in a center position of LEDs receives backscattered light from the VLID tag. A microcontroller and a commercial liquid crystal display(LCD) shutter for 3D-TV glasses are used to implement a VLID tag. Experiments were conducted to confirm VLID system performance. We successfully demonstrated experiments to send NRZ-OOK signal of 100 bps over a distance of 35 cm at daytime. Also, we suggested the theoretical maximum transmission rate and the various methods to enhance the separation distance between a VLID reader and a tag.

• Journal of The Korean Association of Information Education
• /
• v.18 no.2
• /
• pp.325-334
• /
• 2014

There are management and price problems that have been caused by requirement of RFID reader, Fingerprint Identification System and Clicker for the construct of automatic attendance system to check the students' attendance accurately and quickly. Therefore, in the thesis, we developed smartphone based attendance check system by utilizing Wi-Fi and the smartphones that has been already built without using additional equipments and establishing construction of system additionally. It recognizes date, time, location and the seat number in classroom if a student logs the attendance chocking application in and it also allows students to get lecture feedback and check attendance by taking quizzes and questionnaires that are related to the lecture. As a result, by applying the attendance check system, instructors state that it is convenient since the app allows instructors to communicate with students though the quizzes and questionnaires. Especially, the instructors state that it is convenient because the results of the quizzes, questionnaires and attendance can be downloaded it the from of Excel files.

• 한국정보통신설비학회:학술대회논문집
• /
• 2009.08a
• /
• pp.157-161
• /
• 2009

In recent years, there is a remarkable progress in ICTs (Information and Communication Technologies), and then many attempts to apply ICTs to other industries are being made. In the field of disaster managements, ICTs such as RFID (Radio Frequency IDentification) and USN (Ubiquitous Sensor Network) are used to provide safe environments. Actually, various types of early warning systems using USN are now widely used to monitor natural disasters such as floods, landslides and earthquakes, and also to detect human-caused disasters such as fires, explosions and collapses. These early warning systems issue alarms rapidly when a disaster is detected or an event exceeds prescribed thresholds, and furthermore deliver alarm messages to disaster managers and citizens. In general, these systems consist of a number of various sensors and measure real-time stream data, which requires an efficient and rapid data processing technique. In this study, an event-driven architecture (EDA) is presented to collect event effectively and to provide an alert rapidly. A publish/subscribe event processing method to process simple event is introduced. Additionally, a complex event processing (CEP) technique is introduced to process complex data from various sensors and to provide prompt and reasonable decision supports when many disasters happen simultaneously. A basic concept of CEP technique is presented and the advantages of the technique in disaster management are also discussed. Then, how the main processing methods of CEP such as aggregation, correlation, and filtering can be applied to disaster management is considered. Finally, an example of flood forecasting and early alarm system in which CEP is incorporated is presented It is found that the CEP based on the EDA will provide an efficient early warning method when disaster happens.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.1
• /
• pp.151-156
• /
• 2017

In case of massive water leakage, it's crucial for field manager to quickly positioning the problematic valve and related ones. However, it's not easy for the system to find the corresponding valve and even if it's found, it can not respond quickly because it can't know the relevant information immediately. In this paper, we implement the system for identifying sluice valve positions using GPS and AR techniques. The proposed system is composed of hand held android device, remote database server and data acquisition device for DB creation. We utilize the android device's sensors including GPS, gyro, accelerometer, magnetic sensor. The system identifies the valve with matching between the position data from the remote database server, and current GPS locations of device. We use AR techniques to overlay the graphics pattern of valve positions and some additional informations on captured real scene. With this system, it will be fast and accurate for maintenance of sluice valve of municipal water system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.391-392
• /
• 2008

최근 나노 금속의 대량 생산에 대한 기술이 확보됨에 따라, 메탈젯을 이용한 연구가 활발히 진행되고 있다. 메탈젯의 연구 범위는 RFID, PCB, MLCC 전극, 태양전지전극, PDP 전극, EMC용재료 등 그 응용 범위를 넓혀 가고 있다. 이러한 응용 기술 대표적인 배선형성 기술인 PCB 제조에 대한 연구는 40um 이하의 고해상도 기판 개발을 요구하고 있다. 선폭은 40um 이하를 유지하면서, 두께는 10um 이상으로 CCL을 대체 하기 위한 기판 형성 기술은 응용기술은 가장 어려운 난이도의 기술이다. 메탈젯 기술은 매우 복합적인 연구분야로 나노 재료의 개발, 인쇄공정의 개발, 기재 표면처리 기술, 헤드 기술의 개발을 동시에 만족할 때 가능하다. 배선 형성을 위하여 나노 잉크를 이용하여 직접 인쇄를 진행하고, 소결하여 전도성을 얻게 된다. 본 연구에서는 미세노즐에 토출 가능한 잉크젯용 잉크 조성을 결정하고, 기판과의 신뢰성을 확보하기 위하여 접착력의 평가, 전도도의 평가, 건조 시간 조절을 통한 Crack 문제 해결, 미세 선폭의 균일성 조절에 관한 실험을 진행하였다.

• Journal of the Microelectronics and Packaging Society
• /
• v.12 no.3 s.36
• /
• pp.267-274
• /
• 2005

This paper presents the fabrication of surface acoustic wave (SAW)-based pressure sensor for long-term stable mechanical compression force measurement. SAW pressure sensor has many attractive features for practical pressure measurement: no battery requirement, wireless pressure detection especially at hazardous environments, and easy other functionality integrations such as temperature, humidity, and RFID. A $41^{\circ}$ YX $LiNbO_3$ piezoelectric substrate was used because of its high SAW propagation velocity and large values of electromechanical coupling factors $K^2$. A silicon substrate with $\~200{\mu}m$ deep cavity was bonded to the diaphragm with epoxy, in which gold was covered all over the inner cavity in order to confine electromagnetic energy inside the sensor, and provide good isolation of the device from its environment. The reflection coefficient $S_{11}$ was measured using network analyzer. High S/N ratio, sharp reflected peaks, and clear separation between the peaks were observed. As a mechanical compression force was applied to the diaphragm from top with extremely sharp object, the diaphragm was bended, resulting in the phase shifts of the reflected peaks. The phase shifts were modulated depending on the amount of applied mechanical compression force. The measured $S_{11}$ results showed a good agreement with simulated results obtained from equivalent admittance circuit modeling.