• Title/Summary/Keyword: Location measurement

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Method to Improve Localization and Mapping Accuracy on the Urban Road Using GPS, Monocular Camera and HD Map (GPS와 단안카메라, HD Map을 이용한 도심 도로상에서의 위치측정 및 맵핑 정확도 향상 방안)

  • Kim, Young-Hun;Kim, Jae-Myeong;Kim, Gi-Chang;Choi, Yun-Soo
    • Korean Journal of Remote Sensing
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    • v.37 no.5_1
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    • pp.1095-1109
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    • 2021
  • The technology used to recognize the location and surroundings of autonomous vehicles is called SLAM. SLAM standsfor Simultaneously Localization and Mapping and hasrecently been actively utilized in research on autonomous vehicles,starting with robotic research. Expensive GPS, INS, LiDAR, RADAR, and Wheel Odometry allow precise magnetic positioning and mapping in centimeters. However, if it can secure similar accuracy as using cheaper Cameras and GPS data, it will contribute to advancing the era of autonomous driving. In this paper, we present a method for converging monocular camera with RTK-enabled GPS data to perform RMSE 33.7 cm localization and mapping on the urban road.

A Scheme of Identity Authentication and Anomaly Detection using ECG and Beacon-based Blockchain (ECG와 비콘 기반의 블록체인을 이용한 신원 인증 및 이상징후 탐지 기법)

  • Kim, Kyung-Hee;Lee, Keun-Ho
    • Journal of Internet of Things and Convergence
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    • v.7 no.3
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    • pp.69-74
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    • 2021
  • With the recent development of biometric authentication technology, the user authentication techniques using biometric authentication are increasing. Various problems arised in certification techniques that use various existing methods such as ID/PW. Therefore, recently, a method of improving security by introducing biometric authentication as secondary authentication has been used. In this thesis, proposal of the user authentication system that can detect user identification and anomalies using ECGs that are extremely difficult to falsify through the electrical biometric signals from the heart among various biometric authentication devices is studied. The system detects user anomalies by comparing ECG data received from a wrist-mounted wearable device-type ECG measurement tool with identification and ECG data stored in blockchain form on the database and identifying the user's location through a beacon system.

Multi-slit prompt-gamma camera for locating of distal dose falloff in proton therapy

  • Park, Jong Hoon;Kim, Sung Hun;Ku, Youngmo;Kim, Chan Hyeong;Lee, Han Rim;Jeong, Jong Hwi;Lee, Se Byeong;Shin, Dong Ho
    • Nuclear Engineering and Technology
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    • v.51 no.5
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    • pp.1406-1416
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    • 2019
  • In this research, a multi-slit prompt-gamma camera was developed to locate the distal dose falloff of the proton beam spots in spot scanning proton therapy. To see the performance of the developed camera, therapeutic proton beams were delivered to a solid plate phantom and then the prompt gammas from the phantom were measured using the camera. Our results show that the camera locates the 90% distal dose falloff (= d90%), within about 2-3 mm of error for the spots which are composed $3.8{\times}10^8$ protons or more. The measured location of d90% is not very sensitive to the irradiation depth of the proton beam (i.e., the depth of proton beam from the phantom surface toward which the camera is located). Considering the number of protons per spot for the most distal spots in typical treatment cases (i.e., 2 Gy dose divided in 2 fields), the camera can locate d90% only for a fraction of the spots depending on the treatment cases. However, the information of those spots is still valuable in that, in the multi-slit prompt-gamma camera, the distal dose falloff of the spots is located solely based on prompt gamma measurement, i.e., not referring to Monte Carlo simulation.

The Development of a beam measurement system for improving the beam output characteristics. (빔 출력 특성 개선을 위한 빔 측정 시스템 개발)

  • Kim, Dong-Myung;Moon, Ha-jung;Hur, Min-Gu;Yang, Seung-Dae;Lee, Dong-hoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.10a
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    • pp.693-695
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    • 2014
  • Radioactive isotopes for radiation diagnosis is production by using Cyclotron like a PET. Radioactive isotopes is influenced product yield according to shape and size of the proton beam and target irradiation position by cyclotron. And to develop a device for measuring the distribution of the beam to increase the loss of the beam. Beam measuring device is measured vertically beam current according move the two wires. In this way, by using the beam current value in each position you are able to know the cross section and location information of the beam. By scanning cross-section for X-axis Y-axis of beam acquires data of beam. Print this into 2D graph, and analyze the result. You can save this result by documentation process.

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The Measurement of Spatial Dose Rate by Gravity Ventilation after Technegas Scanning (Technegas 스캐닝 후 중력환기에 의한 공간선량율 측정)

  • Kim, Sung-Bin;Won, Do-Yeon
    • Journal of the Korean Society of Radiology
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    • v.13 no.4
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    • pp.667-674
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    • 2019
  • Because examination with technegas produces images through simple diffusion accumulation, the examination room can become contaminated after scan. Therefore, radiation workers and patients awaiting examination will be affected by internal exposure from technegas inhalation. Before and after gravity ventilation, I am trying to find a way to reduce the exposure dose of waiting patients according to a comparative analysis of horizontal spatial dose rates over time. Spatial dose ratio were measured for 10 minutes from various distances and angles around ventilator's location before and after gravity ventilation. Then, mean values, standard deviation and reduction ratio were calculated. The highest reduction rate of gravity ventilation was 95.31% and the highest reduction ratio was 1 to 3 minutes. Therefore, the gravity ventilation could reduce the exposure dose of radiologic technologists, waiting patients, patient guardians and nurses. In conclusion, the reduction of the exposure dose during the technegas ventilation study through gravity ventilation will play a role in optimiging the protection and it is in accordance with the recommended reduction of the medical exposure by ICRP 103.

A Review of Dose Rate Meters as First Responders to Ionising Radiation

  • Akber, Aqeel Ahmad;Wiggins, Matthew Benfield
    • Journal of Radiation Protection and Research
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    • v.44 no.3
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    • pp.97-102
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    • 2019
  • Background: Dose rate meters are the most widely used, and perhaps one of the most important tools for the measurement of ionising radiation. They are often the first, or only, device available to a user for an instant check of radiation dose at a certain location. Throughout the world, radiation safety practices rely strongly on the output of these dose rate meters. But how well do we know the quality of their output? Materials and Methods: This review is based on the measurements 1,158 commercially available dose rate meters of 116 different makes and models. Expected versus the displayed dose patterns and consistency was checked at various dose rates between $5{\mu}Gy{\cdot}h^{-1}$ and $2mGy{\cdot}h^{-1}$. Samples of these meters were then selected for further investigation and were exposed to radiation sources covering photon energies from 50 keV to 1.5 MeV. The effect of detector orientation on its reading was also investigated. Rather than focusing on the angular response distribution that is often reported by the manufacturer of the device, this study focussed on the design ergonomics i.e. the angles that the operator will realistically use to measure a dose rate. Results and Discussion: This review shows the scope and boundaries of the ionising radiation dose rate estimations that are made using commonly available meters. Observations showed both inter and intra make and model variations, occasional cases of instrument failure, instrument walk away, and erroneous response. Conclusion: The results indicate the significance of selecting and maintaining suitable monitors for specific applications in radiation safety.

A Study on the Concave Type Hull Plate Forming using Induction Heating System (고주파 유도가열을 이용한 오목 곡면 곡가공에 관한 연구)

  • Hyun, Chung Min;Kim, Dae Kyung;Mun, Seung Hwan;Park, Jung Seo;Dohr, Kyu Won
    • Journal of the Society of Naval Architects of Korea
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    • v.56 no.2
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    • pp.128-134
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    • 2019
  • In shipbuilding, accurate fabrication of curved hull plates is one of the most important steps, since the shape of ship hull, which is very critical in the overall performance of a ship, is a collection of such plates. The curved hull plates forming process requires a significant amount of time by skilled workers in shipbuilding. In general, the workers cause thermal distortion in the plate and forming initial shape using gas heat source. So shipbuilding companies need skilled workers who have long experience. To solve the problem, a lot of researchers tried to develop automation system for curved hull plates. In this paper, we propose automatic heating system with gantry robot, high frequency induction heater to replace the gas heat source and automatic measurement system. We apply the system to forming concave type plate that is actually used in ship manufacturing. In addition, a system was developed to automatically generate heating information, such as the heating location and the heating speed, for actual heating process. Then the system was applied to the actual heating material. It is shown that the proposed triangle heating pattern makes desired concave shape successfully. The induction heating system showed that it can be used for automation system of curved hull plates forming process replacing gas heat source.

Integrated Navigation Filter Design for Trains Considering the Mounting Misalignment Error of the IMU

  • Chae, Myeong Seok;Cho, Seong Yun;Shin, Kyung Ho
    • Journal of Positioning, Navigation, and Timing
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    • v.10 no.3
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    • pp.179-187
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    • 2021
  • To estimate the location of the train, we consider an integrated navigation system that combines Inertial Navigation System (INS) and Global Navigation Satellite System (GNSS). This system provides accurate navigation results in open sky by combining only the advantages of both systems. However, since measurement update cannot be performed in GNSS signal blocked areas such as tunnels, mountain, and urban areas, pure INS is used. The error of navigation information increases in this area. In order to reduce this problem, the train's Non-Holonomic Constraints (NHC) information can be used. Therefore, we deal with the INS/GNSS/NHC integrated navigation system in this paper. However, in the process of installing the navigation system on the train, a Mounting Misalignment Error of the IMU (MMEI) inevitably occurs. In this case, if the NHC is used without correcting the error, the navigation error becomes even larger. To solve this problem, a method of easily estimating the MMEI without an external device is introduced. The navigation filter is designed using the Extended Kalman Filter (EKF) by considering the MMEI. It is assumed that there is no vertical misalignment error, so only the horizontal misalignment error is considered. The performance of the integrated navigation system according to the presence or absence of the MMEI and the estimation performance of the MMEI according to the method of using NHC information are analyzed based on simulation. As a result, it is confirmed that the MMEI is accurately estimated by using the NHC information together with the GNSS information, and the performance and reliability of the integrated navigation system are improved.

A Study on Characteristics of a Plot Plan and a Floor Plan of Modern Private Housing Architecture in Gunsan (군산 근대 민간 건축의 배치 및 평면 유형 특징에 관한 연구)

  • Kim, Jong-Sung;Bae, Jin-A
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.2
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    • pp.43-52
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    • 2019
  • The purpose of this study is to classify the building layout and plan types according to the urban location, use and function of civil and to analyze the characteristics by the type classified. After constructing a framework (Mathia type, Nagaya type, Detached House type) for analyzing Modern Private Housing Architecture in Gunsan, the research was conducted on 30 representative buildings, and a plot plan, a floor plan and elevation were created. After analyzing the relationship between the lot of land and the urban street, we classified the type of arrangement into Mathia type and Nagaya type which directly enter the building from the road, and derived the Detached House type which indirectly enters from the road. When we look at the use of the derived arrangement types, most of the Mathia type are commercial and residential buildings, and some of them are specially designed for commercial buildings. The Nagaya type appears in the form of commercial and residential house or residential private house, and the Detached House type is classified as residential style. As a relation with the urban street, the Mathia type and the Nagaya type are generally located on the main urban street, whereas the Detached House type is located on the small urban street. As a result of analyzing, the floor plan was changed according to the plot plan. The plan of the Mathia and Nagaya type are arranged to enter directly from the street, with commercial space being mainly located on the street, and the residential space being composed on the back or the second floor. the plan of the Detached House is a type that enters indirectly into the interior through a separate space (Courtyard), and forms an organic space between the residential interior and the front and rear yard. The purpose of this study is to investigate the Characteristics of a plot plan and a floor plan of Modern Private Housing Architecture in Gunsan by means of analysis considering the urban street, Uses of buildings, Construction method and the yard through actual measurement.

A Study on the Path Loss of Underwater Acoustic Channel Based on At-sea Experiment at the South Sea of Korea (남해 실해역 시험 기반 수중음향채널 경로손실에 관한 연구)

  • Kim, Min-Sang;Lee, Tae-Seok;Cho, Yong-Ho;Im, Tae-Ho;Ko, Hak-Lim
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.24 no.3
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    • pp.405-411
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    • 2020
  • Recently, studies on underwater communication, related to the development of underwater resources, disaster monitoring and defense, have been actively carried out. In the design of wireless communication systems, path loss is the most important information to derive a link budget that is required to guarantee communication reliability by calculating received power level for the given communication link. The underwater acoustic channel have different characteristics according to geographical location and relevant environmental factors such as water temperature, depth, wave height, algae, and turbidity. Subsequently, many research institutes aiming to develop underwater acoustic communication systems are researching actively on the underwater acoustic channels in various sea areas. In Korea, however, studies on the path loss of the acoustic channel are still insufficient. Therefore, in this study, the path loss of the acoustic channel are studied based on measurement data of the at-sea experiment conducted at Geohae-do, southern sea of Korea.