• Title/Summary/Keyword: Modem.

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A Self-Regulated Robot System using Sensor Network (센서 네트워크를 이용한 자율 로봇 시스템)

  • Park, Chul-Min;Jo, Heung-Kuk;Lee, Hoon-Jae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.11
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    • pp.1954-1960
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    • 2008
  • Modem Robot is used in all industries. Previous Robot was used by simplicity work, at recent times, robot is developed in form that can do action such as a person. Robot's action runs according to command repeat or in the every moment according to sensor's output value, achieve other action. In this raper, we studied about self-regulation transfer robot that follow Object autonomously. This robot can be used by purpose that carry heavy burden instead of human. Robot's composition is drive part which run object's position awareness Sensor, Processor that control action and Motor part. After robot is connects with Network, we did robot remote control and monitor the action situation of robot. For the methode to reduce drive error, we developed algorithm for outside environment. For an experiment we made the self-regulation robot. We showed the directivity of sensor, error of directivity and soft moving of robot. We showed the monitoring system and the execution screen for communication between robot and PC.

A Design of ADC with Multi SHA Structure which for High Data Communication (고속 데이터 통신을 위한 다중Multi SHA구조를 갖는 ADC설계)

  • Kim, Sun-Youb
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.9
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    • pp.1709-1716
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    • 2007
  • In this paper, ADC with multi SHA structure is proposed for high speed operation. The proposed structure incorporates a multi SHA block that consists of multiple SHAs of identical characteristics in parallel to improve the conversion speed. The designed multi SHA is operated by non-overlapping clocks and the sampling speed can be improved by increasing the number of multiplexed SHAs. Pipelined A/D converter, applying the proposed structure, is designed to satisfy requirement of analog front-end of VDSL modem. The measured INL and DNL of designed A/D converter are $0.52LSB{\sim}-0.50LSB$ and $0.80LSB{\sim}-0.76LSB$, respectively. It satisfies the design specifications for VDSL modems. The simulated SNR is about 66dB which corresponds to a 10.7 bit resolution. The power consumption is 24.32mW.

Realtime Long-Distance Transmission Method of DGPS Error Correction Signal (DGPS 보정 신호 실시간 장거리 전송 방안)

  • 조익성;임재홍
    • Korean Journal of Remote Sensing
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    • v.17 no.3
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    • pp.243-251
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    • 2001
  • GPS is one of today's most widely used surveying techniques. But, users can't acquire an enough accuracy in applications of the navigation or geodesy by the GPS positioning technique because of the effects of the ionosphere and troposphere. The solution of these restrictions in the DGPS technique that is to eliminate the common errors and can achieve a high accuracy. Although of sufficient density for good DGPS, accuracy of positioning is just not dense enough to provide complete coverage for real-time positioning, because distances between base and rover is short. In this paper, we suggest Realtime Long-Distance Transmission Method of DGPS Error Correction Signal, which consist of TCP, UDP and IP, which allows a user to increase the distance at which the rover receiver is located from the base, due to radio modem.

Design Study for Power Integrity in Mobile Devices (모바일 기기의 전원 무결성을 위한 설계 연구)

  • Sa, Gi-Dong;Lim, Yeong-Seog
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.5
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    • pp.927-934
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    • 2019
  • Recently, mobile devices have evolved into small computers with various functions according to user requirements. Careful attention must be paid to the design of the power supply network for the stable operation of the application processor (AP), the wireless communication modem, the high performance camera, and the various interfaces of the mobile device to implement various functions of the mobile device. In this paper, we analyzed and verified the method of optimizing the design parameters such as the position, capacity, and number of decoupling capacitors to meet the target impedance required by the driver IC chip to ensure the stability of the power supply network of mobile devices that should be designed as wiring type due to mounting density limitation. The proposed wired power supply network design method can be applied to various applications including high-speed signal transmission line in addition to mobile applications.

The Analysis of Underground Power Line Communication Channel Characteristics by Measurements (지중전력선 통신채널 측정에 의한 특성해석)

  • Shin, Dong-Hwan;Choi, Jeong-Yeon;Lee, Seung-Jun;Woo, Hui-Gon;Shin, Jai-Ho;Eom, Ki-Hwan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.86-89
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    • 2009
  • In this paper, a broadband power line communication modem and network technology to develop tests with actual characteristics of the underground power line communication channel to be interpreted. Length and structure of the underground distribution line due to underground distribution line to the broadband powerline communication channels to measure the amount of attenuation on the signal generator, spectrum analyzer, such as contactless coupler was used to configure the channel measurement system. Demonstration tests in the test line as a single line by selecting the longest high-voltage lines where the two-channel measurement and signal attenuation on the noise level was measured. Measuring results degrade communication performance can be quite sure that was the presence of impulse noise, long lines, the line length was confirmed by the high-frequency attenuation appears.

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Analysis of a fixed source-to-receiver underwater acoustic communication channel parameters in shallow water (송수신기가 고정된 천해 수중음향통신 채널 매개변수 해석)

  • Bae, Minja;Park, Jihyun;Yoon, Jong Rak
    • The Journal of the Acoustical Society of Korea
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    • v.38 no.5
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    • pp.494-510
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    • 2019
  • Underwater acoustic communication channel parameters consist of impulse response, delay spreading, scattering function, coherence bandwidth, frequency selective fading, coherence time and time variant magnitude fading statistics on which communication system modem and channel coding are designed. These parameters are influenced by sound velocity profile, platform motion and sea surface roughness in given acoustical oceanography condition. In this paper, channel model based on phasor, channel simulator, measurement and analysis method of channel parameters are given in a fixed source-to-receiver system and the parameters are analyzed using shallow water experimental data. For two different source-to-receiver ranges of 300 m and 600 m, the parameters are characterized by three multipaths such as a direct, a surface reflection path with time variant scattering and a bottom reflection path. The results present a channel modelling method of a fixed source source-to-receiver system, channel parameters measurement and analysis methods and a system design and performance assessment method in shallow water.

A Study on the Automatic Seam Tracking of Triangular Wave Form (삼각파 형태의 용접선 자동추적에 관한 연구)

  • Bae Cherl-O;Kim Hyun-Su;Ahn Byong-Won
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.12 no.2 s.25
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    • pp.151-155
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    • 2006
  • In these days, welding is the most commonly used metallic connection technology and also is the fundamental production technology of the modem industrial, which is used in various areas of the industrial fields, such as shipbuilding, automobiles, airplanes and plant facilities. However welding process produces strong light, electric currents, and fume gases etc., and the welding automation is not so easy compared to the other works of manufacturing industries which produce the standardized products in large quantities. So it is difficult to weld and detect the all kinds of seams automatically by a specific sensor. In this paper the sensor applying strain gauges is used to detect the seams of triangular wave form. With the auto carriage having the sensor we proposed the experiment to weld and track the seam automatically.

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A Crew Location Recognition System for a Naval Ship by Applying Ubiquitous Technologies

  • Lee, Jin-Tae;Cho, Seong-Rak;Kim, Seong-Jeon
    • Journal of Ship and Ocean Technology
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    • v.12 no.3
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    • pp.26-35
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    • 2008
  • Recognition of real time locations of crews for a naval ship is important, not only for the operation efficiency but also for the safety of onboard crews in the ship. More than 100 crews are dwelling in a modem naval ship and they are involved in various duties. Moreover many visitors come in and out frequently while the ship is moored in a harbor. It sometimes requires considerable time and efforts to find a person for urgent mission. It would enhance the operational efficiency if locations of onboard crews are recognized and monitored in real time. An active type RFID tag, which has a specific ID number, is distributed to each crew member, which should be carried during his stay in the ship. A number of fixed type RFID readers are to be located at the major passages of the ship, which are connected to the main computer via Local Area Network. The location of a crew would be identified by the ID number of his RFID tag and the location of the RFID reader which detected the RFID tag. A middleware is needed to process the collected data in the main computer. The data is fed to application softwares, which actually display locations of the concerned crews. The software is coded using GUI (Graphic User Interface) for better user friendliness, which has the function of storing the location history of a crew, and sending warning messages to appropriate persons, if unallowable behavior is detected. An auxiliary naval ship is selected for an experimental application study of the proposed system. It turns out that the required budget and time for the realization of the system is within the allowable limits. But complementary measures to protect the privacy of onboard crews should be considered and adopted, before the application of the system is realized.

Synthesis of $^{99m} Tc$-tricarbonyl Precursors for Labeling of Bioactive Molecules

  • Jang, Beom-Su;Kim, Yong-Mi;Cho, Sang-Mu;Shin, Byung-Chul;Park, Sun-Ju;Hong, Young-Don;Gwon, Hui-Jeong;Park, Kyung-Bae;Yun, Hyo-In
    • Nuclear Engineering and Technology
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    • v.34 no.2
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    • pp.146-153
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    • 2002
  • To radiolabel bioactive molecules, we synthesized $^{99m}$Tc-tricarbonyl precursor, [$^{99m}$Tc(CO)$_3$($H_2O$)$_3$]$^{+}$ with a low oxidation state ( I ). The [$^{99m}$Tc(CO)$_3$($H_2O$)$_3$]$^{+}$ was prepared by low pressure carbonylation (1 atm of CO) of [$^{99m}$Tc $O_4$)]$^{[-10]}$ in the presence of NaB $H_4$ resulting in higher than 98% of labeling yield and stability up to 8 hrs. We evaluated the characteristics of $^{99m}$Tc- tricarbonyl labeled bioactive molecules by carrying out in vitro and in vitro study. Prepared [$^{99m}$Tc(CO)$_3$($H_2O$)$_3$]$^{+}$ was then reacted with some ligands of significance in modem diagnostic nuclear medicine and some amino acids. Labeling yields were checked by HPLC and found to be usually high, excluding $^{99m}$Tc-tricarbonyl-MDP, -EDTMP and -mIBG. And the biodistribution properties of $^{99m}$Tc-tricarbonyl complexes applied in rabbit showed different appearance comparing with that of the $^{99m}$Tc-labeling by conventional means. From these results, we conclude that [$^{99m}$Tc(CO)$_3$($H_2O$)$_3$]$^{+}$ is a potential precursor for development of radiopharmaceuticals, especially for labeling of biomolecules.

Development of a Data Acquisition System for the Long-term Monitoring of Plum (Japanese apricot) Farm Environment and Soil

  • Akhter, Tangina;Ali, Mohammod;Cha, Jaeyoon;Park, Seong-Jin;Jang, Gyeang;Yang, Kyu-Won;Kim, Hyuck-Joo
    • Journal of Biosystems Engineering
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    • v.43 no.4
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    • pp.426-439
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    • 2018
  • Purpose: To continuously monitor soil and climatic properties, a data acquisition system (DAQ) was developed and tested in plum farms (Gyewol-ri and Haechang-ri, Suncheon, Korea). Methods: The DAQ consisted of a Raspberry-Pi processor, a modem, and an ADC board with multiple sensors (soil moisture content (SEN0193), soil temperature (DS18B20), climatic temperature and humidity (DHT22), and rainfall gauge (TR-525M)). In the laboratory, various tests were conducted to calibrate SEN0193 at different soil moistures, soil temperatures, depths, and bulk densities. For performance comparison of the SEN0193 sensor, two commercial moisture sensors (SMS-BTA and WT-1000B) were tested in the field. The collected field data in Raspberry-Pi were transmitted and stored on a web server database through a commercial communications wireless network. Results: In laboratory tests, it was found that the SEN0193 sensor voltage reading increased significantly with an increase in soil bulk density. A linear calibration equation was developed between voltage and soil moisture content depending on the farm soil bulk density. In field tests, the SEN0193 sensor showed linearity (R = 0.76 and 0.73) between output voltage and moisture content; however, the other two sensors showed no linearity, indicating that site-specific calibration is important for accurate sensing. In the long-term monitoring results, it was observed that the measured climate temperature was almost the same as website information. Soil temperature information was higher than the values measured by DS18B20 during spring and summer. However, the local rainfall measured using TR 525M was significantly different from the values on the website. Conclusion: Based on the test results obtained using the developed monitoring system, it is thought that the measurement of various parameters using one device would be helpful in monitoring plum growth. Field data from the local farm monitoring system can be coupled with website information from the weather station and used more efficiently.