• Title/Summary/Keyword: Electronic communication

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A Study on the SAR Measurement System Validation at 150 MHz Band (150 MHz 대역에서의 SAR 측정시스템의 유효성 연구)

  • Choi, Donggeun;Kim, Kihwea;Choi, Jaehoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.10
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    • pp.1008-1016
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    • 2013
  • SAR measurement which was applied only to the mobile phone has been expanded in the Korean radio regulation law to the portable wireless communication equipments within 20 cm from the human body since Jan. 2012. The two-way radio operating at 150 MHz frequency band was newly included following the revised radio regulation in the target equipment of measurement. SAR measurement system at 150 MHz satisfying this regulation is necessary accordingly for SAR conformity assessment. The international SAR measurement standard(IEC 62209-2) includes the evaluation method on frequencies above 300 MHz, and the commercial SAR measurement system can measure SAR above 300 MHz only. The size of the reference dipole antenna(760 mm, return loss: -27.57 dB) and flat phantom ($1,300 mm(L){\times}900 mm(W){\times}200 mm(H)$), targeted SAR values for numerical analysis(1 g: 1.08 W/kg, 10 g: 0.77 W/kg) for SAR validation evaluation at 150 MHz frequency are proposed in this paper. The suggested dipole antenna and flat phantom are assembled and used to verify the conformity assessment of commercial SAR measurement system. The measured SAR values of 1 g and 10 g were obtained respectively to be 1.13 W/kg, 0.81 W/kg, and they satisfied the effective range(within ${\pm}10$ %) of IEC international standard. The standards based on this study are expected to be used for the domestic SAR measurement standard and IEC(International Electrotechnical Commission) international standard.

A Study on Development of Remote Crane Wire Rope Flaws Detection Systems (원격 크레인 와이어 로프 결함 탐지 시스템 개발에 관한 연구)

  • Min, Jeong-Tak;Lee, Jin-Woo;Lee, Kwon-Soon
    • Journal of Navigation and Port Research
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    • v.27 no.1
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    • pp.97-102
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    • 2003
  • Wire ropes are used in a myriad of various industrial applications such as elevator, mine hoist, construction machinery, lift, and suspension bridge. Especially, the wire rope of crane is important component to container transfer. If it happens wire rope failures during the operation, it may lead to safety accident, economic loss by productivity decline and so on. To solve this problem, we developed remote wire rope fault detecting system, and this system is consisted of 3 parts that portable fault detecting part, signal processing part and remote monitoring part. All detected signal has external noise or disturbance according to circumstances. So, we applied to discrete wavelet transform to extract a signal from noisy data. It is verified that the detecting system by de-noising has good efficiency for inspecting faults of wire ropes in service. As a result, by developing this system, container terminal could reduce expense because of extension fo wire ropes exchange period and could competitive power. Also, this system is possible to apply in several field such as elevator, lift and so on.

EEG 16 channel variations between the non-stimulation and the moxibustion stimulated subjects for CV4, CV8, and CV12 acupuncture points (중완, 신궐 및 관원 경혈의 뜸 자극과 무 자극 대상군의 16채널 뇌파 변화에 관한 연구)

  • Yoon, Dong-Eop;Song, Hong-Bok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.12
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    • pp.2755-2760
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    • 2010
  • The moxibustion therapy of orient medical is well known. Moxibustion method is used to burning moxibustion. The variation factors of the moxibustion stimulation for body can be applied to the electronic moxibustion method. This study is to analyze and examine the electroencephalogram(EEG) variations for moxibustion stimulation. In experiment, we divided six healthy male subjects into two same sized groups : with and without stimuli. The given stimuli are the moxibustion for CV4(Kwan-Won), CV8(Shin-Guel), and CV12(Jung-wan) acupuncture points. We have analyzed the power spectrum for ${\alpha}$, ${\beta}$, ${\delta}$, ${\Theta}$ waves and the average EEG variation level and each channels variation level of EEG. The result was that the moxibustion stimulation decreased the EEG levels of parietal lobe(ch 2, 3, 6, 7) according to the somatosensory system. And the apparent different points are that mild-heat($42{\sim}44^{\circ}C$) stimulation generating ${\alpha}$-wave is increased and ${\beta}$-wave is decreased, also slight-hot($45{\sim}48^{\circ}C$) stimulation made ${\alpha}$-wave decrease and ${\beta}$-wave increase for occipital lobe(ch 4,8) on the simulation group.

A Study on the Propagation Environment for VHF Maritime Digital Communications Operation in South Sea Area (남해안의 VHF 해상디지털통신 운용을 위한 전파환경 연구)

  • Ju, Yang-Ro;Kim, Kab-Ki;Choi, Jo-Cheon;Lee, Seong-Ro
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.6
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    • pp.1310-1316
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    • 2014
  • The IMO has recommended on VHF digital communications operation for sailing ships from 2017. And ships more than 5 tons is obliged to digital communications by fishing Vessels Act and Vessel Safety Act in domestic. The owner of all vessel is equipped to the automatic position reporting device in accordance with the Notice of the Ministry of Oceans and Fisheries to regulations, It shall be ensure to navigations safety and in order to respond quickly in the event of maritime accidents on all vessels. The info-communications station of fishery is operating the automatic position reporting system using the VHF DSC in east sea from 2012, Continuously, which is underway the install plan in south sea and yellow sea. But this plan is very difficult, because of propagation environment is poor on account of complicated coastline and many islands. This paper has analyzed the propagation coverage for position setting of coast station in south sea and the traffic zone set up by compare with RSSI and methode of navigation tracking by VMS.

Analysis and Forecasting for ICT Convergence Industries (ICT 융합 산업의 현황 및 전망)

  • Jang, Hee S.;Park, Jong T.
    • Journal of Service Research and Studies
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    • v.5 no.2
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    • pp.15-24
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    • 2015
  • The trade balance for the information and communications technology (ICT) industries in 2014 have reached 863 hundred million dollars as the main export products such as smart phone and semi-conductor increase, since the ICT industries have played an important role in economic growth in Korea. Until now, the consistent supporting of government and investment of company have been doing with the growth of ICT industries, as a result, Korea marked as the first in the UN electronic government preparing index, and rank 12 in the network preparing index through the policy of national information and basic plan of inter-industry convergence. However, as the unstable international economic circumstances, ICT industries is faced with the stagnation, and then preemptive development of products and services for ICT convergence industries is needed to continually get definite ICT Korea image. In this paper, the ICT convergence industry is analyzed and forecasted. In specific, the international and domestic market for cloud, 3D convergence, and internet of things is diagnosed. The market for ICT convergence industries is predicted to be 3.6 trillion dollar in the world, and 110 trillion won in domestic. From the analytical results for technology and services development, the preemptive supporting of the technology development and policy for the internet of things and 3D convergence industries is required. In addition to, through the future forecasting by socio-tech matrix method, the policy supporting for the ICT convergence area of healthcare, fintech, artificial intelligence, body platform, and human security is needed.

Single Path Phase-only Security System using Phase-encoded XOR Operations in Fourier Plane (푸리에 영역에서의 위상 변조 Exclusive-OR 연산을 이용한 단일 경로 위상 암호화 시스템)

  • Shin, Chang-Mok;Cho, Kyu-Bo;Kim, Soo-Joong;Noh, Duck-Soo
    • Korean Journal of Optics and Photonics
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    • v.16 no.4
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    • pp.326-333
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    • 2005
  • Phase-only encryption scheme using exclusive-OR rules in Fourier plane and a single path decryption system are presented. A zero-padded original image, multiplied by a random phase image, is Fourier transformed and its real-valued data is encrypted with key data by using XOR rules. A decryption is simply performed based on 2-1 setup with spatial filter by Fourier transform for multiplying phase-only encrypted data by phase-only key data, which are obtained by phase-encoding process, and spatial filtering for zero-order elimination in inverse-Fourier plane. Since the encryption process is peformed in Fourier plane, proposed encryption scheme is more tolerant to loss of key information by scratching or cutting than previous XOR encryption method in space domain. Compare with previous phase-visualization systems, due to the simple architecture without a reference wave, our system is basically robust to mechanical vibrations and fluctuations. Numerical simulations have confirmed the proposed technique as high-level encryption and simple decryption architecture.

A study on the service satisfaction of Chinese mobile Apps -Comparing paid and free services- (중국 모바일 앱 서비스 만족에 관한연구 -유료와 무료 모바일 서비스의 비교-)

  • Qin, Ying;Lee, Sang-Joon;Lee, Kyeong-Rak
    • Journal of Digital Convergence
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    • v.15 no.4
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    • pp.127-137
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    • 2017
  • The role of smartphones is changing from a communication system for exchanging calls and information into a universal platform for cultural services. Also, satisfaction for mobile application services on smartphones is a very important factor in the smart business. In This paper, we analyze the effects of the outcome, service scape, costs, and especially the impact of whether costumers having to pay or free for the app on customer satisfaction. For this purpose, we analyzed survey data on service quality of mobile app service from Chinese mobile app service users. We also analyzed the moderating effects of paid and free mobile app services. As a result, it was confirmed that the quality, servicescape quality and cost of mobile app service that customers perceive have a positive effect on customer satisfaction. In addition, the effect of the cost of mobile app service perceived by the customer on customer satisfaction showed that free mobile app service was more significant than paid mobile app service. This paper can be used as an alternative to monetization for providing a mobile app service provider or a mobile app service provider who wants to switch mobile app service from free to paid service.

5G Mobile Communications: 4th Industrial Aorta (5G 이동통신: 4차 산업 대동맥)

  • Kim, Jeong Su;Lee, Moon Ho
    • The Journal of the Convergence on Culture Technology
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    • v.4 no.1
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    • pp.337-351
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    • 2018
  • This paper discusses 5G IOT, Augmented Reality, Cloud Computing, Big Data, Future Autonomous Driving Vehicle technology, and presents 5G utilization of Pyeongchang Winter Olympic Games and Jeju Smart City model. The reason is that 5G is the main artery of the 4th industry.5G is the fourth industrial aorta because 5G is the core infrastructure of the fourth industrial revolution. In order for the AI, autonomous vehicle, VR / AR, and Internet (IoT) era to take off, data must be transmitted several times faster and more securely than before. For example, if you send a stop signal to LTE, which is a communication technology, to a remote autonomous vehicle, it takes a hundredth of a second. It seems to be fairly fast, but if you run at 100km / h, you can not guarantee safety because the car moves 30cm until it stops. 5G is more than 20 gigabits per second (Gbps), about 40 times faster than current LTE. Theoretically, the vehicle can be set up within 1 cm. 5G not only connects 1 million Internet (IoT) devices within a radius of 1 kilometer, but also has a speed delay of less than 0.001 sec. Steve Mollenkov, chief executive officer of Qualcomm, the world's largest maker of smartphones, said, "5G is a key element and innovative technology that will connect the future." With 5G commercialization, there will be an economic effect of 12 trillion dollars in 2035 and 22 million new jobs We can expect to see the effect of creation.

Development of an EEG Software for Two-Channel Cerebral Function Monitoring System (2채널 뇌기능 감시 시스템을 위한 뇌파 소프트웨어의 개발)

  • Kim, Dong-Jun;Yu, Seon-Guk;Kim, Seon-Ho
    • Journal of Biomedical Engineering Research
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    • v.20 no.1
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    • pp.81-90
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    • 1999
  • This paper describes an EEG(electroencephalogram) software for two-channel cerebral function monitoring system to detect the cerebral ischemia. In the software, two-channel bipolar analog EEG signals are digitized and from the signals various EEG parameters are extracted and displayed on a monitor in real-time. Digitized EEG signal is transformed by FFT(Fast Fourier transform) and represented as CSA(compressed spectral array) and DSA(density spectral array). Additional 5 parameters, such as alpha ratio, percent delta, spectral edge frequency, total power, and difference in total power, are estimated using the FFT spectra. All of these are effectively merged in a monitor and displayed in real-time. Through animal experiments and clinical trials on men, the software is modified and enhanced. Since the software provides raw EEG, CSA, DSA, simultaneously with additional 5 parameters in a monitor, it is possible to observe patients multilaterally. For easy comparison of patient's status, reference patterns of CSA, DSA can be captured and displayed on top of the monitor. And user can mark events of surgical operation and patient's conditions on the software, this allow him jump to the points of events directly, when reviewing the recorded EEG file afterwards. Other functions, such as forward/backward jump, gain control, file management are equipped and these are operated by simple mouse click. Clinical tests in a university hospital show that the software responds accurately according to the conditions of patients and medical doctors can use the software easily.

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Conduction Path Dependent Threshold Voltage for the Ratio of Top and Bottom Oxide Thickness of Asymmetric Double Gate MOSFET (비대칭 이중게이트 MOSFET의 상하단 산화막 두께비에 따른 전도중심에 대한 문턱전압 의존성)

  • Jung, Hakkee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.11
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    • pp.2709-2714
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    • 2014
  • This paper has analyzed the change of threshold voltage and conduction path for the ratio of top and bottom gate oxide thickness of asymmetric double gate MOSFET. The asymmetric double gate MOSFET has the advantage that the factor to be able to control the current in the subthreshold region increases. The analytical potential distribution is derived from Poisson's equation to analyze the threshold voltage and conduction path for the ratio of top and bottom gate oxide thickness. The Gaussian distribution function is used as charge distribution. This analytical potential distribution is used to derive off-current and subthreshold swing. By observing the results of threshold voltage and conduction path with parameters of bottom gate voltage, channel length and thickness, projected range and standard projected deviation, the threshold voltage greatly changed for the ratio of top and bottom gate oxide thickness. The threshold voltage changed for the ratio of channel length and thickness, not the absolute values of those, and it increased when conduction path moved toward top gate. The threshold voltage and conduction path changed more greatly for projected range than standard projected deviation.