• Title/Summary/Keyword: Sending condition

Search Result 52, Processing Time 0.027 seconds

Channel Transfer Function Estimation based on Delay and Doppler Profile for Underwater Acoustic OFDM Communication System

  • Shiho, Oshiro;Tomohisa, Wada
    • International Journal of Computer Science & Network Security
    • /
    • v.23 no.1
    • /
    • pp.96-102
    • /
    • 2023
  • In this paper, we proposed Channel Transfer Function estimation based on Delay and Doppler Profile for underwater acoustic OFDM communication system. It improved the estimation accuracy of the channel transfer function by linear time interpolation the change of Scattered Pilot (SP) insertion frequency in the time direction and the time by Delay and Doppler profile that analyzes the multipath situation of the channel investigated the performance of interpolation by simulation and report it. Previous works is inserted SP every 4 OFDM. It was effective under the environment without multipath, but it has observed that the effect of CTF compensation has been lowered in multipath channel condition. In addition to be better when inserted SP every 2 OFDM. But the amount of sending data will be decrease. Therefore, we conducted research to improve 4 OFDM with new interpolator. A computer simulation was performed as a comparison of SP inserted every 4 OFDM, SP inserted every 2 OFDM, and 4 OFDM with new interpolator. the performance of the proposed system is overwhelmingly improved, and the performance is slightly improved even 64 QAM.

Control software for temperature sensors in astronomical devices using GMT SDK 1.6.0

  • Kim, Changgon;Han, Jimin;Pi, Marti;Filgueira, Josema;Cox, Marianne;Roman, Alfonso;Molgo, Jordi;Schoenell, William;Kurkdjian, Pierre;Ji, Tae-Geun;Lee, Hye-In;Pak, Soojong
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.44 no.2
    • /
    • pp.78.2-78.2
    • /
    • 2019
  • The temperature control of a scientific device is essential because extreme temperature conditions can cause hazard issues for the operation. We developed a software which can interact with the temperature sensor using the GMT SDK(Giant Magellan Telescope Software Development Kit) version 1.6.0. The temperature sensor interacts with the EtherCAT(Ethernet for Control Automation Technology) slave via the hardware adapter, sending and receiving data by a packet. The PDO(Process Data Object) and SDO(Service Data Object), which are the packet interacts with each EtherCAT slave, are defined on the TwinCAT program that enables the real-time control of the devices. The user can receive data from the device via grs(GMT Runtime System) tools and log service. Besides, we programmed the software to print an alert message on the log when the temperature condition changes to certain conditions.

  • PDF

Performance Improvement of AODV Routing Algorithm Using Timestamp (Timestamp를 이용한 AODV 라우팅 알고리즘의 성능 개선)

  • Lee Jae-Suk;Park Hae-Ryeon;Lee Kee-Hyun;Suk Jung-Bong
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.31 no.8A
    • /
    • pp.830-836
    • /
    • 2006
  • One of the seminal operation parameters of AODV is the node-to-node travel time of data, which is currently set to fixed value of 40 ms in the RFC3561 and widely used to compute other parameters such as the expected round-trip time of the connection setup message, etc. We have naturally thought the network performance could be improved by dynamically varying the node-to-node travel time with respect to the traffic condition in the networt rather than using the fixed value, which motivates this work. To this end, we apply the idea of using timestamp; every node places the current time in the message before sending it out, and the receiver node computes the node travel time based on the moving average algorithm by considering not only the current value but also the previous ones in an accumulated and exponentially decreasing fashion with time. We evaluate the performance of the proposed scheme in respect of the number of RREQ messages generated, throughput, and delay as a function of traffic load and node mobility, and compare the result with the original AODV scheme. The results show that the proposed scheme presents noticeable performance improvements, expecially under the condition of high node mobility and high traffic load.

A study on the Greeting's Types of Ganchal in Joseon Dynasty (간찰(簡札)의 안부인사(安否人事)에 대한 유형(類型) 연구(硏究))

  • Jeon, Byeong-yong
    • (The)Study of the Eastern Classic
    • /
    • no.57
    • /
    • pp.467-505
    • /
    • 2014
  • I am working on a series of Korean linguistic studies targeting Ganchal(old typed letters in Korea) for many years and this study is for the typology of the [Safety Expression] as the part. For this purpose, [Safety Expression] were divided into a formal types and semantic types, targeting the Chinese Ganchal and Hangul Ganchal of modern Korean Language time(16th century-19th century). Formal types can be divided based on whether Normal position or not, whether Omission or not, whether the Sending letter or not, whether the relationship of the high and the low or not. Normal position form and completion were made the first type which reveal well the typicality of the [Safety Expression]. Original position while [Own Safety] omitted as the second type, while Original position while [Opposite Safety] omitted as the third type, Original position while [Safety Expression] omitted as the fourth type. Inversion type were made as the fifth type which is the most severe solecism in [Safety Expression]. The first type is refers to Original position type that [Opposite Safety] precede the [Own Safety] and the completion type that is full of semantic element. This type can be referred to most typical and normative in that it equipped all components of [Safety Expression]. A second type is that [Safety Expression] is composed of only the [Opposite Safety]. This type is inferior to the first type in terms of set pattern, it is never outdone when it comes to the appearance frequency. Because asking [Opposite Safety] faithfully, omitting [Own Safety] dose not greatly deviate politeness and easy to write Ganchal, it is utilized. The third type is the Original position type showing the configuration of the [Opposite Safety]+Own Safety], but [Opposite Safety] is omitted. The fourth type is a Original position type showing configuration of the [Opposite Safety+Own Safety], but [Safety Expression] is omitted. This type is divided into A ; [Safety Expression] is entirely omitted and B ; such as 'saving trouble', the conventional expression, replace [Safety Expression]. The fifth type is inversion type that shown to structure of the [Own Safety+Opposite Safety], unlike the Original position type. This type is the most severe solecism type and real example is very rare. It is because let leading [Own Safety] and ask later [Opposite Safety] for face save is offend against common decency. In addition, it can be divided into the direct type that [Opposite Safety] and [Own Safety] is directly connected and indirect type that separate into the [story]. The semantic types of [Safety Expression] can be classified based on whether Sending letter or not, fast or slow, whether intimate or not, and isolation or not. For Sending letter, [Safety Expression] consists [Opposite Safety(Climate+Inquiry after health+Mental state)+Own safety(status+Inquiry after health+Mental state)]. At [Opposite safety], [Climate] could be subdivided as [Season] information and [Climate(weather)] information. Also, [Mental state] is divided as receiver's [Family Safety Mental state] and [Individual Safety Mental state]. In [Own Safety], [Status] is divided as receiver's traditional situation; [Recent condition] and receiver's ongoing situation; [Present condition]. [Inquiry after health] is also subdivided as receiver's [Family Safety] and [Individual Safety], [Safety] is as [Family Safety] and [Individual Safety]. Likewise, [Inquiry after health] or [Safety] is usually used as pairs, in dimension of [Family] and [Individual]. This phenomenon seems to have occurred from a big family system, which is defined as taking care of one's parents or grand parents. As for the Written Reply, [Safety Expression] consists [Opposite Safety (Reception+Inquiry after health+Mental state)+Own safety(status+Inquiry after health+Mental state)], and only in [Opposite safety], a difference in semantic structure happens with Sending letter. In [Opposite Safety], [Reception] is divided as [Letter] which is Ganchal that is directly received and [Message], which is news that is received indirectly from people. [Safety] is as [Family Safety] and [Individual Safety], [Mental state] also as [Family Safety Mental state] and [Individual Safety Mental state].

Network Monitoring Mechanism For High Quality Real-Time Streaming Service (고품질 실시간 스트리밍 서비스 제공을 위한 네트워크 모니터링 기법)

  • Kim, Yong-Sul;Kim, Hwa-Sung
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.31 no.11B
    • /
    • pp.969-978
    • /
    • 2006
  • Recently, there has been explosive growth in Internet service contents, and we have witnessed the emergence of many real-time applications on the Internet. These types of applications require special support from the underlying network such as reliability, timeless, and guaranteed delivery, as well as different levels of service quality. Estimation network status and transcoding data rate are researching for QoS of multimedia service by using the RTP/RTCP. We propose two schemes that the way to calculate the one-way delay by expanding the structure of RTP/RTCP in Internet that provides us 'best effort' service and to estimate the network condition by using this in this paper. And we propose the dynamic RTCP mechanism based on one-way delay to deal with rapidly changed network situation immediately. In simulation, proposed monitoring schemes using the one-way delay has similar in performance to monitoring schemes using the GPS, proposed dynamic RTCP scheme obtain the desired result of decreased packet loss rate by sending RTCP RR packet lower than other schemes.

Market trends and business opportunities of the smart insole technology (스마트인솔기술의 시장동향 및 사업화 기회)

  • Park, Jae-Sue;Park, Jung-Yong
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.20 no.7
    • /
    • pp.1389-1397
    • /
    • 2016
  • This study was to evaluate opportunities for the commercialization of smart insole. smart technology is evolving to Insole. Pressure-sensitive sensor or an acceleration sensor is applied to create a balance of the feet and body, is also evolving for entertainment (sports, entertainment, etc.) and health care. Moreover, smart insole can fix an incorrect walking habit by sending a weight value measured by the sensor on a smartphone and during the movement, smart insole helps to correct body balance by measuring the center of gravity moving condition. However, smart tendency of the insole has yet to create a clear boundary in the entertainment and healthcare markets. This is because the fitness band, smart socks, smart shoes can also replace the benefits of a smart insole. Interestingly, the business opportunities are appearing more frequently in health care solution service of electrocardiogram, body temperature, blood pressure, etc., rather than smart devices.

Job Analysis of the CHP Program in the Kangwon Area (강원도 보건진료원의 업무분석)

  • Kim, Sung-Sil
    • Research in Community and Public Health Nursing
    • /
    • v.15 no.3
    • /
    • pp.376-384
    • /
    • 2004
  • Purpose: The CHP program has been evaluated as one of the most successful program in the public health area in Korea. The objects of this study were as follows: 1) to evaluate the job activities of the CHP program, using service contents analysis. 2) to figure out personal factors and the outcome of CHP's activities. Method: Data were collected by sending questionnaires to 130 subjects through the mail from May to December 2003. The response rate was 48.0%. The Data were analyzed by the SPSS WIN program with t test and Pearson correlation coefficient. In using these methods. independent variables are CHP's personal factors (age, experience, certification of specialty) and regional factors (geographical classification, aged population, village workers, cooperation of community leaders, work-conditions), and a dependent variable is the outcome of CHP's job activities. Result: The results of t test analysis show that regional differences between factors are influential in the welfare service, the routine job, and the consultation. As a whole, this is shown that CHPs represent experience, the number of village workers and CHPs living condition of work and most of the categories of jobs that influenced over statistical meaning of differences (t=2.417, p=1.043, t=6.123, p=.004, t=4.309, p=.000). There is a significant positive relation between the routine job and the consultation(r=.455, p=.000), the consultation and the education(r=.461, p=.000). Conclusion: Finally, according to the results of this study, the CHP program should be developed and continue to meet the basic health care needs of the residents in accordance with the philosophy of their own primary health care.

  • PDF

Quality Adaptation with Temporal Scalability for Efficient Video Streaming (효율적인 비디오 스트리밍을 위한 일시적인 확장성을 이용한 품질 적응 기법)

  • Lee, Sun-Hun;Chung, Kwang-Sue
    • Journal of KIISE:Information Networking
    • /
    • v.34 no.3
    • /
    • pp.143-155
    • /
    • 2007
  • In video streaming applications over the Internet, TCP-friendly rate control schemes are useful for improving network stability and inter-protocol fairness. However it does not always guarantee a smooth quality for video streaming. To simultaneously satisfy both the network and application requirements, video streaming applications should be quality-adaptive. In this paper, we propose a new quality adaptation mechanism to adjust the quality of congestion controlled video stream by controlling the frame rate. Based on the current network condition, it controls the frame rate and sending rate of video stream. Through the simulation, we prove that our adaptation mechanism appropriately adjusts the quality of video stream while improving network stability.

A Stability of P-persistent MAC Scheme for Periodic Safety Messages with a Bayesian Game Model (베이지안 게임모델을 적용한 P-persistent MAC 기반 주기적 안정 메시지 전송 방법)

  • Kwon, YongHo;Rhee, Byung Ho
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.38B no.7
    • /
    • pp.543-552
    • /
    • 2013
  • For the safety messages in IEEE 802.11p/WAVE vehicles network environment, strict periodic beacon broadcasting requires status advertisement to assist the driver for safety. In crowded networks where beacon message are broadcasted at a high number of frequencies by many vehicles, which used for beacon sending, will be congested by the wireless medium due to the contention-window based IEEE 802.11p MAC. To resolve the congestion, we consider a MAC scheme based on slotted p-persistent CSMA as a simple non-cooperative Bayesian game which involves payoffs reflecting the attempt probability. Then, we derive Bayesian Nash Equilibrium (BNE) in a closed form. Using the BNE, we propose new congestion control algorithm to improve the performance of the beacon rate under saturation condition in IEEE 802.11p/WAVE vehicular networks. This algorithm explicitly computes packet delivery probability as a function of contention window (CW) size and number of vehicles. The proposed algorithm is validated against numerical simulation results to demonstrate its stability.

The Design and Implementation of Telemedicine System for Emergency Patients in a Ship (해상응급환자를 위한 원격진료 시스템의 설계 및 구현)

  • Lee, Dong-Hoon;Kwon, Jang-Woo;Kim, Gyu-Dong;Hong, Jun-Eui;Lee, Sang-Min
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.13 no.3
    • /
    • pp.537-545
    • /
    • 2009
  • Though there were many research and development about telemedicine on land recently, not yet applied to that on the shore. In this paper, when emergency clinic situation were generated in a ship on shore, the telemedicine system was designed and implemented for transfer and clinic service to doctors on the land by measuring basic body signals of patients. Presently, wireless communication and inmarsat telephone are usually used by simple questions and clinic consults to remote doctors when emergency situation were happened in the ship. In this paper, the telemedicine system on the shore were developed for improving this problems by measuring patient's fundamental conditions such as the blood pressure, pulse, the respiratory condition, electrocardiogram, body temperature, patient image and sending these information to remote doctors on land for more accurate prescription. The developed system can supply the high level clinic service to emergency patients on the shore and cope with the emergency situation in ship.