• Title/Summary/Keyword: HDLC

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Composition Rule of Character Codes to efficiently transmit the Character Code in HDLC(High-level Data Link Control) Protocol (HDLC(High-level Data Link Control) 프로토콜에서 효율적 문자부호 전송을 위한 문자부호화 규칙)

  • Hong, Wan-Pyo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.7 no.4
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    • pp.753-760
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    • 2012
  • This paper is to show the character coding rule in computer and information equipment etc to improve the transmission efficiency in telecommunications. In the transmission system, the transmission efficiency can be increased by applying the proper character coding method. In datalink layer, HDSL ptotocol use FLAG byte to identify the frame to frame which consists of data bit stream and other control bytes. FLAG byte constits of "01111110". When data bit stream consist of the consecutive 5-bit "1" after "0", the decoder can not distinguish whether the data bit sequence is flag bit stream or data bit stream. To solve the problem, when the line coder in transmitter detects the consecutive 5-bits "1" after "0" in the input data stream, inserts violently the "0" after 5th "1" of the consecutive 5-bit "1" after "0". As a result, when the characters are decoded with the above procedure, the efficiency of system should be decreased. This paper shows the character code rule to minimize the consecutive 5-bits "1" after "0" when the code is given to each characters.

Bi-directional information transmission in MAGLEV (자기부상열차에서의 양방향 정보전송)

  • Ahn, Sang-Kwon;Park, Jeong-Soo;Chang, Dae-Sik;Kim, Yang-Mo
    • Proceedings of the KIEE Conference
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    • 1996.11a
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    • pp.434-436
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    • 1996
  • This paper deals with the signal communication system for MAGLEV which is indispensible to train control with safety and high speed operation. Therefore it is necessary for signal system to ensure high speed transmission. massive transmission, low error rate, and reliability of information. And the ensured information should be transmitted between ground and on-board for safety and high speed operation. For these reasons, we have considered the guaranteed reliability by applying FSK method and HDLC protocol. Because HDLC has the advantages of high efficiency, high reliability, low bit rate, and bit transparency. HDLC is the appropriate method for data transmission in MAGLEV.

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Implementation of IWF function based on MG(Media Gateway) System (MG(Media Gateway) System에 기반한 IWF 기능 구현)

  • Kang, Deok-Ki;Lee, Jong-Chan
    • 한국정보통신설비학회:학술대회논문집
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    • 2008.08a
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    • pp.491-494
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    • 2008
  • 과거 CDMA 시스템에서 이동단말과 PSTN 및 PSDN간의 통신이 가능하게 하기 위해서는 망간의 정합기능을 수행하는 연동장치(IWF Inter-Working Function)가 필요로 되는데, 이때 이동단말과 BSC/MSC간의 무선 데이터를 IWF로 HDLC 프레임 형태로 구동하고 반대로 IWF로부터 수신된 데이터 프레임을 이동 단말측으로 전달하기 위하여 HDLC frame driver의 역할이 필요하다. 또한 교환기와 IWF간의 데이터 통신은 Frame-relay 프로토콜을 이용하며 정합기능을 수행해 주어야 한다. 본 논문에서 구현된 기능은 과거 CDMA 의 MSC 내에 구현된 본 기능이 HDLC 정합, Frame-Relay 정합, IPC, Datapath 등의 기능들로 구분되어 분리되어 있는 구조를 통합하여 하나의 기능 Board로 통합하였고 이러한 기능을 MG(Media Gateway) System에 기반하여 구현하여 적용하였다.

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Development of HDLC communication system using SIU(8344) for the group control of motor drives (SIU(8344)를 이용한 전동기 제어장치 연동제어용 HDLC 통신 시스템 개발)

  • Kim, K.H.;Kim, K.S.;Cho, W.J.;Song, S.H.;Park, I.Y.
    • Proceedings of the KIEE Conference
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    • 1993.07b
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    • pp.889-891
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    • 1993
  • In order to perform the group control of motor drive systems in such as steel process line, high performance communication system is indispensible. In this paper, we introduce newly developed communication system which is suitable for these group control application. Using HDLC protocol, this system can transfer data to a long distance(up to 1km) at high speed(1Mbps) with reliability and efficiency. The performance of this communication system was proven through the application to the group control of DAEKYOUNG Bar Mill Line.

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Relationships among Fasting Serum Insulin, Free Fatty Acid, Lipid Levels and Anthropometric Measurements in Female College Students (여대생의 혈청 인슐린, 유리지방산, 지질 농도와 신체계측치와의 관련성)

  • 김석영
    • Journal of Nutrition and Health
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    • v.32 no.2
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    • pp.189-196
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    • 1999
  • This study was conducted to investigate the relationships among the levels of fasting serum insulin, free fatty acid, lipids and anthropometry in normal-weight female college students. Serum insulin and free fatty acid levels were negatively correlated. However, insulin, triglyceride, and cholesterol levels were not correlated with fat mass or BMI(body mass index). The ability of anthropometric and biochemical indicators to predict fatness could be important for epidemiologic and clinical research. In the subjects, waist cirumference was correlated with BMI, fat mass and percent body fat, and HDLC/CHOL (high density lipoprotein cholesterol/cholesterol)was correlated with body weight, BMI, and fat mass. Our data suggests than waist circumference and HDLC/CHOL are predictors of fatness, whereas WHR apears to be a less important contributor to fatness in female college students.

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The Relationship between Serum Cholesterol Level and Dietary Intake in Obese Children (비만 아동의 식이 섭취 양상과 혈청 콜레스테롤 수준과의 상관성)

  • 이숙희;한지숙
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.25 no.3
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    • pp.433-440
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    • 1996
  • To assess the relationship between serum cholesterol level and dietary intake in obese children, 50 subjects were selected as an obese group and 50 subjects as a normal group depending upon body mass index. Fasting blood samples were obtained and analyzed for serum total cholesterol(TC), high density lipoprotein cholesterol(HDLC), low density lipoprotein cholesterol(LDLC) and triglyceride(TG). The dietary intake and information on dietary behavior and family environment were obtained by questionaire using 24 hour dietary recall method for 2-consecutive days. The concentrations of TC, LDLC, HDLC and TG of obese group were estimated to be 193.3mg/dl, 122.5mg/dl, 53.7mg/dl and 86.0mg/dl, respectively. The obese group showed higher TC, LDLC, TG level(p<0.001) and lower HDLC level(p<0.001) than normal group. Food intakes in obese group were similar to those of normal group except meats & fishes(P<0.01), milk & dairy products, fruits(p<0.05), and green & yellow vegetables(p<0.001). Nutrient intakes in obese group exceeded Korean recommended dietary allowance for the corresponding ages. Saturated fatty acid(p<0.05) and cholesterol(p<0.001) intakes in obese group were higher than those of normal group. In correlation analysis, meats & fishes, eggs and milk & dairy products intakes were positively related to serum TC, LDLC and TG ; on the contrary, green & yellow vegetables and fruits intakes were negatively related to serum TC, LDLC and TG ; but positively to HDLC. Obesity index, serum cholesterol level, cholesterol and saturated fatty acid intake were positively correlated with parent's obesity index, frequency of snack per day, eating rate and late snack.

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Analysis of Serum Lipids and Lipoprotein Electrophoresis Fractions in Hypertensive Patients

  • Kim, Chong-Ho
    • Biomedical Science Letters
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    • v.17 no.2
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    • pp.123-128
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    • 2011
  • We analyzed the concentration of serum total cholesterol (TC), high density lipoprotein cholesterol (HDLC), low density lipoprotein cholesterol (LDLC), triglyceride (TG) and the serum lipoprotein electrophoresis fractions in hypertensive patients (hypertension group, n=182). The average concentration of lipids and lipoprotein fractions in the hypertension group was compared to that of the normal group. The average concentrations of serum TC, LDLC and TG in the hypertension group were significantly higher than those of the normal group (3.3%, 11% and 70%, respectively) (P<0.05). But HDLC was nonsignificantly lower (2%) (P<0.05). In the hypertension group, the percentages of patients who had an abnormally high level of total cholesterol, HDLC, LDLC and TG were 12.1%, 8.2%, 24.2% and 44.5%, respectively. The average of ${\beta}$-lipoprotein (27.5%) and pre ${\beta}$-lipoprotein (12.6%) were significantly higher, whereas ${\alpha}$-lipoprotein (15.2%) was significantly lower in the hypertension group than in the normal group (P<0.05). The percentages of patients who had an abnormally high level of very low density lipoprotein (pre ${\beta}$-LP), LDLC (${\beta}$-LP) and chylomicron were 31.3%, 17.0% and 12.6%, respectively. This study suggests that an increasing of total cholesterol, LDLC and TG, pre ${\beta}$-LP, ${\beta}$-LP and chylomicron are associated with a risk factor for hypertension.

DLMS Traffic Monitoring System base on HDLC Protocol (HDLC 프로토콜 기반 DLMS 트래픽 모니터링 시스템)

  • Song, Byung-Kwon;Kim, Sae-Byuk;Kim, Kyeong-Hun;Jeong, Tae-Eui;Kim, Jin-Cheol;Kim, Yeong-Eok
    • Proceedings of the Korean Information Science Society Conference
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    • 2008.06d
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    • pp.491-494
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    • 2008
  • 기존의 전력량계의 원격 검침을 위한 DLMS/COSEM(Device Languag Message Specification / Companion Specification for Energy Meters) 시스템에서의 실제 송, 수신되는 데이터를 수집하여 이를 표현 및 분석 할 수 있는 프로그램을 구현하여 이로 하여금 실제 검침원에게 시스템에서의 송 수신되는 데이터의 흐름을 한 눈에 볼 수 있게 하였다. 또한 데이터의 실제 값 들을 분석하여 이틀을 가시적으로 볼 수 있어 오류 발생 시에 세부적으로 데이터를 분석하여 오류 원인을 찾아 낼 수 있다.

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Consideration of Roman Character in KS × 1001 Code System for Information Interchange considered AMI/HDB-3 and HDLC FLAG (AMI/HDB-3 회선부호화 및 HDLC FLAG를 고려한 KS × 1001 정보 교환용 로마문자 부호체계고찰)

  • Hong, Wan-Pyo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.7
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    • pp.1017-1023
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    • 2013
  • Datacommunications transmit the source codes that are coded in information devices, such as computer to the transmission line by means of the line coded signal. AMI method is applied to the line coding method to transmit the signal for long distance. The disadvantage of the AMI method is to loss the bit synchronization when consecutive binary bit '0' over 4ea is coming into line coder. The scrambling technique is used to overcome the problem. The HDB-3 scrambling method is used in Korea standard which standard in ITU-T. When the HDB-3 technology is used. the method should convert the consecutive bit '0' over 4ea to certain bits format. As a result, when there are many such kind of '0' bit stream in source codes, data transmission efficiency will be decreased to treat in line coder, etc. This paper is directed to study the Roman character code system in $KS{\times}1001$, Korea standard for information exchange code in datacommunication systems. Based on the study result, this paper proposed the maximum optimized Roman character code system. In the study, Character coding rule for $4{\times}4$bits and the statistical data for roman character using frequency were considered to simulate. The paper shows the result that when the proposed new roman character coding system is applied to use, the data transmission efficiency could be increased to about 134% compared to existing code system.