• Title/Summary/Keyword: First In First Out

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A Study on the Cell Resequence Method at the ATM Switch (공유 버퍼형 순서 재정렬 ATM스위치에 관한 연구)

  • 박성헌;전용일박광채
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.273-276
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    • 1998
  • This paper proposes a new Asynchronous Transfer Mode(ATM) switch architecture for the Broadband ISDN. The proposed switch has the architecture to prohibit the out-of-sequence in shared buffer switch system with being fixed buffer size in the out-buffered large scale ATM Switch System. then in this paper proposes cell resequence algorithm to decrease the out-of-sequence problem. also, we studied the out-of-sequence problem that was occurred by the cell transfer delay and the cell overflow due to the fixed buffer size when cell resequenced and we propose to implement optimal ACFIFO(Address Counter First In First Out) buffer size which has the minimized cell loss.

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Psycho-Social Comparison among First Time Offenders and Repeated Offenders on Probation (보호관찰 청소년의 사회 심리적 특성 -초범과 재범군의 비교-)

  • Lee, Hee-jung;Lee, Sung Chil
    • Korean Journal of Child Studies
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    • v.26 no.5
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    • pp.367-377
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    • 2005
  • Semi-structured in-depth interview method were used to test psycho-social comparison among first time offenders and repeated offenders. Data were analyzed by t-test and chi-square. Differences between first time offenders and repeated offenders were that there were more male offenders than female offenders, and violent and theft offenders were more than sex offenders fraud and traffic offenders; early starters were more repeated offenders than late starters; there were some variables such as runway of home, parents' caring attitude, school drop out and maladjustment affecting in repeated offenses; developmental environment of repeated offenders were more negative than first time offenders. Therefore, intervention and prevention program development of good parenting and schooling and forensic counseling focused on optimal developmental environment is needed.

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Evaluation of First Flush Rainfall Inflow and Pollution Loads into Manhole against Combined and Sanitary Sewer Overflows (초기우수 관거유입계수 산정 및 오염부하 기여도 평가)

  • Kim, Hongtae;Shin, Dongseok;Kim, Yongseok
    • Journal of Korean Society on Water Environment
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    • v.31 no.1
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    • pp.67-70
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    • 2015
  • Some data into combined and sanitary sewer system were collected in order to find out the characteristics of discharge from first flush rainfall inflow. The inflow ratios of combined and sanitary sewer system were 0.46 and 0.27 during rains from various survey data. The average inflow ratio 0.31 was appropriate for general application because many watersheds were not classified clearly as combined or sanitary sewage treatment areas. The percentage of first flush loads in the whole BOD load was about 10%. This result was thought some meaningful, comparing with similarity of first flush pollution load contribution previous surveyed by KECO (2004).

Factors of Korean Students' Achievement in Scientific Literacy

  • Shin, Dong-Hee;Ro, Koog-Hyang
    • Journal of The Korean Association For Science Education
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    • v.21 no.5
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    • pp.893-905
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    • 2001
  • Korean students ranked the 3rd out of 32 participating countries in the first cycle of PISA(Programme for International Student Assessment) science field, which assessed 15-years-old students' scientific literacy. PISA developed several variables such as parents' socio-economic status, parents' educational attainment, family wealth, and cultural possession, to investigate the effects of background variables on scientific literacy. On the other hand, motivation and engagement in science study were not given much attention, partly because science was the minor area in the first cycle of PISA. Therefore, PISA Korea developed a series of variables to collect data on students' learning motives and out-of-school activities in science as a national option. The results are as followings. First, Korea was found to be one of the PISA participating countries with the scientific literacy achievement least influenced by parents' socio-economic status, family wealth, and parents' cultural possession. Second, the degree of achievement in scientific literacy according to parents' educational attainment was in a positive correlation, similar to the overall tendency of PISA. Third, the most crucial learning motive for Korean students was their desire to develop scientific thinking abilities or obtain science knowledge. On the other hand, choosing jobs in the field of science or parental expectation was the least important learning motive. In particular, the motive for scientific learning was found to have a positive relationship with the degree of scientific literacy achievement. Therefore, the higher the students achievement, the stronger the motive for scientific learning in order to develop their ability to think scientifically or acquire science knowledge. Fourth, Korean students were shown to participate very little in out-of-school scientific activities other than watching TV programs related to science. Whatever the activities may be, the more actively involved students are in out-of-school scientific activities, the higher their scientific literacy achievement. Fifth, Korean girls were rather passive compared to boys in all areas, including science learning motive and out-of-school scientific activities. The gender difference was especially more pronounced in out-of-school scientific activities with wider gaps in such activities as reading scientific books or articles and visiting science-related web sites.

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Bayesian Analysis for the Ratio of Variance Components

  • Kang, Sang-Gil
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.2
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    • pp.559-568
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    • 2006
  • In this paper, we develop the noninformative priors for the linear mixed models when the parameter of interest is the ratio of variance components. We developed the first and second order matching priors. We reveal that the one-at-a-time reference prior satisfies the second order matching criterion. It turns out that the two group reference prior satisfies a first order matching criterion, but Jeffreys' prior is not first order matching prior. Some simulation study is performed.

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A Study on the Two-Dimensional Scheduling for Minimization of Moving Distance on the Remote Controllable Web-Camera (원격조정 가능한 웹 카메라의 이동거리 최소화를 위한 이차원 스케줄링에 관한 연구)

  • Cho, Soo-Young;Song, Myung-Nam;Kim, Young-Sin;Hwang, Jun
    • Journal of Internet Computing and Services
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    • v.1 no.2
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    • pp.61-67
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    • 2000
  • In case of the remote controllable web-camera that was took notice especially in internet real-time broadcasting systems, a great many clients connect the server of web-camera to request the service. So, the scheduling methods are important. Web-camera systems have used to the traditional FIFO(First In First Out) or SDF(Shortest Distance First) scheduling method. But they does not satisfy both the minimization of moving distance on the web-camera and the fairness on the users. In this paper, We propose the 2D scheduling method, As a result, the moving distance of the web-camera decreases compared with FIFO scheduling method. And the starvation state on the user's request does not happen compared with SDF scheduling method. Thus, if the remote controllable web-camera systems use the 2D scheduling method, they are satisfied with the minimization of moving distance on the remote controllable web-camera and the fairness on the users simultaneously. Therefore the user's satisfaction and the performance of the systems are improved.

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A Study on the Structural Reform of Urban Transit Vehicle Considering Elevation of Fire Safety (화재안전성을 위한 도시철도 차량의 구조개선)

  • Lee, Keun-Oh;Kim, Kyu-Joong
    • Journal of the Korean Society of Safety
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    • v.21 no.5 s.77
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    • pp.22-27
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    • 2006
  • Even though the interior of urban transit vehicle has been changed as a preventing measure against fire to make it inflammable, there remains a possibility of fire breaking out in case of gasoline etc being brought in the subway. However, there is also the possibility that in case if fire toxic gas is generated and hot air spreads in carriage it will prove very dangerous for people sitting inside. This is a comparative study where we compare simulation results with model examining the time and direction the fire spreads when it breaks out. Also there is vertical distribution of temperature in carriage where the fire spreads out. This study is about demonstrating how to establish smokeless system in urban vehicle, about its necessity, and about vehicle system restructuring. This study also makes an effort to find more advanced method for efficient fire safety in trains. In existing vehicles, in case of fire, the smoke can't go out when doors are closed and hence it spreads in whole train. Even though the method of using ventilation or exhaust established inside the carriage to throw smoke out is much better than the way of opening end doors in each carriage, this study is trying to do research on second way. Through simulation we see that in second case, even though not as good as the first one, smoke can exit through gates. Even though the first method is better, the second can also be uses to let fire out. We can know that in the first case as the smoke can exit out faster, it provides more safety for people. So this system provides better fire safety condition.

Design of single rate Rate Adaptive Shaper Using FPGA (FPGA를 이용한 single rate Rate Adaptive Shaper 설계)

  • Park, Chun-Kwan
    • Journal of Advanced Navigation Technology
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    • v.10 no.1
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    • pp.70-78
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    • 2006
  • This paper has addressed the scheme to design single rate Rate Adaptive Shaper (srRAS) proposed in RFC2963. srRAS is the shaper used in conjugation with downstream single rate Three Color Marker (srTCM) described in RFC269. it is tail-drop First Input First Out (FIFO) queue that is drained at a variable rate. srTCM meters IP packet streams from srRAS and marks its packets to be either green, yellow, or red. This shaper has been proposed to use at the ingress of differentiated services networks providing AF PHB. And then srRAS can reduce the burstiness of the upstream traffic of srTCM. This paper addresses algorithm, architecture of srRAS, and the scheme to implement srRAS using Field-Programmable Gate Arrays (FPGA) and the related technology.

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Development of Voice Signal Detection System using FPGA (FPGA를 이용한 음성 신호 감지 시스템 개발)

  • Kim, Jang-Won
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.6
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    • pp.141-146
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    • 2015
  • In order to classify and analyze variously compounded sound and voice signal from FPGA microphone, there are numerous systems to detect abnormality signal, however, they have a lot of problems to implement the abnormality signal detection efficiently and effectively. Therefore, we proposed a method that implements classifying the signal effectively and outputting the detection efficiently based on the algorithm applied FIFO structure (First-in First-out) by using microphone sensor which able to input the sound signal, and statistical variance and coefficient of variation (CV). The result showed 96.3% detection when the experiment was performed more than 100 times with the proposed algorithm applied system.