• Title/Summary/Keyword: Active Period

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Adaptive Partitioning for Efficient Query Support

  • Yun, Hong-Won
    • Journal of information and communication convergence engineering
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    • v.5 no.4
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    • pp.369-373
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    • 2007
  • RFID systems large volume of data, it can lead to slower queries. To achieve better query performance, we can partition into active and some nonactive data. In this paper, we propose two approaches of partitioning for efficient query support. The one is average period plus delta partition and the other is adaptive average period partition. We also present the system architecture to manage active data and non-active data and logical database schema. The data manager check the active partition and move all objects from the active store to an archive store associated with an average period plus data and an adaptive average period. Our experiments show the performance of our partitioning methods.

PERFORMANCE ANALYSIS OF A STATISTICAL MULTIPLEXER WITH THREE-STATE BURSTY SOURCES

  • Choi, Bong-Dae;Jung, Yong-Wook
    • Communications of the Korean Mathematical Society
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    • v.14 no.2
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    • pp.405-423
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    • 1999
  • We consider a statistical multiplexer model with finite buffer capacity and finite number of independent identical 3-state bursty voice sources. The burstiness of the sources is modeled by describing both two different active periods (at the rate of one packet perslot) and the passive periods during which no packets are generated. Assuming a mixture of two geometric distributions for active period and a geometric distribution for passive period and geometric distribution for passive period, we derive the recursive algorithm for the probability mass function of the buffer contents (in packets). We also obtain loss probability and the distribution of packet delay. Numerical results show that the system performance deteriorates considerably as the variance of the active period increases. Also, we see that the loss probability of 2-state Markov models is less than that of 3-state Markov models.

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A Historical Research on Improved Changes of Korean Traditional Costume (한복개량에 대한 사적 고찰)

  • Koo, Mi-Ji
    • The Journal of Natural Sciences
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    • v.10 no.1
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    • pp.123-131
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    • 1998
  • This research was investigated the improved changes of Korean traditional costume after introducing the western costumes in this society. For this study microfilms of Chosun llbo, the popular newspaper since 1920s, and costume magazines for 1950s and 1960s were examined. The periods of the improved changing of Korean traditional costume were divided by the characteristics of qualitative and quantitative changes. Those were two, such as passive period and active period of change. At passive period, the change was not far from the original from of traditional costume and it was limited to the waist of skirt, length and width. But at active period, there was distinctive change from the previous period. Active period is divided by 2 sub-period again. In 1950s, the concept of darts of western costume was accepted to Korean costume and there was the western clothing for everyday costume, the characteristics of Korean costume were added to the base of the western clothing. It was named 'Arirang dress'. Original Korean costume had worn for special occasions since late 1950s.

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Preliminary Studies on the Quality Changes of Eggplant as Influenced by Active Packaging

  • Zuo, Li;Seog, Eun-Ju;Lee, Jun-Ho;Rhim, Jong-Whan
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.38 no.5 s.118
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    • pp.66-73
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    • 2006
  • The effects of active packaging on the surface stiffness, mass, volume, density and weight changes of fresh as well as stored eggplant were studied at 11 and $25^{\circ}C$ for 10 days with active packaging material Type 1 and 2 and control. Mass, volume, and surface stiffness of eggplant decreased linearly throughout the storage period regardless of storage conditions; while the mass density showed a reverse trend in the ease of $11^{\circ}C$ storage. Reduction rate of mass, mass density and weight was observed minimum at $25^{\circ}C$ storage temperature with active packaging Type 1. The weight of eggplant decreased at a higher rate in the initial 4 days compared to that in the later period of storage regardless of storage temperature and type of packaging.

A Study on the relationship between architecture and urban context in B. Ammannati's Project - Focused on Palazzo Firenze a Roma - (암만나띠(B. Ammannati) 건축의 도시적 특성에 관한 연구 - 팔라쪼 피렌체을 중심으로 -)

  • Cho, Sung-Yong;Choi, Jin-Hee
    • Journal of architectural history
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    • v.15 no.5
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    • pp.57-74
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    • 2006
  • This paper presents a study on the Palazzo Firenze of B. Ammannati, designed between 1550~572. He was active in Rome and Firenze in the middle of 16th Century. His most important project, such as Palazzo Pitti, is located in Firenze. But there are some projects that are important as well as Palazzo Pitti in Rome, such as villa Giulia and Palazzo Firenze. Usually, in the history of Western Architecture, the period in which Ammannati was active is denominated as late-Renaissance or Mannerism. In this period there was very important progress in field of artistic theory. There were active many great Masters such as Michelangelo, Vignola and Giulio Romano. But, over the all, the most important characteristic of this period was a transition period between Renaissance and Baroque. This paper try to reveal such characteristics reflected in architectural projects designed in this period, focusing on, over the all, B. Ammannati and his Palazzo Firenze project.

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A Study on the Body Measurements of Early Adolescent Boys (청소년 전기 남학생의 인체 계측치에 관한 연구)

  • Kim, Kyung-A;Suh, Mi-A
    • The Research Journal of the Costume Culture
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    • v.13 no.1
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    • pp.60-74
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    • 2005
  • The purpose of this study was to systematize accurate data about the body measurements of early adolescent boys, as there was a broad individual variance between their bodies, and it's additionally attempted to identify the unique physical characteristics of different age groups. The subjects in this study were boys who were at the ages of 10 to 14 in the capital area. Their bodies were measured by anthropometric and photographic method, and data on 549 boys were analyzed. The total of 100 items(47 anthropometric items, 10 indexed items and 43 photographic items) were selected to be measured. For data analysis were performed descriptive statistics, ANOVA and Duncan test using SPSS Ver. 10. The results of the study are as follows. According to the result of comparing the body measurements of early adolescent boys, a period of active growth and a period of slow growth were repeated alternately as they aged and the age of active growth tended to get younger.

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Bottleneck Detection Based on Duration of Active Periods (생산 활동기간 기반 애로공정의 발견)

  • Kwon, Chi-Myung;Lim, Sanggyu
    • Journal of the Korea Society for Simulation
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    • v.22 no.3
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    • pp.35-41
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    • 2013
  • This paper applies an active period based bottleneck detection method to flow shop manufacturing system with limited buffer size. Manufacturing systems are constrained by one or more bottlenecks which degrades the system throughput. Conventional bottleneck detection methods include the waiting time or queue length of production stations and their utilization. Due to the random events such as production time of items, machine failure and repair times, the systems may change over time, and subsequently bottlenecks shift from one station to another station. Active period of working station may cause other stations to wait for productions. Information when and where active periods occur helps to find bottlenecks in production systems. Based on these informations, we predict bottlenecks in applying AweSim simulation language. We compare the simulation results of conventional methods with those obtained from duration of active period method, and duration ratio method of both sole and shift bottleneck periods. Even though simulation results are from simple flow shop model, they are quite promising for predicting bottlenecks of production stations. We hope this study aids in decision making regarding the improving system production yield and allocation of available resources of system.

Fluttering Characteristics of the Ropes and Nets as an Active Stimulating Device inside the Cod End of a Trawl Net

  • Kim, Yong-Hae
    • Fisheries and Aquatic Sciences
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    • v.16 no.2
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    • pp.101-108
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    • 2013
  • An active stimulating device (ASD) consisting of a net panel or ropes fluttering in the turbulence inside the cod end was effective in driving fish near the cod end to reduce juvenile by-catch. The fluttering characteristics of the rope and net panel were examined by video observations and analyzed for fluttering amplitude and period in a water channel and in field experiments with a bottom trawl. The amplitude ratio of the fluttering ropes or nets in the tank test increased with the fluttering index as the diameter of the twine, mesh size, flexibility, and flow velocity changed, whereas the period decreased with the above factors. In bottom trawl experiments, the range of mean depth difference in the fluttering net panel was 12-17% of the length of the fluttering net, and the period of depth difference or three-dimensional (3D) tilt was revealed, with shorter ones ranging from 2 to 6 s. The amplitude as depth difference and period from field measurements were similar to those of nets in tank experiments and also to the period of 3D flow velocity inside the cod end. These results could be used to design an ASD that could be used for to the cod end of actual towed fishing gear to reduce juvenile by-catch.

THE EFFECT OF THE INTERFACE ACTIVE MATERIAL ON THE TRACKING FAILURE (TRACKING 파괴(破壞)에 미치는 계면활성(界面活性)의 영향)

  • Lee, Bo-Ho;Park, Dong-Wha;Ko, In-Whan
    • Proceedings of the KIEE Conference
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    • 1987.11a
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    • pp.486-488
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    • 1987
  • Studine the characteristic or C.T.I affectine on the tracking failure when interface active materials are diffused into the phenolic resin. we conclude as follow: 1) As the density of $NH_4Cl$ increase the quality or sludge increase the value of C.T.I decreases. 2) The materal of ion absorption can make the period of sludge metallic matal generation delay more than times and the value of C.T.I increase. 3) By addition of interface active material that makes forming period delay, the starting voltage of corona blackdown id delayed and the value of C.T.I is increased.

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Analog active valve control design for non-linear semi-active resetable devices

  • Rodgers, Geoffrey W.;Chase, J. Geoffrey;Corman, Sylvain
    • Smart Structures and Systems
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    • v.19 no.5
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    • pp.487-497
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    • 2017
  • Semi-active devices use the building's own motion to produce resistive forces and are thus strictly dissipative and require little power. Devices that independently control the binary open/closed valve state can enable novel device hysteresis loops that were not previously possible. However, some device hysteresis loops cannot be obtained without active analog valve control allowing slower, controlled release of stored energy, and is presents an ongoing limitation in obtaining the full range of possibilities offered by these devices. This in silico study develops a proportional-derivative feedback control law using a validated nonlinear device model to track an ideal diamond-shaped force-displacement response profile using active analog valve control. It is validated by comparison to the ideal shape for both sinusoidal and random seismic input motions. Structural application specific spectral analysis compares the performance for the non-linear, actively controlled case to those obtained with an ideal, linear model to validate that the potential performance will be retained when considering realistic nonlinear behaviour and the designed valve control approach. Results show tracking of the device force-displacement loop to within 3-5% of the desired ideal curve. Valve delay, rather than control law design, is the primary limiting factor, and analysis indicates a ratio of valve delay to structural period must be 1/10 or smaller to ensure adequate tracking, relating valve performance to structural period and overall device performance under control. Overall, the results show that active analog feedback control of energy release in these devices can significantly increase the range of resetable, valve-controlled semi-active device performance and hysteresis loops, in turn increasing their performance envelop and application space.