• Title/Summary/Keyword: Loss of time

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A Note on the Inter-Loss Time Distribution of an M/G/1/1 Queuing System (M/G/1/1 대기체계의 고객 손실간격 분포에 대한 소고)

  • Lee, Doo Ho
    • Journal of the Korean Operations Research and Management Science Society
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    • v.41 no.3
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    • pp.37-43
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    • 2016
  • This note discusses the inter-loss time ofan M/G/1/1 queuing system. The inter-loss time is defined as the time duration between two consecutive losses of arriving customers. In this study, we present the explicit Laplace transform of the inter-loss time distribution of an M/G/1/1 queuing system.

Fair delay and loss priority control in ATM networks (ATM 망에서 공평한 지연 및 손실 우선순위 제어)

  • 박창욱;임인칠
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.6
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    • pp.23-32
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    • 1996
  • This paper proposes a new buffer management scheme to service delay-sensitive traffic and loss-sensitive traffic fairly in ATM networks. The proposed scheme uses tow buffers for delay-sensitive traffic and loss-sensitive traffic. To satisfy the average delay time of delay-sensitive traffic, cells in real-time buffer are served first. When congestion occurs in nonreal-time buffer, low loss priority cell in real-time buffer can be pushed out by high loss priority cell in nonreal-time buffer can be transferred to real-time buffer considering threshold value in real-time buffer. Using computer simulation, the existing methods and proposed scheme are compared and analyzed with respect to cell loss rate and average delay time. Simulation results show that the proposed scheme have superior performance to conventional schemes.

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A Study on the Accident Analysis of Architectural Work (건축건설공사의 재해분석에 관한 연구)

  • Kim, Jeongmin;Lee, Jong-Bin;Chang, Seong Rok
    • Journal of the Korean Society of Safety
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    • v.31 no.3
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    • pp.96-101
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    • 2016
  • Previous literature has been investigated various aspects of accident occurrence and prevention in construction field. However, those studied were limited in that they only focused on the death accident without considering the loss time accident. Based on this, the goal of current study was to investigate the nature of the loss time accident, and compare the results with the death accident. Results showed that 1) the occurrence rate of death accident was significantly higher in the form work, temporary work, and steel frame work; 2) the temporary work showed significantly higher occurrence rate of the loss time accident and the death accident as compared to others; 3) ratio of the loss time accident to the death accident in domestic construction field was 50:1; 4) fall accident showed biggest occurrence rate in both the loss time accident and the death accident; and 5) more that 80% of workers in both the loss time accident and the death accident was between 41 and 65 years old.

Changes in Surface Shape and Physical Properties of Acetate Fabrics by Alkaline and Cellulase Treatment (알칼리와 셀룰라아제 처리에 의한 아세테이트 직물의 표면 형태 및 성능의 변화)

  • 이애진;이혜자;유혜자
    • Textile Coloration and Finishing
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    • v.13 no.1
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    • pp.9-17
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    • 2001
  • The purpose of this study is to present basic data for the enzymatic modification of acetate fabrics. The weight loss and rate of weight loss of acetate fabrics increased with increasing NaOH concentration and treating time. Acetyl value decreased as the weight loss became higher. The weight loss of alkaline-treated acetate fabrics were directly proportional to the concentration and treating time of cellulase. The optimum temperature and pH in cellulase treatment were $55^\circ{C}$ and pH 3.5. The surface shape revealed that density of fiber decreased by alkaline-treatment. With the treating time of cellulase, fibrillation occurred. In case of higher weight loss in alkaline treatment, fibril is removed after 180 min. The tensile strength decreased by alkaline and cellulase treatment. Especially, in case of higher weight loss of alkaline treatment, tensile strength decreased suddenly. Alkaline treatment increased the drapability of acetates, while cellulase treatment increased it initially but decreased gradually with treatment time. The dyeability after alkaline treatment was improved for reactive dye, but deteriorated for disperse dye. The cellulase treatment of acetate lowered the dyeability for both types of dyes.

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A Study on the Standard Time & Loss Time (표준작업시간과 손실시간에 관한 연구 - Radiator 제조공정의 시간연구사례를 중심으로 -)

  • 강경식
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.4 no.5
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    • pp.27-42
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    • 1981
  • The object of this paper is to Study the work measurement which is one of the principal technique in work study for the improvement of Productivity in the foundry industry. Most of domestic mechanical enterprise using the expensive foreign machinerise is inoufficient for the standardization of the operation method and time. Therefore, the improvement of operation and productivity through the introduction of the work measurement is an urgent task. Therefore, this paper is contribute to the improvement of operation and to reduce the loss time through the application of the work measurement based on the case study conducted at W-Foundry Corporation. The summary of this study is follows; 1. The measurement of operation efficiency can be accomplished by the standard time. 2. The detailed causes and counter-proposal of loss time can be established, 3. More than 50% of loss time is attributed to c/p.

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Combining Four Elements of Precipitation Loss in a Watershed (유역내 네가지 강수손실 성분들의 합성)

  • Yoo, Ju-Hwan
    • Proceedings of the Korea Water Resources Association Conference
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    • 2012.05a
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    • pp.200-204
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    • 2012
  • In engineering hydrology, an estimation of precipitation loss is one of the most important issues for successful modeling to forecast flooding or evaluate water resources for both surface and subsurface flows in a watershed. An accurate estimation of precipitation loss is required for successful implementation of rainfall-runoff models. Precipitation loss or hydrological abstraction may be defined as the portion of the precipitation that does not contribute to the direct runoff. It may consist of several loss elements or abstractions of precipitation such as infiltration, depression storage, evaporation or evapotranspiration, and interception. A composite loss rate model that combines four loss rates over time is derived as a lumped form of a continuous time function for a storm event. The composite loss rate model developed is an exponential model similar to Horton's infiltration model, but its parameters have different meanings. In this model, the initial loss rate is related to antecedent precipitation amounts prior to a storm event, and the decay factor of the loss rate is a composite decay of four losses.

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The Mechanical Properties and Alkali Hydrolysis on Composition Ratio of Nylon 6-Polyester Split-type Yarn (Nylon 6-Polyester 조성비에 따른 분할사의 알칼리 분해거동과 물성 변화)

  • Park, Myung Soo
    • Textile Coloration and Finishing
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    • v.26 no.4
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    • pp.331-338
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    • 2014
  • In this research, split-type complex yarn of 20:80, 40:60, 50:50 nylon6/polyester composition ratio was used in order to impose unique sense on split-type complex woven. After treating both split-type complex yarn of each ratio and its produced woven in alkali solution, we got the following results by checking physical properties based on alkali proportion and treatment time. Under the condition of NaOH 20% in this experiment, it took approximately double time 20% loss of weight. The loss of weight became high when polyester proportion of N/P(nylon6/polyester) composition ratio was low, in the same fineness yarn. Even though polyester proportion was low, the loss of weight was low when the fineness was high. N/P division was well processed at about 25% loss of weight under the condition of NaOH 20%, treatment temperature $50^{\circ}C$, and treatment time 60 minutes. The research provides that the loss of weight should be processed around treatment time 24 hours in the case of NaOH concentration 15%, and treatment time 15 hours in the case of NaOH concentration 18%, respectively, in order to achieve N/P woven division ratio of about 70%-80% in industrial fields.

The Effect of Residence Time and Heat Loss on NOx Formation Characteristics in the Downstream Region of CH4/Air Premixed Flame (CH4/Air 예혼합화염의 하류영역에서 체류시간 및 열손실에 의한 NOx의 생성특성)

  • Hwang, Cheol-Hong;Hyun, Sung-Ho;Tak, Young-Jo;Lee, Chang-Eon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.1 s.256
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    • pp.99-108
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    • 2007
  • In this study, the NOx formation characteristics of one-dimensional $CH_4$/Air premixed flame using detailed-kinetic chemistry are examined numerically. The combustor length and the amount of heat loss are varied to investigate the effect of residence time and heat loss on the NOx formation in a post-flame region. In the flame region, NO is mainly produced by the Prompt NO mechanism including $N_2$O-intermediate NO mechanism over all equivalence ratios. However, thermal NO mechanism is more important than Prompt NO mechanism in the post-flame region. In the case of adiabatic condition, the increase of combustor length causes the remarkable increase of NO emission at the exit due to the increase of residence time. On the other hand, NO reaches the equilibrium state in the vicinity of flame region, considering radiation and conduction heat losses. Furthermore the NO, in the case of $\phi$=1.2, is gradually reduced in the downstream region as the heat loss is increased. From these results, it can be concluded that the controls of residence time and heat loss in a combustor should be recognized as an important NOx reduction technology.

Stability Analysis of Networked Control System with Time Delay and Data Loss (시간 지연과 데이터 손실을 고려한 네트워크 제어시스템의 안정도 분석)

  • Jung Joonhong;Choi Sooyoung;Park Kiheon
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.53 no.10
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    • pp.678-689
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    • 2004
  • The major concern of networked control system is network uncertainties such as time delay and data loss. Because these uncertainties may degrade the performance of networked control system and destabilize the entire system. Therefore, the performance and the stability variation of networked control system due to network uncertainties must be considered first in designing networked control system. In particular, the stability analysis of networked control system is most important issue since time delay and data loss can make the overall systems unstable. In this paper, we present a new stability analysis method of networked control system with time delay and data loss, which is impossible in previous works. The proposed method can determine maximum time delay and allowable transmission rate that preserve stability performance of networked control system. The results of the simulation validate effectiveness of our stability analysis method.

Stability Analysis of Networked Control System with Data Loss and Time Delay (데이터손실과 시간지연을 고려한 네트워크 제어시스템의 안정도 분석)

  • Jung, Joon-Hong;Jung, Tae-Soo;Kim, Joon-Kook;Park, Ki-Heon
    • Proceedings of the KIEE Conference
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    • 2003.11c
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    • pp.441-444
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    • 2003
  • Network uncertainties such as data loss and time delay can vary the stability property of networked control system. Therefore, these uncertainties must be considered first in designing networked control system. In this paper, we present a new stability analysis method of networked control system with data loss and time delay. The proposed method can determine maximum allowable time delay and minimum allowable transmission rate that preserves stability performance of networked control system. The results of the simulation validate effectiveness of our stability analysis method.

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