• Title/Summary/Keyword: Time available

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A Study on Level-of-Service Changes of Expressway in Accordance with the Revision of Traffic Capacity at Work-Zone (교통용량 개정에 따른 고속도로 공사구간의 서비스 수준에 대한 연구)

  • Ryu, SungWoo;Park, Kwon-Jea;Han, SeungHwan;Cho, Yoon-Ho
    • International Journal of Highway Engineering
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    • v.16 no.3
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    • pp.109-117
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    • 2014
  • PURPOSES : This study analyzes the available working time at work-zone on the Expressway in accordance to the new capacity manual. METHODS : Sensitivity analysis on variables were conducted to calculate the adjusted capacity at work-zone based on previous researches. RESULTS : The main factors which affect available working time at the work-zone were its capacity, number of lanes, terrain and lane width. Other factors have minimal effect on the available working time. Based on the analysis, a calendar of lane closures was suggested. CONCLUSIONS : A series of studies concluded that the capacity at work-zone in the new capacity manual reduced to 76-82% of the existing manual. As such, the available working time decreased. Furthermore, the factors affecting the available working time needs to be considered when making a plan to rehabilitate the distressed pavement.

Fire Growth of Wood Cribs and Available Safe Egress Time (목재연소시의 실내화재성상과 안전대피시간)

  • 정길순;태순호;이병곤
    • Journal of the Korean Society of Safety
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    • v.8 no.2
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    • pp.72-77
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    • 1993
  • Available Safe Egress Time(ASET) is the time available for occupants to evacuate safely In compartment fire, and It depends on the time of fire detection and hazardous conditions. The purpose of thls study Is to provide an analytical basis and experimental data for estimating the fire growth in compartments and the available safe egress time, and to compare the experimental data with those proposed equations. As a result, hazard order Is poison to CO, descent of smoke layer, poison to $CO_2$, burn to hot smoke layer, and lack of $O_2$, ASET is lengthened in this order. Also, The more fire load is increased, the more ASET is shorted.

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Probabilistic Approach to Time Varying Available Transfer Capability Calculation (확률론적 기법을 이용한 시변 가용송전용량 결정)

  • Shin, Dong-Jun;Kim, Kyu-Ho;Kim, Jin-O
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.54 no.11
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    • pp.533-539
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    • 2005
  • According to NERC definition, Available Transfer Capability (ATC) is a measure of the transfer capability remaining in the physical transmission network for the future commercial activity. To calculate Available Transfer Capability, accurate and defensible Total Transfer Capability, Capacity Benefit Margin and Transmission Reliability Margin should be calculated in advance. This paper proposes a method to quantify time varying Available Transfer Capability based on probabilistic approach. The uncertainties of power system and market are considered as complex random variables. Total Transfer Capability is determined by optimization technique such as SQP(Sequential Quadratic Programming). Transmission Reliability Margin with the desired probabilistic margin is calculated based on Probabilistic Load Flow analysis, and Capacity Benefit Margin is evaluated using LOLE of the system. Suggested Available Transfer Capability quantification method is verified using IEEE RTS with 72 bus. The proposed method shows efficiency and flexibility for the quantification of Available Transfer Capability.

A Study on the Effective Command of Disaster Site: Lessons Learned from Sinking of the Sewol Ferry (효과적인 재난현장 지휘에 관한 연구: 세월호 사례의 교훈)

  • Kim, SungGeun;Hwang, K.T.
    • Journal of Digital Convergence
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    • v.12 no.11
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    • pp.1-12
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    • 2014
  • Today, scale of a disaster becomes huge, all the available resources should be mobilized to control the disaster situation, and situations of the disaster site is broadcasted by the various media on a real-time basis. Accordingly, The commander of the disaster site should manage the situation taking all the factors into consideration. Despite the importance of the factors affecting the command of disaster site, there are not much research on this topic. This study utilizes METT-TC(Mission, Enemy, Troops, Terrain and weather, Time available, and Civilian considerations) which is applied in a combat situation by the military area and proposes MORT-TEC(Mission, Object, Resources available, Terrain and weather, Time available, Exercise, and Civilian considerations) as factors affecting the effective command of disaster site. These factors are applied to the Sewol Ferry Incidents and policy implications which can help researchers and practitioners in the area are suggested.

A Study on the Elements(MORT-TAC) of Situation Assessment at Disaster Sites (재난현장 상황평가 고려요소(MORT-TAC)에 관한 연구)

  • Kim, Sung-Geun;Lee, Young-Jai
    • Journal of Digital Convergence
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    • v.15 no.1
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    • pp.117-127
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    • 2017
  • Even well trained personnel may fall victim to panic, and a wrong assessment of the situation can turn a small accident into a huge disaster. At the disaster site, the event is commonly broadcasted in real time and is unfiltered. Thus, the commander of the site must be able to accurately assess the scene while not missing out on key considerations. Despite the necessity of good situational assessment, there is barely any research on this topic. This study utilizes METT-TC(Mission, Enemy, Troops, Terrain and weather, Time available, and Civil considerations) which is used by militaries to assess combat situations, and proposes MORT-TAC(Mission, Object, Resources available, Terrain and weather, Time available, Ability, and Civil considerations) as factors to consider in effectively controlling the disaster site. The standard model is used for assessing disaster scenes by applying the Delphi analytical method on each sub-factor of MORT-TAC.

Assessing Phosphorus Availability in a High pH, Biochar Amended Soil under Inorganic and Organic Fertilization

  • Kahura, Millicent Wanjiku;Min, Hyungi;Kim, Min-Suk;Kim, Jeong-Gyu
    • Ecology and Resilient Infrastructure
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    • v.5 no.1
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    • pp.11-18
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    • 2018
  • Phosphorous remains as one of the most limiting nutrients to plant growth, second only to nitrogen. Research on use of biochar as a soil amendment for available phosphorus in temperate calcareous soils has limited studies compared with to tropical acidic soils. An incubation experiment to assess phosphorous availability in a biochar amended calcareous soil under inorganic (Fused superphosphate, FSP) and organic fertilizer (bone meal, BM) and respectively, at the dose of 40, 80 and $120mg\;P\;kg^{-1}$ was carried out. Soil was incubated at $25^{\circ}C$ for 70 days. Results show that the rate of increase in available P was proportional to the fertilizer application rate with or without biochar amendment. Biochar did not have a significant effect on soils amended with either fertilizeron the values of available P. However, time had a significant effect (p<0.001) on the amount of available P during the incubation period. Inorganic fertilizer treatments had recorded high amount of available P with time compared to organic fertilizer treatments. Organic fertilizer treatment sample were significantly not different from control and for most of the incubation time biochar acted as a soil conditioner. Further research is required to understand the holistic and long-term effect of biochar.

Bayesian Method in Forecasting of time Series (Bayesian 시계열 예측방법에 관한 소고)

  • 박일근
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.7 no.10
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    • pp.47-51
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    • 1984
  • In many forecasting problem, there is little or no useful historical information available at the time the initial forecast is required, The propose of this paper is study on Bayesian Method in forecasting. I : Introduction. II : Bayesian estimation. III : Constant Model. IV : General time series Models. V : Conclusion. The Bayesian procedure are then used to revise parameter estimates when time series information is available, in this paper we give a general description of the bayesian approach and demonstrate the methodology with several specific cases.

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The effect of mixing of calcium superphosphate and urea on the change of the available phosphate and urea-nitrogen (과인산석회(過燐酸石灰)와 요소(尿素)의 배합(配合)에 의한 요소태(尿素態) 질소(窒素) 및 유효성(有?性) 인산(燐酸)의 변화(變化)에 관(關) 연구(硏究))

  • Maeng, Do-Won
    • Applied Biological Chemistry
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    • v.7
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    • pp.39-43
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    • 1966
  • This experiment was carried out to determine how the water soluble, the available phosphoric acid and the urea-N would change as time went by, when mixtures of calcium superphosphate and urea were made. Two kinds of materials, i. e., calcium superphosphate and urea were engaged in this experiment. Two kinds of mixed fertilizer, i. e., A and B were made up by mixing these materials to satisfy the following ratio. 1) Urea 1+ calcium superphosphate 1${\cdots}\;{\cdots}$A 2) Urea 1+ calcium superphosphate 2${\cdots}\;{\cdots}$B A and B pIaced placed in desiccators respectively a six-month period. During the time of storage, the water soluble, the available $P_2O_5$ and the urea-N were measured once a month, seven times with the control measurement. The results may be summarized as follows. 1. The urea-N in both A and B showed no change by the passage of time. This fact suggested that the mixing of calcium superphosphate with urea was not unfavourable. 2. A and B showed no diminishing in the water soluble and the available $P_2O_5$ in the process of time. This fact indicated that the combination of calcium superphosphate with urea was not unfeasible.

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Development of an AGV Controller in Semiconductor and LCD Production Systems (반도체 및 LCD 제조 공정의 AGV Controller 개발)

  • Suh, Jungdae;Jang, Jaejin;Koo, Pyung-Hoi
    • Journal of Korean Institute of Industrial Engineers
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    • v.29 no.1
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    • pp.1-13
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    • 2003
  • In this paper, LAC(Look-ahead AGV Controller) has been developed for efficient routing of parts in semiconductor and LCD production systems. Several procedures have been developed as sub-modules. LACP(Look-ahead AGV Control Procedure) which controls AGVs using the information on the current and future status of the systems is the main element of the LAC. To support LACP, DSP(Destination Selection Procedure) which determines a destination of a part and AGV call time, SSP(Source Selection Procedure)which selects a part coming next to a buffer when the buffer becomes available. and RTM(Response Time Model) which estimates empty travel time of AGVs and waiting time for an available AGV have been developed. A simulation experiment shows that LAC reduces part's flow time, AGV utilization, average and maximum inventory level of a central buffer, empty travel time of an AGV, and waiting time for an available AGV.

Calculation of CBM, TRM and ATC using Quadratic Function Approximation (이차함수 근사화를 이용한 가용송전용량과 송전신뢰 및 설비편익 여유도 산정)

  • 이효상;신상헌;신동준;김진오
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.53 no.5
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    • pp.296-301
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    • 2004
  • The Available Transfer Capability (ATC) is defined as the measure of the transfer capability remaining in the physical transmission network for further commercial activity above already committed uses. Available Transfer Capability (ATC) calculation is a complicated task, which involves the determination I of total transfer capability (TTC), transmission reliability margin (TRM) and capability benefit margin (CBM). As the electrical power industry is restructured and the electrical power exchange is updated per hour, it is important to accurately and rapidly quantify the available transfer capability (ATC) of the transmission system. In ATC calculation,. the existing CPF method is accurate but it has long calculation time. On the contrary, the method using PTDF is fast but it has relatively a considerable error. This paper proposed QFA method, which can reduce calculation time comparing with CPF method and has few errors in ATC calculation. It proved that the method can calculate ATC more fast and accurately in case study using IEEE 24 bus RTS.