• Title, Summary, Keyword: Quantitative fluctuation

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Predicting Construction Project Cost using Sensitivity Analysis in Stochastic Project Scheduling Simulation (SPSS) (확률 통계적 일정 시뮬레이선 - 민감도 분석을 이용한 최종 공사비 예측)

  • Lee Dong-Eun;Park Chan-Sik
    • Korean Journal of Construction Engineering and Management
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    • v.6 no.4
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    • pp.80-90
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    • 2005
  • Activity durations retain probabilistic and stochastic natures due to diverse factors causing the delay or acceleration of activity completion. These natures make the final project duration to be a random variable. These factors are the major source of financial risk. Extending the Stochastic Project Scheduling Simulation system (SPSS) developed in previous research; this research presents a method to estimate how the final project duration behaves when activity durations change randomly. The final project cost is estimated by considering the fluctuation of indirect cost, which occurs due to the delay or acceleration of activity completion, along with direct cost assigned to an activity. The final project cost is estimated by considering how indirect cost behaves when activity duration change. The method quantifies the amount of contingency to cover the expected delay of project delivery. It is based on the quantitative analysis to obtain the descriptive statistics from the simulation outputs (final project durations). Existing deterministic scheduling method apply an arbitrary figures to the amount of delay contingency with uncertainty. However, the stochastic method developed in this research allows computing the amount of delay contingency with certainty and certain degree of confidence. An example project is used to illustrate the quantitative analysis method using simulation. When the statistical location and shape of probability distribution functions defining activity durations change, how the final project duration and cost behave are ascertained using automated sensitivity analysis method

A Quantitative Study on the Effect of Temperature Control by a Shade Tree and the Lawn Area (식물의 온도 완화효과에 관한 기초적 연구)

  • 안계복;김기선
    • Journal of the Korean Institute of Landscape Architecture
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    • v.14 no.1
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    • pp.1-13
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    • 1986
  • The purpose of this study is to investigate the effect of temperature control by a shade tree and the lawn area. In this investigation, we find out that artificial-lawn, concerte, and exposed soil are more higher temperature than covered with plant materials. The results of the measurement may to summerized as follows; 1) Low-temperature effects of zoysia japonica is more controlled by condition of growth than leaf length of grass. Surface temperature make 0.7$^{\circ}C$ difference between long grass (15cm), and short grass (5cm), but make 5$^{\circ}C$ difference between good growth grass (230/10$\textrm{cm}^2$) and bad growth grass (80/10$\textrm{cm}^2$). 2) The surface temperature of the lawn area is 40.5$^{\circ}C$ lower on a maxinum than that of the artificial lawn (July 28, 1985). During the day of summer, shade area under the shade tree is 0.9$^{\circ}C$ lower then lawn area surface temperature, 6.9$^{\circ}C$ lower than bad growth lawn, 10.3$^{\circ}C$ lower than exposed soil, and 18$^{\circ}C$ lower than concrete surface temperature. 3) Natural irrigation effect on the surface temperature fluctuation. But this effect is changed by compositions of ground materials and time-lapse. 4) Sunny day is more effective than cloud day. 5) In summer season, surface temperature make a difference compare to temperature of 0.5-1.5m height from ground : Surface temperature is 3.4$^{\circ}C$ lower at the lawn area (11 a.m.), 4.2$^{\circ}C$ lower at the shade area the shade tree, 12.7$^{\circ}C$ higher at the concrete area (3p.m.), 38.8$^{\circ}C$ higher at the artificial lawn (2p.m.) 6) According to compositions of ground materials and season have specific vertical temperature distribution curve. 7) In summer season, temperature distribution of 0.5-1.5m hight at the shade tree is 4.8-5.7$^{\circ}C$ lower than concrete area (noon-3p.m.)

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The Gaiting Behaviour of the Grass Crab, Hemigrapsus penicillatus on the Nettings (망지에 대한 풀게(Heyhigrapsus penirillatus)의 보행운동)

  • KIM Yong-Hae;KO Kwan-Soh
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.20 no.3
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    • pp.177-184
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    • 1987
  • The quantitative mechanics on the sideways walking of the crabs may provide a basic solution for entanglements of the walking legs in gillnets. The gaiting behaviour of the crabs on the flat board and the nettings 10, 16 and 23 mm in mesh size were experimented concerning about stepping positions and times in the laboratory using video set on July, 1984, It was found that the irregular movements of walking crabs in stepping positions and patterns were appeared on the nettings due to the absence of mechanical contact in spite of neural control of compensating, while on the flat surface evolved systematic leg movements. The mean stride length and walking velocity, which were increased with the carapace width on the flat board, as well as the step period and forward by backward stroke time were greater than those values on the netting, not associated with the carapace or the mesh size. Also, the step period and the Phase difference on the nettings revealed larger fluctuation than on the flat board. The joint angles of the walking legs, on the nettings in meropodite-carporodite and thorax-meropodite, which joint was varied especially up to below horizon because of the falling legs through the netting twine, were virtually wider than those on the flat substrate.

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Location and Spatial Variations of Ceramic Industry in Miryang City, Kyongnam Province, Korea (밀양시 요업의 입지와 공간변화)

  • Lim, Yeong-Dae
    • Journal of the Korean association of regional geographers
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    • v.8 no.1
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    • pp.40-64
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    • 2002
  • The locational characteristics of ceramic industry in Miryang city, Kyongnam province, were clarified by means of examining the process of its formation, spatial variation, locations and their changes. The government policy on industry and the business fluctuation are important in the quantitative changes of the industry. The spatial variation of industry toward the outer part of area are the results of equilibrium between the decrease of firms in inner city and the increase of firms in outer part. The births and deaths of firms played important role in the processes of spatial variations. The industry location has lasted by the accumulation of location decision of 'potential entrepreneurs' who learned knowledges on the industry and had personal contacts with the business-related persons for long time. The main factors on the locational decision of firms are personal factor, raw materials, land, water and market. The locational problems have mainly related with plant expansion, land, marketing, labour and capital. They caused investment changes and caused relocations of firms. Such disadvantages as raw material exhaustion, shortage of land and congestion within the agglomeration area, development of road transportation and local government policy on industry location, induced recent decentralization of industry to outer part.

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Adaptive Delay Differentiation in Next-Generation Networks (차세대 네트워크에서의 적응형 지연 차별화 방식)

  • Paik Jung-Hoon;Park Jae-Woo;Lee Yoo-Kyung
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.43 no.6
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    • pp.30-38
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    • 2006
  • In this paper, an algerian that provisions absolute and proportional differentiation of packet delays is proposed with an objective for enhancing quality of service (QoS) in future packet networks. It features a scheme that compensates the deviation for prediction on the traffic to be arrived continuously It predicts the traffic to be arrived at the beginning of a time slot and measures the actual arrived traffic at the end of the time slot and derives the difference between them. The deviation is utilized to the delay control operation for the next time slot to offset it. As it compensates the prediction error continuously, it shows superior adaptability to the bursty traffic as well as the exponential traffic. It is demonstrated through simulation that the algorithm meets the quantitative delay bounds and shows superiority to the traffic fluctuation in comparison with the conventional non-adaptive mechanism.

Examination of Factors Influencing Urban Higher Temperature using E-GIS DB (E-GIS DB를 활용한 도시 고온화 영향인자 검토)

  • Kim, Keum-Ji;Yoko, Kamata;Lee, Jung-Jae;Yoon, Seong-Hwan
    • 한국태양에너지학회:학술대회논문집
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    • pp.44-49
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    • 2009
  • In this study, we performed urrban climate simulation how both the factor of environmental land and artificial factors influence on the formation of urban temperature. With deducing quantitative data, this study could get more accurate results of the urban temperature using urban climate simulation system. In the case of natural land cover, it appeared that there are effects on the lowering temperature and the lower temperature rate appeared in the water land cover on the whole. This is considered as temperature in water land was low because of the characteristics of water land having evaporation latent heat was high and convective sensible heat was low. In case of building which has building coverage ratio, 5% with 10 floors and building coverage ratio, 15 % with 6 floors, it appears that the temperature in the water land is $33.6^{\circ}C$. In case of building coverage ratio 5%, temperature dropped when buildings has more than 4 stories. This is regarded as the size of building is bigger, the temperature dropped in relatively because of the fluctuation of the rate of solar heat from the land. At the present time, the urban temperature are higher because of various artificial factors in the city. With these results, this study supposed to be a basies of the future studies for considering both the composition of building coverate ratio and floor plan.

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Expressional Profiling of Connexin Isoforms in the Initial Segment of the Male Reproductive Tract during Postnatal Development

  • Seo, Hee-Jung;Seon, Chan-Wook;Choi, In-Ho;Cheon, Yong-Pil;Cheon, Tae-Hoon;Lee, Ki-Ho
    • Reproductive and Developmental Biology
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    • v.34 no.2
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    • pp.103-109
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    • 2010
  • Functional regulation of a specific tissue or organ is controlled by a number of ways, including local cell-cell interaction. Of several forms of cell-cell junctional complexes, gap junctions are caught a great attention due to a formation of direct linkage between neighboring cells. Gap junctions are consisted of connexin (Cx) isoforms. In the present study, we evaluated expressional profiling of Cx isoforms in the rat initial segment (IS) of the male reproductive tract at different postnatal ages. The presence and expression of 13 Cx isoform mRNAs were determined by semi-quantitative real-time PCR analyses. A total of 8 Cx isoform mRNAs were detected in the IS of the male rats during postnatal development. The highest level of Cx30.3 mRNA was found at 5 months of age, while abundance of Cx31 mRNA was the highest at 1 year of age. Expression of Cx31.1 gene was relatively consistent during the postnatal development. Fluctuation of Cx32 and 37 gene expression was observed during the postnatal period. Significant elevation of Cx40 mRNA abundance was detected at 25 days of age and older ages. Expression patterns of Cx43 and 45 genes were similar with the highest level at 2 weeks of age, followed by gradual decreases at older ages. These results indicate differential regulation on expression of Cx isoforms in the rat IS during postnatal development. A complicated regulation of gene expression of Cx isoforms in the IS at different postnatal ages is suggested.

Minimizing Redundant Route Nodes in USN by Integrating Spatially Weighted Parameters: Case Study for University Campus (가중치가 부여된 공간변수에 의거하여 USN 루트노드 최소화 방안 -대학 캠퍼스를 사례로-)

  • Kim, Jin-Taek;Um, Jung-Sup
    • Journal of the Korean Geographical Society
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    • v.45 no.6
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    • pp.788-805
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    • 2010
  • The present USN (Ubiquitous Sensor Networks) node deployment practices have many limitations in terms of positional connectivity. The aim of this research was to minimize a redundancy of USN route nodes, by integrating spatially weighted parameters such as visibility, proximity to cell center, road density, building density and cell overlapping ratio into a comprehensive GIS database. This spatially weighted approach made it possible to reduce the number of route nodes (11) required in the study site as compared to that of the grid network method (24). The field test for RSSI (Received Signal Strength Indicator) indicates that the spatially weighted deployment could comply with the quality assurance standard for node connectivity, and that reduced route nodes do not show a significant degree of signal fluctuation for different site conditions. This study demonstrated that the spatially weighted deployment can be used to minimize a redundancy of USN route nodes in a routine manner, and the quantitative evidence removing a redundancy of USN route nodes could be utilized as major tools to ensure the strong signal in the USN, that is frequently encountered in real applications.

Band alignment and optical properties of $(ZrO_2)_{0.66}(HfO_2)_{0.34}$ gate dielectrics thin films on p-Si (100)

  • Tahir, D.;Kim, K.R.;Son, L.S.;Choi, E.H.;Oh, S.K.;Kang, H.J.;Heo, S.;Chung, J.G.;Lee, J.C.
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.381-381
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    • 2010
  • $(ZrO_2)_{0.66}(HfO_2)_{0.34}$ thin films as gate dielectrics have been proposed to overcome the problems of tunneling current and degradation mobility inachieving a thin equivalent oxide thickness. An extremely thin $SiO_2$ layer is used in order to separate the carrier in MOSFET channel from the dielectric field fluctuation caused by phonons in the dielectric which decreases the carrier mobility. The electronic and optical properties influenced the device performance to a great extent. $(ZrO_2)_{0.66}(HfO_2)_{0.34}$ dielectric films on p-Si (100) were grown by atomic layer deposition method, for which the conduction band offsets, valence band offsets and band gapswere obtained by using X-ray photoelectron spectroscopy and reflection electron energy loss spectroscopy. The band gap, valence and conduction band offset values for $(ZrO_2)_{0.66}(HfO_2)_{0.34}$ dielectric thin film, grown on Si substrate were about 5.34, 2.35 and 1.87 eV respectively. This band alignment was similar to that of $ZrO_2$. In addition, The dielectric function (k, $\omega$), index of refraction n and the extinction coefficient k for the $(ZrO_2)_{0.66}(HfO_2)_{0.34}$ thin films were obtained from a quantitative analysis of REELS data by comparison to detailed dielectric response model calculations using the QUEELS-$\varepsilon$(k, $\omega$)-REELS software package. These optical properties are similar with $ZrO_2$ dielectric thin films.

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Implementation of Absolute Delay Differentiation Scheme in Next-Generation Networks (차세대 네트워크에서의 절대적 지연 차별화 기능 구현)

  • Paik, Jung-Hoon;Kim, Dae-Ub;Joo, Bheom-Soon
    • 전자공학회논문지 IE
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    • v.45 no.1
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    • pp.15-23
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    • 2008
  • In this paper, an algorithm, that provisions absolute differentiation of packet delays is proposed, simulated, and implemented with VHDL on XPC 860 CPU based test board with an objective for enhancing quality of service (QoS) in future packet networks. It features a scheme that compensates the deviation for prediction on the traffic to be arrived continuously. It predicts the traffic to be arrived at the beginning of a time slot and measures the actual arrived traffic at the end of the time slot and derives the difference between them. The deviation is utilized to the delay control operation for the next time slot to offset it. As it compensates the prediction error continuously, it shows superior adaptability to the bursty traffic as well as the exponential traffic. It is demonstrated through both simulation and the real traffic test on the board that the algorithm meets the quantitative delay bounds and shows superiority to the traffic fluctuation in comparison with the conventional non-adaptive mechanism.