• Title/Summary/Keyword: V-City

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Factors Influencing Cost Overruns in Construction Projects of International Contractors in Vietnam

  • VU, Thong Quoc;PHAM, Cuong Phu;NGUYEN, Thu Anh;NGUYEN, Phong Thanh;PHAN, Phuong Thanh;NGUYEN, Quyen Le Hoang Thuy To
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.9
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    • pp.389-400
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    • 2020
  • A construction project is a designed product made up of labors, materials, and installations in the project positioned on the ground and may include the underground and ground section, and the section in water or on the water surface. It is a civil, industrial, transport, agricultural and rural development, infrastructure, or some other. A key phase in the life cycle of these construction projects is the implementation when building products are made directly with workers, equipment, materials, and managers. If there is a lack of management experience, information, and problem-solving solutions to tackle the risks faced by contractors, especially foreign ones, will fail in controlling the project's cost. This study was conducted with investigations, discussions, and evaluation of the factors that lead to cost overruns in the construction projects of international contractors in Vietnam. The principal component analysis (PCA) showed that those factors that influence cost overruns these construction projects fall into five general groups, including factors related to (i) the owners, (ii) the foreign contractors, (iii) the subcontractors and suppliers, (iv) state management, and (v) the project itself. Besides, the study proposes solutions to limit cost overruns in construction projects and improve the profitability of international contractors in Vietnam.

Annealing Temperature Properties of SBT Thin Film for Semiconductor Device (반도체 소자용 SBT 박막의 후속 열처리 특성)

  • Oh, Yong-Cheul;Kim, Ki-Joon;Jeon, Dong-Keun;Hong, Sun-Pyo;Kim, Sang-Jin;Song, Ja-Yoon;Lee, Joon-Ung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.697-700
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    • 2004
  • The SBT$(Sr_{0.8}Bi_{2.4}Ta_2O_9)$ thin films for semiconductor device were deposited on Pt-coated $Pt/TiO_2/SiO_2Si$ wafer by RF magnetron sputtering method at $400[^{\circ}C]$ and annealed at the temperature range from $600[^{\circ}C]$ to $850[^{\circ}C]$. The top electrodes(Pt) were deposited on SBT thin film by DC sputtering method. The crystallinity of SBT thin films were increased with increase of annealing temperature in the temperature range of $600[{\circ}C]\sim850[^{\circ}C]$. The annealing temperature properties were to be most excellent in the case of annealed SBT thin film at $750^{\circ}C]$. And, the maximum remanent polarization$(2P_r)$ and the coercive electric field$(E_c)$ at annealing temperature of $750[^{\circ}C]$ obtained about $11.60[{\mu}C/cm^2]$ and 48[kV/cm], respectively. Specially, it was seen that fatigue properties does not change in $10^{10}$ switching cycle.

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Development of comprehensive earthquake loss scenarios for a Greek and a Turkish city - structural aspects

  • Kappos, A.J.;Panagopoulos, G.K.;Sextos, A.G.;Papanikolaou, V.K.;Stylianidis, K.C.
    • Earthquakes and Structures
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    • v.1 no.2
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    • pp.197-214
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    • 2010
  • The paper presents a methodology for developing earthquake damage and loss scenarios for urban areas, as well as its application to two cities located in Mediterranean countries, Grevena (in Greece) and D$\ddot{u}$zce (in Turkey), that were struck by strong earthquakes in the recent past. After compiling the building inventory in each city, fragility curves were derived using a hybrid approach previously developed by the authors, and a series of seismic scenarios were derived based on microzonation studies that were specifically conducted for each city (see companion paper by Pitilakis et al.). The results obtained in terms of damage estimates, required restoration times and the associated costs are presented in a GIS environment. It is deemed that both the results obtained, and the overall methodology and tools developed, contribute towards the enhancement of seismic safety in the Mediterranean area (as well as other earthquake-prone regions), while they constitute a useful pre-earthquake decision-making tool for local authorities.

Gender Differences in Influence of Socio-demographic Characteristics on Mode Choice in India

  • SAIGAL, Taru;VAISH, Arun Kr.;RAO, N.V.M.
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.1
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    • pp.531-542
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    • 2021
  • The study aims to investigate differences between men and women in influence of various socio-demographic factors on choice of mode of transport. For this purpose, a binary logit model of choice probabilities is implemented on survey data of a developing country city. Results indicate women's choice of travel mode to be more environment-friendly than that of men. Well-educated, working and middle-aged individuals appear to be the most likely to choosing more-polluting modes of transport for frequent travelling purposes. Individuals in the sample who are the least socioeconomically well off are found the most likely to be promising for the environment. The findings of this study suggest the future transportation policies toward development of existing infrastructure of greener modes of transportation in the city such as, public transportation services and pedestrian lanes, so as to manage the rising issues of degrading environmental quality. The study highlights how the consideration and inclusion of socio-demographic factors is crucial for policy recommendation regarding curtailing the environmental damages contributed by transportation sector. Because mobility crucially affects all other indicators of empowerment, and women are the ones using green modes extensively, the city's transportation system should be so developed which gives their safety and security due importance.

Assessment of shear resistance of corroded beams repaired using SFRC in the tension zone

  • Jongvivatsakul, Pitcha;Laopaitoon, Phattarakan;Nguyen, Yen T.H.;Nguyen, Phuoc T.;Bui, Linh V.H.
    • Computers and Concrete
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    • v.27 no.5
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    • pp.395-406
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    • 2021
  • This study experimentally and analytically investigates the shear behavior of corroded reinforced concrete (RC) beams repaired using steel fiber-reinforced concrete (SFRC) in the flexural zone. The experimental parameters are the corrosion degree (0%, 12%, and 17%) and the steel fiber volume in the SFRC (1.0%, 1.5%, and 2.0%). The test results reveal that corrosion degree significantly affects the shear resistance of the beams. The shear capacity of the beam with the corrosion degree of 17% was higher than that of the uncorroded beam, whereas the shear capacity of the beam with the corrosion degree of 12% was lower than that of the uncorroded beam. The shear efficiency of damaged beams can be recovered by repairing them using SFRC that contains a reasonable amount of steel fibers. In addition, two methods to estimate the shear capacity of the repaired beams are developed using the modified truss analogy and strut-and-tie models. The estimated shear capacity of the beam using the modified truss analogy model agrees well with the experimental data.

Trace element Analysis and Source Assessment of Apartment Parking Lot Dust in Daegu, Korea (공동주택 주차장의 축적먼지 중 미량원소성분 분석과 오염원 평가)

  • Bae, Gun-Ho;Jung, Cheol-Su;Park, Kyu-Tae;Lee, Myoung-Sook;Shin, Dong-Chan;Kim, Yong-Hye;Yoon, Min-Hye;Han, Young-Jin;Choi, Hyuek;Baek, Sung-Ok
    • Journal of Korean Society of Environmental Engineers
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    • v.33 no.10
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    • pp.756-766
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    • 2011
  • In order to investigate the degree of apartment parking lot dust contamination, total 72 samples of parking lot dust (36 from ground parking lots and 36 from the underground parking lots) were collected in Daegu city from the end of March to the early June 2010. The dust samples were sieved below $100{\mu}m$, and analysed by ICP for 14 elements after an acid extraction. Results obtained from the source assessment of trace element using enrichment factor showed that Fe, K, Mg, Mn, Na and V were influenced by natural sources, while Cd, Cr, Cu, Ni, Pb and Zn were influenced by anthropogenic sources in both the ground parking lot and the underground parking lot. And results showed that Ca were influenced by natural sources in the ground parking lot, but influenced by anthropogenic sources in the underground parking lot. The measured values were remarkably higher in components from natural sources than in components from anthropogenic sources. Underground parking lot dust was more affected by anthropogenic sources and contaminated compared with the ground parking lot dust. Pollution index of heavy metals revealed that underground parking lot dust was 5.5 times more contaminated with heavy metal components than the ground parking lot dust. The results of correlation analysis among trace elements indicated that components in the ground parking lot were more correlated than those in the underground parking lot, and especially more correlated with natural sources-natural sources. Analysis for correlations between components and influencing factors in the underground parking lot showed that concentrations of heavy metals were higher with smaller number of parking spaces and no ventilation system, and older apartments in last paint and cleaning had relatively higher contents of heavy metals than those of recently painted and cleaned.

Consumers Preference and Dissatisfaction on knitted Golf Wear (골프니트웨어의 소비자 선호도와 불만족에 관한 연구)

  • 신상무;이종림
    • Journal of the Korean Society of Costume
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    • v.51 no.4
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    • pp.97-112
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    • 2001
  • The purposes of this study were to investigate consumers preference and dissatisfied factors in knitted golf wear The 430 questionnaires were sent to consumers who live in the Seoul Metropolitan district including Pundang-city and Iisan-city, The return rate was 89.5%. Statistical devices were t-test, ANOVA, $X$2. frequency with SAS program. The results of this study were as follows: First, Preferred colors were pastel, straw yellow, and black in descending order. Preferred coordination was analogous rather than complementary coordination. The classical look with T-neck, pullover, and V-neck was preferred. The preferred materials were pure cotton and cotton/wool blend in solid colors or plain and intasia structure. There were significant differences that pure cotton was preferred the forties and fifties or housewife, and cotton blend was preferred the thirties or service jobholders. Second, dissatisfied factors were pilling, deformation and de-coloration. The pilling problem was indicated in all income levels. Customers complained about no exchange and no refund policy with sales persons'discourtesy and time delay for repairing.

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Development and Test of a Macro Traffic Simulation Model for Urban Traffic Management (도시 간선도로 교통류관리를 위한 교통모형의 개발 및 검증)

  • 이인원
    • Journal of Korean Society of Transportation
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    • v.13 no.4
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    • pp.79-103
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    • 1995
  • The elasticity of a model is considered most important. Without showing the proper elasticity any model cannot provide useful information for decision making. This paper demonstrates a macro model which can generate dynamic transport informations every 15 minutes. Without the Wardrop principles and the monotonicity assumptions for the link travel time and link volume relationship, the basic elements of this new modeling approache are composed of link density simulation, stochastic incremental route choice, departure time choice, destination choice and mode choice. The elasticity of the proposed model is examined based on elasticity equations and simulation results. Also the transferability from a mega city like Seoul to a big city like Daejon is demonstrated for the choice model. The issues centering around the dynamic relations among density(k), speed(u), and flow rate(v) are also discussed for the modeling of highly congested situations.

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Simulation of Charging Process in PTFE Electret (PTFE 일렉트렛트의 대전 과정 시뮬레이션)

  • Park, Geon-Ho;Kim, Sang-Jin;Sung, Nak-Jin;Bae, Duk-Kwun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.05b
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    • pp.123-126
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    • 2005
  • In this study, the Thermally Stimulated Current(TSC) of corona charged PTFE is studied and the simulation of corona charging process is also calculated by Finite Element Method. The electrets which were formed by applying high voltages (DC ${\pm}5{\sim}{\pm}8$ [kV]) to PTFE, are used to measure TSC in the temperature range of $-100{\sim}+200$ [$^{\circ}C$] and then the Finite Element Method is performed to examine corona charging process using a obtained physical constants. As a result. it is confirmed that the charging negative corona is profitable as the applications are manufactured, because the time constant of negative corona is much larger than it of positive corona. And it is attempted to estimate the corona charging process in space using simulation.

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Cultural Characteristics of Chromogenic and Teleomorphic Strains of Collectotricum gloeosporioides Isolated from Apple and Red pepper (사과와 고추에서 분리한 Colletotrichum gloeosporioides의 색소형성형 및 유성세대형 계통의 배양적 특징)

  • Lee, Du-Hyung
    • The Korean Journal of Mycology
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    • v.25 no.4 s.83
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    • pp.340-347
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    • 1997
  • Conidia and cultural characteristics of isolates of chromogenic and teleomorphic strains of Colletotrichum gloeosporioides from apple and red pepper were compared. The mycelial growth of teleomorphic strains was faster than that of chromogenic strains in potato dextrose agar and V-8 agar. The chromogenic isolates from apple and red pepper developed. white gray to gray green mycelial rings interspersed with salmon to apricot colored conidial masses in colonies on potato dextrose agar and V-8 agar and none formed on ascigerous stage in cultures. The chromogenic isolates from red pepper produced conidia, most with one apex attenuated on apple and potato dextrose agar whereas fusiform and smaller conidia were produced in V-8 agar and water agar leaf medium. The chromogenic isolates from apple produced fusiform conidia in the media tested. The teleomorphic isolates from apple and red pepper produced cylindrical conidia, most with both apices rounded, developed white gray to dark olive green in a zonate pattern with small dark spots throughout colonies and formed the ascigerous stage in cultures.

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