• Title/Summary/Keyword: Air transport

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How Destination Image Factors Affect Domestic Tourists Revisit Intention to Ba Ria-Vung Tau Province, Vietnam

  • GIAO, Ha Nam Khanh;NGAN, Nguyen Thi Kim;PHUC, Nguyen Pham Hanh;TUAN, Huynh Quoc;HONG, Ha Kim;ANH, Huynh Diep Tram;NHU, Duong Thi Huynh;LAN, NgoThi
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.6
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    • pp.209-220
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    • 2020
  • This research examines the affect of destination image factors on revisit intention of domestic tourists at Ba Ria Vung-Tau (BRVT), by questioning directly 510 domestic tourists. The convenient sampling method is used in dividing the crowds into four groups; the four main surveyed areas in BRVT are: Vung Tau, Long Hai-Phuoc Hai, Xuyen Moc and Con Dao. A combination of qualitative and quantitative methodologies were utilized.A focus group of 10 domestic tourists wasset up to review and explore the variousfactors as well as the conceptual model. An in-depth interview with 12 participants was developed to fine-tune measurement items. The questionnaire applied a 5-point Likert scale. Checking the reliability by Cronbach's Alpha, exploratory factor analyzing and linear multiple regression were used with the SPSS program. The results show that there are eight main destination image factors affecting domestic tourists revisit intention to BRVT using linear regression and arranged by decreasing importance: Infrastructure, Variety Seeking, Accessibility, Local food, Atmosphere, Environment, Price Value, Leisure and Entertainment. From that, the research offers some suggestions and policy recommendations for the tourism business and provincial policy-makers to identify the main issues and develop better customer services to increase domestic tourists'revisit intention.

Analysis of Tropospheric Carbon Monoxide over East Asia

  • Lee, S.H.;Choi, G.H.;Lim, H.S.;Lee, J.H.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.615-617
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    • 2003
  • Carbon monoxide (CO) is one of the important trace gases because its concentration in the troposphere directly influences the concentrations of tropospheric hydroxyl (OH), which controls the lifetimes of tropospheric trace gases. CO traces the transport of global and regional pollutants from industrial activities and large scale biomass burning. The distributions of CO were analyzed using the MOPITT data for East Asia, which were compared with the ozone distributions. In general, seasonal CO variations are characterized by a peak in the spring, which decrease in the summer. The monthly average for CO shows a similar profile to that for O$_3$. This fact clearly indicates that the high concentration of CO in the spring is possibly due to one of two causes: the photochemical production of CO in the troposphere, or the transport of the CO into East Asia. The seasonal cycles for CO and O$_3$ in East Asia are extensively influenced by the seasonal exchanges of different air mass types due to the Asian monsoon. The continental air masses contain high concentrations of O$_3$ and CO, due to the higher continental background concentrations, and sometimes to the contribution from regional pollution. In summer this transport pattern is reversed, where the Pacific marine air masses that prevail over Korea bring low concentrations of CO and O$_3$, which tend to give the apparent summer minimums.

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Study on UAV Flight Patterns and Simulation Modelling for UTM (저고도 무인기 교통관리 체계에서 무인기 비행패턴 분류 및 시뮬레이션 모형 개발)

  • Jung, Kyu-sur;Kim, Se-Yeon;Lee, Keum-Jin
    • Journal of Advanced Navigation Technology
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    • v.22 no.1
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    • pp.13-19
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    • 2018
  • In this paper, we classified a flight pattern of unmanned aerial vehicle(UAV) which will be operating in UTM system and analyzed its flight pattern by purpose of use. Flight patterns of UAV are sorted into three patterns which are circling, monitoring and delivery. We considered four cases of industry areas using UAV which are agriculture, infrastructure monitoring, public safety & security(p.s.s) and delivery. It is necessary to build a simulation model as a verification tool for applying the flight pattern according to the use of UAV to the real UTM system. Therefore, we propose the simulation model of UAV with updating states over time. We applied simulation to UAV monitoring flight pattern, and confirmed that the flight was done by the given input data. The simulation model will be used in the future to verify that the UAV has various flight patterns and can operate safely and efficiently for the intended use.

Effect of Fiber Content, Yarn Size and Construction of Knit Fabrics on the Buffering Capacity against Water Vapor (편성물의 섬유의 종류, 실의 굵기 및 니트타입에 따른 투습완충능력)

  • Yoo, Hwa-Sook;Hu, Yoon-Sook;Kim, Eun-Ae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.1
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    • pp.228-238
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    • 1996
  • The purpose of this study was to evaluate the effect of chacteristics of knit fabrics on the microclimate of the skin simulating system. To determine the effect of characteristics of knit fabrics, vapor state of sweat pulse was simulated in the closed system. Different contents of fibers such as cotton, wool and polyester with different yarn size and knit types were chosen for specimens. The changes of humidity and temperature of air layer in the simulated systems were measured. Buffering indices, $K_d$ and $\beta_r$, were determined by considering $\alpha_p, \DeltaP_{max}, t_{max}, and tan\beta$. Physical properties of knit fabrics such as thickness, porosity, air resistance and moisture vapor transport were measured. Results showed that vapor pressure of wool was lower than cotton or polyester This was attributed to the hydrophilicity of wool which absorbed moisture rather quickly and retained in the knit fabric. The time to decrease vapor pressure was faster for polyester than cotton or wool. As a result, $K_d$ was in the order of wool> polye, item> cotton. $\beta_r$ of wool was rower than cotton or polyester due to its lowers porosity and slower desorption rate. For the yarn size, $K_d$ was in the order of 80's> 60's> 30's; thinner and lighter yarn showed better water vapor transport property. For knit type, buffering capacity of single jersey was better than interlock knit fabric. Statistical analysis showed that the air permeability was the most influential factor far the water vapor transport properties.

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Merge Control using Reserve Ahead Point in Baggage Handling System (수하물시스템의 사전할당지점을 이용한 병합제어)

  • Kim, Minhee;Shin, Hyunwoo;Chae, Junjae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.40 no.2
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    • pp.60-67
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    • 2017
  • A baggage handling system (BHS) in airport is an unified system for moving the passengers' baggage in designated time. Input baggage from the check-in counter travels to the baggage claim area or cargo handling terminal through this system. In particular, entryway BHS consists of conveyors, X-ray and sorters such as tilt-tray to send the baggage to departing airplane and it could have various problems for handling certain amount of baggage in restricted time such as baggage jamming at certain merge point. This causes systemic error such as delay of the time, omissions of the baggage and even breakdown of the equipment and inefficiency. Also the increasing maximum time of the baggage passing through the BHS could delay the flight schedule and finally decrease the service level. Thus, the algorithm for controlling the flow of the merge is essential to the system. The window reservation algorithm is the one of the most frequently used methods to control the merge configuration. Above all, the reserve location, so called reserve ahead point, that allocates the window is important for the performance of the algorithm. We propose the modified window reservation algorithm and the best reserve locations by changing the reserve ahead point in the induction conveyors. The effect of various reserve ahead points such as the capacity and utility of the system were analyzed and the most effective reserve ahead point combination was found. The total baggage processing time and the utilization of the tilt-tray are properly considered when choosing the optimal Reserve ahead point combination. In the layout of this study, the configuration of four conveyors merged into one tilt-tray is studied and simulation analysis is done by AutoMod(R), 3D simulation software. Through the simulation, the window reservation algorithm is effectively operated with the best combination of reserve ahead point which reduces the maximum baggage travel time.

A Fair Flow Control For Baggage Handling System in Airport (공항 수하물 처리시스템의 균형적인 흐름제어 기법 연구)

  • Kim, Junbeom;Kim, Gukhwa;Chae, Junjae
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.10
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    • pp.1317-1327
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    • 2016
  • The baggage handling system (BHS) is one of the most complex system in the airport. A highly economical operating system is required to ensure its performance in consideration of its enormous cost on the extension. Furthermore, the inefficient operation deteriorates not only the system performance but the imbalance among the check-in counters because of a bottleneck on the conveyors downstream. The objective of this research is to improve the performance of both the BHS and the check-in area by efficiently controlling the flow in the merging area on the conveyors. Thus, we suggest a control logic of which the concept is borrowed from data networks. The simulation is used to analyze impacts of the conveyors bottleneck on the check-in area and optimize some parameters used in the suggested logic. We also discuss some observations from the simulation results into several aspects of performance measures.

Analysis of Departing Passengers' Dwell Time using Clustering Techniques (클러스터링 기법을 활용한 출발 여객 체류 시간 분석)

  • An, Deok-bae;Kim, Hui-yang;Baik, Ho-jong
    • Journal of Advanced Navigation Technology
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    • v.23 no.5
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    • pp.380-385
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    • 2019
  • This paper is concerned with departure passengers' dwell time analysis using real system data. Previous researches emphasize the importance of dwell time analysis from perspective of airport terminal planning and non-aeronautical revenue. However, short-term airport operation using passengers' dwell time is considered impossible due to absence of passengers' behavior data. Recently, in accordance with the wave of smart airport, world leading airports are systematically collecting passenger data. So there is high possibility of analyzing passengers' dwell time with the data stacked in the airport database. We conducted dwell time analysis using data from Incheon Int'l airport. In order to handle passenger data, we adapted clustering algorithm which is one of data mining techniques. As a clustering result, passengers are divided into 3 clusters. One is the cluster for passengers whose dwell time is relatively short and who tend to spend longer time in the airside. Another is the cluster for passengers who have near 3 hours dwell time. The other is the cluster for passengers whose total dwell time is extremely long.

A Review of Routing Plan for Unmanned Aerial Vehicle : Focused on In-Country Researches (국내 무인항공기의 경로계획 연구)

  • Kim, Jinwoo;Kim, Jinwook;Chae, Junjae
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.38 no.4
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    • pp.212-225
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    • 2015
  • UAV (Unmanned Aerial Vehicle), the pilotless plane or drone, draws researchers' attention at these days for its extended use to various area. The research was initiated for military use of the UAV, but the area of applicable field is extended to surveillance, communication, and even delivery for commercial use. As increasing the interest in UAV, the needs of research for operating the flying object which is not directly visible when it conducts a certain mission to remote place is obviously grown as much as developing high performance pilotless plane is required. One of the project supported by government is related to the use of UAV for logistics fields and controlling UAV to deliver the certain items to isolated or not-easy-to-access place is one of the important issues. At the initial stage of the project, the previous researches for controlling UAV need to be organized to understand current state of art in local researches. Thus, this study is one of the steps to develop the unmanned system for using in military or commercial. Specifically, we focused on reviewing the approaches of controlling UAV from origination to destination in previous in-country researches because the delivery involves the routing planning and the efficient and effective routing plan is critical to success to delivery mission using UAV. This routing plan includes the method to avoid the obstacles and reach the final destination without a crash. This research also present the classification and categorization of the papers and it could guide the researchers, who conduct researches and explore in comparable fields, to catch the current address of the research.

Performance Analysis of Water Direct Contact Air Conditioning System (물 직접접촉식 공기조화장치의 성능해석)

  • Yoo, S.Y.;Kwon, H.K.;Song, J.;Kim, K.Y.;Park, J.T.
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.158-163
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    • 2001
  • Performance of the water direct contact air conditioning system, in which heat and mass are transferred directly between air and water droplet, is simulated by semi-empirical method. This system improves transport efficiency compared to conventional indirect contact system and cooling, heating, dehumidification and humidification are attained with one unit. In this study, temperature and flowrate for air and water are measured in the various cooling and heating conditions, and correlations for $h_{c}A/c_{pm}$ are derived from these data. Cooling and heating characteristics of the water direct contact air conditioning system are investigated using correlations.

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Ionizing Characteristic of Glow Discharge by Controlled Air Flow Rate (공기유량에 따른 글로우 방전의 제전 특성)

  • Choi, Sang-Won
    • Journal of the Korean Society of Safety
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    • v.23 no.5
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    • pp.49-53
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    • 2008
  • Glow discharge has lots of attractive properties, such as lower discharge sustaining voltage, no generation of ozone, and so on. And more, ionizer was developed recently using an atmospheric pressure glow discharge. On the other hand, ionizer needs a compressed or blown air to transport ion for charged objects. This air is very useful in explosive hazardous area to prevent the explosion of flammable gas and/or vapor by ignition sources, e.g. electrical spark. In this paper, we investigated the ionizing characteristic of atmospheric pressure glow discharge by controlled air flow rate from 5 liters to 60 liters a minute, and compared with decay time between the corona discharge and glow discharge as a function of some direction and distance from discharge ion source. We confirmed that an air flow rate needs 25 liters a minute to sustain the most suitable atmospheric pressure glow discharge and to increase an ionizing efficiency.