Determining Critical Rail Line Blocks and Minimum Train Headways for Equal and Unequal Block Lengths and Various Train Speed Scenarios

This paper presents a primary model to maximize rail line capacity by minimizing the train headway, defining block time as the time when a train first enters until it leaves the block. The analysis was conducted under a fixed-block system, which allows only a single train to remain in the block. A critical block was identified to determine the minimum safe headway as a function of the train speed, train length, number of trains, and block length. A time–distance diagram was used to analyze operations with equal and unequal block lengths. For two trains operating at the same speed on unequal blocks, the maximum block length defined the minimum headway. For two trains operating at different speeds, a hierarchical analysis was required to identify the minimum headway. Shorter block lengths and a strategic train order affected rail line capacity. The maximum capacity was achieved when two trains operated at the same speed.This paper presents a primary model to maximize rail line capacity by minimizing the train headway, defining block time as the time when a train first enters until it leaves the block. The analysis was conducted under a fixed-block system, which allows only a single train to remain in the block. A critical block was identified to determine the minimum safe headway as a function of the train speed, train length, number of trains, and block length. A time–distance diagram was used to analyze operations with equal and unequal block lengths. For two trains operating at the same speed on unequal blocks, the maximum block length defined the minimum headway. For two trains operating at different speeds, a hierarchical analysis was required to identify the minimum headway. Shorter block lengths and a strategic train order affected rail line capacity. The maximum capacity was achieved when two trains operated at the same speed

การศึกษาปริมาณแอสฟัลต์ซีเมนต์ที่เหมาะสมในแอสฟัลต์คอนกรีตชนิดผสมอุ่นที่มีผิวทางเก่าเป็นส่วนผสม

This research aims to determine the optimum asphalt content (OAC) for mixed virgin materials with reclaimed asphalt pavement (RAP) as the key parameter to be used for pavement design. The results of this research showed that OAC increases when reducing the mixing temperature. It is well known that the viscosity of asphaltic cement (AC) increases when the temperature is reduced resulting in the adhesion efficiency between AC and the aggregates decreasing which induces the OAC value to increase. Besides, the density and Marshall Quotient can be improved by increasing the RAP added. On the other hand, VMA, VFA and stability were reduced with increasing the amount of RAP. The range of the RAP that had higher stability is 20% to 35%, and then the range of the optimum asphalt content is 4.5% to 5

Risk Factors Affecting Driver Severity of Single- Vehicle Run Off Road Crash for Thailand Highway

Single-Vehicle Run Off Road (ROR) crash has been the leading crash type in terms of frequency and severity in Thailand. In this study, multinomial logit analysis was applied to identify the risk factors potentially influencing driver injury severity of single-vehicle ROR crash using accident records between 2011 and 2017 which were extracted from Highway Accident Information Management System (HAIMS) database. The analysis results show that the age of driver older than 55 years old, male driver, driver under influence of alcohol, drowsiness, ROR to left/right on straight roadway increase the probability of fatal crash, while other factors are found to mitigate severity such as the age of driver between 26-35 years old, using seatbelt, ROR and hit fixed object on straight and curve segment of roadway, mounted traffic island, intersection-related and accident in April. This study recommends the need to improve road safety campaign, law enforcement, and roadside safety features that potentially reduce level of severity of driver involving in single-vehicle ROR crash

A Heuristic for the Two-Echelon Multi-Period Multi-Product Location–Inventory Problem with Partial Facility Closing and Reopening

In this paper, the two-echelon multi-period multi-product location–inventory problem with partial facility closing and reopening is studied. For each product and period, plants serve warehouses, which serve consolidation hubs, which service customers with independent, normally distributed demands. The schedule of construction, temporary partial closing, and reopening of modular capacities of facilities, the continuous-review inventory control policies at warehouses, the allocation of customer demands to hubs, and the allocation of hubs to warehouses are determined. The service levels for stockout at warehouses during lead time and the violation of warehouse and hub capacities are explicitly considered. The proposed mixed-integer non-linear program minimizes the weighted summation of the number of different facilities and logistical costs, so that the number of different facilities can be controlled. Since the proposed model is np-hard, the multi-start construction and tabu search improvement heuristic (MS-CTSIH) with two improvement strategies and the modified MS-CTSIH incorporating both strategies are proposed. The experiment shows that the two improvement strategies appear non-dominated, and the modified MS-CTSIH yields the best results. The comparison of the modified MS-CTSIH and a commercial solver on a small instance shows the efficiency and effectiveness of the modified MS-CTSIH. The sensitivity analyses of problem parameters are performed on a large instance

ปัจจัยด้านแรงจูงใจในการเดินทางท่องเที่ยวของผู้สูงอายุในประเทศไทย

This study aimed to analyze several motivation factors related to travel activities of seniors or elderly people in Thailand, and to identify group variables of motivation to enhance the tourism poll. A total of 750 respondents were elderly Thai with the age above 60-year-old in Thailand. Data were analyzed using the Second-ordered Confirmatory Factor to determine the push and the pull factors that motivated the travel activities of the elders. The results of motivation factors shown that the value of chi-square was 801.909 with 218 degrees of freedom, p-value=0.0001, CFI=0.935, TLI=0.925, RMSEA=0.060 and SRMR=0.051. The model indicated that the motivation factors related to the travel activities of elderly people in Thailand were that (1) the push motivation composed of 3 factors: novelty and pursuit of knowledge, self-development and enhancement, and relaxation, (2) the pull motivation composed of 3 factors: natural and historic attractions, festival or events and shopping resources, travel and security, and weather atmosphere and climate. The results of the study could enhance in the development of tourism industry in planning, and to develop tourist attractions and suitable tourism arrangement for the elderly people, which can be applied by the Tourism Authority of Thailand

การศึกษาปัจจัยที่มีผลต่อความตั้งใจในการสวมหมวกนิรภัยโดยทฤษฎีแบบแผนความเชื่อด้านสุขภาพ

This research aimed to study the factors affecting the intention in helmet use for motorcycles in the context of Thailand. The factors to be considered were applied from Health Belief Model by questioning 801 nationwide motorcycle riders divided into 401 of urban society and 400 of rural society. For data analysis, Stepwise Multiple Regression analysis was used. Regarding urban society, it was found that the four factors affecting the intention in helmet use for motorcycles were motivation (β = 0.411), Cue to Action (β = 0.173), Perceived Severity (β = 0.177), and Perceived Barriers (β = 0.053) at statistical significance .000, .001, .004 and .047 respectively. These four factors predicted that the intention in helmet use would be 26.40 percent. Regarding rural society, the four factors including Perceived Benefits (β = 0.249), Perceived Severity (β = 0.244), Cue to Action (β = 0.237) were at statistical significance .000 while motivation (β = 0.126) was at statistical .040. These factors predicted that the intention in helmet use would be 40.40 percent. The results from this study acknowledged the factors affecting the intention in helmet use between urban society and rural society. Thus, the organizations in government sectors potentially take the data to develop the suitable policies for each area

Understanding relationship between road median type and accident frequency

Road medians play an important role in the design of four or more lanes highways with high traffic volume and the large number of accidents. This study focused on effect of factors (such as traffic volume, road characteristics, land use and road median types) on the number of accidents. The data was collected from nationwide highway, and further used to build the models by using Generalized linear with Negative binomial model distribution classified by road median types including raised-, depressed-, flush-and barrier median. The result found that the increase in traffic volume and truck ratio are positively associated with more number of accidents in all four road median model. The finding also recommends that raised-, depressed-and flush median should be implemented within agriculture and rural area in order to decrease crashes frequency. The contributions of this study could be used as guideline regarding highways median type implementation decision-making to enhance road safety in Thailand

Impacts of accident severity factors and loss values of crashes on expressways in Thailand

The number of road accidents and the level of accident severity have been extensively applied as the indicators for measuring the efficiency of service provision in road network systems of each country. This research utilized accident data on expressway networks during B.E.2550 (2007) to B.E.2553 (2010) (updated data was collected), in which Expressway Authority of Thailand (EXAT) as legislatively mandated unit has taken responsibility for the execution of nine expressway routes covering distances totaling over 207 km with a record of 2194 crashes. The chief objective of the study aims to forecast the accident severity through formulating Multiple Logistic Regression Model to analyze the probability of injury accident and fatal accident in comparison with property damage only accident. Its measurement comprehensively considers statistical relationship among variables such as average speed on road section, average traffic volume per day, period of time, weather conditions, physical characteristics of accident area, and causes of accident. Together, the research question is to verify whether these variables affect the opportunity or probability of three levels of accidents and investigate impacts of accident loss values due to the reduction in crash severity measures

Determinant Factors Influencing Thai Tourists’ Intentions to Use Social Media for Travel Planning

Currently, information technology plays an important role in the tourism industry. Tourists like to use social media more widely for their travel planning, which affects the high competition between entrepreneurs while facing the challenge of improving the quality of data services provided through social media. This study developed a model of the relationships between structure factors that affect intentions to use social media for travel planning. The said model integrates the technology acceptance model (TAM) theory, the theory of planned behavior (TPB), and trust and satisfaction factors. In reference to a survey of 1333 samples from domestic tourists who used social media through their smartphone, it was found that satisfaction, attitudes, subjective norms, and perception can be used to control behavior, with a positively direct effect on intentions of use. In addition, we examined the indirect effect on intentions of use. Perceived ease of use, perceived usefulness, and subjective norms had a positively significant indirect effect on intentions of use. These research results allow tourism entrepreneurs to precisely understand the stimulating factors of tourists’ intentions to use social media for travel-planning decisions, which will help lead to the development of tourism-marketing strategies and the support of sustainable competition

Methodologies for Determining the Service Quality of the Intercity Rail Service Based on Users’ Perceptions and Expectations in Thailand

There is a significant need to change people’s travel mode from personal cars to public rail, because rail transport is a more environmentally friendly travel mode. Over the past decade, the number of rail passengers has reduced because of service quality problems. Thus, this study aims to propose guidelines for precise service quality (SQ) improvements of intercity rail services in Thailand. Data were collected from 615 train passengers by distributing questionnaires at train stations in six provinces, covering all regions of Thailand. Cluster analysis (CA), factor analysis (FA), and importance-performance analysis (IPA) were applied in this research, which were used based on gap analysis. As a result of CA and FA, the 45 quality indicators were grouped into four factors, namely, vehicles, staff, services, and infrastructures/stations. The FA results seem more appropriate than those of CA in terms of providing factor loadings that indicate the importance of each indicator. The results of IPA show that the seven indicators that were analyzed fell into the “concentrate here” quadrant. To summarize the current policy, the factor most in need of rapid improvement in order to increase the quality of the intercity rail service in Thailand is that of the train car variables group; on the other hand, the main strength of the current services relates to the services provided by staff