scholarly journals The Impact of Walking Time on U-Shaped Assembly Line Worker Allocation Problems

2010 ◽  
Vol 14 (2) ◽  
pp. 53-78 ◽  
Author(s):  
Ronnachai Sirovetnukul ◽  
Parames Chutima
2019 ◽  
Vol 11 (3) ◽  
pp. 691
Author(s):  
Lizhen Zhao ◽  
Zhenjiang Shen ◽  
Yanji Zhang ◽  
Yan Ma

By means of on-site and network investigation, we collected data relevant to residents of communities, point of interest (POI) data, and land-use data of Fuzhou. We set traffic walking time and leisure walking time as an independent variable, built environment as dependent variable, and gender, age, education level and income level as control variables. Six linear regression models were established using Statistical Product and Service Solutions (SPSS). The results showed that in the 5D (i.e., Density, Diversity, Design, Destination and Distance) elements of the built environment, the density was negatively correlated with the traffic walking time, whereas other elements were positively correlated with the walking time, but the degree of influence was different.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 11559-11559
Author(s):  
Lawson Eng ◽  
Jie Su ◽  
Steven Habbous ◽  
Katrina Hueniken ◽  
M. Catherine Brown ◽  
...  

11559 Background: Continued smoking after a cancer diagnosis is associated with poorer outcomes. Tobacco retail availability is negatively associated with cessation in non-cancer patients (pts), but has not been explored in cancer survivors. We evaluated the impact of tobacco retail availability on cessation in lung and HN cancer pts. Methods: Lung and HN cancer pts (Princess Margaret Cancer Centre, Toronto) completed questionnaires evaluating changes in tobacco use with a median of 26 months apart. Validated tobacco retail location data were obtained from Ministry of Health and pt home addresses were geocoded using ArcGIS 10.6.1, which calculated walking time/distance to nearest vendor, and vendor density within 250 meters (m) and 500m from pts. Multivariable logistic regression and Cox proportional hazard models evaluated the impact of vendor availability on cessation and time to quitting after diagnosis respectively, adjusting for significant clinico-demographic and tobacco covariates. Results: 242/721 lung and 149/445 HN pts smoked at diagnosis; subsequent overall quit rates were 66% and 49% respectively. Mean distance and walking time to a vendor was 1 km (range 0-13) and 11 min (range 0-156). On average, there was one vendor (range 0-19) within 250m and four vendors (range 0-40) within 500m from pts; 37% and 61% of pts lived within 250m and 500m from at least one vendor respectively. Greater distance (aOR 1.18 per 1000m [95% CI 1.00-1.38] p = 0.05) and increased walking time (aOR 1.01 per minute [1.00-1.02] p = 0.05) were associated with quitting at one year. Living within 250m (aOR 0.52 [0.32-0.84] p = 0.008) or 500m (aOR 0.57 [0.35-0.92] p = 0.02) to at least one vendor reduced quitting at one year. Living near more vendors within 500m had an increasing dose effect on reducing cessation rates at one year (aOR 0.96 per vendor [0.93-1.00] p = 0.05). Living within 500m to a vendor reduced chance of quitting at any time (aHR 0.66 [0.48-0.91] p = 0.01). HN and lung subgroups revealed similar associations. Conclusions: Close access to tobacco retail outlets is associated with reduced cessation rates for lung and HN cancer survivors. Reducing density of tobacco vendors is a cessation strategy that can positively impact cancer pt outcomes.


2012 ◽  
Vol 502 ◽  
pp. 127-132 ◽  
Author(s):  
L.P. Ferreira ◽  
E. Ares ◽  
G. Peláez ◽  
A. Resano ◽  
C.J. Luis-Pérez ◽  
...  

The aim of the work presented in this paper describes the development of a decision support system based on a discrete-event simulation model of an automobile assembly line. The model focuses at a very specific class of production lines with a four closed-loop network configuration. One key characteristic in the closed-loop system is that the number of pallets inside the first three loops has been made constant. The impact of the number of pallets circulating on the first three closed-loops and of the proportion of four-door car bodies on the performance of the production line has been thoroughly investigated. This has been translated into the number of cars produced per hour, in order to improve the availability of the entire manufacturing system.


2015 ◽  
Vol 35 (1) ◽  
pp. 3-15 ◽  
Author(s):  
Matteo M. Savino ◽  
Antonio Mazza

Purpose – The aim of the present work is to provide a case study where lean production (LP) techniques are implemented in a semi-automated assembly line with O-shaped (closed-loop) layout configuration. The action research has been conducted within an assembly line for automotive components. The work aims to provide insights on the impact of loop layout features with respect to lean principles’ application; operative solutions related to some logistic limit of loop layout; and how kanban technique can be adapted to an O-shaped layout. Design/methodology/approach – The main research methodology is based on action research within an assembly line of oil pumps. The two research questions find answer through literature analysis and implementation of LP in the O-shaped layout. In the A3 step, we identify the main weak points of a loop layout also under the perspective of operators’ feeling. The analysis of the main constraints is conducted in this step, with respect to the most common layout used within LP adoption. Steps A4 and A5 answer to RQ2 by an on-field results’ analysis. Findings – The use of an O-shaped layout may allow to improve ergonomic conditions for workers; to better organize parts feeding through slides and chutes because of the presence of operators outside the line. The new approach to determine the number of withdrawal kanban potentially extends the findings of Tardif et al. (2012): the minimum of the objective function is reached with a higher number of withdrawal kanbans. Research limitations/implications – The approach is applied within a stand-alone line, while in several industrial contexts, we may find several of these lines in the same shop floor. In this case, LP implementation would cope with the several kanban cards circulating, the over-saturation of the logistic operator in supplying all the lines with smaller quantities of materials. Practical implications – The action research resulted in the introduction of a new concept of supermarket, conceived as a decoupling buffer that lies near the line and in the review feeding devices, with the adoption of bins and operators’ feeding chutes. Parts’ feeding systems is reorganized with a two levels of withdrawal kanban. The introduction of line supermarket and the change of supply policies from pallets to bins contributed to the strong reduction of average work-in-progress. Yet, the double-withdrawal kanban and the small quantities supplied may cause an increase of material handling times and meters covered by operators. Social implications – Better working condition of the line operators because of the presence of ergonomic chutes for parts’ feeding. In contrast, we observed a high saturation of logistic operator because of the small quantities of components supplied on the line, with an increased stress of this worker. Originality/value – A decoupled withdrawal kanban (DWK) is developed. In DWK, the first withdrawal is issued to the supermarket that serves the line. The second withdrawal kanban is issued from the supermarket to the central warehouse. Within DWK, we propose a modified dimensioning formula through minimization of the objective function Z(k). Parts’ feeding is now organized with sliding chutes on operators’ workstations to collect components in accordance to kanban dimensioning.


2021 ◽  
Author(s):  
◽  
Omid Khazaeian

<p><b>Researchers in commuting studies predominantly focus on movements. However, every trip starts and terminates in a place. For drivers, commuting is a journey between parking locations. They start their journey from home parking, park near work, and eventually return to home parking. Cars spend most of the day parked, with associated externalities. Drivers waste time and fuel cruising for parking in city centres and waste other drivers’ time and fuel by slowing traffic. More fuel consumption implies more carbon emissions and local air pollution. Providing off-street home parking increases house prices and reduces house affordability. Nonetheless, parking is a small part of the transportation literature and further research is needed to support a comprehensive understanding of parking and its impacts on travel behavior. </b></p> <p>This thesis is centreed around three questions; “How does the quantity of home parking affect car ownership and commute mode?”, “How do home parking type and quantity affect car ownership?”, “How does walking time from parking location to work impact parking type choice?”. Each question is answered in a separate chapter using a discrete choice model and a sample of commuters surveyed in the New Zealand Household Travel Survey (NZHTS) in the Greater Wellington Region (GWR), New Zealand.</p> <p>We find that home parking quantity strongly and positively affects car ownership and proclivity for driving. Residential parking is the most important factor in encouraging carless households to acquire a car. High home parking supply motivates households to drive more often. More car trips from suburbs means higher demand for parking downtown and highlights the relationship between home parking and work parking. More garage spaces at home noticeably motivates households to have multiple cars. The number of driveway spaces positively influences owning more than two cars. An inverse relationship exists between on-street parking demand and car ownership. For work parking, we find that walking time from public off-street parking to work significantly discourages commuters from choosing public off-street parking. Walking time from an on-street parking to work is also a significant disincentive for choosing On-street parking. The cost of on-street parking is important, followed by the number of on-street parking spaces. Elasticities show that the motivation of drivers to change parking type is close to their willingness to choose non-driving modes, if any parking features change. This similar willingness indicates a potential for achieving lower car use through parking restriction and improving non-driving modes.</p> <p>This research contributes to the home parking literature by considering residential location as a choice that is interrelated with car ownership and mode choice. We study commuters who could live and work anywhere in a region (GWR) with a diverse range of socioeconomic characteristics, parking features, and traffic conditions, in order to give results that are more realistic and comprehensive. We mitigate the endogeneity between car ownership and home parking using novel instrumental variables for home parking. Our measure for on-street parking carefully considers parking competition and quantity. Commute length is measured as commute time to better represent commuters’ perception of commute length. For work parking, we consider mode choices and parking alternatives simultaneously, and use novel demand-based measures for parking features.</p> <p>We expect the findings of this research will contribute to a better understanding of how parking arrangements in cities can affect commuting patterns, and how parking policies can impact urban design, land use and transport outcomes.</p>


Sign in / Sign up

Export Citation Format

Share Document