scholarly journals  Evaluation of full tree skidding by HSM-904 skidder in patch cutting of aspen plantation in Northern Iran

2012 ◽  
Vol 58 (No. 2) ◽  
pp. 79-87 ◽  
Author(s):  
R. Mousavi ◽  
M. Nikooy ◽  
E. NezhadA ◽  
M. Ershadfar
Keyword(s):  
Populus Deltoides ◽  
Unit Cost ◽  
Travel Speed ◽  
Average Output ◽  
Northern Iran ◽  
Time Consumption ◽  
Effective Time ◽  
Harvesting Method ◽  
Total Productivity ◽  
Phase Models

This paper presents research results of the performance of HSM-904 grapple skidder using a full tree harvesting method in a non-native aspen Populus deltoides plantation in even terrain conditions in Shafaroud, Northern Iran. Patch cutting as a silvicultural method was used in the plantation (2,000 ha). To evaluate the newly introduced machine to a ground skidding system in the aspen plantation and the possibility to increase the production rate, an empirical time study was conducted. The elements of the skidding work phase were identified and 58 cycles were recorded for the study. The models for effective time consumption, total productivity and work phase models are calculated. The average load per cycle was 2.2 m<sup>3</sup>, the average one-way skidding distance was 253 m. The average travel speed of unloaded skidder was 5.53 km·h<sup>-1</sup> and the average speed of loaded skidder was lower than the speed of the unloaded one by 2.94 km·h<sup>-1</sup>. The average output in the study was 7.1 m<sup>3</sup> per effective hour and the unit cost was 13.9 USD·m<sup>-3</sup>.  

scholarly journals Effect of log length on productivity and cost of Timberjack 450C skidder in the Hyrcanian forest in Iran

2012 ◽  
Vol 58 (No. 11) ◽  
pp. 473-482 ◽  
Author(s):  
R. Mousavi
Keyword(s):  
Unit Cost ◽  
Hyrcanian Forest ◽  
Time Study ◽  
Northern Iran ◽  
Research Results ◽  
Time Consumption ◽  
Effective Time ◽  
Several Variables ◽  
Average Slope ◽  
Total Productivity

This paper presents research results on the performance of the Timberjack 450C skidder in timber skidding at two working sites of broadleaved trees in mountainous conditions in the Hyrcanian forest. To evaluate the current skidding system in the Hyrcanian forest in northern Iran and possibility of finding out better techniques and group organization an empirical time study has been conducted. The elements of the skidding work phase were identified and 123 cycles were recorded for short-log and long-log method. The models for effective time consumption, total productivity and unit cost of skidding in short-log and long-log method were calculated. The time consumption and productivity of skidding depend on several variables such as distances and slope, number of logs per cycle and volume. The average load per cycle in short-log and long-log method was 2.77 m<sup>3</sup> and 3.08 m<sup>3</sup>, the average one-way skidding distance was 380 and 497 m, the average slope was 18 and 20% in the short-log and long-log method, respectively. The average travel speeds of unloaded skidder were 5.74 km·h<sup>–1</sup> and the average speeds of loaded skidder were 7.67 and 6.16 km·h<sup>–1</sup> in short-log and long-log method, respectively. The average speeds of pulling the cable were 1.71 km·h<sup>–1</sup>, and of load winching 0.72 km·h<sup>–1</sup> and 0.69 km·h<sup>–1</sup>. The average outputs in short-log and long-log method were 10.86, 11.11 m<sup>3</sup>·effective h<sup>–1</sup>. Results indicated that hourly costs of operation were higher for the short-log method than for the long-log method (12.69 vs.12.40 USD·m<sup>–3</sup>). 

scholarly journals Time consumption and productivity analysis of timber trucking using two kinds of trucks in northern Iran

2013 ◽  
Vol 59 (No. 5) ◽  
pp. 211-221 ◽  
Author(s):  
R. Mousavi ◽  
R. Naghdi
Keyword(s):  
Work Performance ◽  
Unit Cost ◽  
Route Planning ◽  
Forest Harvesting ◽  
Dump Truck ◽  
Time Study ◽  
Productivity Analysis ◽  
Long Distance ◽  
Northern Iran ◽  
Time Consumption

Increasing productivity and reducing cost in long-distance transportation have become increasingly important in the logistics of forest harvesting operations. This paper presents the research results of the performance of loading with Volvo 4500 BM and timber trucking using two types of common trucks in the Nav watershed in Iran. Both trucks can carry logs shorter than 7.8 m in length. The study used a time study based on empirical data for loads collected from one procurement district in the Nav watershed. The models included the following explanatory factors: driving distance, number of logs, and load volume. The time consumption and productivity of loading and timber trucking depends on several variables such as volume and number of logs per cycle. To evaluate the current transportation system in the Nav watershed, the empirical time study was conducted. Since transportation includes several phases and since many factors affect the work performance, significant variation in the total transportation time was observed. This makes planning and cost accounting more difficult. The models developed in the study are a promising way to support route planning and optimization, and cost and profitability calculation for trucking en­trepreneurs and the forest industry. The average productivity of log transportation was 2.84 and 3.4 m3·effective h–1 for the dump truck and chassis truck, respectively. The average hauling unit cost was 18 and 15 USD·m–3 in the dump truck and chassis truck, respectively.  

scholarly journals Evaluation of Microsimulation Models for Roadway Segments with Different Functional Classifications in Northern Iran

2021 ◽  
Vol 6 (3) ◽  
pp. 46
Author(s):  
Amir Masoud Rahimi ◽  
Maxim A. Dulebenets ◽  
Arash Mazaheri
Keyword(s):  
Intelligent Transportation Systems ◽  
Network Performance ◽  
Traffic Simulation ◽  
Transportation Networks ◽  
Transportation Network ◽  
Travel Speed ◽  
Transportation Systems ◽  
Mitigation Strategies ◽  
Northern Iran ◽  
Microsimulation Models

Industrialization, urban development, and population growth in the last decades caused a significant increase in congestion of transportation networks across the world. Increasing congestion of transportation networks and limitations of the traditional methods in analyzing and evaluating the congestion mitigation strategies led many transportation professionals to the use of traffic simulation techniques. Nowadays, traffic simulation is heavily used in a variety of applications, including the design of transportation facilities, traffic flow management, and intelligent transportation systems. The literature review, conducted as a part of this study, shows that many different traffic simulation packages with various features have been developed to date. The present study specifically focuses on a comprehensive comparative analysis of the advanced interactive microscopic simulator for urban and non-urban networks (AIMSUN) and SimTraffic microsimulation models, which have been widely used in the literature and practice. The evaluation of microsimulation models is performed for the four roadway sections with different functional classifications, which are located in the northern part of Iran. The SimTraffic and AIMSUN microsimulation models are compared in terms of the major transportation network performance indicators. The results from the conducted analysis indicate that AIMSUN returned smaller errors for the vehicle flow, travel speed, and total travel distance. On the other hand, SimTraffic provided more accurate values of the travel time. Both microsimulation models were able to effectively identify traffic bottlenecks. Findings from this study will be useful for the researchers and practitioners, who heavily rely on microsimulation models in transportation planning.

scholarly journals Productivity and cost analysis of skidding with Timberjack 450C in forest plantations in Shafaroud watershed, Iran

2013 ◽  
Vol 59 (No. 7) ◽  
pp. 261-266 ◽  
Author(s):  
M. Nikooy ◽  
A. Esmailnezhad ◽  
R. Naghdi
Keyword(s):  
Linear Regression ◽  
Production Cost ◽  
Forest Plantations ◽  
Total Production ◽  
Northern Iran ◽  
Time Consumption ◽  
Independent Variables ◽  
Dependent Variables ◽  
Pine Trees ◽  
Load Volume

We present research results of timber skidding by a Timberjack 450C skidder in the path cutting of pine trees in Shafaroud watershed. Time studies were conducted to quantify the productivity and perational cost of skidding by a skidder in a plantation in even terrain conditions in Shafaroud, northern Iran. A linear regression model was applied for finding the relation of dependent variables such as total time consumption and productivity with appropriate independent variables. The most influencing variable for skidding were skidding distance, number of logs in each turn and load volume. The results indicated that the total production with and without delays was 5.17 and <br />5.98 m<sup>3</sup>&middot;effective h<sup>&ndash;1</sup>, while the production cost with and without delays was 13.7 and 11.91 USD&middot;h<sup>&ndash;1</sup>, respectively. &nbsp;

scholarly journals The Challenge of Productivity in the Housing Sector of a Developing Country: The Case of Cameroon

2020 ◽  
Vol 4 (2) ◽  
pp. 24-41
Author(s):  
Minfede Koe Raoul ◽  
Keyword(s):  
Affordable Housing ◽  
Unit Cost ◽  
Malmquist Index ◽  
Housing Unit ◽  
Data Envelopment ◽  
Housing Sector ◽  
Use Of Resources ◽  
Total Productivity ◽  
The Cost ◽  
Local Materials

This paper evaluates productivity in terms of housing delivery levels of the housing sector in Cameroon. The data used is from the Centre for Affordable Housing Finance in Africa (CAHF) and the Ministry of Housing and Urban Development. These data relate to: the number of dwellings delivered during the study period; the amount of hours of work required to produce a housing unit; the unit cost of labour; the cost of producing a housing unit; and the area used to produce a housing unit. The technique of analysis was Data Envelopment Analysis (DEA). The level of productivity is evaluated using the Malmquist index. The results revealed that between 2010 and 2018 the housing sector in Cameroon produced an average of 13,126 houses per year. This production gives an average cost per housing unit of $39,612. The study found a fall in total productivity of factors (labour and capital factors) of the order of 24.5% for the period considered. The fall observed is explained by a decrease in both technical efficiency and technological progress. To increase the productivity of the housing sector in Cameroon two types of measures are possible. Firstly, a better use of resources where particular attention is paid to the factors limiting productivity growth, namely the cost of labour, capital and materials. Secondly, use a skilled workforce and implement incentives for innovation based on the use of local materials and better operational organisation. It is argued that the incorporation of these suggestions would make it possible to increase the productive capacities of housing firms in Cameroon.

Modeling Interstation Travel Speed of Hybrid Bus Rapid Transit within A Bayesian Framework

2019 ◽  
Vol 2 (5) ◽  
Author(s):  
Ji-hua Hu ◽  
Jia-xian Liang
Keyword(s):  
Road Traffic ◽  
Travel Speed ◽  
Bayesian Framework ◽  
Bus Rapid Transit ◽  
Rapid Transit ◽  
Important Indicator ◽  
Main Road ◽  
Traffic Lights ◽  
Speed Distribution ◽  
Hybrid Bus

Interstation travel speed is an important indicator of the running state of hybrid Bus Rapid Transit and passenger experience. Due to the influence of road traffic, traffic lights and other factors, the interstation travel speeds are often some kind of multi-peak and it is difficult to use a single distribution to model them. In this paper, a Gaussian mixture model charactizing the interstation travel speed of hybrid BRT under a Bayesian framework is established. The parameters of the model are inferred using the Reversible-Jump Markov Chain Monte Carlo approach (RJMCMC), including the number of model components and the weight, mean and variance of each component. Then the model is applied to Guangzhou BRT, a kind of hybrid BRT. From the results, it can be observed that the model can very effectively describe the heterogeneous speed data among different inter-stations, and provide richer information usually not available from the traditional models, and the model also produces an excellent fit to each multimodal speed distribution curve of the inter-stations. The causes of different speed distribution can be identified through investigating the Internet map of GBRT, they are big road traffic and long traffic lights respectively, which always contribute to a main road crossing. So, the BRT lane should be elevated through the main road to decrease the complexity of the running state.

Is the Slope Between the Alborz Mountains and Caspian Sea in Northern Iran a Bottleneck for Migrating Raptors?

2018 ◽  
Vol 52 (4) ◽  
pp. 530-533 ◽  
Author(s):  
Michele Panuccio ◽  
Bahareh Ghafouri ◽  
Elham Nourani
Keyword(s):  
Caspian Sea ◽  
Northern Iran
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