This research is to develop a possible process to apply k-means clustering to an efficient vehicle routing process under time varying vehicle moving speeds. Time varying vehicle moving speeds are easy to find in metropolitan area. There is a big difference between the moving time requirements of two specific delivery points. Less delivery times are necessary if a delivery vehicle moves after or before rush hours. Various vehicle moving speeds make the efficient vehicle route search process extremely difficult to find even for near optimum routes due to the changes of required time between delivery points. Delivery area division is designed to simplify this complicated VRPs due to time various vehicle speeds. Certain divided area can be grouped into few adjacent divisions to assume that no vehicle speed change in each division. The vehicle speeds moving between two delivery points within this adjacent division can be assumed to be same. This indicates that it is possible to search optimum routes based upon the distance between two points as regular traveling salesman problems. This makes the complicated search process simple to attack since few local optimum routes can be found and then connects them to make a complete route. A possible method to divide area using k-means clustering is suggested and detailed examples are given with explanations in this paper. It is clear that the results obtained using the suggested process are more reasonable than other methods. The suggested area division process can be used to generate better area division promising improved vehicle route generations.

Large enclosure means a space of high ceiling and large floor. Designing the heating system, many thermal conditions exist, such as thermal comfort, IAQ, heating load and energy efficiency etc. The prediction of the temperature distribution is carried out according to some of the diffuser angle. The simulation conditions are 7 m high diffuser, 4/2 inlet/outlet diffusers, 39 °C discharge air temperature, and 6 m/s exit velocity. The results show that 45° diffuser provides an optimal thermal environment, and the reason is that the temperature is closed to the designed temperature 22 °C at 1.18m elevation plane. As the diffuser angle is decreased, the temperature of the upper region is increased for the thermal buoyancy effect. And the asymmetry of the temperature distribution is increased.

An efficient heuristic for two-vehicle-one-depot problems is developed in this research. Vehicle moving speeds are various along hour based time intervals due to traffic jams of rush hours. Two different heuristics are examined. One is that the delivery area assignment is made using Sweep algorithm for two vehicles by splitting the whole area in half to equally divide all delivery points. The other is using common area by leaving unassigned area between the assigned for two vehicles. The common area is reassigned by two stages to balance the completion time of two vehicle's delivery. The heuristic with common area performed better than the other due to various vehicle moving speeds and traffic jams.

A sweep-based heuristic using common area is developed for multi-vehicle VRPs under time various and unsymmetric forward and backward vehicle moving speed. One depot and 2 delivery vehicle are assumed in this research to make the problem solving strategy simple. A common area is held to make adjustment of possible unbalance of between two vehicle delivery completion times. The 4 time zone heuristic is used to solve for efficient delivery route for each vehicle. The current size of common area needs to be studied for better results, but the suggested problem solving procedures can be expanded for any number of vehicles.

An efficient vehicle routing heuristic for different vehicle moving times for forward and backward between two points is studied in this research. Symmetric distance or moving times are assumed to move back and forth between two points in general, but it is not true in reality. Also, various moving speeds along time zones are considered such as the moving time differences between rush hours or not busy daytimes. To solve this type of extremely complicated combinatorial optimization problems, delivery zones are specified and delivery orders are determined for promising results on the first stage. Then delivery orders in each zone are determined to be connected with other zones for a tentative complete delivery route. Improvement steps are followed to get an effective delivery route for unsymmetric-time-varing vehicle moving speed problems. Performance evaluations are done to show the effectiveness of the suggested heuristic using computer programs specially designed and developed using C++.

A possible heuristic to solve metropolitan area vehicle routing problems with variable vehicle speeds is suggested in this research. Delivery hours are classified into 4 different time zones to make variable vehicle speeds no change within the same time zone to make TDVRP simple to solve. The suggested heuristic consists of 2 stages such as initial solution development step and initial solution improvement step. A computer program using C++ is constructed to evaluate the suggested heuristic. Randomly generated vehicle routing problems are used for the experiments. This heuristic could be helpful to logistics companies by increasing delivery efficiencies since the 4 zone classification is taken from the observed traffic information offered by a local government.

Parcel delivery services are a bit different from general vehicle routing problems since the services require a deliver’s walking time to give the parcel to the customer. This time takes more than 1/4 of total delivery time, but it is ignored for the conv

The restrictions and conditions of parcel delivery services are different from other delivery services. There is WTD in the parcel delivery service. WTDs are various along the types of buildings and delivery points. To make the problem solving method simple and efficient using the WTD, the values are observed and grouped based on the type of buildings in this research. Efficient VRP heuristic design could be possible with introduction of WTD concept as well as the delivery time forecasting.

Vehicle routing problem is one of the traveling salesman problems with various conditions such as vehicle capacity limits, delivery time windows, as well as time dependent speeds in metropolitan area. In this research hourly vehicle moving speeds informat

A typical job sequencing problem is studied in this research to improve productivities in manufacturing companies. The problem consists of two-stage parts and assembly processes. Two parts are provided independently each other and then two sequential asse

This research is to sequence flow shop with two parallel parts production and two assembly machines in sequence. Two different objective functions are studied. One is to minimize total completion time and the other is to minimize the difference of 1 job completion time and total completion time. A heuristic is designed to solve the sequencing problem. Initial solution is developed in the first stage and then the initial solution is improved in the second stage. Experimental 5 job problems are used to evaluate the performance of the suggested heuristic. The optimum solutions obtained by enumeration are used to comparisons. Also 20 job problems are generated for evaluations. 100 randomly generated sequences are evaluated and proved that the distributions are normal. And then presented how good the solutions obtained by suggested method. The initial solution stage is different for the minimization of completion time differences.

This research is about developing an efficient solution procedure for the vehicle routing problem under varying vehicle moving speeds for hour-based time interval. Different moving speeds for every hour is too difficult condition to solve for this type of

This research deals with multiple Gantry-type assembly machines for the optimization of PCB assembly line. The automated assembly machine has 6 nozzles which can linearly move the X axis and the Y axis different from the turret type assembly machine. Each