Many companies rely on old fashion design approaches and methods for achieving ease-of-use. With this paper, describing the most contemporary design methods used in the industry, we will try to create awareness by explaining, grouping them listing their k

The State Of Art Design Methods study on Ease-Of-Use Abstract Many companies rely on old fashion design approaches and methods for achieving ease-of-use. With this paper, describing the most contemporary design methods used in the industry, we will try to create awareness by explaining, grouping them listing their key principles and showing them in use in an industrial case study. The outcome of the case study gives ideas at which stage of designing, which design methods are preferred and how they facilitate the process. Keywords ease-of-use, usability, design methods, user-centered-design, informal and structured design methods . Introduction During the last decade ease-of-use became a major part of any system or product development. Fred Davis defines it as "the degree to which a person believes that using a particular system will be free of effort" (F.Davis, 1996). There are many researches suggesting different design methods for achieving better ease-of-use/usability. According to Steve Krug there are no bad usability techniques, there are only wrongly chosen ones (S. Krug, 2005). In Nokia, expert evaluation and remote online evaluation are the evaluation methods for identifying the best concept from usability point of view (V. Roto, H. Rantavuo, and K. Vaananen-Vainio-Mattila, 2009). IBM is relying on User Centered Design (UCD) approach to achieve it:

  • Word count: 2212
  • Level: University Degree
  • Subject: Engineering
Access this essay

The goal of this lab is to understand the dynamic parameters behind a second order oscillatory system. We will see how different inertias, spring coefficients and damping coefficients will affect the natural frequency and damping ratio of the system

Ensc 383 Engineering Science 383 - Control Systems Engineering 2nd order Feedback System Design Introduction The goal of this lab is to understand the dynamic parameters behind a second order oscillatory system. We will see how different inertias, spring coefficients and damping coefficients will affect the natural frequency and damping ratio of the system's response. This lab will help us in verifying mathematical relationships developed using the data gathered from the ECP Torsional Dynamic System (Model 205a). 2 Determining the Dynamic Parameters of the Dynamic System Objective of this exercise is to obtain the dynamic parameters that characterize the torsional dynamic system. Dynamic parameters desired include inertias, spring coefficients, and damping coefficients. This can be done by modeling the damped oscillatory movements of the torsional dynamic system into a 'lightly damped second order system', in which we can easily find those parameters. 2.1 Mathematical Analysis Knowing the transfer function of a system tells much about its behavior. It is given that the torsional system can be modeled as a lightly damped second order system with the following equation: Eq. 2.1-1 From the Laplace transform of this equation: Eq. 2.1-2 Thus we define the transfer function of the system as: Eq. 2.1-3 Note that the general second order transfer function of a system

  • Word count: 3040
  • Level: University Degree
  • Subject: Engineering
Access this essay

The purpose of this study is to obtain a mathematical model for the door closer such that its observations of its behaviour and analysis holds true for the real door closer.

Assignment : 1 Study of a Door Closer via Modelling and Simulation Submitted to Prof. Girja Sharan and Mr. Bhavesh Dharmani For the partial requirement of the course of System modelling and Simulation By Hiren V. Patel (RN 12) Study of a Common Door Closer Purpose of the Study: The purpose of this study is to obtain a mathematical model for the door closer such that its observations of its behaviour and analysis holds true for the real door closer. Developing mathematical model and solving them is more convenient rather than testing actual systems, we model the system using mathematical equations and then analyse its behaviour. Door closers are used on doors to pull the door and shut slowly enough to avoid slamming, which could cause damage to the door itself. The main elements of door closer are a spring and a damper. A mathematical model of the door closer will be derived and its behaviour will be analysed. Observation: . The door is initially at rest. It is at an angle of 0 degree. 2. The door rotates around the hinge when someone pushes the door. When the door is left at an angle less than 90 degrees, the door returns to rest position. 3. The movement is limited to 90 degrees from rest. At this position the door is completely open 4. If the door is pulled to an angle and then released, it will try to reach its rest position at an angle of 0 degree

  • Word count: 987
  • Level: University Degree
  • Subject: Engineering
Access this essay

Members of the design team and their job roles in a construction project.

DESIGN PROCEDURES IN CONSTRUCTION MEMBERS OF THE DESIGN TEAM & ORGANISATIONAL & CONTROL PROCEDURES ASSIGNMENT 1 P1: Identify and explain the roles and responsibilities of members of the design team. Members of the design team: * The client * The Architect * The Structural engineer * The Quantity surveyor * The Building services engineer * The Building surveyor * The Interior designer The Client: In the design team, the client has the need for a building so he/she employs an architect and tells them what kind of a building they want. The architect, who in most cases is the lead designer, designs the kind of building that meets the client needs and interacts with the client throughout the project so that the building stays within the clients requirements and specifications. The Architect: The architect in most cases is the lead designer and is responsible for designing and maintaining the structure of the building and ensuring that it will all meet the clients' requirements. During the whole design and building process of the project the architect is in constant communication with the client so that the design of the building and the project budget does not exceed the clients' constraints. The Architect also communicates with the Quantity surveyor and the Structural engineer along with the landscape architect. The architect is frequently the evangelist for new

  • Word count: 2258
  • Level: University Degree
  • Subject: Engineering
Access this essay

Analysis of bottom brackets

Bottom Bracket for Mountain Bikes Introduction Mountain bikes are the focus of this assignment. Mountain biking is a sport which is performed usually over rough terrain on off-road surfaces. Mountain bikes are different from road bikes in that they are adapted to perform in conditions where the bike has to have increased durability and enhanced performance. The frame is generally smaller and tougher than other bicycle frames to cope with the extra stresses that result from the conditions the bike is put through. Some of these conditions are; landing from a height, hard turning in corners, impact with heavy objects (tree stumps, rocks, boulders, ramps etc.) and in general that the bike is put through these at high speeds. Improvements to the design of the mountain bike in include bigger tires, smaller and stronger frame, wider handlebars, the usage of disc brakes and most importantly for us, a strong rigid bottom bracket system. The bottom bracket requirements are related to the strength in the frame and are the base where the forces from riding are exerted. The bottom bracket holds the crank in place which in turn holds the pedals on which the rider displaces their weight. It provides a rigid base for the rider to stand in as safe and comfortable manner as possible. If the bottom bracket should fail while riding is taking place then the rider will certainly have an

  • Word count: 2538
  • Level: University Degree
  • Subject: Engineering
Access this essay

In this essay, the chemical structure of two polymers, polyethylene (PE) and polystyrene (PS) will be discussed. With this information and a previously conducted experiment, a range of stress strain curves will be created

STRESS-STRAIN ANALYSIS Abstract: In this essay, the chemical structure of two polymers, polyethylene (PE) and polystyrene (PS) will be discussed. With this information and a previously conducted experiment, a range of stress strain curves will be created; from which analysis of the different aspects of each polymer shall be discussed. Aim: The aim of this experiment is to compare the effects of tensile load testing of polyethylene and polystyrene; with the usage of stress-strain analysis. Background Theory: In order to test these polymers it is first essential to have an understanding about the materials that will be used, including their chemical structures. Polyethylene (PE): This is the simplest hydrocarbon polymer [PPE]. This is commonly shown as: Where represents a monomer, and are the repeat units used to make the chain for polyethylene. The subscript shows the number of repeats from the repeat units. Polyethylene is a thermoplastic polymer. Some of the major characteristics of polyethylene are its electrically insulating, tough, low strength and poor resistance to effects of weathering [Callister]. As one of these properties is tough, this means that polyethylene can undergo a lot of plastic deformation before reaching the breaking stress. Polystyrene (PS): This polymer is made from chains of styrene monomers (left). The heptagonal element bonded to

  • Word count: 1940
  • Level: University Degree
  • Subject: Engineering
Access this essay

Stress-Strain analysis of PE and PS. In this essay, the chemical structure of polyethylene (PE) and polystyrene (PS) will be explained in detail. The polymers will be stretched till they fracture under lab conditions and the result will be analysed.

STRESS-STRAIN ANALYSIS Abstract: In this essay, the chemical structure of polyethylene (PE) and polystyrene (PS) will be explained in detail. The polymers will be stretched till they fracture under lab conditions and the result will be analysed. Aims: The aim of this report is to analyse the stress-strain graphs and deduce the mechanical properties of thin and thick polyethylene and polystyrene samples from the data provided. Background: Polymers are organic compounds that are made up of smaller repeating molecules known as monomers. These molecules are held together by intermolecular forces. The atoms within a polymer molecule are held together by covalent bonds. Polymers are usually made up of long molecular chains with irregular and entangled coils. The physical properties depend upon the length of the chain of molecules. Polymers are viscoelastic materials since they include characteristics of both elastic materials and viscous materials [Callister]. Polyethylene: Polyethylene is formed when the ethylene gas is reacted under the appropriate conditions [Callister]. This process begins when a reaction takes place between the initiator or catalyst species and the ethylene monomer. This sequential addition of monomers units to the actively growing chain molecule gives a rise to a polymer chain. After the addition of many ethylene monomer units, the final result

  • Word count: 2205
  • Level: University Degree
  • Subject: Engineering
Access this essay

Heat and mass. Heat Conduction in Cylinders and Spheres

Heat Conduction in Cylinders and Spheres 3-64C When the diameter of cylinder is very small compared to its length, it can be treated as an indefinitely long cylinder. Cylindrical rods can also be treated as being infinitely long when dealing with heat transfer at locations far from the top or bottom surfaces. However, it is not proper to use this model when finding temperatures near the bottom and the top of the cylinder. 3-65C Heat transfer in this short cylinder is one-dimensional since there will be no heat transfer in the axial and tangential directions. 3-66C No. In steady-operation the temperature of a solid cylinder or sphere does not change in radial direction (unless there is heat generation). 3-67 A spherical container filled with iced water is subjected to convection and radiation heat transfer at its outer surface. The rate of heat transfer and the amount of ice that melts per day are to be determined. Assumptions 1 Heat transfer is steady since the specified thermal conditions at the boundaries do not change with time. 2 Heat transfer is one-dimensional since there is thermal symmetry about the midpoint. 3 Thermal conductivity is constant. Properties The thermal conductivity of steel is given to be k = 15 W/m?°C. The heat of fusion of water at 1 atm is . The outer surface of the tank is black and thus its emissivity is = 1. Analysis (a) The inner and

  • Word count: 3915
  • Level: University Degree
  • Subject: Engineering
Access this essay

Fluid mechanics. The aims for the calibration of a sharp Crested Weir where to show the difference between Q theoretical, supposed theoretical discharge over the Weir and Q actual (Qa) the actual discharges of water over the Weir.

Calibration of a Sharp Crested Weir Discharge Qa falls the difference between the theoretical discharge Qt become the greater as a flow of water become slower. This due to the height of the head falling the distance between Qt and Qa basically remains as a constant as the Cd coefficient of discharge drops. . Introduction/aims The aims for the calibration of a sharp Crested Weir where to show the difference between Q theoretical, supposed theoretical discharge over the Weir and Q actual (Qa) the actual discharges of water over the Weir. 2. Method Water pumped into the channel behind the Weir, The Vernier scale was set to zero. When water level just did not flow over the edge of the Weir (U Notch Weir). The pump and Valve where then switched on so that there was a constant flow of water over the Weir. The water was left to obtain a constant and settled flow. The drain plug was then inserted to allow the flow of water to collecting in the tank in order for measurement (L) to be taken. At the level of 20 litres the value of (H) was taken and the discharge for the 20 litres was timed by 2 students T1(Second) and T2(Second), Then the Mean time was recorded as Tmean (Second) . The same procedure was repeated with different volumes of water (20L, 10L, 5L) at each time the high of head (H) of water over the Weir, T1(Second) and T2(Second) as Tmean recorded. 3. Results See

  • Word count: 1396
  • Level: University Degree
  • Subject: Engineering
Access this essay

The overall objective of this laboratory experiment is to investigate the effects of proportional, derivative and integral control on system performance, in particular transient response (overshoot, speed of response) and steady state error.

Introduction The overall objective of this laboratory experiment is to investigate the effects of proportional, derivative and integral control on system performance, in particular transient response (overshoot, speed of response) and steady state error. In this lab we study the effect of adding proportional, derivative, and integral action on the control feedback systems. Propotional-plus-integral (PI) controllers are ideal integral compensators that are used to improve the steady-state error of systems. Propotional-plus-derivative (PD) controllers are ideal derivative compensators that are used to improve the transient response of systems. Propotional-plusintegral-plus-derivative (PID) controllers combine the benefits of PI and PD controllers and are used to improve the steady-state error and the transient response of systems independently. By introducing each compensator at a time we can clearly see the effects they have on the output and characteristics of the system (such as percent overshoot and steady state error). One advantage of adding compensators is that they won't effect the power output requirements of the system. A possible disadvantage of compensating a system is that the system order can increase (as we will se in section 4 of this report), with a subsequent effect on the desired response. Part 1- Determine Hardware Gain The hardware gain khw is a the

  • Word count: 3411
  • Level: University Degree
  • Subject: Engineering
Access this essay