Uji Chi Square adalah Suatu pengujian untuk mengetahui perbandingan antara frekuensi observasi atau faktual dengan frekuensi harapan atau ekspektasi. Frekuensi observasi berasal dari percobaan sedangkan frekusensi harapan berasal dari pemikiran teoritis. Bentuk distribusi Chi-square selalu salam X Kuadrat, oleh karena itu selalu positif.
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Communication and Display Design
Communication and Display Design
Work Posture Analysis
Work Posture Analysis
Anthropometry and Design Product
Anthropometry and Design Product
Biomechanics Study
Biomechanics is the study of the structure and function of biological systems such as humans, animals, plants, organs, and cells by means of the methods of mechanics. Prevent problems that can cause injury to workers, i.e. Musculoskeletal Disorders (MSDs). It could improving organizational performance such efficiency, quality, worker satisfaction, and manual working conditions. We can lost a lot of money if we ignoring ergonomics in our workplace. Probability of accident and errors will be more. The unexpected cost can be told as unseen cost. We have to see direct and indirect cost around the way to get maximum productivity, such labor turnover, product quality, and staff morale. In Biomechanics, there is a term “EASNEP”, that including the human limitation, capability, and function. These are about human system that processed from eyes and ears sensory subsystem input, then taken by nervous to brain as central process. And then muscle and bones will work as effector subsystem to produce physical energy as output. The system is supported by human body subsystem (lungs, Heart, and Circulatory). Biomechanics system can’t be seperated from musculoskeletal. Musculoskeletal is a part of organ system that gives the human an ability to move using muscular and skeletal systems. In sort, Musculoskeletal is an activity system. Musculoskeletal stand from 4 part, there are Bones, Connective Tissue, Joints, and Muscle. Bones are built in solid structure to sustain part of body to move. Connective Tissue is consist of ligaments and tendons. Both bones and connective tissue have same functions to force movement and transmission, support body posture, metabolism, protection, and storage. Joints are interfaces between two bones. And muscle, has force production and skeletal stability. Muscle has 75% compotition of water and 20% of proteins. The rest are carbohydrates, enzimes, fats, etc. In the industries, like factory, there is always a lift activity in work time. As human in general, lift activity is a hard work. It would take an impact on body sctructures. That activity is called Manual Material Handling (MMH). MMH is important in ergonomic principles that particularly focuses back injuries prevention. MMH involves five main activities, there are lifting/lowering, pushing/pulling, twistering, Holding, Carrying. MMH addresses most occupational fatigue and low back pain.
The design and evaluation of manual lifting task are refer to NIOSH (National Institute of Occupational Safety and Health) Revised in United States. NIOSH have standarize the meazuring of establishment if too heavy. There are Load Constant (LC) and Recommended Weight Limit (RWL). Same with its name, Load Constant has constant value, 23. RWL have 6 variables considered in determining the result, there are horizontal distance (H), vertical distance (D), starting height (V), frequency of lifting (F), angle of relation to the body (A), and quality of grasp (C).
RWL = LC x HM x VM x DM x FM x AM x CM
•HM : the “Horizontal Multiplier” factor
•VM : the “Vertical Multiplier” factor
•DM : the “Distance Multiplier” factor
•FM : the “Frequency Multiplier” factor
•AM : the “Asymmetric Multiplier“ factor
•CM : the “Coupling Multiplier” factor
If RWL is lower than actual object weight, it determines that factor contribute to the high risk. It mean the lift must be modified accordingly.
Multiplier Values
Horizontal Multiplier (HM)
|
H = Horizontal Distance (cm) |
HM Factor |
|
25 or less |
1.00 |
|
30 |
0.83 |
|
40 |
0.63 |
|
50 |
0.50 |
| 60 |
0.42 |
Vertical Multiplier (VM)
|
V = Starting Height (cm) |
VM Factor |
|
0 |
0.78 |
|
30 |
0.87 |
|
50 |
0.93 |
|
70 |
0.99 |
|
100 |
0.93 |
|
150 |
0.78 |
|
175 |
0.70 |
|
>175 |
0.00 |
Distance Multiplier (DM)
| D = Lifting Distance (cm) |
DM Factor |
|
25 or less |
1.00 |
|
40 |
0.97 |
|
55 |
0.90 |
|
100 |
0.87 |
|
145 |
0.85 |
|
175 |
0.85 |
|
>175 |
0.00 |
Asymmetric Multiplier (AM)
| A = Angle
(º) |
AM Factor |
|
90° |
0.71 |
|
60° |
0.81 |
|
45° |
0.86 |
|
30° |
0.90 |
|
0° |
1.00 |
Frequency Multiplier (FM)
| F=Time Between Lifts |
FM Factor |
|||
|
Lifting While |
Lifting While |
|||
|
One Hour or Less |
Over One Hour | One Hour or Less |
Over One Hour |
|
|
5 min |
1.00 | 0.85 | 1.00 | 0.85 |
|
1 min |
0.94 | 0.75 | 0.94 |
0.75 |
|
30 sec |
0.91 | 0.65 | 0.91 |
0.65 |
|
15 sec |
0.84 | 0.45 | 0.84 |
0.45 |
|
10 sec |
0.75 | 0.27 | 0.75 |
0.27 |
|
6 sec |
0.45 | 0.13 | 0.45 |
– |
|
5 sec |
0.37 | – | 0.37 |
– |
Coupling Multiplier (CM)
|
C = Grasp |
CM Factor: | |
| Standing |
Stooping |
|
|
Good (handles) |
1.00 |
1.00 |
|
Fair |
1.00 |
0.95 |
|
Poor |
0.90 |
0.90 |
Source :
http://en.wikipedia.org/wiki/Biomechanics
http://en.wikipedia.org/wiki/Manual_handling_of_loads
Slide APK Telkom University
Introduction to Ergonomic
“Fitting a job to a person not fitting a person to the job”
Have you ever heard ergonomic ? Have you realized it ? Maybe we hear a word such fine, well, or fast to meazure the quality of work. Ergonomic mostly used by engineers especially industrial engineers in their workplace. So, what is Ergonomics mean ? Ergonomics comes from Greek, that separated by Ergo and Nomos. Ergo means work and Nomos means Rules. In 1949, an Oxford scientist, K.F.H. Murrel, give a definition of ergonomics, that ergonomics is a discipline that studies human abilities, limitations, and functions, and applies this information in designing consumer products, tools, and equipment. Ergonomics discipline is inspirated by the invantion before. In the 19th century, Frederick Winsow Taylor pioneered the scientifict method, which proposed a way to find the optimum method of carrying out a given task. Taylor found that he could, for example, triple the amount of coal that workers were shoveling by incrementally reducing the size and weight of coal shovels until the fastest shoveling rate was reached. He told us that efficiency would be got by Time and Motion study. Then productivity is the result of well designed tools. In early 1900s, a couple, Frank and Lillian Gilbreth expanded Taylor’s method. They aimed to improve efficiency and eliminating unnecessary steps and actions. By their approach, they reduce the number of motions in bricklaying, to increase productivity. Based on study from 2 scientist, we can conclude that the work systems are close with human factor. Actually, the terms “human factors” and “ergonomics” are essentially synonymous. The expression human factors is a North American term which has been adopted to emphasise the application of the same methods to non work-related situations. A “human factor” is a physical or cognitive property of an individual or social behaviour specific to humans that may influence the functioning of technological systems. Therefore, Human factors and ergonomics is multidisciplinary that incorporating physique, psychology, design, engineering, statictics, and antropometry. A psychologist, Paul Fitts (1912–1965) develop developed a model of human movement, Fitts’s law, based on rapid, aimed movement, which went on to become one of the most highly successful and well studied mathematical models of human motion. He made Human Performance same as function, that may refer to Learning, Individual Differences, Motivation, Environment, and Task. People are the most important resources in industry that take a main role system. People are also prospective customers. In process improvement, a SIPOC is a tool that summarizes the inputs and outputs of one or more processes in table form. The suppliers, inputs, process, outputs, customers (SIPOC) diagram defines the scope of work for a team and identifies at a high level the potential gaps (deficiencies) between what a process expects from its suppliers and what customers expect from the process.
The system must be noticed to a Form Follow Failure. It is clear that difficulties resulting from a particular product design inspire new inventions by prompting people to identify and solve those problems. It would be better if we minimize risk of the produck that used. It would minimize many accident.
Human is the most important thing in industry. A scientist, Mark R. Lehto, tells that Human Centered Design is a design that tell us about the focus is on design for people. Designing workplaces, tools, workstations, equipment people use in the manufacturing and service industries, as well as the products from these industries for use by people. As a good engineer we have to make our work be efficiency. In 1990, a scientist, Grandjean, said that “Fitting the Task to the Human”. By then, it would better work result. Performance Criteria are evaluative statements, which specify what is to be assessed and the required level of performance. They detailing the activities, skills, knowledge and understanding that provide evidence of competent performance of each element. Criteria of performance including speed/time/delivery time. Faster work process are better and more efficient. After that, Accuracy is needed. It makes zero error. If we have idel situation, it may called “Trade Off” that indicate speed equals accuracy. But we have to remember that slower performance slower performance speeds improve accuracy and faster speeds cause errors. Those are related situation that can be found around us. Besaide them, we have to aware to our health and safety when we were worked. It would be affected to ease when jobs are easily performed, endurance improves and fewer rest breaks are needed. Amount of learning required, and rate of learning must be upgraded. High quality of service and better morale will improve customer sastisfaction inline with economic criteria. Ergonomics can be changed depend on the development of era. To stabilize it there are many professional organizations such HFES (Human Factor Engineering Society), NIOSH (National Institute of Occupational Safety and Healthy), OSHA (Occupational Safety and Health Agency), Ergonomics Society and many more.
Source :
http://asq.org/service/body-of-knowledge/tools-sipoc
http://en.wikipedia.org/wiki/Paul_Fitts
Slide Kuliah APK Telkom University
Industrial Engineering
“There is no the best way but there is always a better way”
This is the short quote that tell us about the system, that explain us about unperfect way to get it. It can be determined as our daily activities. For example, when we study at school, work in office, or repair something in garage. Firstly we should think about the purpose of our activity. Then think how to reach it. Usually, people do just a rational steps. They see the real situation, simple, and fast steps. Are they physique and psychologycal capable to work on? Or otherwise? So, what else that can be a limitation?
Before we explore further, let’s we analyze them. Engineering is a practical application of theory to solve problems everywhere around us. Engineering is extremely broad and encompasses a range of of more specialized fields. Someone who do an engineering called engineer.
Engineering has many disiplines to specialize the type of practical application. One of them is Industrial Engineering. What is Industrial Engineering? Industrial Engineering is a branch of engineering with concerned about development, improvement, implementation, evaluation of integrated system from people, money, knowledge, information, equipment, material and process. Industrial engineers make their work more efficient and effective. They make the product more manufacturable, consistent in quality and increase them. They have to elliminate wastes time, money and many resource in their work. Industrial engineers are commonly known as management engineers or even health system engineers.
source :
http://en.wikipedia.org/wiki/Engineering
http://www.newworldencyclopedia.org/entry/Industrial_engineering
telkom3603 by Muchamad Reza Ali Akbar 