Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Korean Institute of Industrial Engineers
Journal Basic Information
Journal DOI :
Korean Institute of Industrial Engineers
Editor in Chief :
Volume & Issues
Volume 24, Issue 4 - Dec 1998
Volume 24, Issue 3 - Sep 1998
Volume 24, Issue 2 - Jun 1998
Volume 24, Issue 1 - Mar 1998
Selecting the target year
Workload Evaluation of Squatting Work Postures
Lee, In-Seok ; Chung, Min-Keun ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 167~173
Many workers like welders work in squatting postures with the object on the ground during an entire work shift. It is suspected that such prolonged squatting without any supporting stool would gradually cause musculoskeletal injuries to workers. This study is to examine the physical stress caused by the prolonged squatting and to recommend a safe work/rest schedule for a welding task with squatting posture based on the lab experiments. In this study, 8 healthy student subjects participated in the experiment. They maintained a squatting work posture for 16 minutes with 4 different stool height conditions: no stool; 10cm height; 15cm height; and 20cm height. Every 2 minutes, the discomfort was subjectively assessed with the magnitude estimation method for the whole body, lower back, upper leg and lower leg. Based on discomfort ratings, we found that a 10cm height stool relieved the workload most. Discomfort rating results also indicated that a 20cm height stool showed the highest workload, and the there were no difference in workload between a 15cm height stool and no stool. We recommend to use low height stools and to maintain such working postures no longer than 6 minutes for prolonged squatting tasks.
The Minimization of Tolerance Cost and Quality Loss Cost by the Statistical Tolerance Allocation Method
Kim, Sunn-Ho ; Kwon, Yong-Sung ; Lee, Byong-Ki ; Kang, Kyung-Sik ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 175~183
When a product is designed, tolerances must be given to the product so that required functions are guaranteed and production costs are minimized. In this research, a model is suggested which allocates tolerances to components optimally according to the STA(Statistical Tolerance Allocation) method. Taking into account the concept that dimensional errors have characteristics of statistical distributions, this model presents the discrete pseudo-boolean approach for the tolerance optimization by minimizing the tolerance cost and the quality loss cost. In this approach, two methods are proposed for the reduction of the problem scale; 1) a method for converting the minimization model for casts into the maximization model for cost savings, and 2) procedures to reduce the number of constraints and variables.
A Heuristic Approach Solving for the Complex Design with Precedence Constraints in Concurrent Engineering
Cho, Moon-Soo ; Kim, Chang-Yeong ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 185~197
Engineering design involves the specification of many variables that define a product, how it is made, and how it behaves. Before some variables can be determined, other variables must first be known or assumed. This fact implies a precedence order of the variables, and of the tasks of determining these variable consequently. Moreover, design of complex systems may involve a large number of design activities. In this paper, the activity-activity incidence matrix is considered as a representation of design activity analysis which mainly focuses on the precedence constraint. In order to analyze the activity-activity incidence matrix, a heuristic algorithm is proposed, which transforms an activity-activity, parameter-formula, and parameter-parameter incidence matrix into a lower triangular form. The analysis of the structured matrices can not only significantly reduce the overall project complexity by reorganizing few critical tasks in practice, but also aims at obtaining shorter times considering the solution structure by exploring concurrency.
A Study of the Time Prediction with Hand Control in Vehicle
Yu, Seung-Dong ; Park, Peom ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 199~209
Consumers turn away their face from a vehicle that doesn't satisfy their sensibility and is designed without consideration of driver's performance. In terms of driver's performance, the manual motor processor carries out the primary interactions between driver and vehicle. Therefore, in this paper, time prediction model is studied that is an important part when drivers manipulate the manual control during driving. Experiments were executed for 20 subjects using two kinds of vehicles and regressed to Fitts' Law. The noise filtering method was suggested for the performance times of manipulating the manual control. Especially, it was shown that Fitts' Law derived by an approximation of Shannon's theorem can predict drivers performance time more appropriately than other methods.
Economic Evaluation of Measurement System by Principal Component Analysis
Kang, Chung-Oh ; Byun, Jai-Hyun ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 211~221
It is very important to have a satisfactory measurement system, since it is useless to try to improve the manufacturing process without an adequate measurement system. Therefore, evaluation of the measurement system is the first step for the quality improvement of the manufacturing process. To estimate the measurement error we must conduct a controlled gage repeatability and reproducibility(gage R&R) study. Many manufacturers use a gage or instrument to measure multiple dimensions for the overall quality of the manufactured parts. In this case, it is necessary to estimate the gage R&R for multiple dimensions. When a gage measures a large number of dimensions of a part, it is very time-consuming and costly to measure all the dimensions. In this paper we propose the use of the principal component analysis method to identify a few principal components out of the original multivariate measurement capability to explain most of the measurement system variation pattern.
The Robust Pattern Recognition System for Flexible Manufacture Automation
Wi, Young-Ryang ; Kim, Mun-Hwa ; Jang, Dong-Sik ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 223~240
The purpose of this paper is to develop the pattern recognition system with a 'Robust' concept to be applicable to flexible manufacture automation in practice. The 'Robust' concept has four meanings as follows. First, pattern recognition is performed invariantly in case the object to be recognized is translated, scaled, and rotated. Second, it must have strong resistance against noise. Third, the completely learned system is adjusted flexibly regardless of new objects being added. Finally, it has to recognize objects fast. To develop the proposed system, contouring, spectral analysis and Fuzzy ART neural network are used in this study. Contouring and spectral analysis are used in preprocessing stage, and Fuzzy ART is used in object classification stage. Fuzzy ART is an unsupervised neural network for solving the stability-plasticity dilemma.
An optimal link capacity problem of on-line service telecommunication networks
Kim, Byung-Moo ; Lee, Young-Ho ; Kim, Young-Hui ; Kim, Yu-Hwan ; Park, Seok-Ji ; Kim, Joo-Sung ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 241~249
In this paper, we seek to find an optimal allocation of link capacity in a data communication network. The architecture of the data communication network considered in the study is an online-service network based on public switched telephone network(PSTN) and packet switched data network(PSDN). In designing the architecture of the network, we need to deal with various measures of quality of service(QoS). Two important service measures are the call blocking probability in PSTN and the data transfer delay time in PSDN. Considering the tradeoff between the call blocking probability and the data transfer delay time in the network, we have developed the optimal link capacity allocation model that minimizes the total link cost, while guarantees the call blocking probability and the data transfer delay time within an acceptable level of QoS. This problem can be formulated as a non-linear integer programming model. We have solved the problem with tabu search and simulated annealing methods. In addition, we have analyzed the sensitivity of the model and provided the insight of the model along with computational results.
Simulated Annealing Neural Network Model for Sequencing in a Mixed Model Assembly Line
Kim, Man-Soo ; Kim, Dong-Mook ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 251~260
This paper deals with a simulated annealing neural network model for determining sequences of models inputted into a mixed model assembly line. We first present a energy function fitting to our problem, next determine the value of the parameters of the energy function using convergence ratio and the number of searched feasible solution. Finally we compare our model NMS with the modified Thomopoulos model. The result of the comparison shows that NMS and Thomopoulos offer a similar output in the problems having good smoothness.
Analysis of Muscular Characteristics of Lower Extremity Movement for Seated Operators by EMG
Hwang, Kyu-Sung ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 261~278
The paper represented the lower extremity muscle model as four rigid-body segments: trunk, shank, and foot. We transformed their tibial data into our shank data by rotating their tibial X and Y axes by 5.483 degrees, so the revised coordinate data used to translating the origin of their tibial reference frame to our shank reference frame. According to weight of subject, physiological cross-setional area(PCSA) of each lower extremity muscle was calculated by scaling those data by Brand. The objectives of this paper are to investigate the variations of the recruitment patterns of the lower extremity muscles, and to analyze the changes of the role assigned to each muscle during the seated foot operation. For exertion levels, the transition point of type F motor unit of each muscle is inferred by analyzing the electromyogram at the seated postures. Also, for predetermined seated foot operations exertion levels, the recruitment pattern and the changes of the role assigned are identified in the continuous exertion, by analyzing the electromyogram changes due to the accumulated muscle fatigue. This study can be used to design and to assess the pedals and foot-related equipments design.
Design of Complete Inspection Procedures Using the Performance and Screening Variables
Hong, Sung-Hoon ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 279~285
A quality inspection procedure interchangeably using the performance and screening variables is proposed. At the start of the inspection, the performance variable is measured for all items. As soon as i consecutive items are found to be free of defects, the screening variable is measured instead of the performance variable. If an item is rejected, the inspection based on the performance variable is resumed. All nonconforming items found in the inspection are either reworked or replaced with conforming items. It is assumed that the performance variable is dichotomous, and the screening variable given the performance variable is normally distributed with known mean and variance. The average outgoing quality (AOQ) expression is derived, and the methods of finding the inspection procedure with a specified average outgoing quality limit (AOQL) are presented.
A Desirability Function Approach to the Robust Design for Multiple Quality Characteristics
Byun, Jai-Hyun ; Kim, Kwang-Jae ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 287~296
We often have multiple quality characteristics to develop, improve and optimize industrial processes and products. It is not easy to find optimal control factor setting when there are multiple quality characteristics, since there will be conflict among the selected levels of the control factors for each individual quality characteristic. In this paper we propose a desirability function approach and devise a scheme which gives a systematic way of solving multiple quality characteristic problems. A numerical example is provided.
Parameterization of Dynamic Electromyographic Signal for Diagnosing L4/L5 Disc Patients
Hyun, Soo-Don ; Kim, Jung-Yong ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 297~309
Numerical parameters have been developed to diagnose L4/L5 disc patients during repetitive flexions and extensions. Electromyography(EMG) has been used to define the muscle excitation and movement cycle in this study. Twenty healthy subjects and twenty L4/L5 disc patients were recruited for the experiment. The subjective pain levels of patients were recorded as
according to visual analogue scale where 10 was the maximum pain level. Variance ratio of motion cycle was suggested as a new parameter to examine the consistency of the trunk movement. The results indicated that the temporal EMG pattern such as peak time difference between Quadriceps and Hamstrings, the duration of coexcitation between Erector spinae and Rectus abdominis muscle pairs showed a statistically significant difference between healthy subjects and patients. Variance ratio of External oblique and Internal oblique also showed a statistically significant difference. It is expected that those results could be used for diagnosis by building a database for various back pain patients and healthy subjects. This method can eventually help physicians for early diagnosis and prevention of low back disorders.
A Study on the Generation of Modular BOM and Efficient Database Construction using Value Clustering Method
Ji, Young-Gu ; Kim, Jong-Han ; Shin, Ki-Tae ; Park, Jin-Woo ;
Journal of Korean Institute of Industrial Engineers, volume 24, issue 2, 1998, Pages 311~322
Modular BOMs are typically used in TWO-Level Master Production Schedule. To solve the problems of Modular BOM generation and efficient DB construction, we proposed Value Clustering Method. Based upon Where-Used matrix of products and components, VCM is the method to find out module by generating product family group value, product value, and component value. We also proposed method to find out information about Modules, algorithms to find out Modules that show Alternative Usage Pattern, and method to find out Modules used in a given product. We also compared the DB creation method by Value Clustering Method and by conventional method. We compared the size of DB in both methods. We mathematically proved that the proposed method is doing better as the size and complexity of product family gets larger and more complicated.