• Journal of Information Technology Services
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• v.16 no.3
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• pp.103-111
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• 2017

The real time scheduling is a key research area in high performance computing and has been a source of challenging problems. A periodic task is an infinite sequence of task instance where each job of a task comes in a regular period. The RMS (Rate Monotonic Scheduling) algorithm has the advantage of a strong theoretical foundation and holds out the promise of reducing the need for exhaustive testing of the scheduling. Many real-time systems built in the past based their scheduling on the Cyclic Executive Model because it produces predictable schedules which facilitate exhaustive testing. In this work we propose hybrid scheduling method which combines features of both of these scheduling algorithms. The original rate monotonic scheduling algorithm didn't consider the uniform sampling tasks in the real time systems. We have enumerated some issues when the RMS is applied to our hybrid scheduling method. We found the scheduling bound for the hard real-time systems which include the uniform sampling tasks. The suggested hybrid scheduling algorithm turns out to have some advantages from the point of view of the real time system designer, and is particularly useful in the context of large critical systems. Our algorithm can be useful for real time system designer who must guarantee the hard real time tasks.

• Korean Management Science Review
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• v.30 no.1
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• pp.15-24
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• 2013

We consider the single machine scheduling problem with a rate-modifying activity and time-dependent deterioration after the activity. The class of scheduling problems with rate-modifying activities and the class of scheduling problems with time-dependent processing times have been studied independently. However, the integration of these classes is motivated by human operators of tasks who has fatigue while carrying out the operation of a series of tasks. This situation is also applicable to machines that experience performance degradation over time due to mal-position or mal-alignment of jobs, abrasion of tools, and scraps of operations, etc. In this study, the integration of the two classes of scheduling problems is considered. We present a mathematical model to determine job-sequence and a position of a rate-modifying activity for the integration problem. Since the model is difficult to solve as the size of real problem being very large, we propose genetic algorithms. The performance of the algorithms are compared with optimal solutions with various problems.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.4
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• pp.257-265
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• 2009

This paper considers the hybrid flow shop scheduling problem for the objective of minimizing the number of tardy jobs. In hybrid flow shops, each job is processed through multiple production stages in series, each of which has multiple identical parallel machines. The problem is to determine the allocation of jobs to the parallel machines at each stage as well as the sequence of the jobs assigned to each machine. Due to the complexity of the problem, we suggest search heuristics, tabu search and simulated annealing algorithms with a new method to generate neighborhood solutions. In particular, to evaluate and select neighborhood solutions, three surrogate objectives are additionally suggested because not much difference in the number of tardy jobs can be found among the neighborhoods. To test the performances of the surrogate objective based search heuristics, computational experiments were performed on a number of test instances and the results show that the surrogate objective based search heuristics were better than the original ones. Also, they gave the optimal solutions for most small-size test instances.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.5
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• pp.42-52
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• 1997

Computer aided process planning and Offline programming are decisive factors in successful implementation of automated robotic production. However, conventional offline programming procedure has proven ineffective due to time-consuming teaching process for robot programming and due to inefficient system modeling. The paper presents an efficient procedure to semi-automatically generate robot job programs for ship block welding applications. In the research, the teaching positions are automatically determined by predefined rules which are functions of the type and the dimensions of the given welding section of ship block. And a sequence of robot movements and welding conditions such as welding type, welding current, welding speed, and welding torch orientation, are determined by use of Standard Program which is experimentally proved to work well for the welding wection group. Finally, a robot program for the welding section is generated automatically. Based on the algorithm, a offline automatic teaching software is developed. The paper presents also the algorithm and structure of the software.

• Korea journal of population studies
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• v.26 no.2
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• pp.63-90
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• 2003

This study aims to discover patterns of Korean women's life course in terms of their life time sequence of family roles and economic activity. Primary factors for the change and diversity of family-work role sequence are also examined. Data used in this study is the Fourth Survey of Korean Women's Economic Activity which was conducted by Korean Institute of Women Development (KIWD) in 2002. According to the main results, five distinctive patterns of life course are to be disentangled for ever married women: First, doing simultaneously family and work roles with no maternal leave (13.7%); second, reentry into labor market after maternal leave (M type, 18.6%); third, no reentry into labor market after maternal leave (latent M type, 26.9%); fourth, first job entry after child rearing (23.5%); and finally, no work experience (17.3%). The relative composition of the respective life course has changed over marriage cohorts. M type including latent M type became a dominant life pattern among married women since marriage cohorts of 1980 and later. The share of married women who begin to work first after maternal role or have no work experience has declined with recent marriage cohorts. It is also noted that the share of women with simultaneous family and work roles has increased among marital cohorts of 1990 and later. Marriage cohort differences being controlled, life patterns significantly differ by women's educational level, existence of role model of working mother at growth, women's own and husbands' gender role attitude, and family economy. Finally, some policy concerns for gender role division of family and work are raised.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2760-2769
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• 2011

An intelligent autonomous robot generates a plan to achieve a goal. A plan is a sequence of robot actions that accomplish a given mission by being successfully executed. However, in the complex and dynamic real world, a robot may encounter unexpected situations and may not execute its planned actions any more. Therefore, an intelligent autonomous robot must prepare an efficient handling process to cope with these situations to successfully complete a given mission. Plan repair with milestone states is an efficient method to cope with the situation. It retains the advantages of other plan repair procedures. This paper proposes a regressive method of formulating milestone states and a method of assigning weighting values on conditions that compose a milestone state. The task to repair a plan may employ the weighting values as its job priority. The regressive method formulates less complex milestone states and leads to the conditions of a milestone state to take pertinent weighting values for an efficient handling procedure to repair a plan with milestone states.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.496-502
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• 2006

The complexity of IC has rapidly increased as VLSI fabrication technology has grown up quickly. This paper proposes verification methods for data conflicts and protocol between IPs for SoC with coverage metrics. The high-level events is defined to cooperation between blocks or process statement in HDL, or a sequence of performing a job compared to low-level event. They are classified into two categories, resource conflicts and protocol or specification-dependent conflicts. And two coverage metrics used for code coverage in low-level event are proposed to verify the hish-level events. The events of resource conflicts can be detected by using statement coverage metric if global signal or variable has flags in a testbench program, and protocol-dependent events can be checked by data flow metric or path metric.

• Journal of the Korean Society of Food Culture
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• v.14 no.5
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• pp.555-563
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• 1999

This study was executed for 300 mothers bringing up a child below 3 years in the area of Kangnung to assess the current weaning practice of infants. 24.6% of mother surveyed were breast-fed, 57.8% were formula-fed and 17.5% were mixed-fed. The rate of breast feeding was lower and the rate of bottle feeding was higher in infants whose mothers had more income or higher educational period or full-time job. Most of the respondents knew the significance of supplementary food. 41.4% of the subjects started weaning of their infants at 3-4 months, and 84.1% of them set on weaning in less than 7 months after babies were born. And 39.4% of the subjects finished weaning of their infants in less than one year. The infants of this study preferred the fruits and fishes to meats, vegetables and beans that served to them as supplementary food. Mothers showed deep interest in recipe of weaning food(48.5%), adequate quantity of weaning food(36.3%), information on commercial food for infants(32.2%), and sequence in which semi-solid food are introduced(31.9%). From these results, it is suggested that education program in primary health center for improvement of weaning practice of infants should be implemented reflecting needs of mothers.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.2
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• pp.97-106
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• 2013

Since human genome project finished, the cost for human genome analysis has decreased very rapidly. This results in the sharp increase of human genome data to be analyzed. As the need for fast analysis of very large bio data such as human genome increases, non IT researchers such as biologists should be able to execute fast and effectively many kinds of bio applications, which have a variety of characteristics, under HPC environment. To accomplish this purpose, a biologist need to define a sequence of bio applications as workflow easily because generally bio applications should be combined and executed in some order. This bio workflow should be executed in the form of distributed and parallel computing by allocating computing resources efficiently under HPC cluster system. Through this kind of job, we can expect better performance and fast response time of very large bio data analysis. This paper proposes a workflow-based data analysis system specialized for bio applications. Using this system, non-IT scientists and researchers can analyze very large bio data easily under HPC environment.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.4
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• pp.159-167
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• 2015

We consider a wafer lot transfer/release planning problem from semiconductor wafer fabrication facilities to probing facilities with the objective of minimizing the deviation of workload and total tardiness of customers' orders. Due to the complexity of the considered problem, we propose a two-level hierarchical production planning method for the lot transfer problem between two parallel facilities to obtain an executable production plan and schedule. In the higher level, the solution for the reduced mathematical model with Lagrangian relaxation method can be regarded as a coarse good lot transfer/release plan with daily time bucket, and discrete-event simulation is performed to obtain detailed lot processing schedules at the machines with a priority-rule-based scheduling method and the lot transfer/release plan is evaluated in the lower level. To evaluate the performance of the suggested planning method, we provide computational tests on the problems obtained from a set of real data and additional test scenarios in which the several levels of variations are added in the customers' demands. Results of computational tests showed that the proposed lot transfer/planning architecture generates executable plans within acceptable computational time in the real factories and the total tardiness of orders can be reduced more effectively by using more sophisticated lot transfer methods, such as considering the due date and ready times of lots associated the same order with the mathematical formulation. The proposed method may be implemented for the problem of job assignment in back-end process such as the assignment of chips to be tested from assembly facilities to final test facilities. Also, the proposed method can be improved by considering the sequence dependent setup in the probing facilities.