• IE interfaces
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• v.9 no.2
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• pp.75-82
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• 1996

A scheduling system is developed for a parallel machine flow shop which reflects the situations of the manufacturing processes in the tire industry. The schedule is generated via simulation using heuristic rules to get satisfaction on such constraints as due dates, demands, work-in-process, process capacity, set-up times and scheduling speed. This system, constructed with relational DB, SQL and C language, consumes less than 10 minutes of PC simulation to handle real size problems.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1132-1135
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• 2004

Recently. our construction industry is using 4D-CAD system but the public Database (DB) for the 4D-CAD system is insufficiently built. It is difficult to connect 4D-CAD system information such as schedule, drawings. Therefore this study suggest a methodology to link the 4D-CAD system information with work breakdown structure(WBS) and the methodology suggested in this study was applied to a 4D-CAD system

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.4
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• pp.344-350
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• 2001

In this paper, we are focused on the analysis of acyclic schedule for the determination of the opti-mal cycle time and minimization of work in process. Especially, this paper deals with the product ratio-driven cyclic scheduling problem in FMS with different products and ratio using the TPN(Time Petri Nets)un-folding.

• ETRI Journal
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• v.9 no.3
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• pp.139-156
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• 1987

The problems in software cost management are well known. Cost estimates are too low. Software development projects frequently have cost overruns, which are due to poor estimates. A fair amount of work have been done toward developing cost estimation models. These models vary in their outputs (e. g., total cost, manning schedule) and in the factors used to calculate their estimates. They also vary with regard to the type of formula, parameters, use of previous data, and staffing considerations. This paper will distinguish them by the type of formula they use to calculate total effort and staffing level, and will discuss enough models to demonstrate the characteristics of each model category.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.463-465
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• 2003

This paper adopts the methods of dynamic programming based on priority and the objective function is to maximize the amount of priority. The Purpose of this work is to schedule the direct load control with approciate constrints. To demonstrate the effectiveness of the study, sample data is used about 54 load. And the results of sample are described in this.

• The Journal of Information Systems
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• v.29 no.3
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• pp.179-195
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• 2020

Purpose & Design/methodology/approach Amidst the COVID-19 spread, interest in telework has been increasing as a way to respond to environmental changes and improve organizational performance. In this study, causal loop diagram, thinking process, and four principles of TRIZ were used to find various ways to achieve work-life balance for workers and firms in teleworking environment. Findings The result of the causal loop diagram shows that keeping work-life balance is needed to provide free extra time for workers and achieve the firm's performance through efficient coordination between departments in teleworking environment. Using thinking process of TOC, we proposed a evaporating cloud for work-life balance and reviewed assumptions and premises to maintain extra free time for workers and achieve firm's performance paradoxically, and suggested solutions through the breakdown of the assumptions and premises. Resolving the contradiction(RC) by spatial separation is to divide working spaces into home, smart center, and mobile work types, to find both ways to achieve the organizational performance, and to provide extra time for workers. RC by temporal separation is to divide working time into various unit time, and to find ways to achieve organizational performance through doing work at office or home periodically or shiftly according to a predetermined schedule and time setting. RC by situational separation is to give options of flexible methods of performing work according to the conditions of the company or the worker. RC by separation between part and a whole is to find ways to organize and do the work so that the entire work can be completed efficiently even if each work is performed separately in teleworking way. This study is meaningful in that it provides basic thinking framework for achieving work-life balance in teleworking environment and proposes ways to resolve conflict from various perspectives, but it is limited in that it has not been tested empirically.

• Korean Journal of Construction Engineering and Management
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• v.8 no.5
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• pp.80-91
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• 2007

Crack in Pavements have been continually increased a by water penetration Therefore, the cracks can result in deterioration of the pavements that could be extremely dangerous fro road users. Creak sealing work performed in outdoor is very dangerous, costly and labor intensive. To slove these problems, automated crack sealing systems have been developed. it Would be needed that work information related to crack sealing must be gathered in an effort to used for existing or future crack sealing work. Furthermore, work information related to crack sealing could be utilized in analyzing work productivity and condition. The primary objective of this study is to propose a PDA and Web-based system for work information management of crack sealing which enables to effectively interchange work information between head office and fields, and to accurately collect work information. Finally, it is anticipated that the effective use of the developed PDA and web-based system would be able to effectively share work Information, measure productivity, estimate costs as well as plan future work schedule.

• Journal of Korean Academy of Nursing
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• v.48 no.5
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• pp.622-635
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• 2018

Purpose: This study aimed to develop and test a structural model for sleep quality in female shift work nurses. The hypothetical model was constructed on the basis of Spielman's 3P model of insomnia and previous research related to the sleep quality of shift nurses. Methods: This cross-sectional study used structural equation modeling and recruited 285 female shift work nurses from four general and university hospitals with over 300 beds located in C and J cities in Gyeongsangnamdo. Data were collected from September 27 to October 20, 2016, and then analyzed using descriptive statistics, Pearson's correlation, and structural equation modeling. The study used SPSS/Win 18.0 and AMOS 18.0 in processing the data. Results: The final model showed good fit to the empirical data: ${\chi}^2/df=2.19$, SRMR=.07, RMSEA=.07, AGFI=.85, TLI=.91, GFI=.93, GFI=.89, NFI=.87. The factors that influenced sleep quality were sleep hygiene (${\beta}=.32$), perceived shift work status (${\beta}=-.16$), stress response (${\beta}=.16$), shift work experience (${\beta}=.15$), perceived health status (${\beta}=-.14)$, and circadian rhythm (${\beta}=-.13$) explaining 36.0% of the variance. Conclusion: The model of sleep quality of the shift work nurses constructed in this study is recommended as a model to understand and predict the sleep quality of shift work nurses. The results suggest that strategies for improving the sleep quality of shift work nurses should focus on sleep hygiene, perceived health status, stress response, circadian rhythm, perceived shift work status, and shift work experience.

• Journal of the Korean Society of Safety
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• v.23 no.5
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• pp.119-124
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• 2008

Many automobile assembly workers often do several cycles of tasks continuously, i.e., without breaks, to get a longer break. This is not recommended since the dose of fatigue increases exponetially with time and it takes much longer time to recover. In this study, a laboratory experiment was conducted to investigate the effect of work/rest schedules on workload of a repetitive upper-limb task. Eleven male subjects participated in the experiment, in which simulated screw driving tasks were carried out repetitively with 3 different work/rest schedules: standard breaks(1 cycle of work at a time, 60 20-s breaks), medium breaks(5 cycles of work at a time, 12 100-s breaks), and long breaks(10 cycles of work at a time, 6 200-s breaks). The result showed that medium- and long-breaks schedules significantly increased the level of perceived discomfort and %HRR as compared to the standard-break schedule. The subjects' preference was not statistically different among work/rest schedules, which might be caused from the absolutely low level of workload of the experimental tasks. From the results, it is recommended to have frequent and shorter breaks rather than infrequent and longer breaks to decrease the level of physical workload. A more expanded studies, however, should be carried out to provide more practical safety guidelines on the work practice of continuous working without breaks among automobile assembly workers.

• Journal of Korean Clinical Nursing Research
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• v.24 no.2
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• pp.170-177
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• 2018

Purpose: The aim of this study was to examine effectiveness of 12-hour shifts for nurses compared to 8-hour shifts for the variables: Work-Life Balance, fatigue and work errors. Methods: In 2014, an opportunity to choose a 12-hour shift duty was given to a group of 8-hour shift nurses. In 2016, two years after this change, this study was done to compare the two groups. Data were collected using questionnaires. Data were sampled by a matching method with propensity score matching (PSM). The participants were 128 nurses: 64 nurses on 12-hour shifts and 64 nurses on 8-hour shifts. The comparison was analyzed using $x^2$ test, t-test. Results: The nurses on 12-hour shifts showed higher scores for Work-Life Balance (3.37) than the groups on 8-hour shifts (2.99)(p=.018) whereas were no statistical differences between the groups for fatigue (p=.132) or work errors (p=.703). Conclusion: The Work-Life Balance scores for nurses who chose the 12-hour shift shows an enhancement without an increase in fatigue or work errors.