• Korean Journal of Construction Engineering and Management
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• v.22 no.6
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• pp.107-119
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• 2021

Recently, interest in remodeling apartment houses has been increasing due to problems such as a lack of parking spaces for old apartment houses. However, no method was suggested to predict the construction period of the apartment remodeling project. Unlike general apartment new construction, apartment remodeling construction involves demolition or reinforcement work, so a realistic remodeling construction period calculation plan differentiated from the existing construction period should be proposed. Therefore, this study intends to present a model for deriving the construction period of the underground parking lot of the apartment remodeling construction. Each construction period was calculated based on 19 activities of underground parking lot remodeling work through review of previous studies and expert advice. Activity's workload data and productivity data were derived to calculate the construction period, and the number of inputs and equipment inputs by Activity were determined to correct the productivity data. The construction period of Activity was calculated using the derived data, and the criteria for calculating the overlapping period for each Activity were presented to enable realistic construction period and scheduled schedule. As a result of predicting the accuracy of the construction period through the verification of the case complex, it is expected that it will be possible to predict the approximate construction period of the underground parking lot of the apartment remodeling construction in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.7
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• pp.1267-1273
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• 2022

Although the Korea shipbuilding industry has recently been receiving most of the orders for ships in the world, production processes are being disrupted due to a shortage of manpower at the production site. This is because the workers quit the shipyard as both work and wages were reduced due to the long slump in the shipbuilding industry. The main reason for the increase in orders was the large-scale orders for Qatar LNG carriers, and the situation in which the technical specifications required for ships are becoming more complex is also working to an advantage. Because the contract delivery time is of utmost importance for ships, the dock launch plan is the most important management item among the shipyard's major processes. The structure to be built in the dock may be a hull that has left the design work or a finished vessel, and in some cases, it is often at the level of some blocks of the hull. When launching, the hull is affected by the hogging or sagging moment due to the fluid force, and securing the safety of the structural strength of the block connection is of utmost importance. In a normal process, the connecting member launches after welding has been completed, but in actual shipbuilders, quick decision-making is needed on the conditions for securing structural safety to comply with the docking schedule. In this study, a detailed analysis method and applicability using a bending stress evaluation method and finite element analysis modelling were analyzed to rationally judge the above-mentioned problems from an engineering point of view. The main contents mentioned in the thesis can be used as good examples when conducting similar structural strength evaluations in the future.

• Journal of Distribution Science
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• v.10 no.4
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• pp.13-20
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• 2012

The "flextime" system, which was initially designed to maintain a balance between work and personal life, has recently received much attention as an alternative form of work, enabling employees to fully exert their creativity. Most studies show that the effects of flextime on performance, productivity, attitude toward the organization, absenteeism, and turnover differ between managerial and non-managerial workers. This suggests that workers' personal characteristics affect their preference for flextime by directly or indirectly influencing its result variables. As most Korean companies have not adopted the flextime system, little research has been conducted on it in Korea. Recently, Korean companies have been discussing flextime as one of several measures for enhancing international competitiveness. Therefore, this study aims to offer a theoretical framework for the introduction of the system by analyzing the effects of the precedent factors on the preference for flextime. Though not statistically significant, a higher preference for flextime is noted among workers over the age of 36. Older workers usually are more conservative and less adaptable to change but here the older Korean workers may be anxious and resistant. Additional research on workers in different types of businesses using improved research methods will lead to more meaningful results. Married workers display a lower preference to flextime than single workers. In Korea, the current atmosphere focused on a happy home encourages married workers to prefer regular work hours, enabling them to go to and from work on a regular schedule. This means that normal working hours, from morning to evening, are preferred as it is the most suitable system for families. However, this is not so in the case of single workers. Unmarried singles tend to prefer flextime for investing in self-development toward future prosperity, over the benefits of regular working-hours. Flextime is designed to meet their needs to some extent as it is helpful in maintaining a balance between work life and self-development. If flextime is selected, workers can spend mornings on self-development and work in the afternoons. Therefore, when flextime is introduced in Korea, it would be desirable to start with unmarried workers, to increase corporate creativity and productivity and develop individual potential. In particular, when the five-day workweek, the main concern for companies and labor unions, is adopted, synergy with flextime could be expected and a gradual implementation of flextime will be effective. Gender difference shows similar results to marital status with male workers displaying a higher preference for flextime. It is inferred that male workers' attitudes toward flextime are more favorable than female workers' because flextime enables self-development and work life to coexist. A relatively weak, though statistically significant, correlation exists between control position and flextime preference with inner-control-oriented workers displaying favorable attitudes toward flextime. Generally, inner-control-oriented workers tend to attribute the consequences caused by any person or partner relationship to themselves. Thus, when a new system is introduced they are likely to have less reluctance and fear than outer-control-oriented workers, because they think it is important to deal with the new system. A weak but slight correlation exists between the desire for achievement and flextime preference. People who have a higher desire for achievement are willing to consider the new system, especially if significant success is reasonably expected. This result is derived from a reasonable judgment that flextime offers an individual the time for self-development while the organization benefits from the resulting creativity and performance enhancements. Although not the primary analysis, a high correlation is found between control position and the desire for achievement, which is consistent with the results of previous research. The regression analysis not only supports the preceding ANOVA and correlation analysis but also shows the existence of a causal relationship. Married workers have a weak preference for flextime, which is consistent with the results of the preceding ANOVA. Relative to men, women have a weak preference for flextime. No statistically significant correlation was noticed for age. Inner-control-oriented workers prefer flextime more than outer-control-oriented workers as the former view the consequences of change to be their own responsibility. However, the preference for flextime seems to be weak. As expected, people with a higher desire for achievement have a stronger preference for flextime, presumably because the greater the desire for achievement, the stronger the spirit of challenging an uncertain future. No significant correlation exists between job satisfaction and flextime preference.

• The Journal of Korean society of community based occupational therapy
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• v.11 no.1
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• pp.11-22
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• 2021

Objective : The purpose of this study was to investigate the changes in occupational balance and quality of life caused by COVID-19 in occupational therapy students. Methods : From May 27 to June 26, 2020, questionnaires were distributed to a total of 35 universities among 62 occupational therapy departments nationwide. General characteristics, COVID-19 related characteristics, OBQ and WHOQOL-BREF were used to evaluate and analyze occupational balance and quality of life. The SPSS/PC 24.0 program was used to analyze frequency analysis, crossover analysis, chi-square test, independent t-test, analysis of variance, and Pearson correlation analysis. Results : There were significant differences in school system(years), class, life pattern, quality of life, personal and public schedule depending on whether they are interested in occupational balance. There were significant differences in occupational balance(OBQ) and quality of life(WHOQOL-BREF), 'Hobby', 'new hobbies after COVID-19', 'life patterns', 'use of public transportation', 'maintenance of occupational balance', and 'quality of life'. There was a significant positive correlation occupational balance and quality of life. Conclusion : This study showed that the more people who have changed their lives due to COVID-19 are interested in work balance, and the better they maintain their work balance and emotional well-being, the higher the work balance and quality of life, and the positive correlation between work balance and quality of life was confirmed. This will be the basis for studies related to intervention strategies that can improve occupational balance and quality of life in a time when social isolation is easy due to the COVID-19 epidemic.

• Journal of Korean Academy of Nursing
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• v.21 no.2
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• pp.129-149
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• 1991

Circadian rhythm is entrained in the 24-hour time interval by periodic factors in the environment, known as zeitgeber. But most rotating work schedules are outside the range of the entrainment of the pacemaker timing the human circadian sleep - wake cycle. It has been postulated that physiological and emotional disturbances occur in most human functions when the circadian rhythm is disturbed. So application of circadian principles to the design of shift schedules can aid in maintaining the temporal integrity of the circadian system and thereby minimize for the shift worker any detrimental consequences of circadian disruption. This study was a quasi-experimental study to test the effect of shift intervals for the clinical nurse on the circadian rhythm. Twenty nurses newly employed in general units of two hospitals were selected as an experimental group and twelve college nursing students as a control group. Both groups were selected according to an established criteria using a purposive sampling technique. Ten subjects were assigned to a weekly shift group and another ten to a biweekly shift group engaged in a semi -continuous shift schedule(sunday off) with a backward direction, that is, morning -evening - night shift. The control group worked a morning shift for 42 days. Oral temperature rhythm, waking tim, sleep - wake cycle, fatigue, and mental performance were measured during the experimental period. The data collection period was from April 30, 1990 to June 10, 1990. MANOVA, paired t-test, ANOVA, and Student Newman Keuls method were used for statistical analysis. The results are summarized as follows. 1. Phase delay in the acrophase of temperature rhythm was shown according to the backward rotating shift. A complete adaptation to work on the night shift was achieved between the sixth and ninth day of the night shift. 2. There was no difference in either waking time or sleep- wake cycle according to the duration of the working day for every shift group. Significant difference was found in the waking time and the sleep -wake cycle for subjects on the morning, evening, and night shift in both of the shift groups(weekly shift group : λ＝0.121, p＜0.01, λ＝0.112, p＜0.01, biweekly shift group : λ＝0.116, p＜0.01, λ＝0.084, p＜0.01). 3. There was no difference in fatigue between the first working day and the last working day for the control group and for the biweekly shift group. In the weekly shift group, physical fatigue was significantly different for the first day and the sixth day of the night shift(t＝-2.28, p＜0.05). Physical fatigue and total fatigue on the first day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝5.79, p＜0.01, F＝4.56, p＜0.05). There was a significant difference between the shift groups and the control group(p＜0.05), Physical fatigue, neurosensory fatigue and total fatigue on the last day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝12.65, p＜0.01, F＝7.77, p＜0.01, F＝9.68, p＜0.01). There was a significant difference between the shift groups and the control group(p＜0.05). 4. No difference in mental performance was seen between the first day and the last day of work in each case. An arithmatic test on the first day of the night shift revealed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝3.79, p＜0.05). There was a significant difference between the shift groups and the control group(p＜0.05) . The digital symbol substitution test and the arithmetic test on the last day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝3.68, p＜0.05, F＝5.55, p＜0.01), and both showed a significant difference between the shift groups and the control group(p＜0.05). Accordingly, this study showed that during night duty, the waking time, sleep- wake cycle, and fatigue increased and mental performance decreased compared with morning and evening duty. It was also found that the weekly shift group had a higher fatigue score on the sixth day of night duty as compared to the -first day, but the waking time, sleep- wake cycle, and mental performance revealed no difference for the duration of the night duty or between shift groups, and complete adaptation of temperature rhythm was achieved between the sixth and ninth day of night duty. It is possible to conclude from these results that for intermediate circadian type in a healthy young woman, a biweekly shift system is more compatible with the circadian timing system than weekly shift system.

• Journal of Convergence for Information Technology
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• v.10 no.9
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• pp.222-228
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• 2020

The purpose of this study was to investigate activity participation level and functional disability based on ICF for the elderly aged over 65 years. Subjects were 100 senior citizens. We performed data collection using Korean Activity Card Sorting(KACS) and World Health Organization Disability Assessment Schedule 2.0(WHODAS 2.0). Data were analyzed using descriptive statistics, Pearson's correlation, multiple regression. As a result of the survey of activity participation levels, retained level of activity participation of instrumental activity was highest at 75.06%. Among the WHODAS 2.0 sub-domain, 'getting along with people', 'participation in society' had the most difficulties and 'self-care', 'life activities' were the lowest. An analysis of the correlation between the activity retention rate and functional disability showed that there was a significant negative correlation. Significant factors influencing functional disability were activity participation level of social activity, instrumental activity and main work(retirement). We confirmed that activity participation level was important factor on functional disability. Further, we need standardization study for generalization.

• The Journal of Korean Society for Radiation Therapy
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• v.29 no.2
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• pp.119-128
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• 2017

Purpose: The purpose of this study was to measure the average actual treatment time at the time of Tomotherapy treatment. We want to investigate the time required for the procedure in the treatment process that affects the actual treatment time. Patients and Methods: We measured the time required by the procedure in 31 patients who were treated with tomography therapy. Beam-on time, Image registration time, Set-up with scan time and Actual treatment time were measured and stepwise regression analysis was performed. Result: The average treatment time per a patient was 21.44 - 23.92 minutes. Beam-on time, Image registration time, and Set-up with Scan time were the important factors affecting the actual treatment time. The biggest influence was Beam-on time and Registration time was less affected by analysing. Conclusion: The average treatment time per a patient in tomotherapy treatment was $22.68{\pm}3.37$ minutes. The Approximately 21 patients are expected to be treated within 8 hours of regular work time. However, if the treatment is interrupted or the time of the procedure is changed during the treatment process, it affects the schedule of the daily treatment patients and the workload is expected to increase.

• Journal of the Korea Institute of Building Construction
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• v.17 no.6
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• pp.577-585
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• 2017

HPC method is developing to improve the constructability and structural performance of the existing PC method. The objective of this study is to develop construction procedures and to analysis of construction period for HPC method. In order to develop construction procedures, the building construction data of the existing half-slab method was analyzed. Analyzing design drawings and specifications of nine construction cases, a prototype of half-slab method, was drawn. Applying the core technology of HPC method to the drawn prototype of half-slab method, a prototype of HPC method, was developed. The differences of both methods were 'installing PC column' and 'placing topping concrete'. To analysis the differences of both methods, seven construction cases were analyzed. According to the analysis for HPC method, cases1 and 2 had columns divided for construction shortened about 16% of a construction period. The schedule of column assembly work was analyzed to be shortened much. That is judged to be because the use of a hollow PC column leads to a decrease in the number of columns. In particular, if HPC method is applied to a building construction site using large columns, it is analyzed to shorten a construction period more than the existing Half-slab method.

• Cartoon and Animation Studies
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• s.37
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• pp.491-508
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• 2014

As number of making 3D feature animation films is increasing, 3D production pipeline become more complicated and more artists are needed than before. Major studios in foreign countries, in burden of producing high quality films with limited amount of budget and time, have been handling such difficulties by hiring technical directors in each department such as animation, rigging, cloth hair, and effect. Technical director is new occupation which appears after trend of producing animation is changed from 2D to 3D. Importance of technical director is increasing in respect to studios' needs which are related to complication in production time, manpower, budget, and production pipeline. This research is based on the researcher's work experience as an animation TD at Walt Diseny Animation Studio and Sony Pictures Imageworks, interview with working professionals, and related books and thesis. It focuses on the role of animation technical director in Disney's 3D feature animation film from two perspectives, 'Designing Production Pipeline' and 'Analyzing Problem of Shot'. Animation technical directors design and test production pipeline so that they can detect and solve problems that may arise in production process as early as possible. They not only analyze numerous problems of characters or shots limited to animation department but also in other departments such as modeling, mapping, character rigging, cloth, hair, lighting, rendering, software development in order to support artists to complete their shots according to the production schedule. In accordance with recent trend of increasing number of 3D feature animation film production in South Korea and collaboration with foreign studios outside of South Korea, it is vital to train animation technical directors who can develop production pipeline, analyze various problems of shots and characters to escalate efficiency in production.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.3
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• pp.156-161
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• 2011

Objectives: Tetrahydrofuran (THF) is a colorless, water-miscible organic liquid with low viscosity at standard temperature and pressure. THF has been used as a solvent and a precursor for various syntheses of polymers. However, THF is known to irritate to the eyes, skin and mucus membranes. Overexposure by inhalation, ingestion or skin contact may produce nausea, dizziness, headaches, respiratory irritation and possible skin burns. The purpose of this study is to evaluate of the worker exposure and characteristics of workers in the workplaces that use or manufacture THF. Methods: Sixteen factories in Korea, which manufacture or use THF, were selected for this study and a total of 130 air samples including 104 time-weighted average (TWA) samples and 26 short-term exposure limit (STEL) samples, were collected. Air samples were collected with charcoal tube (100mg/50mg) and analyzed by gas chromatograph/flame ionization detector(GC/FID). Results: The TWA concentration of THF was 16.05ppm (GM) at PS script printing, 2.32ppm (GM) at PVC stabilizer, 1.03ppm (GM) at Lithium triethylborohydride, 0.63ppm (GM) at Polytetramethylene ether glycol(PTMEG), 0.42ppm (GM) at Manufacturing THF, 0.13ppm (GM) at Glue and 0.12ppm (GM) at synthetic rubber/resins. Two out of sampes for PS script printing exceeded 50ppm as 8-hour exposure limit of MOEL. The short term exposure to THF was 54.77ppm (GM) at PS script printing, 17.10ppm (GM) at PTMEG, 13.76ppm (GM) at Manufacturing THF, 2.86ppm (GM) at Lithium triethylborohydride, 0.87ppm (GM) at synthetic rubber/resins and 0.13ppm (GM) Glue. We found that the highest exposure process for both the TWA and STEL samples was PS script process. Two samples exceeded 100ppm as short term exposure limit of Ministry of Employment and Labor(MOEL). Conclusions: Characteristic of STEL concentration for THF is considerably different from TWA concentration in workplaces because workers could exposure high concentration of THF in a moment when they work irregularly schedule. So exposure controls for momentary works have to be prepared, and considered the skin absorption and inhale of THF.