• Safety and Health at Work
• /
• v.8 no.3
• /
• pp.276-281
• /
• 2017

Background: The present study was carried out to assess the relationship between sickness absence and occupational stress, sleep quality, and amplitude and stability of circadian rhythm as well as to determine contributing factors of sickness absence. Methods: This cross sectional study was conducted on 400 randomly selected employees of an Iranian gas company. The data were collected using Pittsburgh sleep quality index, Karolinska sleepiness scale, circadian type inventory, and Osipow occupational stress questionnaires. Results: The mean age and job tenure of the participants were $33.18{\pm}5.64years$ and $6.06{\pm}4.99years$, respectively. Also, the participants had been absent from work on average 2.16 days a year. According to the results, 209 participants had no absences, 129 participants had short-term absences, and 62 participants had long-term absences. The results showed a significant relationship between short-term absenteeism and amplitude of circadian rhythm [odds ratio (OR) = 6.13], sleep quality (OR = 14.46), sleepiness (OR = 2.08), role boundary (OR = 6.45), and responsibility (OR = 5.23). Long-term absenteeism was also significantly associated with amplitude of circadian rhythm (OR = 2.42), sleep quality (OR = 21.56), sleepiness (OR = 6.44), role overload (OR = 4.84), role boundary (OR = 4.27), and responsibility (OR = 3.72). Conclusion: The results revealed that poor sleep quality, amplitude of circadian rhythm, and occupational stress were the contributing factors for sickness absence in the study population.

• Journal of Power System Engineering
• /
• v.16 no.2
• /
• pp.66-74
• /
• 2012

In this paper, the authors propose a new approach to control a barge type surface vessel. It is based on the Dynamic Positioning System(DPS) design. The main role of barge ship is to carry and supply the materials to the floating units and other places. To carry out this job, it should be positioned in the specified area. However sometimes the thrust systems are installed on it, and in general the rope control by mooring winch system is used. It may be difficult to compare the control performances of two types. If we consider this problem in point of usefulness, we can easily find out that the winch control system is more useful and applicable to the real field than the thrust control system except a special use. Therefore, in this paper we consider a DPS design problem which can be extended to the many application fields. The goal of this paper is twofold. First, the sliding mode controller (SMC) for positioning the our vessel is proposed. Especially, in this paper, a robust stability condition is given based on descriptor system representation. In the result, the sliding mode control law guarantees to keep the vessel in the defined area in the presence of environmental disturbances. And second, the thrust allocation problem is solved by using redistributed pseudo-inverse (RPI) algorithm to determine the thrust force and direction of each individual actuator. The proposed approach has been simulated with a supply vessel model and found work well.

• Journal of Institute of Control, Robotics and Systems
• /
• v.17 no.9
• /
• pp.897-901
• /
• 2011

This paper presents a TS (Takagi-Sugeno) type FLC (Fuzzy Logic Controller) with only 3 rules. The choice of parameters of FLC is very difficult job on design FLC controller. Therefore, the choice of appropriate linguistic variable is an important part of the design of fuzzy controller. However, since fuzzy controller is nonlinear, it is difficult to analyze mathematically the affection of the linguistic variable. So this choice is depend on the expert's experience and trial and error method. In the design of the system, we use a variety of response characteristics like stability, rising time, overshoot, settling time, steady-state error. In particular, it is important for a stable system design to predict the steady-state error because the system's steady-state response of the system is related to the overall quality. In this paper, we propose the method to choose the consequence linear equation's parameter of T-S type FLC in the view of steady-state error. The parameters of consequence linear equations of FLC are tuned according to the system error that is the input of FLC. The full equation of T-S type FLC is presented and using this equation, the relation between output and parameters can represented. As well as the FLC parameters of consequence linear equations affect the stability of the system, it also affects the steady-state error. In this study, The system according to the parameter of consequence linear equations of FLC predict the steady-state error and the method to remove the system's steady-state error is proposed using the prediction error value. The simulation is carried out to determine the usefulness of the proposed method.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.3 no.2
• /
• pp.259-271
• /
• 1996

This reserch has been done in order to improve quality of nursing and medical service. In order to improve those qualities the study has been done to know inpatient perception of kindness and meaning of kindness which patients receive from nurse and also what effect inpatient have when they experience kindness from nurse. The subjects were 454 people who admitted in K Hospital. Time period was from October to December 1995. This survey has been done by personal interview with a written questionnaire. Analysis of data has been done by $X^2-test$ and percentage. The results of the research may be summarized as follows. 1. The inpatients perception of kindness on nurse were explanation(26.8%), tolerance(16.3%), warm-heartedness(12.8%), interest(9.5%), ability(8.4%), confidence(6.4%), respect(4.0%), support(2.65%). 2. In order to find out general moaning of kindness, study classified by age, sex, education, job, experience of hospitalization, inpatient ward. As a result of $X^2-test$, no special meaning of kindness was presented in inpatient perception of kindness. 3. Contents kindness which inpatient experienced were, warm-heartedness(23%), understanding(18.1%), interest(17.8%), ability(12.8%), tolerance(5.7%), confidence(2.6%), 4. Over half of subjects(59.1%) answered stability to effect on kindness of Nurse. Next are self-confidence(7.9%), respect(5.3%), confidence(4.6%), warm-heartedness(3.5%), understanding(2.6%). According to above results inpatient feels that meaning of kindness were explanation, tolerance, warm-heartedness. This meaning has no distinctive difference other than consistent meaning. Likewise, inpatient experience about contents of kindness is similar to meaning of kindness. As a result of this research, which show that kindness of nurse gives patient stability, respect and confidence, we would kindness is important for recovery of inpatient. Therefore, this research outcome could be able to help to improve quality of nursing and medical service.

• Journal of the Society of Disaster Information
• /
• v.15 no.4
• /
• pp.514-523
• /
• 2019

Purpose: This study was designed to provide necessary institutional improvements for job security for foreign workers in the domestic construction sector. Method: I analyzed the National Statistical Office and related reports to investigate the status of foreign workers. Based on this, the government came up with measures to improve the system. Results: Based on the current comparative advantage index (RCA) analysis, the technology standard of foreign workers compared to Korean workers was evaluated, and the results were analyzed in order of moldwork, rebar, concrete work, stone work, and waterproof work. Conclusion: A foreign worker's work system was introduced to solve the problem of local Lunar New Year's Day field manpower. To ensure stable implementation of the system, there is a need to improve the operation of the employment permit system at construction sites and limit the size of the construction industry that introduces the employment permit system.

• Geomechanics and Engineering
• /
• v.18 no.4
• /
• pp.339-352
• /
• 2019

Rockmass parameters are used in the design of engineering structures built in rock and soil. One of the most important of these parameters is the rockmass Emass (Emass). Determination of the Emass of rockmass is a long, hard and expensive job. Therefore, empirical formulas developed by different researchers are used. These formulas use the elastic modulus of the material as a parameter. This value is a constant value in the design. However, engineering structures remain under different loads depending on many factors, such as topography, geometry of the structure, rock / soil properties. Time is other important parameter for rock/soil structure. With the start of the excavation, the loads that the structure is exposed to will change and remain constant at one level. In the new proposed method, the use of different Emass calculated from empirical formulas using the different material elastic modulus, which has different values under different loads as time dependent, was investigated in rock/soil structures during design. The performance of the stability analysis using different deformation modules was questioned by numerical modeling method. For this query, a sub-routine which can be integrated into the numerical modeling software has been developed. The integrated sub-routine contains the formula for the Emass, which is calculated from the material elasticity modules under time dependent and different constant loads in the laboratory. As a result of investigations conducted in 12 different field studies, the new proposed method is very sensitive.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2003.03a
• /
• pp.545-552
• /
• 2003

For temporary excavation support in a congested urban area, the strand of ground anchor should be removed to get permission of the private land to install anchors. But the strand doesn't need to be removed in the outside city area after use. So the anchor body, tension anchor, is fabricated in-situ. The unbonded length of This anchor has several strands, which wrap only one sheath. When the anchor body is carried into job-site or installed in the bore hole, the sheath is torn easily because it is a very week material. So the grout permeate into the torn sheath. Because of that, the load doesn't transfer to the bond length of ground anchors. It may indicate that load is being transferred along the unbonded length and thus within the potential slip surface assumed for overall stability of the anchored system. The load tests were performed on seven low-pressure grouted anchors installed in weathered soil to verify its problems. Four anchors(Type A) have the unbonded length, which consist of five strands and a week sheath and three anchors(Type B) have strands, which is covered by plastic sheath filled with grease, in the unbonded length. Both anchors are compared with load tests results.

• The Journal of Korean Academic Society of Nursing Education
• /
• v.14 no.2
• /
• pp.167-175
• /
• 2008

Purpose: The purpose of this study was to explore the structure and characteristics of male college nursing students' personality-based career attitudes. Method: The Q-methodology was used to identify factors in male nursing students' personality-based career attitudes. A Q sample was collected from literature reviews (Kim & Kim, 2005). The subjects consisted of 30 male nursing students. Result: The results of the study show that male nursing students can be categorized into four types. The five factors extracted all had eigen values greater than 1.0 and explained approximately 50.84% of the variation in responses (32.62, 7.59, 5.70 and 4.93% respectively). The categories were labeled 'Repair intention style', 'Belief intention style', 'Stability intention style', and 'Self-regulation intention style'. Conclusion: Through a process that analyzes subjective structure, male nursing students' personality based career attitudes create occupational consciousness, professional accomplishment and professional ethics as a nursing profession. Content of curriculum and development of a reasonable and realistic course consultation program should be done.

• Korean Institute of Interior Design Journal
• /
• no.11
• /
• pp.31-37
• /
• 1997

This study intens to provide available guideline of useful plants in interior and be used by designer. It focuses on evaluating the character of plants, the method of installation and the form of composition for suitable design of using plants. The study finds out that using plants in interior are necessary positively by 94% respondents. And results of factor analysis are that plants are needed for emothional stability(factor 1), visual charming(factor 2), and educational effection(factor 3). According to job, the group of students is visual charming (P=0.0037), the public servants and housewives is educational effection(p=0.0029). The most available space of plants as follows : Department(30.5%), Hotell(26.3%), House and Restuarant(12.7%). It has been identified that the public institution and commercial space are much indused plants. The most indused plants in house is ordered that the veranda, the living room, the entrance. This result is concerned about relation of natural light plants. The repondants reply that the favorite arrangement style is the corner form(63%), the center garden form(52.1%), the large planter(19.7%), the planter box(11.3%). They respond that they are more favorite light green color than dark, and mono color than mixture color. Finally, interior Designers should be understood the functional and aesthetic elements and the special interest about plants for developing desigv.

• Journal of Labour Economics
• /
• v.31 no.2
• /
• pp.35-72
• /
• 2008

This paper examines whether me effects of product demand shocks on employment are different between unionized and non-unionized firms, using new firm-level longitudinal data in Korea over the period 1997~2004. The estimation result shows that the effects of both negative and positive demand shocks on employment are smaller in unionized firms than in non-unionized firms. The result implies that unions appear to provide their members with job stability in response to negative demand shocks, while playing a very limited role in employment determination in response to positive demand shocks leading to employment expansion.