• 한국안전학회지
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• 제31권4호
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• pp.111-119
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• 2016

This study aimed to analyze postures that were frequently conducted in manufacturing industry. To find grip strength and muscle activities of each posture, Maximum Voluntary Contraction (MVC) and ElectroMyoGraphy (EMG) were measured. Based on the results of this study, the most appropriate posture could be suggested and used as a basic information for preventing musculoskeletal disorders. Most work-related musculoskeletal disorders have been occurred in the fields of manufacturing industry. According to previous studies, it was reported that the rate of musculoskeletal diseases of upper extremity was higher than that of other body parts. Accordingly, there were many studies about discomfort and grip strength of upper extremity. However, these studies dealt with single selection of wrist, elbow and shoulder. So, it was insufficient for comprehensive studies about upper extremity. And in order to improve the work posture, the physiological changes being generated by the combination of wrist, elbow and shoulder postures should be observed and analyzed. In order to conduct this study, thirty university students who had no records of MSDs involved were recruited. Independent variables were postures of wrist(pronation, neutral, supination), postures of elbow(flexion $45^{\circ}$, $90^{\circ}$) and postures of shoulder(flexion $0^{\circ}$, $90^{\circ}$). And dependent variables were MVC values and EMG values. Jamar dynamometer and TeleMyo 2400T G2 was used to measure MVC and EMG. MVC and EMG for 12 postures were measured for three second and for three times. Experiment was performed randomly. A 10 minutes rest period was provided after each t. To measure muscle load, the EMG signals of eight muscles (Biceps, Medial triceps, Lateral triceps, Brachioradialis, Extensor carpi ulnaris, Extensor carpi radialis, Flexor carpi ulnaris and Flexor carpi radialis) were evaluated. MVC values and EMG values were analyzed using Minitab ver. 14. The results showed that MVC value was the highest at shoulder $0^{\circ}$, elbow $45^{\circ}$ and wrist supination. In case of wrist postures, MVC of supination is the highest. In case of elbow and shoulder postures, MVC of flexion $45^{\circ}$ and $0^{\circ}$ was the highest. It was found that there were interaction between wrist and elbow posture under shoulder flexion and between shoulder and wrist under elbow flexion $45^{\circ}$. In case of the angle of shoulder $0^{\circ}$, elbow $45^{\circ}$ and wrist supination, the EMG values of four muscles(Medial Triceps, Extensor carpi ulnaris, Extensor carpi radialis, Flexor carpi ulnaris) were the highest. Based on this study, it is worth to note that the combination postures of upper extremity have a large impact on the MVC and EMG. The optimal condition upper extremity was shoulder flexion $0^{\circ}$, elbow flexion $45^{\circ}$ and wrist supination for preventing work-related musculoskeletal disease.

• 한국식품조리과학회지
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• 제23권1호통권97호
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• pp.62-69
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• 2007

Competitions among domestic foodservice businesses get more intense as the presence of new competitors has rapidly increased. For the past decade, our domestic foodservice industry has shown outstanding growth and overcome poor industrial environments. The poor work conditions employees suffer from will cause negative effects on organization values and effectiveness. Although facing severe problems, most of foodservice businesses do not take aggressive counteraction to eliminate these issues. With this in mind, the study has been implemented to empirically investigate the effects of the foodservice business on organization values and organization effectiveness and then to utilize the findings of the study to develop various marketing strategies for the foodservice industry. The findings of the study were as follows: first, with respect to the effects among organization values, job satisfaction, and organization loyalty, the organization value was found to have positive effects both on job satisfaction, and organization loyalty. The findings demonstrated that the levels of job satisfaction and organization loyalty of employees may be increased by promoting organization values, as positive relationships were found between organization values, job satisfaction, and organization loyalty of employees. second, organization values were found to have a positive effect on organization loyalty. Therefore, job satisfaction should be considered as a key factor for achieving overall organizational loyalty of employees in the foodservice industry.

• Journal of Preventive Medicine and Public Health
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• 제41권5호
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• pp.331-338
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• 2008

Objectives : The purpose of this study was to measure the workload of home visit care activities and their relative values. This study examined also factors that affect the workload of home visit care activities. Methods : The participants of this study were 126 home-helpers of 50 home visit care agencies at the 2nd Long-term Care Insurance Demonstration Project. The workload of home visit care activities was divided into total work and four dimensions ; physical efforts, mental efforts, stress and time. Home visit care activities consisted of four categories with 24 items. We used magnitude estimation method to measure their relative values of the four dimensions. The participants answered the relative values of each activities based on the reference service. We used the activity for supporting their elderly's evacuation as the reference service. Results : Most of the respondents were over 40 years old female. They consumed most their time supporting elderly's going out. They consumed their highest physical, mental efforts, and stress for activities of coping with emergency situation. The Pearson correlation coefficients showed significant relationships between workload and each dimensions. This study showed that all four dimensions are statistically significant predictors of workload of home visit care activities. Also, we found that the home-helper's career affects the workload of home visit care activities. Conclusions : The workload of home visit care activities could be explained by physical efforts, mental efforts, stress and time.

• Industrial Engineering and Management Systems
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• 제10권3호
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• pp.209-220
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• 2011

Self-tapping screws have some operational peculiarities. In spite of their economical advantage that requires no prior tapping operation, a weakness of self-tapping screw-tightening operations is that screws can easily be tightened at a non-right angle, thus resulting in an improper tightening strength. Increases in outsourced workers have reduced labor costs, but the accompanying high worker fluidity means that new workers are more frequently introduced into factories. It is necessary to train new workers for self-tapping screw-tightening operations, which occupies a considerable portion of ordinary assembly works. The purpose of this study is to develop and implement a skill transfer system for the operation. This study (1) proposes a set of characteristic values for evaluating the quality of the operation and develops a device that can measure these values; (2) proposes criteria for evaluating the resultant quality of the tightening; and (3) develops a skill training system for better work performance. Firstly, sets of characteristic values for evaluating the quality of the operation, namely, torque, vertical pressure forces and horizontal vibration forces, are proposed. A device that can measure these values is developed. Secondly, criteria for evaluating the resultant quality of the tightening are identified, involving tightening torque, maximum vertical pressure and timing, vibration area during the processing and tightening period, and work angle. By using such parameters, workers with the proper aptitude can be identified. Thirdly, a skill training system for the operation is developed. It consists of screwdriver operation training and screw-tightening training with feedback information about the results of the operation. Finally, the validity of the training system is experimentally verified using new operators and actual workers.

• 한국터널지하공간학회 논문집
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• 제21권4호
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• pp.561-571
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• 2019

NATM 공법을 이용한 터널굴착 시 발파공 천공 및 장약 작업은 전체 터널 굴착 시간의 30% 이상을 차지하는 중요한 과정이다. 최근에는 이 공정을 활용하여 천공작업 도중 얻어지는 타격압, 천공속도 등을 바탕으로 터널 굴착면 전방의 지반상태, RMR 등을 예측하는 연구들이 진행되어 왔다. 하지만 선행 연구들은 대부분 화강암으로 대표되는 화성암질 지반에 대해서만 수행되어 왔다. 본 연구에서는 유사한 RMR의 범위를 가지는 화성암의 천공속도를 퇴적암(특히, 역암, 사암 및 셰일)의 천공속도와 비교/분석하였으며, 유사한 RMR 값을 가지는 암이라 하더라도 암질 종류에 따라서 천공속도가 크게 달라질 수 있음을 확인하였다. 퇴적암에서의 천공속도가 화성암에서의 속도보다 더 빨랐으며, 또한 화성암의 경우 천공속도와 RMR등급에 따른 천공속도의 차이는 거의 없는 것에 반하여, 퇴적암의 경우는 RMR등급이 낮아질수록 천공속도는 증가함을 알 수 있었다.

• 한국전문물리치료학회지
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• 제30권3호
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• pp.174-183
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• 2023

Background: Office workers experience neck or back pain due to poor posture, such as flexed head and forward head posture, during long-term sedentary work. Posture correction is used to reduce pain caused by poor posture and ensures proper alignment of the body. Several assistive devices have been developed to assist in maintaining an ideal posture; however, there are limitations in practical use due to vast size, unproven long-term effects or inconsistency of maintaining posture alignment. We developed a headphone and necklace posture correction system (HANPCS) for posture correction using an inertial measurement unit (IMU) sensor that provides visual or auditory feedback. Objects: To demonstrate the test-retest reliability and concurrent validity of neck and upper trunk flexion measurements using a HANPCS, compared with a three-dimensional motion analysis system (3DMAS). Methods: Twenty-nine participants were included in this study. The HANPCS was applied to each participant. The angle for each action was measured simultaneously using the HANPCS and 3DMAS. The data were analyzed using the intraclass correlation coefficient (ICC) = [3,3] with 95% confidence intervals (CIs). Results: The angular measurements of the HANPCS for neck and upper trunk flexions showed high intra- (ICC = 0.954-0.971) and inter-day (ICC = 0.865-0.937) values, standard error of measurement (SEM) values (1.05°-2.04°), and minimal detectable change (MDC) values (2.92°-5.65°). Also, the angular measurements between the HANPCS and 3DMAS had excellent ICC values (> 0.90) for all sessions, which indicates high concurrent validity. Conclusion: Our study demonstrates that the HANPCS is as accurate in measuring angle as the gold standard, 3DMAS. Therefore, the HANPCS is reliable and valid because of its angular measurement reliability and validity.

• 가정과삶의질연구
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• 제18권3호통권47호
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• pp.129-146
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• 2000

The purpose of this study was to investigation the variables that affected the generational transmission of household work form mothers to their married daughter. The subjects were 415 married daughters and their mothers living in Seoul and metropolitan areas. Statistical techniques used for this study included descriptive statistics and multiple regression analysis. The results of this study were as follows : First, married daughters; value of household work was significantly affected by total periods of marriage of daughters, daughter's perceived similarity to their mothers' household work. Second, married daughters' preference for household work was significantly affected by mother's occupation (managerialㆍprofessional), mother's perceived similarity, daughter's experience of living with mother-in-law, daughter's sex-role attitude, and daughter's perceived similarity. Third, married daughters' ability to do household work was significantly affected by total periods of marriage for mothers, mother's perceived similarity, and daughter's perceived similarity. Fourth, married daughters' standard of household work was significantly affected by mother's perceived similarity, daughter's occupation (techniciansㆍclerk), daughter's monthly income, and daughter's perceived similarity. Fifth, married daughters' usage level of home equipments was significantly affected by mother's birth order, mother's education, mother's occupation (managerialㆍprofessional), daughter's birth order, daughter's education, and daughter's monthly income. Sixth, Mother related variables had greater power than daughter related ones in explaining daughters' values and preference for household work value and preferences and usage of home equipments. In conclusion, married daughter's consciousness and performance of household work were significantly influenced by their mothers. It was especially so in daughter's usage level of hoe equipments. Accordingly, the results of this study support the existence of generational transmission of household work from mothers to their married daughters with regard to its consciousness and performance. Findings of this study have implications for counsellors, practitioners and educators.

• 한국건설관리학회논문집
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• 제11권1호
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• pp.29-37
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• 2010

최근의 공동주택 마감재는 고급화 다양해지고 있으며, 그 종류는 기하급수적으로 증가 하고 있다. 또한 공동주택 사업 초기의 마감재 디자인 설계 및 대안 선정 단계에서 수많은 마감재 정보가 생성, 변경 되고 있다. 그러나 초기단계에서 마감재정보들은 체계적으로 관리되지 못하고 있는 실정이고 이는 마감재 원가 관리의 문제점으로 작용하고 있다. 이에 본 연구는 공동주택 프로젝트 초기 단계에서 발생되는 마감재 정보를 관리하기 위한 방안으로 원가기반의 정보관리 시스템을 제안하였다. 제안된 시스템을 구축하기 위하여 시스템의 개념 및 구성을 통하여 정보관리 시스템을 설계 하였다. 마감재 정보 초기값 구축, 대안별 정보관리, 원가고정 또는 원가변경의 조건별 마감재 선정 시나리오를 설정한 후 프로젝트 관리자, 인테리어 디자이너, 시공자등 프로젝트 참여자 측면에서 활용할 수 있으며, 참여자간 의사를 조정할 수 있는 원가기반의 마감재 정보관리 시스템의 프로토타입을 구현 및 적용하였다.

• 대한기계학회논문집A
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• 제27권5호
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• pp.750-757
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• 2003

In order to determine creep stress intensity limit of high-temperature components, the usefulness of the creep work and time equation, defined as W$\_$c/t$\^$p/ = B(where W$\_$c/ = $\sigma$$\varepsilon$ is the total creep work done during creep, and p and B are constants), was investigated using the experimental data. For this Purpose, the creep tests for generating 1.0% strain for commercial type i16 stainless steel were conducted with different stresses; 160 MPa, 150 MPa, 145 MPa, 140 MPa and 135 MPa at 593$^{\circ}C$. The plots of log W$\_$c/ - log t showed a good linear relation up to 10$\^$5/ hr, and the results of the creep work-time relation for p, B and stress intensity values showed good agreement to those of isochronous stress-strain curves (ISSC) presented in ASME BPV NH. The relation can be simply obtained with only several short-term 1% strain data without ISSC which can be obtained by long-term creep data. Particularly, this relation is useful in estimating stress intensity limit for new and emerging class of high-temperature creeping materials.

• 패션비즈니스
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• 제17권3호
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• pp.1-14
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• 2013

This study is about the evaluation of the color arrangements of working clothes that are harmonized with working environment and assist in the protection of workers in industrial sites. This study attempted color arrangement design with the intention of giving order to the colors of working environment and working clothes so as to help improve the safety of work and the management aspects including human resource management, efficiency improvement, and the practice of business ethics. The study method consisted of literature research, empirical research, and evaluation research. The literature research performed theoretical examination about colors, industrial safety, and visibility. Three actual outdoor work sites in the machine industry were chosen and pictures were taken at 20-30 m from workers. The background colors of the work environment of each work site and the colors of the working clothes that were actually worn were analyzed through color values measured with a color-difference meter(CR-400). As a result, it was found that between value and chroma which affect visibility, color arrangement based on differences in chroma could be a greater influence than color arrangement based on differences in value. The results of this study could assist the integration of color schemes among working environment colors, people and working clothes by suggesting color arrangements with improved visibility that are applicable to the working clothes of domestic machine manufacturers that are playing a pivotal role in domestic industries and by presenting appropriate guidelines.