• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.3
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• pp.428-433
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• 2010

The notion "block rotation" denotes the operation of exchanging two consecutive sequences of elements uv to vu. There are three already well-known block rotation algorithms called BlockRotation, Juggling and Reversal algorithm. Recently we presented a novel block rotation algorithm called QuickRotation. In this paper we compare QuickRotation to these three known block rotation algorithms. This comparison covers a complexity analysis as well as benchmarking and shows that a switch to QuickRotation is almost always advantageous.

• PNF and Movement
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• v.19 no.1
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• pp.1-8
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• 2021

Purpose: The purpose of this study was to determine how the position of tibial rotation affects peak force and hamstring muscle activation during isometric knee flexion in healthy women. Methods: Seventeen healthy women performed maximum isometric knee flexion at 30˚ with three tibial rotation positions (tibial internal rotation, neutral position, and tibial external rotation). Surface electromyographic (EMG) activity was recorded from the medial hamstring (MH) and lateral hamstring (LH) muscles. The strength of the knee flexor was measured with a load-cell-type strength-measurement sensor. Data were analyzed using one-way repeated analysis of variance. Results: The results showed that MH and LH activities and peak force were significantly different among the three tibial rotation conditions (p < 0.01). The post-hoc comparison revealed that the MH EMG activity in tibial neutral and internal rotation positions were significantly greater than tibial external rotation (p < 0.01). The LH activity in tibial external rotation was significantly greater than the tibial neutral position and internal rotation (p < 0.01). The peak force of the knee flexor was also greater in the external tibial rotation position compared with the tibial neutral and internal rotation positions (p < 0.01). Conclusion: Our findings suggest that hamstring muscle activation could be changed by tibial rotation.

• Journal of the Korean Statistical Society
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• v.29 no.1
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• pp.29-44
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• 2000

In this paper, we consider one-level rotation designs with finite rotation groups such that the design satisfies two basic requirements: all rotation groups are included in any given survey period, and overlapping rates depend only on the time lag. First we present the necessary number of rotation groups and a rule for the length of time the sample units are to be in or out of the sample to satisfy the requirements. Second, an algorithm is presented to put rotation groups to proper positions in a panel in order to include all finite rotation groups for any survey period. Third, we define an one-level rotation pattern which is invariant in the survey period and has useful properties in practical sense.

• Journal of Korean Academy of Nursing Administration
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• v.7 no.1
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• pp.127-144
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• 2001

The purpose of this study is to provided a basic administrative data for effective personnel management of nurses' by investigation their assessment and satisfaction with the job rotation and by analyzing the relation between their satisfaction and organizational commitment. Data were collected from Nov. 20 to Nov. 25, 2000 through self-reporting questionnaires taken by 280 nurses working at a university hospitals The 3 structured instruments were used for collecting the data; Questionnaires for measuring the utility and the problem of job rotation, Questionaires for measuring the satisfaction with the job rotation, and Mowday's Organizational Commitment Questionnaires. The data obtained were analyzed using frequency, percentage, average, standard deviation, range, Cronbach's alpha coefficients, Peason's correlation coefficients, t-test, one-way ANOVA, and chi-square test, multiple regression. The Results were as follows : 1. The supporters for regular job rotation account for 67% while the opponents to it account for 33%. The chief reason for endorsing the regular job rotation is quoted ${\lceil}$to attain more diverse job experiences${\rfloor}$, followed in order by ${\lceil}$to improve the job motivation and morale through the realization of personal needs${\rfloor}$, ${\lceil}$to place the right man in the right position${\rfloor}$. The reasons for opposing to the regular job rotation were listed in order ${\lceil}$difficulties to secure the expertise of nursing${\rfloor}$, ${\lceil}$personal needs not fully reflected in the job rotation${\rfloor}$, ${\lceil}$job rotations prompted rather by the administrative needs than by personal aptitude and ability${\rfloor}$. 2. In the assessment of job rotation, the points affirming the utility of the job rotation are $2.60({\pm}.66)$ out of possible 5 points and those admitting the problems the job rotation are $3.58({\pm}.59)$. The satisfaction with the job rotation is rated at $2.98({\pm}.55)$. 3. In the analysis into the relation between the assessment of job rotation and satisfaction with the job rotation, fairly high positive correlation is revealed between the satisfaction and utility of job rotation, whereas, considerably high negative correlation is seen between the satisfaction and problems with the job rotation(p=.000). 4. There is relatively high positive correlation between the satisfaction with the job rotation and organizational commitment(p=.000). In conclusion, the utility of on the job rotation and their satisfaction with the job rotation have positive correlation and the satisfaction with the job rotation and organizational commitment showed the positive correlation, too. Therefore, it is thought desirable to take administrative strategies well as education to improve the recognition of the job rotation's utility and to reduce the recognition of the problems with the job rotation to remain in the direction toward contributing to enhancement of the organizational commitment.

• Journal of the Korean Society of Physical Medicine
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• v.12 no.1
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• pp.43-49
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• 2017

PURPOSE: This study investigated the relationship among hip adduction angle, tibial rotation, and ITB length during an Ober test to determine the most appropriate position for performing the test. METHODS: The study included thirty-nine asymptomatic participants (23 males, 16 females). Their hip adduction angles were measured using the Ober test during three tibial rotation conditions (internal tibial rotation, external rotation, and neutral position). ITB length was calculated by measuring the position of the patella to lateral femoral condyle using ultrasonography (patella-condyle distance; PCD). RESULTS: The relationship among hip adduction angle, tibial rotation, and ITB length was analyzed under the three conditions using the Pearson correlation. The hip adduction angle of the internal tibial rotation, the external rotation, and the neutral position were significantly related to ITB length. Moreover, the hip adduction angle measured during the internal tibial rotation had the highest correlation with ITB length among the three conditions (r=.58, p<.001). CONCLUSION: Internal tibial rotation caused by the Ober test led to increased iliotibial band (ITB) tension and a decreased adduction angle. These findings support that tibial rotation influences the flexibility of ITB. Therefore, therapists should consider the position of the internal tibial rotation when taking measurements using an Ober test.

• Journal of the Korean Society of Physical Medicine
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• v.5 no.1
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• pp.1-6
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• 2010

Purpose : This research intended to find out the effects of scalenus medius muscle relaxed posture on the increase of head-neck rotation for general adults. Methods : This research was conducted on 30 subjects whose both sides head neck rotation angles are not the same and that agreed to participate in the experiment. In a posture of sitting erectly on a mat, both sides head neck rotation angles were measured with C-ROM equipment, and while supporting arm in direction opposite the side where head neck rotation limited and leaning over the body at 45 degree and neck at vertical condition against ground, head-neck rotation angles were measured each with C-ROM equipment. Results : The Head-Neck rotation angle on the side of limited head-neck rotation demonstrated more increase in scalenus medius relaxed posture than in erect sitting posture, showing significant difference statistically(p<0.05). The head-neck rotation angle on the side of non-limited Head-Neck rotation demonstrated more decrease in scalenus medius relaxed posture than in erect sitting posture, not showing any significant difference statistically (p>0.05). Conclusions : This posture may be used for preventing limit of head-neck rotation caused of scalenus medius muscle tension and increasing head-neck rotation.

• Journal of the Korean Statistical Society
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• v.35 no.4
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• pp.343-353
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• 2006

The two-way balanced one-level rotation design, $r_1^m-r_2^{m-1}$, and the three-way balanced multi-level rotation design, $r_1^m(\iota)-r_1^{m-1}$, were discussed (Park et al., 2001, 2003). Although these rotation designs enjoy balancing properties, they have a restriction of $r_2=c{\cdot}r_1$ (c should be a integer value) which interferes with applying these designs freely to various situations. To overcome this difficulty, we extend the $r_1^m(\iota)-r_1^{m-1}$ design to new one under the most general rotation system. The new multi-level rotation design also satisfies tree-way balancing which is done on interview time, rotation group and recall time. We present the rule and rotation algorithm which guarantee the three-way balancing. In particular, we specify the necessary condition for the extended three-way balanced multi-level rotation sampling design.

• Journal of the Ergonomics Society of Korea
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• v.32 no.2
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• pp.199-205
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• 2013

Objective: The aim of this study is to investigate the job rotation implementation at medium- or small-industries and to identify the viewpoint on job rotation as preventive activity of work-related musculoskeletal disorders(WMSDs). Background: Job rotation has been implemented in many industrial areas in order to prevent the WMSDs as one part of ergonomic program. Generally, the cases of implementation of ergonomic program or successful cases of job rotation were reported on the side of major or large company. Therefore, this study tried to inspect the current state of job rotation implementation at medium- or small-industries. Method: Survey was carried out for randomly contacted forty seven mangers responsible for safety. Survey contained the questionnaires on the general state of company, shift-work and job rotation. Results: The ratio of work-shift in medium- and small-industry was 34.0% and the ratio of job rotation was 19.1%. For manufacturing industry, the ratio was 37.9% and 17.2%, respectively. Conclusion: The implementation ratio of job rotation was relatively low considering the results of previous studies. Many managers appealed the quality decreasing of goods and the injuries of workers due to job rotation, though agreed to train the multi-functional worker and to prevent the WMSDs. Application: The results can be used for the fundamental data how the job rotation will be properly implemented in medium- and small-industry as an administrative control for MSDs.

• The Journal of Korean Physical Therapy
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• v.29 no.5
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• pp.241-245
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• 2017

Purpose: This study examined the hip and lumbopelvic movement while the hip was rotating laterally in individuals with chronic low back pain (CLBP). Methods: Sixty healthy subjects and sixty subjects with CLBP were enrolled in this study. Myomotion (Myomotion research pro, Noraxon Inc., German) was used to measure the hip lateral rotation and the lumbopelvic movement. An independent t-test was used to compare the hip lateral rotation and lumbopelvic rotation between the groups. Results: Between healthy males and females, healthy females showed a smaller hip lateral rotation angle (HLRA) than healthy males in the hip lateral rotation test (HLRT). Between the healthy females and females with CLBP, the females with CLBP showed a smaller HLRA and greater lumbopelvic motion than the healthy females in the HLRT, and their lumbopelvic motions occurred earlier during lateral rotation of the hip. Finally, between the males and females with CLBP, the females with CLBP showed a smaller HLRA and greater lumbopelvic motion in the HLRT, and their lumbopelvic motions occurred earlier during lateral rotation of the hip. Conclusion: The results of this study suggest that the CLBP affected the hip lateral rotation, and the lumbopelvic movement depended on gender. In particular, compared to the other groups, the females with CLBP showed a larger lumbopelvic rotation angle and smaller hip lateral rotation angle and lumbopelvic motion occurred early during lateral rotation of the hip.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.347-347
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• 2017

This study is performed to investigate the optimal cropping systems to allow cultivation of upland crops to the paddy rice land. This experiment was conducted at Anseong-si Gyeonggi province of Korea in 2015. In order to investigate growth and yield characteristics of foxtail millet, proso millet and sorghum by different paddy-upland rotation systems, three crops foxtail millet, proso millet and sorghum with four varieties of Samdachal, Samdamae, Kyeongkwan1, Hwanggeumjo in foxtail millet, Leebaekchal, Manhongchal, Hwangsilchal, Hwanggeumgijang in proso millet and Nampungchal, Moktaksusu, Aneunbangisusu, Hwanggeumchal in sorghum were examined. Four paddy-upland rotation systems of paddy-upland rotation, paddy-upland-upland rotation, paddy-upland-upland-upland rotation, and upland-paddy-upland rotation system were tested. Days from seeding to heading and ripening of foxtail millet was the shortest in the paddy-upland-upland-upland rotation system, but proso millet and sorghum did not show statistical difference among four rotation systems. In the average of culm length, paddy-upland-upland-upland rotation system showed the highest culm length in foxtail millet (141.5cm), proso millet (159.6cm) and sorghum (138.6cm) respectively among four paddy-upland rotation systems. In average yield per 10a, foxtail millet and proso millet showed the highest each 234.3kg/10a, 176.2kg/10a in paddy-upland-upland-upland rotation system, whereas sorghum was the highest 221.2kg/10a in paddy-upland-upland rotation system. The most suitable crop and varieties in paddy-upland rotation system was judged to be sorghum among three crops and suitable varieties were Samdachal in foxtail millet, Leebaekchal in proso millet and Nampungchal in sorghum respectively.