• Korean Journal of Applied Biomechanics
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• v.16 no.1
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• pp.151-158
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• 2006

The purpose of this study was to find out the kinematical characteristics of arm's basic position in ballet. In order to achieve the purpose of the study, 3D cinematographic analysis was conducted with a ballerina who might performed the perfect arm's basic position. According to the results of this study, it was appeared that the shoulder kept about 78%-82%, the elbow kept about 62%-96%, the wrist kept 52%-109%, and finger kept 48%-110% with the height. Also, movement was formed with $21^{\circ}-77^{\circ}$ of the upper arm angle, $106^{\circ}-164^{\circ}$ of the elbow, $125^{\circ}-140^{\circ}$ of the wrist, and $83^{\circ}-160^{\circ}$ of the shoulder. The left-right ratio of the total arm angle was 98% in the first, second, and third position, and 100% in the forth position. The angle of arm gradient was remained $-68^{\circ}$ in the first position, $-27^{\circ}$ in the second position, $73^{\circ}$ in the third position, and $-11^{\circ}$ in the forth position. Based on the results mentioned above, balance and symmetry of both arms was an important factor in those four positions. Although it is impossible to maintain the position like robot, it may be a good performance if a certain level of extent was remained With respect to this point of view, it may be a good position if the difference between right and left arm in each joint can be remained within 2%. Angle also was an important factor that if the difference in total angle can be remained within 2% it may be an excellent position, there was difference of right and left based on the joint though. Therefore, practice and instruction to make a perfect symmetry as much as possible were needed Also, it would be a good movement if position and angle of joint within 2% difference of right and left arm can be remained In turn, because ballet is movement with expression of the body, beauty of the body and balance of the movement have to be harmonized for beautiful performance. Therefore, it would be a meaningful future study considering the body condition and movement of ballerina to define the beauty.

• International Journal of Fluid Machinery and Systems
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• v.7 no.1
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• pp.34-41
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• 2014

Computational fluid dynamics (CFD) and particle image velocimetry (PIV) are commonly used techniques to evaluate the flow characteristics in the development stage of blood pumps. CFD technique allows rapid change to pump parameters to optimize the pump performance without having to construct a costly prototype model. These techniques are used in the construction of a bi-ventricular assist device (BVAD) which combines the functions of LVAD and RVAD in a compact unit. The BVAD construction consists of two separate chambers with similar impellers, volutes, inlet and output sections. To achieve the required flow characteristics of an average flow rate of 5 l/min and different pressure heads (left - 100mmHg and right - 20mmHg), the impellers were set at different rotating speeds. From the CFD results, a six-blade impeller design was adopted for the development of the BVAD. It was also observed that the fluid can flow smoothly through the pump with minimum shear stress and area of stagnation which are related to haemolysis and thrombosis. Based on the compatible Reynolds number the flow through the model was calculated for the left and the right pumps. As it was not possible to have both the left and right chambers in the experimental model, the left and right pumps were tested separately.

• Journal of the Korean Applied Science and Technology
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• v.39 no.4
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• pp.507-516
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• 2022

The purpose of this study was to investigate the effect of rotational preference on body stability based on COP and EMG analysis in an quiet standing after turn in the left and right directions. The subjects of this study were 16 subjects with a high lateral preference for the right hand and foot. The subjects of this study were 16 subjects with high unilateral preference for the right hand and foot, and three rotational direction conditions (QS: quiet standing, LT: 10 turns on the left, RT: 10 turns on the right) were performed. In order to evaluate the stability in an quiet standing after turning, the results were derived and analyzed using a COP plate and an EMG. As a result of the study, LT and RT were larger than QS for all COP variables, but there was no difference according to the direction of turning. In EMG, RT showed larger muscle activity than the QS according to the rotational direction in left and right gastrocnemius. In conclusion, although all subjects had a high right lateral preference, there was no effect of rotational preference in COP, and gastrocnemius showed the effect of rotational preference.

• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.197-204
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• 2006

The purpose of this study was to investigate the relationship between the cumulative fatigue of trunk muscles and the period of recovery time during repetitive lifting and lowering task with two different frequencies(4 times/min and 6 times/ min). Eight healthy males with no prior history of LBD(low back disorders) volunteered for this study. Subjects had 2, 3, 4, and 5 minutes recovery time respectively while they were preforming the lifting and lowering task at 15% level of MVC. EMG signals from six trunk muscles were collected and the fatigue level was analyzed quantitatively. In results, the fatigue levels of LES(left elector spinae), RLD(right lattissimus dorsi), LLD(left lattissimus dorsi), RRA(right rectus abdominis) and LRA(left rectus abdominis) were recovered when 3 minutes recovery time was given at 4 times/min frequency. However, the fatgue level of RES(right elector spinae) was recovered when 4 minutes recovery was given. On the other hand, when 6 times/min frequency was used, the RLD, LLD, RRA and LRA were recovered at 5 minutes of recovery time. But for RES and LES, it took longer than 5 minutes to be recovered. This results can be applied to design the adequate length of recovery time to control the cumulative fatigue of trunk muscles in industry with repetitive lifting and lowering task.

• Journal of Microbiology
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• v.37 no.2
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• pp.102-110
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• 1999

Genetic determinant for the secondary metabolism was studied in heterologous expression in Streptomyces lividans TK-24 using Streptomyces griseus ATCC 10137 as a donor strain. Chromosomal DNA of S. griseus was ligated into the high-copy number Streptomyces shuttle plasmid, pWHM3, and introduced into S. lividans TK-24. A plasmid clone with 4.3-kb BamHI DNA of S. griseus (pMJJ201) was isolated by detecting for stimulatory effect on actinorhodin production by visual inspection. The 4.3-kb BamHI DNA was cloned into pWHM3 under the control of the strong constitutive ermEp promoter in both directions (pMJJ202); ermEp promoter-mediated transcription for coding sequence reading right to left: pMJJ203; ermEp promoter-mediated transcription for coding sequence reading left to right) and reintroduced into S. lividans TK-24. The production of actinorhodin was markedly stimulated due to introduction of pMJJ202 on regeneration agar. The introduction of pMJJ202 also stimulated production of actinorhodin and undecylproidigiosin in submerged culture employing the actinorhodin production medium. Introduction of pMJJ203 resulted in a marked decrease of production of the two pigments. Nucleotide sequence analysis of the 4.3-kb region revealed three coding sequences: two coding sequences reading left to right, ORF1 and ORF2, one coding sequence reading right to left, ORF3. Therefore, it was suggested that the ORF3 product was responsible for the stimulation of antibiotic production. The C-terminal region of ORF3 product showed a local alignment with Myb-related transcriptional factors, which implicated that the ORF3 product might be a novel DNA-binding protein related to the regulation of secondary metabolism in Streptomyces.

• Imaging Science in Dentistry
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• v.51 no.1
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• pp.49-54
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• 2021

Purpose: This study was conducted to establish age- and sex-specific reference standards for pterygoid hamulus(PH) dimensions using cone-beam computed tomography (CBCT). Materials and Methods: CBCT scans of 1,000 patients(493 males and 507 females) were retrospectively assessed in coronal sections for length and width measurements of the PH by 3 investigators. The study data were divided into 3 age groups(group 1: <20 years, group 2: 20-50 years, group 3: >50 years). Length and width were compared using one-way analysis of variance and the t-test for age and sex, respectively. Results: The length of the PH on the right side significantly increased from group 1 (6.11±1.47mm), through group 2 (6.65±1.67 mm) to group 3 (6.99±1.79 mm) and on the left side from group 2 (6.58±1.63) to group 3 (6.98±1.70). The width of the PH significantly decreased from group 1 (1.81±0.39 mm) to group 2 (1.61±0.39 mm) on the right side, and similarly from 1.87±0.36mm to 1.67±0.37mm on the left side. PH length (7.18±1.81mm on the right side and 7.10±1.72 mm on the left side) and width (1.68±0.38 mm on the right side and 1.74±0.36 mm on the left side) were significantly greater in males than in females. Conclusion: The length of the PH increased with age, whereas width first decreased and then increased. Length and width measurements were significantly higher in males than in females. These findings will aid in the diagnosis of untraceable pain in the oropharyngeal region related to altered PH morphology.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.2
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• pp.106-110
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• 2017

This paper compared current limiting characteristics of superconducting fault current limiter (SFCL) using E-I core due to the location of windings. Since E-I core has three legs and two magnetic paths, the current limiting characteristics of SFCL were expected to be affected by the installation location of windings, either center leg or right/left leg. To analyze its characteristics, the electrical equivalent circuit of the SFCL were derived and the electromagnetic analysis for the SFCL with the designed structure were performed. From the short-circuit tests, the hysteresis curve and the voltage-current trajectory of the SFCL due to the installation location of windings were extracted and compared each other. The SFCL with windings in the center leg of E-I core was shown to be larger magnetizing inductance compared to the one with windings in the right or left leg of E-I, which was analyzed from the hysteresis curve. In addition, larger decreased fault current right after the fault occurrence in the SFCL with windings in the center leg of E-I core was confirmed than the SFCL with windings in the right or left leg of E-I.

• Journal of Korean Society for Quality Management
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• v.51 no.4
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• pp.481-496
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• 2023

Purpose: The main theme of this study is to derive a profit curve by a cubic cost function for nonlinear CVP analysis. According to the analytical approach to derive a nonlinear profit function in this study, it is possible with only the existing cost structure to calculate the profit maximization and downtime point sales unlike the classical CVP analysis. Furthermore, the profit curve by the mathematical model of this study could serve as a tool to quantify the qualitative evaluation of each stage of the industry life cycle. Methods: This study followed the mathematical approach from the cubic cost function model of microeconomics, and using real data of the Bank of Korea Results: The nonlinear profit function suggested by this study is as follows; ${\pi}(x)=-a\left(x-\frac{f}{1-v}\right)^3+(1-v)x-k$ where $a=\frac{1}{3}v\left(\frac{(1-v)}{f}\right)^2,k=f-a\left(1-\frac{f}{1-v \right)^3$ Conclusion: The process and results of this study would be able to contribute not only in practice of nonlinear CVP analysis required in the management accounting or financial management, but also in cost theory of microeconomics. Also, since the life cycle of all industries in Korea was verified to the growth or mature stage, decision makers should pay careful attention to determining life cycle stages and consider the profit curve by the average variable cost ratio over multi periods.

• Language and Information
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• v.8 no.2
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• pp.1-25
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• 2004

This paper examines two different approaches to resolving a theoretical problem which the bottom-up approach version of Discourse Representation Theory of Kamp et al. (2003) faces in dealing with anaphoric relations between pronouns and their potential antecedents in conditional sentences where consequent clauses precede their corresponding conditional clauses. In one of the approaches, every element is processed in the order of occurrence and conditional operators in a non-sentence-initial position cause the ongoing DR to split in two with the same index. The definition of accessibility is accordingly modified so that the right DR can be accessible from the left DR. In the other approach, a different type of discourse representation structure, K ${\Leftarrow}$ K, is introduced, which allows us to resolve the target problem without modifying accessibility proposed in Kamp et al. (2003). Compatibility of these two approaches with the bottom-up version of DRT is evaluated by examining their applicability to the analysis of quantified sentences where pronominal expressions precede generalized quantifiers.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.679-690
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• 2017

The purpose of this study was to investigate the relationship between neck posture and range of motion and neck disability index(NDI) in young adults with reduced cervical lordosis. This study selected 34 young adults with cervical lordosis reduced (Cobb's angle less than 35 degrees). The assessor measured neck flexion, extension, left lateral flexion, right lateral flexion, left rotation, right rotation and forward displacements of all subjects using cervical of range motion instrument, Then, the NDI was evaluated. After all assessments, degree for cervical lordosis was divided into two groups: bottom group(severe cervical lordosis) and top group(mild cervical lordosis). The bottom group was significantly higher in Cobb's angle, extension, left lateral flexion, right lateral flexion, left rotation, right rotation and forward displacement compared to the top group (p<.05). There was no significant difference between the two groups in flexion, NDI(p >.05). In comparison of subscale of NDI, top group was significantly higher in pain, lifting, and headache than bottom group (p <.05). In correlation analysis, Cobb's angle showed significant positive correlation with flexion, extension, left lateral flexion, right lateral flexion, left rotation and right rotation(p<.05), and showed significant negative correlation with forward displacement, NDI(p<.05). Cobb's angle showed a significant negative correlation with pain, lifting, and headache of subscale of NDI(p<.05). The findings of this study potentially suggest that neck posture may affect the cervical range of motion and pain.