• Journal of the Ergonomics Society of Korea
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• v.27 no.2
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• pp.49-57
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• 2008

This study aims to investigate the effect of handle angles of pliers on performance, wrist motion and subjective rating of satisfaction. An experiment was conducted, in which handle angle of pliers was used as independent variable and 14 subjects participated. Based on the literature survey, plier handles angled at 0$^{\circ}$, 10$^{\circ}$, 20$^{\circ}$, 30$^{\circ}$ and 40$^{\circ}$ were adopted in the experiment. The subjects were instructed to bend iron plates by 90$^{\circ}$ and to cut wires as soon as possible. The results revealed that 1) handle angles of pliers have significant effect on wrist motion and satisfaction(p<0.0001); 2) handle angles of pliers did not affect performance of completing tasks irrespective of types of tasks done in the study; 3) in the initial stage of windup, plier with handle angled at 20$^{\circ}$ produced the least wrist motion of deviation in task of bending iron plates, while plier with handle angled at 40$^{\circ}$ did in task of cutting wires; 4) degree of satisfaction was maximized when handle of pliers was bent by 20$^{\circ}$ in both tasks. On the basis of the results, it is recommended that handle of pliers be bent by 20-30$^{\circ}$ for reducing musculoskeletal disorders related to pliers.

• Journal of the Korean Society of Safety
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• v.23 no.1
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• pp.51-56
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• 2008

This study aims to investigate the effect of handle angles of pliers on performances of task completion time and the number of errors, and subjective ratings of preference. For doing this, an experiment was conducted, where 14 subjects of 11 college-age male and three female students participated. In the experiment, plier handles angled at $0^{\circ}$, $10^{\circ}$, $20^{\circ}$, $30^{\circ}$, and $40^{\circ}$ were used as independent variable, and the task completion time and the number of errors, and subjective ratings of preference as dependent variables. The subjects were instructed to do two tasks of bending an iron plate by $90^{\circ}$ and cutting wires. The results revealed that while the performances of task completion time and the number of errors were not statistically different depending upon the handle angles of pliers, the subjective ratings of preference were significantly different. Based on the results, it is recommended that the pliers with handles bent by $20^{\circ}$ be used in real situations.

• Journal of the Ergonomics Society of Korea
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• v.26 no.4
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• pp.85-90
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• 2007

This study shows a way to develop ergonomic design of a plier through quality function deployment (QFD) approach. User needs for pliers, as well as the engineering characteristics which have influence on the ergonomic quality of pliers were determined from the interviews and questionnaires with various user groups. This information was entered in the house of quality, and the results show that the handle is the most important quality factor. A new model was proposed in which ergonomic and gender aspects were considered. QFD is considered a suitable method especially for the manufacturing and/or design fields where biomechanical or physiological background is not present.

• Proceeding of EDISON Challenge
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• 2014.03a
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• pp.610-613
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• 2014

본 연구에서는 Dyson사의 Air multiplier의 Coanda surface각도에 따른 Air foil 주변의 2차원 유동을 분석하고 Surface각도가 유동에 미치는 영향에 대해 해석하였다. Air multiplier 단면의 작은 Slit을 통해 분류된 공기는 Venturi effect에 의해 가속되며 Coanda effect에 의해 단면을 따라 흐르며 압력차를 발생시켜 주변의 공기를 추가적으로 유입시킨다. EDISON CFD를 이용하여 Surface 각도에 따른 Air foil 주변의 유동을 구현하고 각도가 유동에 미치는 영향을 해석하였다. 또한 다른 논문에서 발췌한 실험값과 CFD 분석을 통해 얻은 값을 비교하여 CFD분석이 유효한지 확인하였다.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.813-823
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• 1998

The frictional force has been considered as an harmful factor in an active unit where tooth movement occurs, but as an advantageous factor in anchor unit that resist tooth movement. That is, efficient tooth movement is planned by using ligation methods that have low levels of bracket-wire frictional force and the anchorage control can be achieved by using ligation methods that have high levels of bracket-wire frictional force that result in binding of the bracket accompanied by little or no tooth movement. The purpose of this study was to evaluate the frictional force generated between bracket and wire in accordance with the methods of ligation, the material of ligation and the passage of time under artificial saliva. Tested were 0.017x0.022 inch stainless steel wires in standard edgewise twin brackets for upper central incisors in a 0.018-inch slot. The wires were ligated into the brackets with elastomeric modules and stainless steel ligatures. Whole tie, half tie, twisting tie and double overlay tie were done with elastomeric modules. With 0.009-inch stainless steel ligature whole tie and half tie were done by needle holder and whole tie by ligature tying plier. With 0.012-inch stainless steel ligature whole ties were done by needle holder. Whole tie groups of elastomeric module were kept in artificial saliva bath at $37^{\circ}C$ for 28 days. The frictional force was recorded by means of an Instron universial testing instrument (4202 INSTRON, Instron Co., U.S.A.) at initial, 7, 14, 21, and 28 days. The results for ligated samples in a simulated oral environment revealed the fellowing : ${\cdot}$In elastomeric module whole tie, 28 days group was significantly greater mean static frictional force than any other group but there were no significant differences among any other group (p>0.05). ${\cdot}$Elastomeric module twisting ties were significantly greater mean static frictional forces than any other ligation method but there were no significant differences between twisting tie and double overlay tie (p>0.05). Twisting tie, double overlay tie, whole tie, half tie showed differences in decreasing order. ${\cdot}$Stainless steel half tie produced lower mean static frictional force than whole tie, ligation by ligature tying plier produced greater mean static frictional force than by needle holder and ligation with 0.012-inch stainless steel ligature produced greater mean static frictional force than with 0.009-inch stainless steel ligature (p<0.05). ${\cdot}$There were no significant differences between the mean static frictional forces of elastomeric whole tie and stainless steel whole tie (p>0.05).

• International Journal of Quality Innovation
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• v.9 no.2
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• pp.11-30
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• 2008

The purpose of this study is to develop BSC model of social enterprise. Performance analysis tool of BSC have been brought over from the business world, designed and created from the perspectives of profit-based businesses. The BSC is a strategic performance measurement and management tool designed for the private sector acting as a communication/information and learning system, to measure 'where we are now' and 'where to aim for next'. It prescribes a plan for translating 'vision' and 'strategy' into concrete action across four perspectives at different stages, depending on the business. These perspectives are 'financial', 'customer', 'internal processes' and 'learning and growth', each of which is connected by cause-and-effect relationships that reflect the firm's strategy. Social aims of social enterprise are to accomplish desired outcomes which are to employ vulnerable people and to provide social services. The measurement factors of financial perspective are stable funding, efficiency of budgeting, stakeholders' financial supports, and trade profit. The measurement factors of customer perspective are government, social service users, employees, local communities, sup plier, social activity company, and partnership with external organizations. The measurement factors of internal process perspective are organizational culture, organizational structure/management, internal/external communication, quality of products and services, information sharing. The measurement factors of learning and growth perspective are training and development, management participation, knowledge sharing, leadership of CEO and manager, and learning culture.

• Journal of the Korea Concrete Institute
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• v.20 no.6
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• pp.681-687
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• 2008

This study presents a technique to quantitatively measure the corrosion level of a reinforcing bar using infrared thermography system. We found out electric heating method having an important effect on thermal data in previous study. This study purposed an efficient way for grip standardization to reduce constriction resistance problem, and providing reliable thermal data using infrared thermographic method. Using vise type earth clamp, the surface resistance of rebar was smaller than that of traditional plier type earth clamp through temperature-distribution relationship. Also this study contains experiments with toque wrench to improve heating contact problem.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.5
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• pp.2519-2525
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• 2016

There are several existing reports of microarray chip use for assessment of altered gene expression in different diseases. In fact, there have been over 1.5 million assays of this kind performed over the last twenty years, which have influenced clinical and translational research studies. The most commonly used DNA microarray platforms are Affymetrix GeneChip and Quality Control Software along with their GeneChip Probe Arrays. These chips are created using several quality controls to confirm the success of each assay, but their actual impact on gene expression profiles had not been previously analyzed until the appearance of several bioinformatics tools for this purpose. We here performed a data mining analysis, in this case specifically focused on ovarian cancer, as well as healthy ovarian tissue and ovarian cell lines, in order to confirm quality control results and associated variation in gene expression profiles. The microarray data used in our research were downloaded from ArrayExpress and Gene Expression Omnibus (GEO) and analyzed with Expression Console Software using RMA, MAS5 and Plier algorithms. The gene expression profiles were obtained using Partek Genomics Suite v6.6 and data were visualized using principal component analysis, heat map, and Venn diagrams. Microarray quality control analysis showed that roughly 40% of the microarray files were false negative, demonstrating over- and under-estimation of expressed genes. Additionally, we confirmed the results performing second analysis using independent samples. About 70% of the significant expressed genes were correlated in both analyses. These results demonstrate the importance of appropriate microarray processing to obtain a reliable gene expression profile.

• Journal of the Ergonomics Society of Korea
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• v.32 no.6
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• pp.511-516
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• 2013

Objective: The objective of this study is designing an optimal hand tool through maximum grip force study accordance to the hand grip span. Background: In order to prevent musculoskeletal diseases, studies on hand tool design are proceeding based on grip strength, finger force, and contribution of individual finger force on total grip strength. However, experimental apparatus using a tool that is actually used in work place was almost non-existent. Method: 19 males were participated in an experiment. Using the load cell inserted real plier, finger force, grip strength, and subjective discomfort rate of both hands (dominant and non-dominant) were measured in 5 different hand grip span(45mm, 50mm, 60mm, 70mm, and 80mm). Results: There was significant difference(p<0.001) of total grip strength, individual finger force and subjective discomfort rating according to various hand grip span(45, 50, 60, 70, and 80mm). Also, statistically significant different(p<0.001) was shown between the dominant hand and non-dominant hand. In addition, individual finger force in maximum grip was in order of middle finger, ring finger, index finger, and little finger. Conclusion: Optimal grip span of pliers that exerting maximum grip strength is 50~60mm. Application: This finding is expected to be used for designing proper pliers.

• The korean journal of orthodontics
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• v.34 no.4 s.105
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• pp.343-349
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• 2004

Laser-aided debonding has advantages in that the heat produced is localized and controlled, the debonding tool is not heated, and it can be used for the removal of various types of ceramic brackets, regardless of their design. However, the range of safe power usage for laser-aided debonding has not vet been confirmed. The Purpose of this study was to evaluate the histologic changes of pulpal tissue in a rabbit's incisor after Nd-YAG laser-aided ceramic bracket debonding at different levels of power. The result were as follows: 1. At 3-5W Nd-YAG laser power level and 3 seconds of exposure time, the ceramic bracket debonding procedure was not easy. At 5W of power a tie-wing fracture occurred on one bracket during debonding using Weingart plier. The histologic section of pulp represented no adverse changes. 2. At 7-13 W power level and less than 5 seconds of exposure time, the debracketing procedure was done easily and bracket facture did not occur. The histologic section of pulp represented mild and reversible changes. All the results were reversible and no pulpal degeneration or necrosis occurred. Considering the results, it appears that the laser-aided debonding technique is a safe method that does not result in irreversible pulpal changes, softens bracket bonding resin within a saie range of power and exposure time, and is useful for ceramic bracket recycling by lowering the tie- wing fracture rate.