• Korean Journal of Applied Biomechanics
• /
• v.28 no.3
• /
• pp.181-185
• /
• 2018

Objective: The purpose of this study was to investigate the effect of types of drive-in initial steps in basketball on technical factors, to provide basic information for the enhancement of basketball skill. Method: Ten men (age: $24.70{\pm}2.26years$; height: $181.00{\pm}5.72cm$; weight: $75.70{\pm}8.23kg$; career length: $10.00{\pm}3.59years$), each with a career length of over five years and no history of injury to the lower extremities within the prior six months, participated in this study. They were asked to perform four types of drive-in movements at $35{\sim}60^{\circ}$, wearing their own shoes, after running from a start line 5 m away and catching a basketball passed by an expert passer. The drive-in movements were measured by eight infrared cameras (Oqus 300, Qualisys, Sweden). Collected raw data were used to calculate total initial step time, displacement, velocity, center of mass (COM) height, and COM velocity. Results: Total initial step displacement and velocity of cross drive-ins (JC, SC) were greater than that of direct drive-ins (JD, SD; p < .05). COM velocity of cross drive-ins (JC, SC) was also greater than that of direct drive-ins (JD, SD; p < .05). Conclusion: Our results indicated that cross drive-ins, regardless of stop step type, are more effective than direct drive-ins. This is because cross drive-ins are technically bold due to less influence from walking violations and double dribble rules in basketball. However, using one-sided movement is too difficult to play in competitive game; therefore, basketball players should develop the ability to choose appropriate movement frequency.

• Korean Journal of Community Nutrition
• /
• v.6 no.4
• /
• pp.678-685
• /
• 2001

Although breastfeeding is recognized to be vital to the health and well-being of children and women, the rate of breastsfeeding among Korean women has continuously decreased. One barrier to breastfeeding has been identified to be associated with health care providers. Health care professionals do not give sufficient advice and encouragement, next do hospitals provide supportive environments for breastfeeding by separating infants from mothers or providing formula. The purpose of this study was to investigate prenatal breastfeeding education and infant feeding practices in public health centers and baby-friendly hospitals. A telephone survey was carried out on 57 public health centers located in the Seoul and Chungcheong areas and 13 baby-freindly hospitals from February to April in 2000. Among the public health centers, 43.8% offered periodic prenatal education for pregnant women who visited the centers. Most of them used leaflets or pamphlets developed by the Ministry of Health and Welfare or UNICEF. Twenty six percent of the public health centers developed their own educational materials. All of the 13 baby-friendly hospitals gave additional fluids to infants, did not allow mothers and infants to stay together 24 hours a day, and did not foster the establishment of breatfeeding support groups among the mothers. Most of the baby-friendly hospitals gave artificial teats, did not help mothers initiate breastfeeding within a half-hour of birth. Findings indicate that current practices even in the baby-friendly hospitals are not consistent with the '10 steps to success breastfeeding'. Therefore, deliberate efforts should be made to incorporate adequate breastfeeding education into prenatal program in both public health centers and hospitals, and create environments to support breastfeeding in hospitals, even in baby-friendly hospitals.

• The Journal of the Korea Contents Association
• /
• v.18 no.1
• /
• pp.314-326
• /
• 2018

The purpose of this study was to evaluate the usability of a hybrid mobile reading game among 14 parents of children with reading disabilities. The reading game consisted of six steps according to the process of reading (familiarizing with consonants and vowels, acquiring whole words, combining consonants and vowels, reading words, phonological rules, reading fluency). In this study, parents experienced steps one through three of the reading-game app and evaluated the general design features and Universal Design for Learning on a five-point scale. Regarding the general design features, parents rated usability (18 items in total) as high in the following order: interactive design, instructional design, and interface design. Regarding the Universal Design for Learning (9 items in total), parents evaluated usability as high in the following order: providing multiple means of representation, providing multiple means of action and expression, and providing multiple means of engagement. Lastly, suggestions for the improvement of the app, practical implications, and suggestions for future research are discussed.

• Imaging Science in Dentistry
• /
• v.42 no.3
• /
• pp.163-167
• /
• 2012

Purpose: ANSI/ADA has established standards for adequate radiopacity. This study was aimed to assess the changes in radiopacity of composite resins according to various tube-target distances and exposure times. Materials and Methods: Five 1-mm thick samples of Filtek P60 and Clearfil composite resins were prepared and exposed with six tube-target distance/exposure time setups (i.e., 40 cm, 0.2 seconds; 30 cm, 0.2 seconds; 30 cm, 0.16 seconds, 30 cm, 0.12 seconds; 15 cm, 0.2 seconds; 15 cm, 0.12 seconds) performing at 70 kVp and 7 mA along with a 12-step aluminum stepwedge (1 mm incremental steps) using a PSP digital sensor. Thereafter, the radiopacities measured with Digora for Windows software 2.5 were converted to absorbencies (i.e., A=-log (1-G/255)), where A is the absorbency and G is the measured gray scale). Furthermore, the linear regression model of aluminum thickness and absorbency was developed and used to convert the radiopacity of dental materials to the equivalent aluminum thickness. In addition, all calculations were compared with those obtained from a modified 3-step stepwedge (i.e., using data for the 2nd, 5th, and 8th steps). Results: The radiopacities of the composite resins differed significantly with various setups (p<0.001) and between the materials (p<0.001). The best predicted model was obtained for the 30 cm 0.2 seconds setup ($R^2$=0.999). Data from the reduced modified stepwedge was remarkable and comparable with the 12-step stepwedge. Conclusion: Within the limits of the present study, our findings support that various setups might influence the radiopacity of dental materials on digital radiographs.

• Preventive Nutrition and Food Science
• /
• v.18 no.4
• /
• pp.249-255
• /
• 2013

Yam (Dioscorea) has long been used as foods and folk medicine with the approved positive effects for health promotion. Although consumption of yam products is increasing for health promotion, reports for the metal contamination in commercial yam powder products to protect the consumers are lacking. In this study, we aimed to assess whether the commercial yam powder products were heavy metal contaminated or not using the yam products from six commercial products from various places in South Korea. The contents of heavy metals (Cd, Cr, As, Pb, Ni, and Sn) in yam powder products were measured and compared to national and international food standard levels. Also, the metal contamination was monitored during the food manufacturing steps. The study results showed that the contents of heavy metals (Cd, Cr, As, and Pb) in yam powder products are similar to those in national 'roots and tubers' as well as in various crops. In comparison to three international standard levels (EU, Codex and Korea), Cd content in yam powder products was lower but Pb content was 5 times higher. Also, Pb, Ni, and Sn may have the potential to be contaminated during food manufacturing steps. In conclusion, the level of heavy metals (Cd, Cr, As, Ni, and Sn) except Pb is considered relatively safe on comparison to national and international food standard levels.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.53 no.3
• /
• pp.256-265
• /
• 2017

Seafood is attracting attention as a future food industry. In recent years, the demand for fishery equipment of mechanization, automation, and unmanned was increased due to the environment affected by seafood processing, stricter regulations on safety, decline and aging of fishery worker. Ark shell (Scapharca subcrenata) was being produced in many steps in the production process. The process has been made such as collection-landing-washing-first sort (goods/non-goods)-transports-second sort (size). It was undergone first and second steps by delivering to the consumer. Here, the first step is to sort goods to collection and the second step is to sort by size. The fishery workers need ten people in first step and six people in second step. The workload of one hour per kg is 4,247 kg/h in first step and 2,213 kg/h in second step. In addition, the goods ratio by work process was 79% in first step and 98% in the second step. In this process, a lot of fishery worker and working time is needed. Therefore, this study developed elemental techniques for an automated size sorting system considering the working process problem, time and situation for washing and sorting of ark shell.

• Clinical and Experimental Reproductive Medicine
• /
• v.32 no.2
• /
• pp.177-185
• /
• 2005

Objective: This study was conducted to find an optimal condition for the vitrification of mouse morulae and expanded blastocysts. Materials and Methods: Mouse embryos were obtained at 2-cell stage and cultured to morula and expanded blastocyst stage in Human Tubal Fluid (HTF) medium supplemented with 10% Serum Substitute Supplement (SSS). The vitrification solutions used were EFS30, EFS35 and EFS40 that contains 30%, 35% and 40% ethylene glycol, respectively, with 18% ficoll and 0.5 M sucrose diluted in Dulbecco's phosphate-buffered saline (DPBS) medium supplemented with 10% SSS. The vitrification procedure was performed in EFS solution with three steps, followed by thawing in 6 steps with 0.5 M sucrose, and then survival and hatching-hatched rate per embryos recovered were compared among six groups. Results: After 24 h culture in different vitrification and thawing solution, the survival rate of morula embryos was 94.1%, 85.4% and 59.7% for EFS30, EFS35 and EFS40 group, respectively. Hatching rate of morula embryos after 72 h culture was 30.6%, 25% and 11.3% for EFS30, EFS35 and EFS40 group, respectively. The survival rate of expanded blastocyst embryos after 24 h culture was 90.4%, 98.5% and 100% for EFS30, EFS35 and EFS40 group, respectively. Hatching rate of expanded blastocyst embryos after 48 h culture was 46.2%, 57.6% and 64.3% for EFS30, EFS35 and EFS40 group, respectively. Conclusion: The EFS30 solution was the best for vitrification of mouse morulae. The EFS40 solution was the best for vitrification of mouse expanded blastocysts. The mouse expanded blastocyst was better than mouse morula for vitrification of mouse embryos.

• Journal of Korean Physical Therapy Science
• /
• v.26 no.1
• /
• pp.35-44
• /
• 2019

Purpose: The purpose of this study is to investigate the effect of visual and auditory stimulation randomly applied to healthy adults on walking. Design: Randomized Controlled Trial. Methods: Twenty-six healthy students in S college were randomly divided into visual feedback group (n=13) and auditory feedback group (n=13). The visual feedback group walked using four conditions. 1) In the red screen was shown, clap twice to the right, 2) In yellow screen, clap twice to the left, 3) In green screen, clap twice over head. 4) Do not clap in purple screen. The auditory feedback group walked using four conditions. 1)in red, clap twice to the right, 2) In yellow, clap twice left, 3) In green, clap twice over your head. 4) Do not clap in purple. All subjects measured gait variables before and after the test using G-walker. Result: The visual feedback group showed a significant decrease (p<.05) in the number of steps per minute, walking speed, and step length compared with that of normal walking. The auditory feedback group showed a significant decrease (p<.05) in the number of steps per minute, walking speed, and step length than that of normal walking. Conclusion: The results of this study suggest that visual and auditory stimulation applied to healthy adults may have significant effects on walking.

• Proceedings of the ESK Conference
• /
• 1997.04a
• /
• pp.56-60
• /
• 1997

The study of human erroneous actions has traditionally taken place along two different lines of approach. One has been concerned with finding and explaining the causes of erroneous actions, such as studies in the psychology of "error". The other has been concerned with the qualitative and quantitative prediction of possible erroneous actions, exemplified by the field of human reliability analysis (HRA). Another distinction is also that the former approach has been dominated by an academic point of view, hence emphasising theories, models, and experiments, while the latter has been of a more pragmatic nature, hence putting greater emphasis on data and methods. We have been developing a method to make predictions about error modes. The input to the method is a detailed task description of a set of scenarios for an experiment. This description is then analysed to characterise thd nature of the individual task steps, as well as the conditions under which they must be carried out. The task steps are expressed in terms of a predefined set of cognitive activity types. Following that each task step is examined in terms of a systematic classification of possible error modes and the likely error modes are identified. This effectively constitutes a qualitative analysis of the possibilities for erroneous action in a given task. In order to evaluate the accuracy of the predictions, the data from a large scale experiment were analysed. The experiment used the full-scale nuclear power plant simulator in the Halden Man-Machine Systems Laboratory (HAMMLAB) and used six crews of systematic performance observations by experts using a pre-defined task description, as well as audio and video recordings. The purpose of the analysis was to determine how well the predictions matiched the actually observed performance failures. The results indicated a very acceptable rate of accuracy. The emphasis in this experiment has been to develop a practical method for qualitative performance prediction, i.e., a method that did not require too many resources or specialised human factors knowledge. If such methods are to become practical tools, it is important that they are valid, reliable, and robust.

• Restorative Dentistry and Endodontics
• /
• v.48 no.4
• /
• pp.36.1-36.15
• /
• 2023

Objectives: This study aimed to compare the effectiveness of a single-file reciprocating system (WaveOne Gold, WOG) and a multi-file rotary system (ProTaper Universal Retreatment, PTUR) in removing canal filling from severely curved canals and to evaluate the possible adjunctive effects of XP-Endo Finisher (XPF), the Self-Adjusting File (SAF), and an erbium, chromium: yttrium, scandium, gallium garnet (Er,Cr:YSGG) laser using microcomputed tomography (µCT). Materials and Methods: Sixty-six curved mandibular molars were divided into 2 groups based on the retreatment technique and then into 3 based on the supplementary method. The residual filling volumes and root canals were evaluated with µCT before and after retreatment, and after the supplementary steps. The data were statistically analyzed with the t-test, Mann-Whitney U test, analysis of covariance, and factorial analysis of variance (p < 0.05). Results: PTUR and WOG showed no significant difference in removing filling materials (p > 0.05). The supplementary techniques were significantly more effective than reciprocating or rotary systems only (p < 0.01). The supplementary steps showed no significant differences in canal filling removal effectiveness (p > 0.05), but XPF showed less dentin reduction than the SAF and Er,Cr:YSGG laser (p < 0.01). Conclusions: The supplementary methods significantly decreased the volume of residual filling materials. XPF caused minimal changes in root canal volume and might be preferred for retreatment in curved root canals. Supplementary approaches after retreatment procedures may improve root canal cleanliness.