• Journal of Periodontal and Implant Science
• /
• v.50 no.1
• /
• pp.28-37
• /
• 2020

Purpose: The aim of our study was to determine the prevalence and degree of lingual concavities in the first molar region of the mandible to reduce the risk of perforating the lingual cortical bone during dental implant insertion. Methods: A total of 163 suitable cross-sectional cone-beam computed tomography images of edentulous mandibular first molar regions were evaluated. The mandibular morphology was classified as a U-configuration (undercut), a P-configuration (parallel), or a C-configuration (convex), depending on the shape of the alveolar ridge. The characteristics of lingual concavities, including their depth, angle, vertical location, and additional parameters, were measured. Results: Lingual undercuts had a prevalence of 32.5% in the first molar region. The mean concavity angle was 63.34°±8.26°, and the mean linear concavity depth (LCD) was 3.03±0.99 mm. The mean vertical distances of point P from the alveolar crest (Vc) and from the inferior mandibular border were 9.39±3.39 and 16.25±2.44, respectively. Men displayed a larger vertical height from the alveolar crest to 2 mm coronal to the inferior alveolar nerve (Vcb) and a wider LCD than women (P<0.05). Negative correlations were found between age and buccolingual width at 2 mm apical to the alveolar crest, between age and Vcb, between age and Vc, and between age and LCD (P<0.05). Conclusions: The prevalence of lingual concavities was 32.5% in this study. Age and gender had statistically significant effects on the lingual morphology. The risk of lingual perforation was higher in young men than in the other groups analyzed.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.25 no.1
• /
• pp.197-208
• /
• 1998

This study was carried out to compare the amount of the maxillary bone remodeling and tooth displacement in each three maxillary superimposition methods, Ricketts, Best-fit, Structural method. Forty cases of the lateral cephalometric radiographs from 27 boys and 13 girls who had been treated to correct anterior cross-bite were selected for the study. The initial radiographs were taken at about 8-year-old and the second radiographs were taken in about 3.3 years later. Followings were the results: 1. With the Structural method, backward movement was shown in PNS, while forward movement was observed in ANS and point A. With the Ricketts method, however, all structures were shown significant backward movement comparing with Structural method(P<0.05). With the Best-fit method, the amount of horizontal movement was similar to that of the Structural method(P>0.05). 2. The palate seemed to be moved downward with Structural method, but there was no measured downward remodeling on nasal floor with Ricketts and Best-fit method(P<0.05). 3. Comparing with Structural method, Ricketts and Best-fit method significantly underestimated the eruption of the teeth by 20% to 30% (P<0.05). 4. The Structural method showed the anteroinferior rotation (43%) and posteroinferior rotation(57%) of the palatal plane, while the Best-fit method showed mostly anterosuperior rotation(87%), but no change was found in the Ricketts method. 5. With the Structural method, there was a statistically significant correlation between the amount of the rotation of the palatal plane and that of N-S line(r=0.86). 6. The measured angles of the long axis of the incisors and molars showed no significant difference in each 3 methods(P>0.05).

• Physical Therapy Rehabilitation Science
• /
• v.6 no.1
• /
• pp.20-25
• /
• 2017

Objective: During the physical therapy education, if we can understand the student's attitude then we can make valuable suggestions with respect to the teaching in the universities and professional employment in the country. The aim of the current study is to develop a questionnaire to test the physical therapy students' attitudes towards their education and profession and to test its test-retest reliability and content validity. Design: Cross-sectional study. Methods: A total of 47 physical therapy students who were in their final year were randomly selected to participate in the study. After the making of the questionnaire, it was given to 6 professional experts teaching in the field of physical therapy to obtain their responses for each question with a 5-point Likert scale grading. Their answers were used in making the content validity of the questionnaire. Afterwards, the physical therapy students were asked to fill the questionnaire. Instrument reliability and test-retest reliability were also assessed by having the students complete the questionnaire after one month of taking the questionnaire. Results: The content validity index was 0.71 for the whole scale and values of individual subdivisions were ranging from 0.69 to 0.75. Instrument reliability measured by Cronbach's alpha coefficient was 0.86 for the whole scale and subdivision values were ranging from 0.32 to 0.86. Test-retest reliability was assessed by intraclass correlation coefficient, which was 0.71 for whole scales and subdivision values were ranging from 0.38 to 0.70. Conclusions: This questionnaire, which assesses the physical therapy student attitude towards their education and profession, has good content validity, instrument reliability, and test-retest reliability.

• Perspectives in Nursing Science
• /
• v.10 no.2
• /
• pp.151-157
• /
• 2013

Purpose: The purpose of this study was to identify difficulties that working mothers face and solutions to the identified problems. Methods: The study design was a cross-sectional, descriptive survey. A survey with 8 items rated on a 5-point scale (1~5) and 5 open-ended questions was administered to 48 married nurses and nurse aides working in 5 nursing units of a teaching hospital in South Korea in April 2013. Results: The score of satisfaction with childrearing patterns (mean=$3.31{\pm}0.79$) was higher than that of satisfaction with spousal support (mean=$3.08{\pm}0.85$). The score of working mother's turnover intention (mean=$2.40{\pm}1.03$) was lowest among the 8 items, but partners did not want their wives to quit work (mean=$3.60{\pm}1.22$). Satisfaction with company employment benefits for childrearing (mean=$2.90{\pm}0.72$) had the lowest score among the 4 satisfaction types analyzed. The turnover intention and satisfactions with childrearing (r=-.51, p<.001), spousal support (r=-.43, p=.002), supervisor's support (r=-.36, p=.013), and company benefits (r=-.37, p=.009) showed significant negative correlations. Conclusion: According to these results, familial support for childrearing is highly correlated with employed mothers' turnover intention. So improvement of familial support for childrearing will reduce married nurses' turnover intention. In addition, well-organized nursery facilities are recommended for enabling working mothers to continue their careers. Furthermore, more family-friendly welfare policies such as a flextime systems or compulsory paternity leave should be reinforced in the workplace.

• Korean Journal of Materials Research
• /
• v.1 no.2
• /
• pp.99-104
• /
• 1991

Trantalum thin films have been prepared by DC sputtering onto As, P, and $BF_2$-implanted ($5{\times}10^15cm^-2$) poly-silicon. The heat treatments by rapid thermal annealing(RTA) have been applied to these samples for the formation of silicides. We have studied the application possibility of Ta-silicide as gate electrode and bit line. The silicide formation and the dopant diffusion after the heat treatment were investigated by various methods, such as four-point probe, X-ray, SEM cross sectional views, ${\alpha}$-step, and SIMS, The tantalum disilicide($TaSi_2$) are formed in the temperature above $800^{\circ}C$, and grown in colummar structure. $TaSi_2$ has a good surface roughness, having range from $80{\AA}\;to\;120{\AA}$, and implanted dopants are incoporated into the $TaSi_2$ layer during the RTA temperature.

• Journal of Korean Biological Nursing Science
• /
• v.21 no.4
• /
• pp.249-258
• /
• 2019

Purpose: The purpose of this study was to assess the psychosocial status of candidates for deceased donor kidney transplantation (DDKT) in South Korea and identify factors associated with high-risk psychosocial status. Methods: The descriptive cross-sectional design included application of a standardized transplantation-specific assessment tool, the Psychosocial Assessment Candidacy Transplantation (PACT) instrument, and review of candidates' medical records. A total of 157 patients awaiting DDKT were recruited from a Korean organ transplantation center. The collected data were analyzed using descriptive statistics and binary logistic regression. Candidates were divided into high- and low-psychosocial risk groups using 3 as the cutoff point of PACT. Results: The mean score for the PACT final rating was 2.10, and the lowest average subscale score was 2.30 for understanding the processes of transplantation and follow up. Poor physical candidacy, especially due to comorbidities, and older age were associated with high psychosocial risk. Conclusion: The results of this study showed that the psychosocial status of Korean DDKT candidates was problematic. Development of systematic management programs for effective clinical strategies in the care of candidates is crucial to maintain their desirable psychosocial status in case of an emergency DDKT operation and improve post-transplantation outcomes. Continuous education is absolutely necessary to enhance understanding of the transplantation process for high-risk psychosocial candidates. Additionally, nurses and transplantation professionals should screen candidates with high-risk psychosocial status early in the process using transplantation-specific assessment tools and provide intensive interventions, particularly for poor physical candidacy patients and older candidates.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.1C
• /
• pp.28-36
• /
• 2009

Time-memory trade-off (TMTO) cryptanalysis proposed by Hellman can be applied for the various crypto-systems such as block ciphers, stream ciphers, and hash functions. In this paper, we propose a novel method to reduce memory size for storing TMTO tables. The starting points in a TMTO table can be substituted by the indices of n-bit samples from a sequence in a family of pseudo-random sequences with good cross-correlation, which results in the reduction of memory size for the starting points. By using this method, it is possible to reduce the memory size by the factor of 1/10 at the cost of the slightly increasing of operation time in the online phase. Because the memory is considered as more expensive resource than the time, the TMTO cryptanalysis will be more feasible for many real crypto systems.

• Journal of Korean Medicine Rehabilitation
• /
• v.28 no.4
• /
• pp.1-9
• /
• 2018

Objectives Disuse muscle atrophy occurs in response to pathologies such as joint immobilization, inactivity or bed rest. Muscle disuse is accompanied by an increase in apoptotic signaling, which mediates some of the responses to unloading in the muscle. GB34 (Yanglingquan) is a acupuncture point on the lower leg and one of the most frequently used points in various skeletomuscular diseases. In this study, the hypothesis that the acupuncture at GB34 could attenuate immobilization-induced skeletal muscle atrophy was tested. Methods The left hindlimb immobilization was performed with casting tape in both GB34 group (n=10) and Control group (n=10). The rats in GB34 group were daily treated with acupuncture at GB34. After 2 weeks of immobilization, the morphology of right and left gastrocnemius muscles in both GB34 and Control groups were assessed by hematoxylin and eosin staining. To investigate the immobilization-induced muscular apoptosis, the immunohistochemical analysis of Bax and Bcl-2 was carried out. Results GB34 group represented the significant protective effects against the reductions of the left gastrocnemius muscles weight and average cross section area to compared with Control group. The acupuncture at GB34 significantly reduced the immunoreactivity of BAX and increased the immunoreactivity of Bcl-2 in gastrocnemius muscle compared with Control group. Conclusions These results suggest that the acupuncture at GB34 has protective effects against immobilization-induced muscle atrophy by regulating the activities of apoptosis-associated BAX/Bcl-2 proteins in gastrocnemius muscle.

• Journal of Navigation and Port Research
• /
• v.34 no.5
• /
• pp.331-336
• /
• 2010

The free surface influenced the wake behind a circular cylinder and its effects were investigated experimentally in a circulating water channel with the variation of water depth. Instantaneous velocity fields were measured in this paper. The measured results has been compared with each other to investigate the flow characteristics of the circular cylinder's 2-dimensional section at $Re=1.0{\times}10^3$ using 2-frame grey level cross correlation PIV method. The flow around the circular cylinder with free surface affected the wake structure. Especially, in case of d=1.0D, the boundary layer was measured in the whole area. The separation point and boundary layer of the circular cylinder could be controlled by the water depth.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.11
• /
• pp.7244-7249
• /
• 2015

In this study, in order to asses the structural performance of trapezoidal PSC girder using a socket joint system and it is possible to calculate the optimized cross-section of the web element tests were carried out for each specimens. we conducted a socket joint performance test, web bending and shear performance tests and all tests were performed at 4 point loading method. The initial crack load of socket joint specimen was significantly lower than the reference specimen but post peak behavior was no significant differences. And the length of the loop joint of the reinforcing bars had no significant effect on the maximum load. As a web shear tests, to obtain a maximum load of the specimen has a prestressing rod reinforced at tension side. As a web flexural tests, to obtain higher diagonal cracking load in specimen of reinforced using prestressing rod than reference specimen.