• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.2430-2434
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• 2005

Automatic FPC punching instrument for the improvement of working condition and cost saving is introduced in this paper. FPC(flexible printed circuit) is used to detect the contact position of K/B and button like a cellular phone. Depending on the quality of the printed ink and position of reference punching point to the FPC, the resistance and current are varied to the malfunctioning values. The size of reference punching point is 2mm and the above. Because the punching operation is done manually, the accuracy of the punching degree is varied with operator's condition. Recently, The punching accuracy has deteriorated severely to the 2mm punching reference hall so that assembly of the K/B has hardly done. To improve this manual punching operation to the FPC, automatic FPC punching system is introduced. Precise mechanical parts like a 5-step stepping motor and ball screw mechanism are designed and tested and low cost PC camera is used for the sake of cost down instead of using high quality vision systems for the FA. 3D Mechanical design tool(Pro/E) is used to manage the exact tolerance circumstances and avoid design failures. Simulation is performed to make the complete vision based punching machine before assembly, and this procedure led to the manufacturing cost saving. As the image processing algorithms, dilation, erosion, and threshold calculation is applied to obtain an exact center position from the FPC print marks. These image processing algorithms made the original images having various noises have clean binary pixels which is easy to calculate the center position of print marks. Moment and Least square method are used to calculate the center position of objects. In this development circumstance, Moment method was superior to the Least square one at the calculation of speed and against noise. Main control panel is programmed by Visual C++ and graphical Active X for the whole management of vision based automatic punching machine. Operating modes like manual, calibration, and automatic mode are added to the main control panel for the compensation of bad FPC print conditions and mechanical tolerance occurring in the case of punch and die reassembly. Test algorithms and programs showed good results to the designed automatic punching system and led to the increase of productivity and huge cost down to law material like FPC by avoiding bad quality.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.4.1-4.10
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• 2019

Background: The mandibular third molar (M3) is typically the last permanent tooth to erupt because of insufficient space and thick soft tissues covering its surface. Problems such as alveolar bone loss, development of a periodontal pocket, exposure of cementum, gingival recession, and dental caries can be found in the adjacent second molars (M2) following M3 extraction. The specific aims of the study were to assess the amount and rate of bone regeneration on the distal surface of M2 and to evaluate the aspects of bone regeneration in terms of varying degree of impaction. Methods: Four series of panoramic radiographic images were obtained from the selected cases, including images from the first visit, immediately after extraction, 6 weeks, and 6 months after extraction. ImageJ software^® (NIH, USA) was used to measure linear distance from the region of interest to the distal root of the adjacent M2. Radiographic infrabony defect (RID) values were calculated from the measured radiographic bone height and cementoenamel junction with distortion compensation. Repeated measures of analysis of variance and one-way analysis of variance were conducted to analyze the statistical significant difference between RID and time, and a Spearman correlation test was conducted to assess the relationship between Pederson's difficulty index (DI) and RID. Results: A large RID (> 6 mm) can be reduced gradually and consistently over time. More than half of the samples recovered nearly to their normal healthy condition (RID ≤ 3 mm) by the 6-month follow-up. DI affected the first 6 weeks of post-extraction period and only showed a significant positive correlation with respect to the difference between baseline and final RID. Conclusions: Additional treatments on M2 for a minimum of 6 months after an M3 extraction could be recommended. Although DI may affect bone regeneration during the early healing period, further study is required to elucidate any possible factors associated with the healing process. The DI does not cause any long-term adverse effects on bone regeneration after surgical extraction.

• Journal of Oral Medicine and Pain
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• v.37 no.4
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• pp.251-256
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• 2012

With today's heightened interest in quality of life, leisure and sports activities were popular in the general public. Accordingly, the incidence of oral and maxillofacial injury are also rising. Use of a mouth protector to prevent the trauma of the oral and maxillofacial region is growing in importance, and among the mouth protector the mouthguard is the most commonly used. Mouthguard has been suggested to protect injuries by (1) preventing tooth injuries by absorbing and deflecting blows to the teeth; (2) shielding the lips, tongue, and gingival tissues from laceration; (3) preventing opposing teeth from coming into violent contact; (4) providing the mandible with resilient support, which absorbs an impact that might fracture the unsupported angle or condyle of the mandible; (5) preventing neck and cerebral brain injuries. Although mouthguard is effective for prevention of oral and maxillofacial injury, it is not widespread to athletes or general public and they are lack of awareness about the importance of mouthguard. We present the types and materials of mouthguard, things to consider when mouthguard fabrication, and the usage. This should be helpful in awareness about the importance and popularization of mouthguard.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.4
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• pp.292-300
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• 2004

Orbital blowout fractures are common consequence to blunt periorbital trauma. Pure orbital blowout fractures first occur at the weakest point of the orbital wall. Computed tomography(CT) is recognized to be the best imaging technique to evaluate orbital fractures. The extent and location of a blowout fractures in the CT scan were noted to have an effect on the clinical outcome. In the early posttraumatic period, the presence of significant enophthalmos is difficult to detect because of orbital edema. Early surgical intervention may improve the ultimate outcome because open reconstruction becomes more difficult if surgery is delayed. In this study, we evaluated isolated blowout fractures of the orbital floor by region-of-interest measurements from CT scans and their relationship to ophthalmologic findings. Six patients of the medial orbital wall fractures, eleven patients of the inferior orbital wall fractures, nineteen of the medial and the inferior orbital wall fractures confirmed by CT scan, were evaluated. The area of fracture and the volume of the displaced orbital tissue were determined from CT scan using linear measurements. Each of the calculated values for the area and the volume were compared with the degree of the enophthalmos, the diplopia, and the eyeball movement limitation to determine whether there was any significant relationship between them. The fracture area and the volume of the herniated orbital tissue were significantly positively correlated with the enophthalmos and the ocular motility limitation and not correlated with the diplopia. For the enophthalmos of 2mm or greater, the mean fracture area was 3.55{\pm}1.25cm^2$ and the volume of the herniated orbital tissue was $1.74{\pm}0.97cm^3$; for less than 2mm enophthalmos, $1.43{\pm}0.99cm^3$ and $0.52{\pm}0.49cm^3$, respectively. The enophthalmos of 2mm can be expected with $2.92cm^2$ of the fracture area and $1.40cm^3$ of the herniated orbital tissue. In conclusion, the enophthalmos of 2mm or more, which is a frequent indication for surgery. It can be expected when area of fracture is $2.92cm^2$ or more, or the volume of herniated orbital tissue is $1.40cm^3$ or more. And the CT scan using linear measurements has an application in the assessment of patients with blowout fractures and provides useful information in the posttraumatic evaluation of orbital fractures.

• 한국초등상담교육학회:학술대회논문집
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• 2004.01a
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• pp.205-222
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• 2004

Fundamental direction of the seventh education curriculum aims to nurture active and creative Koreans for globalized and information-oriented society of 21 century, and emphasizes the importance of career education identifying its subsections that are practices of student-focused education of aptitude, ability and career. Hence, as a clear targeting of career objective from elementary school through relevant career education enables them to recognize appropriate career for themselves, the basis of self- actualization and social contribution must be settled. This paper seeks to identify the relationship between career awareness and self-esteem by examining and analysing differences of sex, region and level. This study selected 536 samples from 4th and 6th year elementary school students in C city and S town of Chungcheong province. Career awareness test and self-esteem test is used as a measurement, statistical process control (SPC) of career awareness and self-esteem (M, SD, r) is made for each variable, and the significance was tested. The result of this research can be summarized as follows: First, generally there is very significant regional differences of career awareness (F=16.817, p<.001), which contains that urban children has higher career awareness (M=120.22) than that of rural children (M=113.87). In subsections of career awareness, self-esteem of urban children is higher than that of rural children, and the attitude & for career and values of girls is higher than that of boys. In terms of the career planning, urban children and 6th year students are higher than rural children and 4th year students. Second, self-esteem generally has very significant regional difference (F=12.123, p<.01), which contains that the self-esteem of urban children (M=106.50) is higher than that of rural children (M=101.80). In comparison of different forms, a very significant difference is as much as p<.01 level (F=11.046), which contains 4th year students (M=105.63) have higher self-esteem than 6th year students (M=102.05). In subsections of self-esteem, gross self-esteem and social self-esteem of urban children are higher than rural children. In terms of family self-esteem, urban children and 4th year students have higher figure than rural children and 6th year students. In school self-esteem, 4th year students had higher level than the 6th. Third, the career awareness and self-esteem are generally related as r= .50, it was very significant at p<. 001 level. All subsections of career awareness had positive relationships except the school self-esteem. According to the result, rural children had relatively low career awareness and self-esteem. This is presumably due to relatively poor circumstances for rural children, comparing to that of urban children. Therefore rural elementary schools should try to let them have appropriate career awareness by associating with family, school and local society to expand the opportunity of experiences for the self perception of aptitude, nature and interest. In addition, we have to strive for the whole-minded education increasing the self-esteem of rural children and giving them positive thinking through career counselling, personal counselling and group counselling.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.4
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• pp.429-434
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• 2012

This paper presents a technology for manipulating external devices by Brain Computer Interface (BCI) system. Recently, BCI based rehabilitation and assistance system for disabled people, such as patient of Spinal Cord Injury (SCI), general paralysis, and so on, is attracting tremendous interest. Especially, electroencephalogram (EEG) signal is used to organize the BCI system by analyzing the signals, such as evoked potential. The general findings of neurophysiology support an availability of the EEG-based BCI system. We concentrate on the event-related synchronization of motor imagery EEG signal, which have an affinity with an intention for moving control of external device. To analyze the brain activity, short-time Fourier transform and particle swarm optimization are used to optimal feature selection from the preprocessed EEG signals. In our experiment, we can verify that the power spectral density correspond to range mu-rhythm(${\mu}8$~12Hz) have maximum amplitude among the raw signals and most of particles are concentrated in the corresponding region. Result shows accuracy of subject left hand 40% and right hand 38%.

• Journal of Korean Home Economics Education Association
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• v.16 no.3
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• pp.43-61
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• 2004

This study is purposed to examine the interests of students and usefulness of TechnologyㆍHome Economics, which is a requirement for both male and female high school students. The targeted subject of this study were 533 high school sophomores and seniors in Kyungsangnamdo region and in consideration of regional differences, three high schools were selected in urban Jinju and three other schools were selected in countryside of Hapchun. The collected data was processed by SAS program, a social, scientific and statistical processing program. and analyzed the date using the statistical methods of frequency, percentage and average along with t-test and one-way ANOVA. The results and conclusions of this study are summarized as follow: 1. The interests of students' Technology. Home Economics. the respondents gave 3.10 points of the perfect 5.0. The influential variables to the interests of high school students to TechnologyㆍHome Economics were sex, type of school, location of inhabitation. grades, favor to textbook, and self-esteem. 2. The practical usefulness of students' TechnologyㆍHome Economics, the respondents gave 3.17 points of the perfect 5.0. The influential variables to the usefulness of TechnologyㆍHome Economics were sex, type of school, location of inhabitation, age of father, occupation of mother, domestic financial status, grades, favor to textbook and self-esteem.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.6
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• pp.102-109
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• 2014

A particle system is used for modeling the physical phenomenon. There are many traditional ways for simulation modeling which can be well suited for application including the landscapes of branches, clouds, waves, fog, rain, snow and fireworks in the three-dimensional space. In this paper, we present a new fireworks modeling technique for modeling 3D firework based on Firework Particle Tracking (FPT) using the particle system. Our method can track and recognize the launched and exploded particle of fireworks, and extracts relatively accurate 3D positions of the particles using 3D depth values. It can realize 3D simulation by using tracking information such as position, speed, color and life time of the firework particle. We exploit Region of Interest (ROI) for fast particle extraction and the prevention of false particle extraction caused by noise. Moreover, Kalman filter is used to enhance the robustness in launch step. We propose a new fireworks particle tracking method for the efficient tracking of particles by considering maximum moving range and moving direction of particles, and shall show that the 3D speeds of particles can be obtained by finding the rotation angles of fireworks. Also, we carry out the performance evaluation of particle tracking: tracking speed and accuracy for tracking, classification, rotation angle respectively with respect to four types of fireworks: sphere, circle, chrysanthemum and heart.

• Imaging Science in Dentistry
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• v.32 no.2
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• pp.107-111
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• 2002

Purpose : To compare the accuracy of digital subtraction images acquired by two different methods different in positioning four reference points for geometrical standardization. Materials and Methods : A total of 36 digital radiographic images of 6 volunteers were taken at the areas of the incisor, premolar, and molar of both the maxilla and mandible using the Digora system. Each image was moved 4 mm vertically and horizontally. Four oral and maxillofacial radiologists performed digital subtraction radiography between the paired images before and after movement using Emago (Oral Diagnostic Systems, Amsterdam, The Netherlands) and Sunny (Biomedisys Co., Seoul, Korea). The standard deviation of the internal gray value in Region of Interest (ROI) was statistically analyzed between the two programs using the paired t-test. Results : The standard deviation of pixel gray values from the digital subtraction images using the Sunny program were lower than that of the Emago program (p<0.05). All observers showed significant differences between each other when the Sunny program was used (p<0.05), but one observer showed a significantly higher score than other observers when they used Emago (p<0.05). The standard deviations of premolar area from both Sunny and Emago programs were significantly higher than those of anterior and molar regions (p<0.05). Conclusion: The subtracted images using the Sunny program were more accurate and sensitive than those taken using the Emago program.

• Korean Journal of Biological Psychiatry
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• v.22 no.4
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• pp.223-232
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• 2015

Objectives In this study, the authors evaluated the correlation between levels of serum lipid, homocysteine, and folate with volumes of hippocampus, amygdala, corpus callosum, and in patients with amnestic mild cognitive impairment (aMCI) or Alzheimer's disease (AD) type. Methods The study recruited patients who visited the dementia clinic of Haeundae Paik Hospital in Korea between March 2010 and June 2014. Among those, patients who had taken the neurocognitive test, brain magnetic resonance imaing, tests for serum lipid, homocysteine, folate, and apolipoprotein E (APOE) genotyping and diagnosed with aMCI or AD were included for analysis. Bilateral hippocampus, entorhinal cortex, amygdala and corpus callosum were selected for region of interest (ROI). The cross-sectional relationships between serum lipid, homocysteine, folate and ROI were assessed by partial correlation analysis and multiple linear regression analysis. Results In patients with aMCI, old age (> 80) and APOE ${\varepsilon}4$ carrier were associated with AD [odds ration (OR) : 12.80 ; 95% confidence interval (CI) : 2.25-72.98 and OR : 4.48 ; 95% CI : 1.58-12.67, respectively]. In patients with aMCI or AD, volumes and thickness of ROI were inversely correlated with levels of serum lipid and homocysteine. In multiple linear regression analyses, higher total cholesterol level was related to lower left, right hippocampus volume and left amygdala volume ; higher low-density lipoprotein cholesterol was related to lower right entorhinal cortex thickness ; higher homocysteine level was related to lower corpus callosum volume. Conclusions Higher serum lipid and homocysteine levels are associated with decreased volume of hippocampus, amygdala, corpus callosum and entorhinal cortex thickness in patients with aMCI or AD. These findings suggest that serum lipid and homocysteine levels are associated with AD as a modifiable risk factor.