• Journal of Technologic Dentistry
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• v.37 no.3
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• pp.131-144
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• 2015

Purpose: This study set out to propose plans for more efficient and effective clinical practice by investigating the current state of clinical practice in the field of dental technology and thus provide basic data to develop pre- and post-education programs for clinical practice. Methods: The subjects include dental technicians at dental technical laboratories that were appointed as the place of clinical practice by the Department of Dental Technology of G University. The survey period spanned from December 22, 2014 to January 20, 2015. Total 250 questionnaires were distributed to them, and 190(76.0%) were returned. After excluding 23 whose answers were uncertain or seemed to lack reliability, total 167(66.8%) were used in final analysis. Results: 1. The most frequent practice the student did during clinical practice was articulator attachment, which was followed by pin operation or model making, one's own task and practice, sand and crow sculpturing, burying, casting, and grinding. 2. In case of going through the entire process, porcelain had the most students at 39(23.4%), being followed by crown & bridge at 28(16.8%), clinical model at 23(13.8%), full denture at 17(10.2%), and partial denture at 17(10.2%) in the order. 3. Of the students, 59.8%(30.5% for reinforced basic practice; 29.3% for intensive practice education) said that intensive practice education should be reinforced in school; and 22.3% said that intensive theory and practice education was needed, which indicates that 82.6% voiced their opinion of reinforcing education around practice. 4. The students felt that they lacked diligence, passion, and theoretical knowledge somewhat and were relatively good at clinical adaptation and operational skills. Conclusion: The findings show that the students felt an absolute lack of practice education as the school education was focused on theory and national exams in the field of dental technology, thus raising a need to reinforce practice education. Of all the respondents, 62.9% said there was a need to improve the current education with a focus on jobs. In future, education of dental technology should work to bring up able dental technicians that can perform in clinical dental technology right after graduation by reinforcing job-based practice education.

• Imaging Science in Dentistry
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• v.33 no.2
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• pp.79-83
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• 2003

Purpose : To assess the relationship between the direction of the indicating rod of the radiographic stent for ideal prosthetic design and the actual possible path of implant fixture placement when residual ridge resorption is considered. Materials and Methods: The study materials consisted of 326 implant sites (male 214 cases and female 112 cases) from a total of 106 patients (male 65 patients and female 41 patients) who desired implant prostheses. Computed tomography of patients were taken and reformatted using ToothPix/sup (R)/ software. Bony defects, bony sclerosis, the change of the direction of indicating rod, and root proximity of the adjacent teeth were examined on the CT-derived images. Results: The rate of the irregular crestal cortex was relatively high on premolar and molar area of maxilla. Mandibular molar area showed relatively high rate of focal sclerosis on the area of implant fixture insertion. The position of the indicating rods were relatively acceptable on the molar areas of both jaws. However, the position of the indicating rods should be shifted to buccal side with lingual rotation of the apical end on maxillary anterior teeth and premolar area. Conclusion: Clinically determined rod direction and position of the indicating rod for implant placement was not always acceptable for insertion according to the reformatted CT images. The pre-operative treatment plan for implant should be determined carefully, considering the state of the alveolar bone using the reformatted CT images.

• International Journal of Advanced Culture Technology
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• v.5 no.1
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• pp.58-63
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• 2017

Emergencies and disasters can happen any time without any warning, and things can change and escalate very quickly, and often it is swift and decisive actions that make all the difference. It is a responsibility of the building facility management to ensure that a proven evacuation plan in place to cover various worst scenario to handled automatically inside the facility. To mapping out optimal safe escape routes is a straightforward undertaking, but does not necessarily guarantee residents the highest level of protection. The emergency evacuation navigation approach is a state-of-the-art that designed to evacuate human livings during an emergencies based on real-time decisions using live sensory data with pre-defined optimum path finding algorithm. The poor decision on causalities and guidance may apparently end the evacuation process and cannot then be remedied. This paper propose a cloud connected emergency evacuation system model to react dynamically to changes in the environment in emergency for safest emergency evacuation using IoT based emergency exit sign system. In the previous researches shows that the performance of optimal routing algorithms for evacuation purposes are more sensitive to the initial distribution of evacuees, the occupancy levels, and the type and level of emergency situations. The heuristic-based evacuees routing algorithms have a problem with the choice of certain parameters which causes evacuation process in real-time. Therefore, this paper proposes an evacuee routing algorithm that optimizes evacuation by making using high computational power of cloud servers. The proposed algorithm is evaluated via a cloud-based simulator with different "simulated casualties" are then re-routed using a Dijkstra's algorithm to obtain new safe emergency evacuation paths against guiding evacuees with a predetermined routing algorithm for them to emergency exits. The performance of proposed approach can be iterated as long as corrective action is still possible and give safe evacuation paths and dynamically configure the emergency exit signs to react for real-time instantaneous safe evacuation guidance.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.36-43
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• 2010

Changes in runoff and soil erosion at slightly hilly erosive plots with pear trees over a three-year period were monitored under two distinct types of weed treatment by herbides : (1) pre-emergence herbicide with glyphosate; (2) post-emergence herbicide with paraquat. The numbers of rainfall events from June to Nov for three years of experimental periods were approximately 50 times in the plots having 5.5%to 10.2%slope at an altitude of 125 m. The steady-state infiltration rate was generally increased in the bare plot from which all weeds were removed while it was decreased in the herbicide treated plots and control. The runoffs from the control plot during the experimental periods were always less than those from plots of the herbicide-treated and the bare. The runoff under the same rainfall intensity was decreased in the order of bare, glyphosate, paraquat, and control. This results indicated that the removal time of weed by the different types of herbicides might influenced the runoff rate. For the first two years of the experimental periods, loss of fine fraction was much greater than that of coarse fraction while soil loss was correlated neither with total rainfall nor amount of runoff. The soil erosion rate under the same rainfall intensity was increased in the order of control, glyphosate, paraquat, and bare plot. However, there were not much differences in the soil loss for all plots under a relatively lower rainfall intensity less than 30 mm $day^{-1}$, resulting in rainfall intensity was important factor on soil erosion.

• Korean Journal of Agricultural Science
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• v.2 no.1
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• pp.151-177
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• 1975

To obtain the informations on the checking factors of the effecient utilization of paddies in chungnam province and study on the effecient working system and high productive cropping system in paddies, the utilization state of paddies including environmental conditions were investigated at sample 1,500 farms. The results obtained are summarized as follows; 1. The difficulty of drainage in paddies was the most important factor checking the utility of paddies. Delayed transplanting of rice and lack of labour were also important checking factors on the efficient utilization of paddies. 2. The utilization of paddies was rather effecient at small size farms of which farmers were almost poor, and most of them cultivated barley for their own food. 3. Considering climatic conditions, pre-crops of rice must be harvested before June 10 tho and the marginal transplanting date of rice plant is June 25 th. 4. In case of planting barley as a post-crop after rice, the spread seeding by rotary before plowing was most efficient with lowest cost. 5. Considering rice cultivation, yield of barley and net income, the most efficient cropping system was "Josaengtongil + Olbori".

• Journal of Korean Foot and Ankle Society
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• v.6 no.2
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• pp.181-189
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• 2002

Purpose: We try to evaluate the functional outcomes of the ankle with isokinetic plantaflexion torque for acute achilles tendon rupture cases those treated by primary repair with the Krackow suture technique and early rehabilization. Materials and Method: The authors studied retrospectively, 15 patients of acute achilles tendon rupture treated and followed over six months, from July 1997 to May 2001. There were 12 men and 3 women, and mean age was 39.6year. The repair method of ruptured tendon was single or double Krackow suture technique. One week(5days-2weeks) after operation, early ROM with ankle-foot orthosis was started. We used Arner-Lindholm Scale for the clinical evaluation and analyzed patient's satisfaction and subjective strength deficit. We analyzed the dorsiflexion peak torque and plantarflexion peak torque of the ankle statistically with strength test with Cybex dynamometer. Result: In clinical results, we had 11 excellent cases(73%) and 3 good cases(20%). In patients satisfaction degree, 11 excellent cases(66.6%), 3 good cases(20%) and 2 fair cases(13.4%). And in strength deficit, 3 none deficit (20%), 9 minimal deficit(60%). We evaluated the isokinetic plantar flexion torque in 3months or 6months after operation. After 3 months, isokinetic test showed the mean functional deficits, 32% and 25% at $30^{\circ}$ and $120^{\circ}/sec$, in 7 cases(46.6%) of 15 cases respectively. After 6 months, the mean deficits were in 21%, 24% at 30. and $120^{\circ}/sec$, respectively. At 3 and 6 months' follow up, absolute value of isokinetic test showed increase of 25. 31bs to 421bs and 19.61bs to 271bs at $30^{\circ}$ and $120^{\circ}/sec$, respectively. Conclusion: We had good result for acute achilles tendon rupture treated by Krakow suture technique and early range of motion exercise of the ankle. After 6 months, strength deficit was 21% in all of cases but were able to return pre-injured state. This study shows Krakow suture technique was recommended method for primary repair and early rehabilization of achilles tendon ruptue.

• Journal of the Korea Convergence Society
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• v.11 no.9
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• pp.277-285
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• 2020

The purpose of this study was to evaluate the effects of wearing Head-Mounted Display (HMD) on the cervical range of motion (CROM), neck muscle thickness, and pain in healthy young adults. The HMD group(male=16, female=7) was asked to perform sitting comfortably in a backless chair with hands on their knees with the HMD was worn on their heads to watch the video for 30 minutes. The control group(male=15, female=8) was asked to sit in the same posture as the HMD group for 30 minutes. CROM, neck muscle thickness, and pressure pain threshold (PPT) of both the upper trapezius and levator scapulae were measured before and after intervention. CROM and PPT of the upper trapezius and levator scapulae in the HMD group were significantly decreased and the thickness of the muscles in the HMD group were significantly increased more than in the pre-test (p<.05). There was no significant difference in CROM, muscle thickness, and PPT in the control group. Wearing HMD for a long time can cause a decrease in CROM and PPT and an increase in muscle thickness, and there is a risk of developing musculoskeletal disorders in the neck and shoulder. Therefore, this study recommends maintaining the correct posture of the neck and shoulder and using HMD only for an appropriate time.

• Reproductive and Developmental Biology
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• v.30 no.3
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• pp.157-162
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• 2006

Endogenous 84 amino acid parathyroid hormone(PTH) is synthesized as a pre-pro hormone by the chief cells of the parathyroid glands. Physiological actions of PTH include regulation of bone metabolism, renal tubular reabsorption of calcium and phosphate, and intestinal calcium absorption. In addition, PTH stimulates new bone formation by extraordinary stimulation of osteoblastic activity and decreasing calcium excretion by the kidney. In this study, we constructed and tested retrovirus vectors designed to express the human parathyroid hormone(hPTH) gene under the control of the tetracycline-inducible promoters. To increase the hPTH gene expression at turn-on state, woodchuck hepatitis virus posttranscriptional regulatory element(WPRE) sequence was also introduced into retrovirus vector at downstream region of either the hPTH gene or the sequence encoding reverse tetracycline-controlled transactivator(rtTA). Transformed primary culture cells(porcine fetal fibroblast, PFF, chicken embryonic fibroblast, CEF) were cultured in the medium supplemented with or without doxycycline(tetracycline derivative) for 48 hours, and induction efficiency was measured by comparing the hPTH gene expression level using two step RT-PCR and ELISA Higher hPTH expression($3{\tims}10^4\;pg/ml,\;5.3{\times}10^4\;pg/ml$) and tighter expression control(up to 8 fold) were observed from the vector in which the WPRE sequence was placed at downstream of the hPTH gene. The resulting tetracycline inducible vector system may be helpful in solving serious physiological disturbance problems which have been a major obstacle in successful production of transgenic animals.

• Nutrition Research and Practice
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• v.12 no.2
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• pp.160-165
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• 2018

BACKGROUND/OBJECTIVES: Korea is quickly becoming an aged society. Dementia is also becoming a vital public health problem in Korea. Cognitive impairment as a pre-stage of dementia shares most risk factors for dementia. The aim of the present study was to determine associations of serum levels of vitamins A, C, and E with the risk of cognitive impairment among elderly Koreans. SUBJECTS/METHODS: In this cross-sectional study, a total of 230 participants aged 60-79 years from Yangpyeong cohort were included. Cognitive function was assessed by the Korean version of the Mini-Mental State Examination for Dementia Screening. The logistic multivariable regression model was applied to determine the effect of serum vitamins A, C, and E on the risk of cognitive impairment. RESULTS: There was no significant association between the risk of cognitive impairment and serum levels of vitamin A and vitamin C. There was a significant odd ratio when the second tertile group of beta-gamma tocopherol level was compared to the first tertile group [odds ratio (OR) = 0.37, 95% confidence interval (CI) = 0.14-0.98, P for trend = 0.051]. In subgroup analyses, there were significant negative associations between beta-gamma tocopherol level and the risk of cognitive impairment in men (OR = 0.17, 95% CI = 0.03-0.87, P for trend = 0.028), non-drinkers or former drinkers (OR = 0.13, 95% CI = 0.02-0.66, P for trend = 0.025), and non-smokers or former smokers (OR = 0.27, 95% CI = 0.09-0.82, P for trend = 0.017). CONCLUSION: Serum beta-gamma tocopherol levels tended to be inversely associated with the risk of cognitive impairment. Further prospective large-scaled studies are needed to examine this association.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.5
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• pp.538-542
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• 2018

Echo generated in digital hearing aid vent give rise to user's discomfort. For cancelling feedback echo in vent, it is required to estimate vent impulse response exactly. The vent impulse response has time varying and sparse characteristics. The IPNLMS has been known a useful adaptive algorithm to estimate vent impulse response with these characteristics. In this paper, subband sparse adaptive filter which applying IPNLMS to subband hearing aid structure is proposed to cancel echo of vent by estimating sparse vent impulse response. In the propose method, the decomposition of input signal to subband can pre-whiten each subband signal, so adaptive filter convergence speed can be improved. And the poly phase component decomposition of adaptive filter increases sparsity of each components, and the better echo cancellation can be possible without additional computation. To derive coefficients update equation of the adaptive filter, by defining the cost function based weight NLMS is defined, and the coefficient update equation of each subband is derived. For verifying performances of the adaptive filter, convergence speed, and steady state error by white signal input, and echo cancelling results by real speech input are evaluated by comparing conventional adaptive filters.