• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.110-117
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• 2008

Clinical performance of resin-based composite material depends on case selection and on the proficiency of the operator. Especially, composite resin restoration on permanent first molar in children have more limitations clinically than adult patients according to stage of tooth eruption and patient's compliance. This study was designed to evaluate the clinical performance of posterior composite resin restoration in children after 5 years. 35 teeth of 16 patients who were received composite resin restoration on permanent first molar in Department of Pediatric dentistry, Pusan National University Hospital between January 2001 and December 2001 were evaluated based on Modified USPHS criteria. From the finding in this study, following conclusions can be made. 1. 6 teeth(17%) of 35 teeth was replaced, so 5-years survival rate of posterior composite resin restoration is 82.9%. 2. As results of each evaluation criteria, on color match, anatomic form, surface roughness, sensitivity/ discomfort, ideal A grade score was 86.2%, 93.1%, 86.2%, 86.2%, clinically accepted B grade score was 13.8%, 0%, 13.8%, 10.3%. On marginal adaptation and marginal discoloration, A grade score was 13.8%, 44.8% and B grade score was 79.3%, 34.5% and secondary caries rate was 20.7%. 3. 69.1% of teeth (20 teeth) was clinically accepted on all evaluation criteria.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.3
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• pp.355-362
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• 2015

Purpose: To investigate the effects of the transmittance of diffusive blurson visual acuity and contrast sensitivity. Methods: Visual acuity and contrast sensitivity were measured by using Optec$^{(R)}$ 6500 in Healthy 30 subjects aged $22.83{\pm}0.50$ (male 13, female 17) who were recruited from university students. Cataract simulator was used as a tool for diffusive blur. Visual acuity and contrast sensitivity were measured with varying the transmittance of diffusive blur in order to simulate progression of cataract and concentration in fog. Results: Visual acuity was reduced proportionally with decreasing the transmittance of the diffusive blur as follows: $VA(T)=1.84{\times}10^{-2}T-0.645$. Contrast sensitivity was decreased in all spatial frequencies. Contrast sensitivity in a high spatial frequency band was a greater effect and was off the normal range of contrast sensitivity. The peak of contrast sensitivity was moved in the direction to low frequency. From an intersection point of contrast sensitivity function, we could calculated the transmittance of the diffusive blur being off the normal range and the shift to peak spatial frequency. The peak of contrast sensitivity function was observed to move from 6 to 3 cpd at transmittance of about 78.70%, the contrast sensitivities for all frequencies at transmittance of about 69.71% were deviated from the normal range. Conclusions: The transmittance of diffusive blur causes a reduction in visual acuity and contrast sensitivity, a deviation of normal range of contrast sensitivity, and a shift of peak contrast sensitivity. Therefore the more attention is required when suffering from cataracts or driving in fog.

• Archives of design research
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• v.17 no.4
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• pp.191-200
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• 2004

The health of feet is connected with individual's health and affects a man's activity. Shoes need to be designed to protect feet and to absorb the impact of land. Thus, design, comfort and economical efficiency are important factors of shoes. Consumers can choose suitable shoes for their feet in off-line shopping. However, in on-line shopping, because they can not wear shoes, compare to the off-line shopping, there are many problems in internet shopping. First, consumers can get limited information of shoes because they must search information of purchase without other's help. Second, because consumers can not get important information such as design, size and a comfort of wearing, they can not make a careful decision. Above these, the solution of user-oriented internet shopping is development of new type of prototype which is accessible to user and to offer visual information through 3D virtual reality.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.139-144
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• 2007

Radiotherapy which is the most effective for orbit lymphoma has been used increasingly due to the increase of orbit or ocular adnexal tumor patients. Curative effects and convalescence have been being more satisfied thanks to remarkable development of cancer chemotherapy and medical treatments, but side effects such as cataract, dry eye and retinopathy still break out. Thus, in this study, a Lens Shielding Device (LSD hereafter) was designed to prevent occurring of cataract due to radiation therapy for orbit lymphoma and its efficacy through dosimetry were evaluated. And in this paper, its manufacturing process was also explained. LSD is composed of a cover body covering the lens and a side fixing part supporting the cover body. To measure radiation, the patient therapy conditions were simulated and the measurement of the radiation was conducted with Thermo Luminescence Detector (TLD) and Markus chamber. The average TLD value was 5.7% and the TLD value and Markus chamber value were acquired as 4.2% and 5.1% respectively at 6 mm depth where zero lens center was located. Only 1.5Gy ($300Gy{\times}\;5%$) or 5% of total 30Gy with 9 MeV electron beam is estimated to affect on patient's lens. That is smaller dose than the threshold value of cataract (2GY) or the value (5Gy) that was reported to cause cataract in clinical conditions. Thus, these findings suggest that LSD be very useful for prevention of cataract during radiotherapy for malignant lymphoma of orbit and ocular adnexa. Furthermore, it might be possible to reduce patient's discomfort caused by alien substances and to make it easier to fix the device with customized manufacturing manners.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.2
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• pp.1-10
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• 1989

The major causes of the facial bone fractures are fractures are automobile collision or other accident, and fights. Of the facial bone fractures, the nasal bone fractures are monst common. According to Schroeder et al., 50% of facial bone fractures are isolated fractures of the nasal pyramid. But the fractured nasal bone is not immediately treated as other facial bone fractures. And it is necessary to delay the treatment of the combined nasal bone fractures with other jaw bone fractures because of the difficult anesthetic techniques. Therefore there are many residual nasal deformities following a fracture; nasal hump, saddle nose and alar rim defect. Many authors have suggested the methods to correct the post-traumatic nasal deformities. We have treated several patients with several methods and this paper presents the operating methods and results.

• Journal of Oral Medicine and Pain
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• v.32 no.4
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• pp.397-402
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• 2007

Sjogren's syndrome is a chronic autoimmune disorder of the exocrine glands with associated lymphocytic infiltrates of the affected glands. Primary SS presents alone as xerostomia, keratoconjunctivitis sicca and patotid gland enlargement, secondary SS occurs in connection with other autoimmune disorder such as rheumatitoid arthritis, systemic lupus erythematosus, or progressive systemic sclerosis. Among many other systemic complication, lymphoma is considered seriously. Patient with SS had a 44 times higher relative risk of lymphoma, and clinically identifiable lymphoma occurs in approximately 5% of patients with SS. So, patients with SS should be closely monitored. In dental office, diagnosis of SS is important in view of high risk of lymphoma. When a dentist diagnose and manage dry mouth, he or she should consider possibility of SS all the times and have knowledge of diagnostic criteria of SS.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.6
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• pp.333-340
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• 2014

Despite the security weakness of reusing passwords, many Internet users are likely to use a single ID and password on various sites to avoid the inconvenience of remembering multiple credentials. This paper proposes a scheme for securely storing, retrieving, and updating randomly chosen (ID, password) pairs by using smart cards as secure and portable storages. The scheme makes a user free from remembering her (ID, password) pairs for Internet accesses. By splitting and scattering the (ID, password) pairs of a user across the user's smart card memory and a remote server's storage, it can protect the logon credentials even from the theft or loss of the smart card. Also, a user, if deemed necessary, can issue and let the server to delete all information belonging to the user. Hence even an attacker who cracked the smart card memory would not be able to obtain any (ID, password) pair of the victim thereafter. The scheme requires a user to input a site information and pass-phrase to her smart card to obtain the logon credentials, but it should be an acceptable overhead considering the benefits of not remembering the freely chosen (ID, password) pairs at all.

• The Journal of Korean Society for Radiation Therapy
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• v.20 no.2
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• pp.103-107
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• 2008

Purpose: This paper describes a electron field presence of magnetic field, intensity and shape surface dose variation to clinical application possibility. Materials and Methods: The using 6 MeV electron and $10{\times}10\;cm^2$ field size, 9 hole to shielding block make the by measure the film, when the magnetic field position inside and outside of the X-Omat film and parallel plate ionization chamber using the surface dose measured. Results: Present of 4 cm to the side at angle about 3 degree from beam center, use of ring type magnetic is 0.9% increase the surface dose, lens block located in the magnetic field the surface dose 1.58% increase, half magnetic field's position on the side of them at the field center of the 3.6% increase of the surface dose. Conclusion: Surface dose variation is with magnetic field about the mean electron beam of progress direction change, orbit region patient's is inconvenient without surface dose increase percentage case goodness will be used as a useful way.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.4
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• pp.352-360
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• 2017

Objectives: This study aimed to determine the effects on musculoskeletal symptoms of both social demographic features and detailed characteristics of each task category of care workers who offer visiting home-help services. And to establish the measures that can reduce musculoskeletal symptoms among care workers. Methods: This study was conducted among 192 care workers from welfare centers C and K located in city P. After participants completed the task burden checklist regarding the scale of musculoskeletal symptoms and the details of their duties, the data collected were analyzed using the SPSS 21.0 program. Results: According to the degree of observable musculoskeletal symptoms in care workers, the highest figures were observed for back and shoulder pain. Based on the results of assessing the effect of detailed task category characteristics on musculoskeletal symptoms, "helping patients eat, helping patients move, helping patients bath, and changing body positions" were found to have an effect from the physical care category, "providing physical therapy assistance, treating bedsores" from the health care category, and "cleaning and doing laundry" from the facility management category. Conclusions: Due to the high proportion of patients requiring burdensome physical labor from care workers such as moving patients who have trouble doing so on their own, helping them change positions, and so on, it is highly likely that pain will occur in the low back, which carries most of the physical weight. So, education on human epidemiological positions that can reduce overload on areas prone to pain such as the low back and shoulders is essential. Proper equipment and personnel support must be provided for dangerous tasks. Further, multidimensional social support is required consistently.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.497-502
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• 1997

A seed pelleting technique was developed for easy handling of small sesame seeds (Chinbaeckkae) and for direct seeding in field. The mixture of pelleting material, binder(sodium alginate) and seeds were dropped in 100mM CaCl$_2$ solution. Charcoal was appeared as a best material among all to make pellets with the characters of hardness, breakdown, destruction rate and germination percentage. Zeolite formed the hardest pellet seeds among the materials and 1~3 seeds contained in a pellet on the treatment of 87g of sesame seeds mixed in 1$\ell$ CaCl$_2$ solution was estimated optimum rate of seed mixure with few appearance of seedless pellet. The moisture absorption rate was greater in the order of peat＋charcoal > peat > charcoal > zeolite. Germination percentage of pelleted seeds with charcoal was the best and similar to that of common non-treated seeds. Germination percentage of pelleted seeds by sowing depth of exposing a quarter of pellet seeds on the surface of vermiculite germination test box and were 92％ in charcoal treatment and was the best among all released materials.