• Restorative Dentistry and Endodontics
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• v.31 no.4
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• pp.300-311
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• 2006

The purpose of this study is to evaluate prospectively the effect of different bonding systems and retention grooves on the clinical performance of resin restorations in non-carious cervical lesions (NCCLs). Thirty-nine healthy adults who had at least 2 NCCLs in their premolar areas were included in this study. One hundred and fifty teeth were equally assigned to six groups: (A) Scotchbond Multi-Purpose (SBMP, 3M ESPE, St. Paul, MN, USA, 4th generation bonding system) without retention grooves; (B) SBMP with retention grooves; (C) BC Plus (Vericom Co., Anyang, Gyeonggido, Korea, 5th generation bonding system) without retention grooves; (D) BC Plus with retention grooves; (E) Adper Prompt (3M ESPE, Seefeld, Germany, 6th generation bonding system) without retention grooves; (F) Adper Prompt with retention grooves. All cavities were filled with a hybrid composite resin. Denfil (Vericom Co., Anyang, Gyeonggido, Korea) by one operator. Restorations were evaluated at baseline and at 6-month recall, according to the modified USPHS (United States Public Health Service) criteria. Additionally, clinical photographs were taken and epoxy resin replicas were made for SEM evaluation. At 6-month recall, there were some differences in the number of alpha ratings among the experimental groups. But, despite the differences in the number of alpha ratings, there was no significant difference among the 3 adhesive systems (p < 0.05). There was also no significant difference between the groups with or without mechanical retention (p < 0.05). Follow-ups for longer periods than 6 months are needed to verify the clinical performance of different bonding systems and retention grooves.

• Journal of Radiation Protection and Research
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• v.45 no.2
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• pp.53-68
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• 2020

Background: International organizations such as the World Health Organization (WHO) and the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) reported public exposure doses due to radionuclides released in the Fukushima nuclear accident a few years after the event. However, the reported doses were generally overestimated due to conservative assumptions such as a longer stay in deliberate areas designated for evacuation than the actual stay. After these reports had been published, more realistic dose values were reported by Japanese scientists. Materials and Methods: The present paper reviews those reports, including the most recently published articles; and summarizes estimated effective doses (external and internal) and issues related to their estimation. Results and Discussion: External dose estimation can be categorized as taking two approaches-estimation from ambient dose rate and peoples' behavior patterns-and measurements using personal dosimeters. The former approach was useful for estimating external doses in an early stage after the accident. The first 4-month doses were less than 2 mSv for most (94%) study subjects. Later on, individual doses came to be monitored by personal dosimeter measurements. On the basis of these measurements, the estimated median annual external dose was reported to be < 1 mSv in 2011 for 22 municipalities of Fukushima Prefecture. Internal dose estimation also can be categorized as taking two approaches: estimation from whole-body counting and estimation from monitoring of environmental samples such as radioactivity concentrations in food and drinking water. According to results by the former approach, committed effective dose due to ¹³⁴Cs and ¹³⁷Cs could be less than 0.1 mSv for most residents including those from evacuated areas. Conclusion: Realistic doses estimated by Japanese scientists indicated that the doses reported by WHO and UNSCEAR were generally overestimated. Average values for the first-year effective doses for residents in two affected areas (Namie Town and Iitate Village) were not likely to reach 10 mSv, the lower end of the doses estimated by WHO.

• Magazine of the Korean Society of Agricultural Engineers
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• v.34 no.2
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• pp.21-39
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• 1992

Many problems were found out the remarkable unbalance between paddy fields and up-land areas, or between plain and mountainous areas, unreasonable establishing of land consolidaton boundaries without consideration of rural development, lower leverl of construction technology of the roads and canals for agricultral use ad operation and maintenance of them by human power far apart from the ages of high technology, high information and free internationalisation, and too slow progress to overcome the weak agricultural circumstances etc. through the survey in the past executed land consolidation projects. The basic ways for solution of these problems for propulsion of land consolidation project through investigation are summarized as follows : 1. Land consolidation project should be executed to the direction of balanced regional development, laying stress on the upland and mountainous areas in order to carry out the agriculture effectively. 2. the acreage of land consolidation project to be conducted anually should be increased to overcome the serious underdeveloped agricultural development. 3. It should be developed to the way in accordance with the order of land use from the view point of rural integral development including the rural readjustment. 4. The level of the structures of road and canal, the size of standard lot and the grouping of land substitution should be to incraese the productivity of land and labour more than ever and reached to a degree in cope with the age of industrialization, information and free internationalisation. 5. The level of the management of agricultural water use and the maintenace of the various facilities should be developed to be automatization, remote control, central control and information processing instead human work. 6. Land substitution should take a measure of grouping method in accordance with the agricultural plan and farming organization, which can overcome high industrialized society in place of the substition by origin land. 7. Land consolidation project should be planned in order to fulfil a conservative function of ecosystem and resources together with improvement of land and labour productivity.

• Journal of Information Technology Services
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• v.15 no.4
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• pp.73-83
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• 2016

Pedestrian safety was recently highlighted with a yellow carpet, a yellow-colored pavement material prepared for children waiting for signals for pedestrian crossing, without validation of its efficiency in practice. It was a promising device likely to assist highway safety by stimulating pedestrian to step on the yellow-colored area; it was generally called nudge effects. This paper delivers a study conducted to check the effectiveness of yellow carpet in three different aspects in vehicle driver's perspective by applying the newly introduced information technology (IT) service: Visual Attention Software (VAS). It was assumed that VAS developed by 3M in the United States should be able explain the Korean drivers' visual reaction behaviors since technology embedded in VAS was developed based on and proved by other various international countries and continents in the world. A set of pictures was taken at thirteen different field sites in seven school zone areas in the Seoul metropolitan area before and after the installation of a yellow carpet, respectively. Sets of those pictures were analyzed with VAS, and the results were compared based on the selective safety measures: the likely focusing on standing pedestrians (waiting for a pedestrian's green signal time) affected by its background (yellow-colored pavement) contrasting him or her. The test results from a set of before-and-after comparison analyses showed that the placement of yellow carpet would (1) increase 71% of driver's visual attention on pedestrian crossing areas and (2) change the sequential order of visual attention on that area 2.4 steps ahead. The findings would enhance deployment of such promising efficiency and thus increase children safety in pedestrian crossing. The result was promising to highlight the way to support the changes in conservative traffic safety engineering field by applying the advanced IT services, while much robust research was recommended to overcome the limitation of simplification of this study.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.392-403
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• 1997

There is a strong international move towards performance based fire regulations for buildings with New Zealand and Australia at the forefront of research in this fold. The reform of regulations is thought to offer more innovation and flexibility in building design and greater cost effectiveness in construction. An important part of the research in this area is related to the development of agreed approaches to fire safety design, such as the Fire Code Reform Centre's "Fire Engineering Guidelines" or New Zealand's "Fire Engineering Design Guide". Such design process documents have incorporated or referenced much of the latest research in areas such as: tenability criteria fire compartment models egress models risk assessment. Use of such design guidelines or equivalents in major projects in countries such as Hong Kong and Australia have highlighted where fro engineering can offer real benefits to building designers and ultimately building owners and operators. However, there is still much research to be done and use of a systematic, logical design approach clearly identifies where design data or modelling techniques are still urgently required. Such areas are: fire growth rates and peak heat release rates for non-residential occupancies pre-movement times related to egress experimental validation and limits of applicability of CFD and other compartment Ire models probability/reliability data on fire protection systems for risk based analysis. Examples from case studies will be shown where lack of such research and poor judgement can lead to inferior design solutions or where unnecessarily conservative designs can lead to cost excesses. In summary, the link between Ire engineering designers and the research community is very important to highlight areas of fire research that will have the most benefit to the building and construction industry.nstruction industry.

• Journal of the Korean Home Economics Association
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• v.37 no.7
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• pp.127-141
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• 1999

The purpose of this study is to classify the elderly over the age of 60 according to their lifestyles and analyze the health and economic status of them that are classified. Data were obtained from 463 elderly living in urban areas. Factor analysis was used for examining dimensions of lifestyles and cluster analysis for classifying the elderly by lifestyles. This study found six different types of lifestyles, Le., the actively self-developing type, the individualist seeing the negative aspects of the world, the sensuous joy oriented type, the obedient to the tradition type, the conservative with discontented attitude toward the world, and the introspective self-fulfilling type. There were significant differences in living status as well as socio-economic characteristics of the elderly among six types of lifestyles. From the results of this study, it is found that the elderly have various lifestyles and, therefore, the understanding the lifestyles of the elderly will enable researchers to capture the problems the elderly face and provide more insight into their living status.

• The Journal of the Korean dental association
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• v.56 no.10
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• pp.556-566
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• 2018

Whether you use a hand file or an engine-driven file, you cannot remove bacteria completely from the root canal by mechanical work alone. If the root canal is well cleaned, endodontic irrigants will well penetrate into these areas that will not be mechanically accessible. It will decompose and remove the biofilm and also remove the smear layer to reach the dentinal tubule. Clinicians who are not yet using NaOCl as their primary irrigant, should be aware that there are no other irrigants that offer all the benefits of NaOCl and are inexpensive. Clinicians may be reluctant to use it because of concern about NaOCl accident, but this possibility is extremely low if used with caution.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.190-191
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• 2014

Recent construction sector integration and fusion technologies in various areas of research and planning systemis being maintained by the system. Past experience of conservative management in this emerging technology-driven business management through the convergence of various technologies and to find synergies to secure the future of construction technology because it is a need. The purpose of this study is builton the basis of technical and Technology Management Contact optimized system for integrated management of the area you want to build.

• Journal of Korean Dental Science
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• v.7 no.1
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• pp.25-30
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• 2014

Subcutaneous emphysema and pneumomediastinum is a relatively uncommon phenomenon. It may occur secondary to dental treatment using high-speed air turbine handpieces, especially after extraction of tooth. Subcutaneous emphysema is often limited only to the areas of head and neck, but also can involve deeper structures. Thorough examination and conservative treatment of these problems are essential in preventing life-threatening complications such as airway obstruction and mediastinitis. The subject of this report is a 57-year-old woman with subcutaneous emphysema and pneumomediastinum during the extraction of maxillary third molar using high-speed air turbine handpiece. If there isn't any appropriate measure, severe complications may occur. Therefore it is important to be well-informed of proper diagnosis and treatment. This article shall present a case report with literature review.

• The Korean Journal of Pain
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• v.24 no.2
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• pp.69-73
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• 2011

Although the incidence of partial-thickness rotator cuff tears (PTRCTs) was reported to be from 13% to 32% in cadaveric studies, the actual incidence is not yet known. The causes of PTRCTs can be explained by either extrinsic or intrinsic theories. Studies suggest that intrinsic degeneration within the rotator cuff is the principal factor in the pathogenesis of rotator cuff tears. Extrinsic causes include subacromial impingement, acute traumatic events, and repetitive microtrauma. However, acromially initiated rotator cuff pathology does not occur and extrinsic impingement does not cause pathology on the articular side of the tendon. An arthroscopic classification system has been developed based on the location and depth of the tear. These include the articular, bursal, and intratendinous areas. Both ultrasound and magnetic resonance image are reported with a high accuracy of 87%. Conservative treatment, such as subacromial or intra-articular injections and suprascapular nerve block with or without block of the articular branches of the circumflex nerve, should be considered prior to operative treatment for PTRCTs.