• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.421-426
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• 1999

The purpose of this study is to investigate the durability design method of reinforced concrete structure in order to establish a rationally combined design system of structural and durability design, that is to say performance-based design. In literature study, the integrated design of concrete structure studied JCI committe is very intensive durability design method for reinforced concrete structure. Specially, B root durability design method for selection of verification level is very effective method in the view of modeling of materials and structural properties to analyze safety and serviceability of RC structures.

• Restorative Dentistry and Endodontics
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• v.40 no.1
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• pp.58-67
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• 2015

Objectives: This study aimed to compare the accuracy of conventional intraoral (CI) radiography, photostimulable phosphor (PSP) radiography, cone beam computed tomography (CBCT) and multidetector computed tomography (MDCT) for detection of strip and root perforations in endodontically treated teeth. Materials and Methods: Mesial and distal roots of 72 recently extracted molar were endodontically prepared. Perforations were created in 0.2, 0.3, or 0.4 mm diameter around the furcation of 48 roots (strip perforation) and at the external surface of 48 roots (root perforation); 48 roots were not perforated (control group). After root obturation, intraoral radiography, CBCT and MDCT were taken. Discontinuity in the root structure was interpreted as perforation. Two observers examined the images. Data were analyzed using Stata software and Chi-square test. Results: The sensitivity and specificity of CI, PSP, CBCT and MDCT in detection of strip perforations were 81.25% and 93.75%, 85.42% and 91.67%, 97.92% and 85.42%, and 72.92% and 87.50%, respectively. For diagnosis of root perforation, the sensitivity and specificity were 87.50% and 93.75%, 89.58% and 91.67%, 97.92% and 85.42%, and 81.25% and 87.50%, respectively. For detection of strip perforation, the difference between CBCT and all other methods including CI, PSP and MDCT was significant (p < 0.05). For detection of root perforation, only the difference between CBCT and MDCT was significant, and for all the other methods no statistically significant difference was observed. Conclusions: If it is not possible to diagnose the root perforations by periapical radiographs, CBCT is the best radiographic technique while MDCT is not recommended.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.1
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• pp.87-92
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• 2008

In the load-carrying fillet weldments, which are common in ship structures, fatigue cracks can occur at the weld root, in addition to the weld toe. In particular, fatigue cracks originating from the weld root are difficult to detect and cause a significant reduction in the fatigue strength of a weldment. Therefore, it is important to note the fatigue failure mode of load-carrying fillet weldment. In this study, a series of fatigue test was carried out for the fatigue strength evaluation of longi-web connections that are typical kinds of the load-carrying fillet weldment.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.4
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• pp.406-412
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• 2001

IP address lookup is to determine the next hop destination of an incoming packet in the router. The address lookup is a major bottleneck in high performance router due to the increased routing table sizes, increased traffic, higher speed links, and the migration to 128 bits IPv6 addresses. IP lookup time is dependent on data structure of lookup table and search scheme. In this paper, we propose a new approach to build a lookup table that satisfies the memory constraint. The design of lookup table is formulated as an optimization problem. The objective is to minimize average depth from the root node for lookup. We assume that the frequencies with which prefixes are accessed are known and the data structure is level compressed trie with branching factor $\kappa$ at the root and binary at all other nodes. Thus, the problem is to determine the branching factor k at the root node such that the average depth is minimized. A heuristic procedure is proposed to solve the problem. Experimental results show that the lookup table based on the proposed heuristic has better average and the worst-case depth for lookup.

• Proceedings of the KWS Conference
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• 1997.05a
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• pp.107-111
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• 1997

In this paper distribution of welding residual stress on the double fillet welded joint which exits and not exits root gap, i.e. full penetration and partial penetration is investigated by two dimensional cunduct and thermal elasto-plastic analysis. And stress distribution on notch-tip of the structure where welding residual stress regarded as initial stress and then external load is added is also investigated.

• Korean Journal of Pharmacognosy
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• v.28 no.3
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• pp.143-148
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• 1997

From the root of Symplocarpus renifolius, four compounds were isolated and their structure was elucidated by chemical and spectroscopic methods. They were identified as ${\beta}-sitosterol$ (compound 1), asparagine (compound 2), isocorydine (compound 3) and 3-hydroxymethyl-4-phenyl phenoxy carboxylic acid glucopyranosyl ester (compound 4). These compounds were firstly isolated from roots of Symplocarpus renifolius. Compound 4 was identified as a new compound, named as symplocarposide.

• Journal of Plant Biology
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• v.21 no.1_4
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• pp.7-12
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• 1978

The results of the relationship between standing crop of Miscanthus sinensis grassland and soil morphological characteristics are as follows. The Miscanthus sinensis grassland seems to grow well in volcainc ash soil. The depth of A layer was closely related to the standing crop of the Miscanthus sinensis grassland. The root systems of Miscanthus sinensis reached to its maximum in A layer. The root systems of Miscanthus sinensis showed its maximum at 20mm and below(soil hardness). The soil texture of A layer showed SL-SiL. The soil structure of A layer contained Massive-Small Granular. The soil colors of A layer expressed Dark Yellowish Orange-Brownish Black.

• Restorative Dentistry and Endodontics
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• v.44 no.4
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• pp.38.1-38.8
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• 2019

Navigation of the main root canal and dealing with a dens invaginatus (DI) is a challenging task in clinical practice. Recently, the guided endodontics technique has become an alternative method for accessing root canals, surgical cavities, and calcified root canals without causing iatrogenic damage to tissue. In this case report, the use of the guided endodontics technique for two maxillary lateral incisors with multiple DIs is described. A 16-year-old female patient was referred with the chief complaint of pain and discoloured upper front teeth. Based on clinical and radiographic findings, a diagnosis of pulp necrosis and chronic periapical abscess associated with double DI (Oehler's type II) was established for the upper left lateral maxillary incisor (tooth #22). Root canal treatment and the sealing of double DI with mineral trioxide aggregate was planned for tooth #22. For tooth #12 (Oehler's type II), preventive sealing of the DI was planned. Minimally invasive access to the double DI and the main root canal of tooth #22, and to the DI of tooth #12, was achieved using the guided endodontics technique. This technique can be a valuable tool because it reduces chair-time and, more importantly, the risk of iatrogenic damage to the tooth structure.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.4
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• pp.467-472
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• 2016

Successful root canal treatment can be obtained by the removal of microorganisms from the pulpal space of the root canal system through biomechanical technique with instruments and irrigation. Due to the difference in the dimension of the pulpal structure such as thin wall of the root, large portion of chamber, the primary teeth should be considered in a different way of approach. Traditionally, fluids have been dispensed passively into the root canals for improve the cleansing. The use of sodium hypochlorite as an irrigant in root canal treatment is widespread and common, because it meets requirements for the ideal irrigants.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.67-68
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• 2017

This paper discusses the application of civil structure use reinforcing fiber mixed with concrete to be used as protection layer of waterproofing material and root resistant layer installed in below-grade parking lot upper slab of residential building. A performance evaluation under the prescribed method outlined in KS F 4938 was used for this new material. The testing results showed that the fiber reinforcement can be used to strengthen the protection for the waterproofing material. Also, plants that were planted in June 2016 have not yet penetrated the specimens used for root resistance testing. The domestic root resistance performance testing usually covers the period of 2 years, thus further observation to make any conclusion about the root resistance property is required.