• Journal of Welding and Joining
• /
• v.7 no.1
• /
• pp.42-50
• /
• 1989

The application of fracture mechanics is being increased gradually to assess the safety of welded structures containing crack. Fatigue crack propagation behavior and elastic-plastic fracture toughness J$_{IC}$ of home made flux cored wire(1.22mm) CO$_{2}$ weldments was discussed. Especially fatigue crack propagation test was carried out by .DELTA.K control instead of load control and elastic-plastic fracture toughness J$_{IC}$ was obtained by ASTM-R curve method on C.T.specimen in transverse direction of weldments. The results obtained are as follows; (1) Weld metal presented an almost complete similarity to base metal on fatigue crack propagation rate in transverse direction. (2) Weld metal was more than base metal on J$_{IC}$ value in transverse direction. (3) F.C.W. CO$_{2}$ weldments had an excellent characteristic of fatigue crack propagation rate and J$_{IC}$ in less than 50kg/mm$^{2}$ steel grade, this would result from that weld metal had good static strength.trength.

• The Journal of the Korean bone and joint tumor society
• /
• v.11 no.2
• /
• pp.175-182
• /
• 2005

Purpose: Bone tumor occurred in femur frequently involve proximal intertrochanteric region or distal metaphyseal region. Sometimes, the pathologic fracture can happen according to the size of tumor due to the substantial biomechanical stresses. Therefore, the prognosis can be improved biomechanically by the angled blade plate considering the anatomic configuration after the excision of tumor. Materials and Methods: Between October 1991 and April 2005, there were a total of 16 patients(17 cases) who were treated by the excision of tumor and internal fixation with the angled blade plate for bone tumor occurred in femur. After the excision of tumor, we filled the cavity by bone graft in 11 cases and bone cement in 6 cases. The internal fixation was used by angled blade plate in all cases. Result: The average follow-up time was 55.5 months(6-144 months) in 16 patients(17 cases). No metal failure occurred after the operation. Reoperation was performed in 4 cases due to tumor recurrence, and the internal fixation was firm until that. Conclusion: The angled blade plate can prevent the fracture until grafted bone incorporated to host bone, and protect fragile connection between cement and host bone.

• Journal of the Korean Institute of Gas
• /
• v.21 no.5
• /
• pp.16-26
• /
• 2017

In chemical industry plants, the raw material, intermediate and final products can leak from unstable joints of flanges and valves as well as cracks of storage tanks. From the safety and economic standpoints, it is very important to understand whether leaks or not and leakage rate. The OGI(optical gas image) technique can tell gas leakages, but cannot give the leakage rate. Some special OGI devices can show the kind of gas in different color concentration in different darkness. Therefore the research on quantification of OGI is necessary. In this research, we have developed the practical method to quantify OGI of methane leakage. To estimate 3-dimensional gas leakages distribution from 2-dimensional OGI, the Monte Carlo Probability technique was applied. First the number of points in the area of width(2.54 cm) and length(2.54 cm) in OGI was counted. Total no of each experiment was compared with the measured flow rate. The correlation average between total points and measured flow rate was found to be 0.980. Reversely we estimated the leakage rate of OGI by use of the correlation table. The results showed good agreement between the estimation value and the measured value.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.46 no.6
• /
• pp.43-57
• /
• 2009

Integrating 3D data acquired in multiple views is one of the most important techniques in 3D modeling. However, the existing integration methods are sensitive to registration errors and surface scanning noise. In this paper, we propose a integration algorithm using the local surface topology. We first find all boundary vertex pairs satisfying a prescribed geometric condition in the areas between neighboring surfaces, and then separates areas to several regions by using boundary vertex pairs. We next compute best fitting planes suitable to each regions through PCA(Principal Component Analysis). They are used to produce triangles that be inserted into empty areas between neighboring surfaces. Since each regions between neighboring surfaces can be integrated by using local surface topology, a proposed method is robust to registration errors and surface scanning noise. We also propose a method integrating of textures by using parameterization technique. We first transforms integrated surface into initial viewpoints of each surfaces. We then project each textures to transformed integrated surface. They will be then assigned into parameter domain for integrated surface and be integrated according to the seaming lines for surfaces. Experimental results show that the proposed method is efficient to face modeling.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.26 no.11A
• /
• pp.1908-1924
• /
• 2001

Interoperability and inter-working in the various network and media environment with different technology background is very important to enlarge the opportunity of service access and to increase the competitive power of service. The ITU-T and advanced counties are planning ahead for provision of GII enabling user to access advanced global communication services supporting multimedia communication applications, embracing all modes of information. In this paper, we especially forced the heterogeneity of end user applications for multimedia networking. The heterogeneity has several technical aspects, like different medium access methods, heterogeneous coding algorithms for audio-visual data and so on. Among these elements, we have been itemized bit rate shaping algorithm on the compressed moving video. Previous manipulations of video has been done on the uncompressed signal domain. That is, compressed video should be converted to linear PCM signal. To do such a procedures, we should decode, manipulate and then encode the video to compressed signal once again. The traditional approach for processing the video signa1 has several critical weak points, requiring complexity to implement, degradation of image quality and large processing delay. The bit rate shaping algorithm proposed in this paper process the manipulation of moving video on the completely compressed domain to cope with above deficit. With this algorithms. we could realized efficient video bit rate shaping and the result of software simulation shows that this method has significant advantage than that of pixel oriented algorithms.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.4
• /
• pp.78-89
• /
• 2021

Organic residues analysis is an analysis method that reveals the types of organic material samples by using the characteristic that main components constituting substances are different depending on the species of animals and plants. In this study, scientific analysis of the organic residues attached to wood coffins in the Joseon Dynasty Hoemyo excavated from the site of Singok-dong, Uijeongbu was used to identify the types of remnants and to use them as information to restore the uses of organic materials and the way they lived in the past. As a result of FT-IR analysis of the residue attached to the inside of the wood, it was estimated to be a natural plant resin material. In addition, as a result of analysis by GC-MS to confirm the characteristic factors of natural resins, diterpenoids (abietane) and pimaran (pimarane), such as dehydroabietic acid and pimaric acid (diterpenoid) compounds, and saturated and unsaturated fatty acid components were detected together. Diterpenoid compounds are components mainly found in Pinaceae resins. It is confirmed in the literature that rosin, a representative material of Pinaceae resin, was used as an adhesive material. Considering the situation where an organic material remained at the joint of the wood, the organic material attached to the wood is judged to be an adhesive material made of Pinaceae resin. In addition, the fatty acid component detected together is a component derived from plant oil, and it is presumed to be made by mixing rosin and oil as recorded in previous studies. This study confirms that organic residues remain in the burial environment without losing their characteristics. It is expected that scientific analysis of organic residues will be conducted in the future to accumulate information necessary for the interpretation of past living culture.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.4
• /
• pp.606-612
• /
• 2019

The main causes of subsidence and sinkholes in the lower part of urban roads are sewage line foundation and inadequate compaction of backfill material. This leads to many problems, such as the breakage of joints in sewer pipes, poor connection, pipe breakage, and cracks. To solve this problem, the support factor related to the sewer foundation and the safety factor according to the excavation depth were evaluated. For the foundation of rigidity tolerance, crushed stone foundation, and abandoned concrete foundation, a recently newly developed site assembly-type lightweight plastic foundation were used. Backfill materials were applied on site (sandy soil and clayey soil) and fluid backfill was recycled onsite. To evaluate the depth of excavation and the safety factor of each sewer pipe foundation, the design load considering the load factor and the support factor was evaluated. The support coefficients were 0.377 for a crushed stone foundation, 0.243 and 0.220 for an abandoned concrete foundation ($180^{\circ}$ and $120^{\circ}$), and 0.231 for a lightweight plastic foundation and fluid backfill. Overall, the safety factor was low when using the crushed stone foundation, and the safety rate was the highest when the foreclosed concrete foundation ($180^{\circ}$) was used. In addition, when the combination of lightweight plastic and fluid backfill materials was used, the safety factor was higher than that of abandoned concrete foundation ($120^{\circ}$), which means that the newly developed lightweight plastic foundation can be used as another alternative base of a steel pipe.

• Parasites, Hosts and Diseases
• /
• v.22 no.1
• /
• pp.66-71
• /
• 1984

Two cases of human infection by adult Spirometra erinacei were proved by collection of worms in Korea. The patients were 24 and 21-year old males residing in a mountainous village in Kangwon-do. They had the clinical complaints of abdominal pain and epigastric discomfort, revealing the diphyllobothriid eggs, $53~59{\times}37-42{\mu}m$ in size, in their stools. They were treated with 500 mg atabrine and purgated with magnesium salts, and 3~4 hours later several chains of tapeworm segments were recovered from the diarrheal stools. The recovered worms revealed the morphological characteristics of spiral-form or coiled uteri, separated vaginal opening from the cirrus sac, incorporated seminal vesicle into the cirrus sac, distribution of testes at the junction between proglottides, asymmetrical eggs with one pointed eggs, etc. and were identified as Spirometra erinacei (Rudolphi, 1819). The cases had the history of eating raw flesh of the snakes and these are considered the source of infection.