• Proceedings of the KSR Conference
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• 2010.06a
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• pp.540-545
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• 2010

As the urban railroad durability period law has revised on march 19, 2009, the life cycle of urban railroad cars has lengthened to 40 years for the longest period. It seems to be attributed to the development of railroad car making technique along with their durability being longer thanks to the quality improvement of their materials and parts. As the stability of urban railroad cars is directly linked to the safety of passengers, safety should be considered first, and more precise examination is necessary for endurance extension. Hereupon, the rolling stocks with their durability near expiration should get precise diagnosis following the revised "RDG for urban railroad cars" This study aims to suggest a diagnosis method for the institute and the urban railroad operating body which enforce the revised diagnosis, through the case of Busan transportation corporation which firstly started the revised diagnosis after the durability related law has been revised.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.3
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• pp.187-194
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• 1999

In this study, a series of items on the safety and stability of cracked main structure in subway are investigated and analyzed. Cracks due to dry contraction under the construction can be found when a tensile stress of cross section is higher than tensile strength at a value of coefficient of dry contraction $200{\times}10^{-6}$. It is concluded that there is no problems when load carrying capacity, that is, an ability of resisting loads of structure is enough in this analytical model. Also, it is concluded that this model has a desirable serviceability because a width of bending crack is lower than allowable one.

• Journal of Korean Foot and Ankle Society
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• v.26 no.2
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• pp.59-65
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• 2022

The posterior malleolar fracture is relatively common fracture of the foot and ankle, but several aspects of this are still controversial. If the posterior malleolus is involved in the ankle fracture, the prognosis is usually poor. A computed tomography scan is essential for accurate diagnosis and treatment planning. Although indirect reduction and the anterior to posterior screw fixation technique have the advantages of a small incision with the requirement of relatively simple skills, direct open reduction and fixation from the posterior side provide a more biomechanically stable and accurate reduction. The precise reduction of the posterior malleolar fragment helps to achieve congruency of the tibia and fibula in the incisura and contributes to syndesmotic stability. It is important to determine the indications for surgical treatment by comprehensively evaluating the three-dimensional structure of the posterior malleolar fracture and all related injuries to the ankle.

• Journal of the Korean Arthroscopy Society
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• v.10 no.2
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• pp.135-140
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• 2006

Diagnosis and treatment of the unstable shoulder is one of the more difficult problems in orthopaedic surgery. There is confusion between the normal laxity with translation and subluxation of the humeral head relative to the glenoid and an abnormal amount of laxity, leading to pain and dysfunction. Unfortunately, there is no single treatment that applied to all lesions that cause the instability. It is imperative, therefore, that an accurate diagnosis be made, including the directions and degree of shoulder instability as well as any coexisting problems. Anatomical defects must be defined. Common factors that could most readily compromised instability repair are examined. These include techniques for making an accurate diagnosis with identification of the precise anatomical pathology, and the rationale for appropriate surgical treatment with the avoidance of technical complication such as unnecessary hardware or exposures that might lead to residual instability, arthritis, and nerve or vascular injuries. Additional injuries may be prevented by careful rehabilitation postoperatively to restore shoulder stability, flexibility, and endurance prior to an individual's return to stressful sports or work.

• Macromolecular Research
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• v.13 no.3
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• pp.167-175
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• 2005

This review explores recent works involving the use of the self-assembled nanoparticles of bile acid-modified glycol chitosans (BGCs) as a new drug carrier for cancer therapy. BGC nanoparticles were produced by chemically grafting different bile acids through the use of l-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC). The precise control of the size, structure, and hydrophobicity of the various BGC nanoparticles could be achieved by grafting different amounts of bile acids. The BGC nanoparticles so produced formed nanoparticles ranging in size from 210 to 850 nm in phosphate-buffered saline (PBS, pH=7.4), which exhibited substantially lower critical aggregation concentrations (0.038-0.260 mg/mL) than those of other low-molecular-weight surfactants, indicating that they possess high thermodynamic stability. The SOC nanoparticles could encapsulate small molecular peptides and hydrophobic anticancer drugs with a high loading efficiency and release them in a sustained manner. This review also highlights the biodistribution of the BGC nanoparticles, in order to demonstrate their accumulation in the tumor tissue, by utilizing the enhanced permeability and retention (EPR) effect. The different approaches used to optimize the delivery of drugs to treat cancer are also described in the last section.

• 보존과학연구
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• s.29
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• pp.163-182
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• 2008

Precise scientific-diagnosis for preserving stone cultural properties has been well-advanced, but research on proper methods for conservation, restoration and repair is still in early stage. Accordingly it is quite difficult to establish conservation treatment methods compatible to unique characteristics and environments of each cultural property. We tried to select most compatible conservation materials through thorough assessment of conservation materials in current use. This research is focused on conservation and restoration materials except cleaner, which are used as adhesive, filler, repellent and consolidant. Conservation treatments for stone cultural properties were first tested in 1960's and have been carried out by various methods under relevant organizations and conservation treatment companies since. We investigated present status of conservation materials being used for cultural properties. Based on these data, we will look through types and properties of the conservation materials to figure out existing problems. Among many kinds of resins, the ratio of conservation materials used in cultural properties is very low. Therefore, new conservation materials equipped with proved long-term stability should be developed as soon as possible.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.2 s.245
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• pp.194-201
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• 2006

Gait analysis is essential to identify accurate cause and knee condition from patients who display abnormal walking. Traditional linear tools can, however, mask the true structure of motor variability, since biomechanical data from a few strides during the gait have limitation to understanding the system. Therefore, it is necessary to propose a more precise dynamic method. The chaos analysis, a nonlinear technique, focuses on understand how variations in the gait pattern change over time. Eight healthy eight subjects walked on a treadmill for 100 seconds at 60 Hz. Three dimensional walking kinematic data were obtained using two cameras and KWON3D motion analyzer. The largest Lyapunov exponent from the measured knee angular displacement time series was calculated to quantify local stability. This study quantified the variability present in time series generated from gait parameter via chaos analysis. Knee flexion-extension patterns were found to be chaotic. The proposed Lyapunov exponent can be used in rehabilitation and diagnosis of recoverable patients.

• Journal of Korea Multimedia Society
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• v.16 no.2
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• pp.226-233
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• 2013

Self-diagnosis, regular examination, completion examination and precise safety examination on an elevator offer primary sources for evaluating performance and stability of the elevator. as critical examination for operating the elevator. The items on vibration of an elevator in the self-diagnosis and safety examination are not especially specified but vibration itself is considered as essential element to provide diverse analysis data. There is the equipment "EVA-625" for measuring vibration of an elevator. It is operated by reading data via computer and analyzing data by skilled engineer. This study aims to design and realize software to analyze data collected through the LabVIEW, a graphic program language and hardware for receiving data measuring vibration of an elevator by using 3-Axis acceleration sensor.

• Economic and Environmental Geology
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• v.52 no.2
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• pp.169-188
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• 2019

This study was carried out unmanned aerial photography and terrestrial laser scanning to establish digital database on original wall of Gyejoksanseong fortress, and measured ground control points for continuity of the monitoring. It also performed precise examination with the naked eye, unmanned aerial photogrammetry, endoscopy, total station and handy measurement to examine the structural stability of the original walls. The ground control points were considered as a point where visual field can be secured, 3 points were selected around each of the south and north walls. For the right side of the south original wall, aerial photogrammetry was conducted using drones and a deviation analysis of 3-dimensional digital models was performed for short-term monitoring. As a result, the two original walls were almost matched in range within 5mm, and no difference indicating displacement of stones was found, except for partial deviation. Regular monitoring of the areas with structural deformation such as bulging, weak and fracture zone by precisely examining with the naked eye and using high-resolution photo data revealed no distinct change. The inner foundation observed through endoscopy found out that filling stones of the original walls were still remained, while most filling soil was lost. As a result of measuring the total station focusing around the points with structural deformation on the original walls, the maximum displacements of the north and south walls were somewhat high with 6.6mm and 3.8mm, respectively, while the final displacements were relatively stable at below 2.9mm and 1.4mm, respectively. Handy measurement also did not reveal clear structural deformation with displacements below 0.82mm at all points. Even though the results of displacement monitoring on the original walls are stable, it is hard to secure structural stability due to the characteristics of ramparts where sudden brittle fracture occurs. Therefore, it is necessary to conduct conservational scientific diagnosis, precise monitoring, and structural analysis based on the 3-dimensional figuration information obtained in this research.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.1
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• pp.26-32
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• 2023

Dental trauma is common in active children and adolescents. Among them, in the case of ankylosis due to avulsion, diagnosis through clinical examination is important, and the treatment is important for esthetic prosthetic restoration after adulthood. This case is a case of esthetic prosthetic restoration of maxillary anterior teeth through decoronation and implant. After that, space was maintained for prosthetic restoration using a decoronated crown. After becoming an adult, precise implant placement and esthetic prosthetic restoration were possible using guide surgery. For soft tissue support, the temporary crown were replaced by changing the contours of the temporary crown, and the final esthetic prosthesis was fabricated by digital wax-up.