• Journal of the Korea institute for structural maintenance and inspection
• /
• v.15 no.2
• /
• pp.107-115
• /
• 2011

This research studies the behavior of the FRP-concrete interface subjected to two environmental substances. Frist is to investigate the behavior by the application of different bonding materials at the interface between FRP and concrete, second is to understand a long-term performance at the interface by Freeze-thaw actions. The parameters considered in this research are the maximum bonding strength and the effective bonding length at the FRP-concrete interface. In the first experimental phase, three types of specimens are fabricated and tested considering the number of applied bonding materials and the Freeze-thaw tests are performed to evaluate the behavior of the interface in the cycle range of 0 to 300 cycles. Finally, it is known that there is a 5~7% difference of the effective bonding length between applied bonding materials and the values for the maximum stress and the effective length under Freeze-thaw action are varied randomly as the freeze-thaw cycle is increased even though initial reduction of their capacities are occurred.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.5
• /
• pp.91-100
• /
• 2018

The new seismic retrofit system in study propose is the Dual system, which aims to be applied to the seismically vulnerable low-story buildings. The Dual system is composed of existing structure, external retrofit frame and hysteretic steel dampers installed between former two components. The Dual system dissipates the energy by plastic deformation of steel damper caused by relative displacement due to the differences in stiffness, weight, and eigenperiod of each components. The dynamic test with shaking table was performed to verify the seismic performance of the proposed Dual system. As a result of the dynamic test, it is expected that the Dual system will improve the seismic performance due to the reduction of strain of 56% and the damage reduction of 93%, even though the energy is 1.84 times higher than that of the dual system. And the results of the study are presented as basic data of the study for setting the design range of the dual system.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.20 no.1
• /
• pp.48-55
• /
• 2016

The assessment and prediction of service life of a structure are usually under uncertainty so that rational probabilistic concepts and methods have to be applied. Based on these rational assessment and prediction, optimum maintenance strategies to minimize the life-cycle cost and/or maximize the structural safety can be established. The service life assessment and prediction considering maintenance actions generally includes effects of maintenance types and times of the structural components on the service life extensions of structural system. Existing researches on the service life management have revealed the appropriate system modeling considering the correlation among the components is required for system reliability analysis and probabilistic service life estimation. However, the study on correlation among the maintenance actions is still required. This paper deals with such a study for more effective and efficient service life management. In this paper, both the preventive and essential maintenances are considered for the extended service life estimation and management.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.2
• /
• pp.141-147
• /
• 2018

In this study, a cyclic loading test was carried out for a reinforced concrete frame installed a TS(tension-spring) damper for the purpose of verifying the seismic strengthening effect of the TS seismic reinforcing method. The test specimens are four specimens of non - reinforced frame and three reinforced frame specimens. Experimental parameters are Shape of damper and construction method of damper. As a result, the construction method of inserting type inside window was twice as much in terms of strength and stiffness, and the method of externally attached type showed a performance improvement of about 2 times in terms of energy dissipation. From these results, it can be confirmed that the TS seismic reinforcing method is a superior method for field application and seismic strengthening.

• Korean Association of Arts Management
• /
• no.56
• /
• pp.349-380
• /
• 2020

The paper is to assess the recent changes in Architectural Artworks system in two regional districts, Seoul and Gyeonggi Province, and to propose policies for further improvement. We focused on four aspects: overall pass rate, top-ranked artists' pass rate, proportion of artists ever passed, genre proportion artworks. It is observed that quality of artworks has improved, market monopolization has been eased, and entry to the market has become more active. However, sculptures accounted for the majority. Public art is gradually changing from 'decorative art' to 'site-specific art', and seeking harmony between architecture and surrounding landscape. To keep pace with this new trend, more institutional efforts should be made: fund raising to induce artwork supplies; introducing life-span concept to secure removal and deformation of artwork; imposing artists' follow-up services; imposing penalties against poor management; and authorizing the committee to choose exhibition sites.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.26 no.3
• /
• pp.21-28
• /
• 2022

The TMD has a simple structure than other vibration control devices and shows excellent control performance for the simple harmonic vibration generated in the structure. However, the vibration control range is narrower than other control devices, making it vulnerable to vibration cycles caused by unexpected external loads. The ETMD developed in this study consisted of Mass with electromagnets. Therefore when supplying a current, the magnetic field is formed to increase the friction force with the friction plate, thereby instantaneously controlling the behavior of the Mass. The experiment was conducted to compare the control performance of the control device by installing the ETMD developed for control performance evaluation in the center of the model simple beam bridge to forced excitation at 3.02 Hz where the maximum bending displacement occurs. As a result of the experiment, ETMD exhibited excellent control performance with a maximum bending displacement attenuation rate of 57.51%.

• Journal of Digestive Cancer Research
• /
• v.6 no.2
• /
• pp.73-77
• /
• 2018

A 70-year-old female diagnosed with pancreatic ductal adenocarcinoma was treated by pylorus-preserving pancreaticoduodenectomy (PPPD) and adjuvant concurrent chemoradiotherapy with 5-fluorouracil. Pancreatic ductal adenocarcinoma pT3N0 (stage IIA) was pathologically confirmed. Abdominal computed tomography (CT) findings 14 months after PPPD showed 10 mm sized solitary liver metastasis in segment 3. After 12 cycles of gemcitabine and 9 cycles of capecitabine plus oxaliplatin, the metastatic nodule increased in size to 27 mm. Tumorectomy at segment 3 of liver was done. 25 months after tumorectomy, chest CT showed 23 mm sized cavitary nodule in right upper lobe of lung. The result of percutaneous biopsy favored metastatic adenocarcinoma. Two sets of stereotactic body radiation therapy were done and the patient has survived without further disease progression for 6 years after initial diagnosis. This case suggests that selected population of recurrent pancreatic cancer patients with solitary liver or pulmonary metastasis can be treated by resection of metastatic site and ablative therapies.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.10 no.2
• /
• pp.59-67
• /
• 2006

The aim of this study is to evaluate the design table for envelope curve analysis of base isolated buildings, which represent the period of base isolated buildings and the lateral displacement of base isolation devices. For the construction of design table, $V_E$ spectrum, which represents the energy, is developed instead of acceleration of seismic hazard. Based on the seismic coefficient of UBC 97, boundary period $T_G$ and maximum velocity response $V_0$ are proposed considering Korea seismic hazard. Using $T_G$ and $V_0$, finally, $V_E$ spectrum is developed for the four types of soil conditions. Base on the $V_E$ spectrum, design table for envelope curve analysis is also developed for soil types.

• Sleep Medicine and Psychophysiology
• /
• v.7 no.1
• /
• pp.34-42
• /
• 2000

Objectives: Periodic limb movements in sleep(PLMS) is a moderately prevalent disorder, of which pathophysiology remains largely unknown. PLMS has been reported to be common in patients with obstructive sleep apnea syndrome(OSAS), but reports on their relationship have been inconsistent in previous studies. Inconsistency of results may be attributable to insufficient number of the study subjects. We attempted to explore the influence of OSAS on PLMS in a large number of subjects. Methods: Three hundred and twenty subjects(M : F=192:128) with PLMS, as identified by the nocturnal polysomnography, were studied. Sample mean age was 53.1(SD=15.1) years and their mean periodic limb movement index(PLMI) is 25.2/hr (SD=24.8). PLMS subjects were divided into two groups, based on the presence or absence of OSAS. Periodic limb movement indices and sleep parameters between two groups were analyzed to evaluate the effects of OSAS on PLMS. Results: Each of PLMI and PLMI with arousal(PLMAI) correlated positively with age. PLMI of men was larger than that of women (p<0.01). The presence of comorbid OSAS independently had influence on PLMI(t=-2.20, p<0.05), but not PLMAI. There were no significant differences between the two groups in their PLMI, PLMAI and sleep parameters. However, the two groups differed in PLMI-correlated sleep parameters. In PLMS subjects with comorbid OSAS, PLMI was negatively correlated with each of slow wave sleep time and REM sleep time. In subjects without comorbid OSAS, PLMI was negatively correlated with sleep efficiency. Conclusion: PLMS patients with OSAS turned out to have increased PLMI than those without OSAS We suggest that OSAS patients may have subtle autonomic arousals and these arousals could, in part, express themselves as PLM.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.7 no.1
• /
• pp.61-73
• /
• 2004

Purpose: Liver function test abnormalities have been reported frequently in patients receiving total parenteral nutrition (TPN). In adults, it is known that liver complications decrease with the use of cyclic parenteral nutrition (CPN), especially if the shift to cycling was not too late. However, there are few studies about the effects of cycling on liver injury in children beyond the neonatal period. The aim of this study is to evaluate the effect of the early use of CPN on total parenteral nutrition induced hepatic dysfunction. Methods: Twelve sets of CPN in 11 children (2 months to 17 years) were included in this study. Data on underlying diseases, age, length of time on TPN, macronutrient intake, complications, and biochemical parameters were collected from clinical records. All children had received CPN in the early period of persistent transaminase elevation or cholestasis complicated by previous continuous PN. The duration of infusion off-time in CPN was 2 hours in patients less than 3 months of age and 4 hours in the older children. Results: All 12 cases showed elevated aminotransferase and 5 of them also showed cholestasis. Serum total bilirubin concentration was normalized in all 5 cases with median periods of 8 days (p<0.05) after initiation of CPN. ALT either decreased significantly or was normalized in all cases with median periods of 30 days (p<0.05) on CPN. The CPN was well tolerated without significant complication except for one case of hyperglycemia. Conclusion: The early use of cyclic parenteral nutrition had a beneficial effect in improving hepatic dysfunction complicated by TPN in children.