• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.153-161
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• 2005

A series of installation damage tests and creep tests are performed to assess the combined effect of installation damage and creep deformation far the long-term design strength of geogrid reinforcement. Three types of geogrids are used to investigate the influence of the geogrid types. From the experimental results, it is shown that installation damage and creep deformation of geogrids significantly depends on the polymer types of the geogrids and the larger the installation damage, the more the combined effect of installation damage and creep deformation. In addition, The results of this study show that the tensile strength reduction factor, RF, considering the combined effect between installation damage and creep deformation is less than that calculated by the current design practice which calculates the long-term design strength of geogrids damaged during installation by multiplying two partial safety factors, $RF_{ID}$ and $RF_{CR}$.

• Advances in concrete construction
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• v.11 no.5
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• pp.375-386
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• 2021

In this paper, a study of stability and health of a newly-built railway tunnel is presented. The field test was implemented to monitor the secondary lining due to the significant cracking behaviors influenced the stability and health of the tunnel structure. Surface strain gauges were installed for monitoring the status of crack openings, and the monitoring outputs demonstrated that the cracks were still in the developing stage. Additionally, adjacent tunnel and poor condition of surrounding rock were identified as the causes of the lining cracking by systematically characterizing the crack spatial distribution, tunnel site and surrounding rock conditions. Reconstruction of partial lining and reconstruction of the whole secondary lining were designed as the maintenance projects for different cracking regions based on the construction feasibility. For assessing the health conditions of the reinforced lining, embedded strain gauges were set up to continuously measure the strain and the internal force of the reconstructed structures. For the partially reconstructed lining, the outputs show the maximum tensile elongation is 0.018 mm during 227 days, which means the structure has no obvious deformation after maintenance. The one-year monitoring of full-section was implemented in the other two completely reconstructed cross-sections by embedded strain gauge. The outputs show the reconstructed secondary lining has undertaken the pressure of surrounding rock with the time passing. According to the calculated compressive and tensile safety factors, the completely reconstructed lining has been in reliable and safe condition during the past year after reinforcement. It can conclude that the aforementioned maintenance projects can effectively ensure the stability and health of this tunnel.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.52-60
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• 2018

In the automobile industry, in order to increase the fuel efficiency and conform to the safety regulations, it is necessary to make the vehicles as light as possible. Therefore, it is crucial to manufacture dual phase steels, complex phases steels, MS steels, TRIP steels, and TWIP from high strength steels with a tensile strength of 700Mpa or more. In order to apply ultra-high tensile strength steel to the body, the welding process is essential. Resistance spot welding, which is advantageous in terms of its cost, is used in more than 80% of cases in body welding. It is generally accepted that ultra-high tensile strength steel has poor weldability, because its alloy element content is increased to improve its strength. In the case of the resistance spot welding of ultra-high tensile steel, it has been reported that the proper welding condition area is reduced and interfacial fracture and partial interfacial fracture occur in the weld zone. Therefore, research into the welding quality judgment that can predict the defect and quality in real time is being actively conducted. In this study, the dynamic resistance of the weld was monitored using the secondary circuit process variables detected during resistance spot welding, and the factors necessary for the determination of the welding quality were extracted from the dynamic resistance pattern. The correlations between the extracted factors and the weld quality were analyzed and a regression analysis was carried out using highly correlated pendulums. Based on this research, a regression model that can be applied to the field was proposed.

• Korean Journal of Biological Psychiatry
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• v.7 no.2
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• pp.191-197
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• 2000

Objectives : Risperidone is a new antipsychotic drug developed to overcome the therapeutic limitation of conventional antipsychotics. It responses to negative as well as positive symptoms by blocking both dopaminergic and serotonergic receptors, causing no significant side effects such as agranulocytosis and seizure. It is, however, not known whether it induces any serious cardiovascular side effects as evoked by other conventional antipsychotic drugs. The aims of this study were to evaluate the effect of risperidone on cardiovascular function, and to discuss the factors affecting the cardiovascular function. Methods : For 42 patients(22 males and 20 females) diagnosed as schizophrenia, schizophreniform disorder or schizoaffective disorder according to the DSM-IV classification, the cardiovascular fuctions such as heart rate, systolic and diastolic blood pressure, PR interval, QRS interval and QT interval were successively checked before and after 2 weeks and 4 weeks risperidone administration. Furthermore, variables such as body weight, Brief Psychiatric Rating Scale(BPRS), Clinical Global Impression(CGI), Extrapyramidal Symptom Rating Scale(ESRS), Anticholinergic Rating Scale(ARS), serum cholesterol level, serum triglyceride level, serum high-density-lipoprotein level, serum WBC, serum Hb, serum platelet level, prothrombin time and partial thromboplastin time were also analyzed before and after 2 weeks and 4 weeks risperidone administration. Results : 1) Risperidone treatment resulted in a significantly decreased heart rate and increased QT interval after 4 weeks administration(p<0.005 respectively). 2) The scores of BPRS and CGI were significantly decreased after 2 weeks and 4 weeks risperidone administration as compared with baseline(p<0.001 respectively). The scores of ESRS and ASRS were significantly increased after 2 weeks and 4 weeks risperidone administration as compared with baseline(p<0.001 respectively). 3) There were positive correlations between heart rate after 4 weeks and total dose(P<0.05). Blood pressure was significantly(p<0.05) correlated with sex(higher in male) and significantly(p<0.05) positive correlated with body weight. QT interval was significantly(p<0.05) correlated with sex(longer in female) and smoking history(shorter in smokers). Conclusions : Risperidone could induce significant change in heart rate and Q-T interval. Therefore, the cardiovascular safety for risperidone should be reconsidered according to the duration and dosage increase.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7171-7177
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• 2013

Purpose: To compare the safety and efficacy of first-line chemotherapy regimen with or without doxorubicin in treating patients with advanced soft tissue sarcoma (STS). Patients and Methods: We retrospectively analyzed a cohort of 56 patients histologically confirmed with STS who were treated at Jiangsu Cancer Hospital and Research Institute from July 2011 to June 2012.The basic element of first line chemotherapy contained epirubicin in group B and lacked epirubicin in group A. Response was assessed using RECIST criteria. The Kaplan-Meier method was used to estimate progress free survival (PFS). Results: According to RECIST criteria, patients in group treated by chemotherapy without epirubicin, the objective response (OR) ratio was 6.5 % (CR0%+PR6.5%). Disease control rate (DCR=CR+PR+SD) was 25.8% with a median follow-up of 14.6 months, including 2 patients achieving a partial response (PR 6.5%) and a stable response (SD 19.4%) in 6. In group B with epirubicin based regimens, no patient had complete response, PR (28 %) was observed in 7 and SD (24 %) in 6. DCR was observed in 13 patients (52%). By Fisher's exact test, the DCR difference between the two groups was statistically significant (p=0.046). In group A, median PFS was 3.0 months (95%CI:2.1-3.8), compared with 4.0 months (95% CI:3.03-4.97) in group B (p=0.0397 by log-rank test). Epirubicin based chemotherapy and ECOG performance status 0-1 were identified as favorable factors for progression in our cohort of patients. Differences of nonhematologic and hematologic toxicities were not statistically significant between the two groups, and the addition of epirobicin was not associated with cardiac toxicity (p=0.446). Conclusion: Our study demonstrates that epirubicin-based chemotherapy is effective and well tolerated, and is superior to chemotherapy without epirubicin regarding efficacy. Therefore it is recommended that epirubicin-based chemotherapy should be considered as first line for patients with advanced STS.

• Fire Science and Engineering
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• v.33 no.3
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• pp.154-165
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• 2019

This study was conducted to investigate whether ego - resilience plays a mediating role in the relationship between adult attachment and job stress of fire officers, and to derive implications for job stress reduction of fire officers. A questionnaire survey was conducted for 480 fire officers working in Seoul and Gyeonggi - do, and correlation analysis and regression analysis were conducted using SPSS 21.0. The results showed that there was a negative correlation between instability attachment and job stress in adult attachment, negative correlation between instability attachment and ego - resilience in adult attachment, and negative correlation between ego - resilience and job stress. Adult attachment and ego - The results showed that there was a statistically significant effect on stress. Ego - resilience was found to full mediate the effect of anxiety of adult attachment on job stress and to partial mediate the effect of avoidance on job stress. This study suggests the need to develop a program that can improve ego - resilience considering the importance of ego - resilience and the occupational characteristics of fire officer. This means that the psychological and psychological factors of the individual should also be considered in order to reduce the level of job stress of the fire service personnel.

• Journal of Korean Society of Steel Construction
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• v.22 no.4
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• pp.325-334
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• 2010

In this study, an unbraced five-story steel-framed structure was designed in accordance with KBC2005 to understand the features of structural behavior for the arrangement of semi-rigid connections. A pushover analysis of the structural models was performed, wherein all the connections were idealized as fully rigid and semi-rigid. Additionally, horizontal and vertical arrangements of the semi-rigid connection were adopted for the models. A fiber model was utilized for the moment-curvature relationship of the steel beam and the column, and a three-parameter power model was adopted for the moment-rotation angle of the semi-rigid connection. The top displacement, base-shear force, required ductility for the connection, sequence of the plastic hinge, and design factors such as the overstrength factor, ductility factor, and response modification coefficient were investigated using the pushover analysis of a 2D structure subjected to the equivalent static lateral force of KBC2005. The partial arrangement of the semi-rigid connection was found to have secured higher strength and lateral stiffness than that of the A-Semi frame, and greater ductility than the A-Rigid frame. The TSD connection was found suitable for use for economy and safety in the sample structure.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.991-999
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• 2018

In urban areas, the proportion of railway traffic in public transport is increasing. The congestion situation is repeated as the passengers concentrate on station and transfer facilities and the inconvenience of the passengers is increasing in terms of safety and convenience. Therefore, the importance of estimating the appropriate area of the station has been emphasized. The area estimation formula used in the metropolitan railway stations currently is a partial modification of the area estimation formula of Japan in the 1970s. It does not reflect changes in the social and cultural environment and patterns of passengers. The technical basis for major decision variables is insufficient. Therefore, the theoretical basis of the area estimation formula and the pedestrian environment satisfaction of the design guideline of metropolitan railway stations were analyzed in order to suggest improvement formula. The improved area estimation formula was verified by conducting field surveys on 5 stations of metropolitan railways and 15 stations of urban railways. The existing area estimation formula is LOS E grade for the main space. However, the LOS D grade is implemented when the improved area estimation formula is applied. Based on the results, the design factors for the area estimation formula are suggested.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.10
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• pp.871-882
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• 2018

This study investigated meaning of life as mediator of the relationships of meaning of work and happiness in Koran middle aged. A sample of 171 middle aged were participated. in survey about meaning of work, meaning of work and happiness. The data were analyzed using correlation test and path analysis. The results was followed. First, every factors was positively correlated. The meaning of work was positively correlated with meaning in life and happiness. And meaning in life was also positively correlated with happiness. Second, the meaning in life had partial mediation effect between meaning of work and happiness. The middle aged's higher score of meaning of work not only directly increased happiness, but also induced higher level of meaning in life, which, in turn, increased happiness. The results of this study suggested that meaning of work is a predictor meaning in life and happness, and meaning in life can be important factor of the relationship between meaning of work and happiness.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.3
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• pp.188-201
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• 2005

This is the first part of a two-part paper which describes comparison of reliability design methods by application to Donghae Harbor Breakwaters. This paper, Part 1, is restricted to stability of armor blocks, while Part 2 deals with sliding of caissons. Reliability design methods have been developed fur breakwater designs since the mid-1980s. The reliability design method is classified into three categories depending on the level of probabilistic concepts being employed. In the Level 1 method, partial safety factors are used, which are predetermined depending on the allowable probability of failure. In the Level 2 method, the probability of failure is evaluated with the reliability index, which is calculated using the means and standard deviations of the load and resistance. The load and resistance are assumed to distribute normally. In the Level 3 method, the cumulative quantity of failure (e.g. cumulative damage of armor blocks) during the lifetime of the breakwater is calculated without assumptions of normal distribution of load and resistance. Each method calculates different design parameters, but they can be expressed in terms of probability of failure so that tile difference can be compared among the different methods. In this study, we applied the reliability design methods to the stability of armor blocks of the breakwaters of Donghae Harbor, which was constructed by traditional deterministic design methods to be damaged in 1987. Analyses are made for the breakwaters before the damage and after reinforcement. The probability of failure before the damage is much higher than the target probability of failure while that for the reinforced breakwater is much lower than the target value, indicating that the breakwaters before damage and after reinforcement were under- and over-designed, respectively. On the other hand, the results of the different reliability design methods were in fairly good agreement, confirming that there is not much difference among different methods.