• Korean Journal of Social Welfare
• /
• v.46
• /
• pp.37-59
• /
• 2001

This paper investigates the long-term social changes and the emerging issues in social insurance that such changes will entail, It does not attempt to resolve the conflict between neo-liberal reforms and neo-corporalist reforms. Nor does it confine itself to proposing the options to secure the financial stability of social insurance schemes. The aim of this paper lies in anticipating various problems that result from social development, analyzing the impacts of these problems on social insurance schemes, and delineating the solutions to these problems. This paper is comprised of three parts. First, it describes the expected long-term changes in society and the ensuing problems. Second, it asks whether these problems can be solved with increased public expenditures. For this purpose, an analysis of the trend in the expenditures by welfare states is attempted. Third, it summarizes the issues in social insurance and presents the possible solutions to the problems. In the chapter that deals with social changes and social problems, various aspects are reviewed, including the globalization process, the development of It industries, the uncertainty in the classification of incomes, the widening gap in earnings due to the bio-economy, and the relation between social insurance schemes and the tax system. It is concluded that there are limits to the role that increased public expenditures can play to solve the social problems. This paper argues for a structural change in the social insurance system. In every social insurance scheme, the state should foe-us its effect on the provision of basic protection against social risks for the whole population. At the same time, the state should improve the financial stability of the scheme and avoid large-scale deficits.

• The Bulletin of The Korean Astronomical Society
• /
• v.43 no.1
• /
• pp.42.4-43
• /
• 2018

Most galaxies are believed to evolve through mergers and accretions. In particular, minor mergers and gas accretion appear to play an important role in galaxy evolution in the present-day Universe. Tidally-disrupted debris from such processes remain as diffuse, low-surface brightness structures because the dynamical timescale in the outskirts is significantly longer than that in the central regions. Although these structures will give us useful insight into the mass assembly history of galaxies, it is difficult to detect them due to their faint surface brightness. In order to investigate the structural properties of outskirts in nearby galaxies, we conduct deep and wide-field imaging survey with KMTNet. We present our observing strategy and an optimal data reduction process to recover faint extended features in the images of KMTNet. Using the imaging data of NGC 1291 obtained from KMTNet, we find that a peak-to-peak sky gradient can be reduced less than 0.4-0.6% of the original sky level in the entire image. We also find that we can reach the surface brightness of ${\mu}_{(B,1{\sigma})}$ ~ 29.5, ${\mu}_{(R,1{\sigma})}$ ~ 28.5 mag $arcsec^{-2}$ in one-dimensional profile, that is mainly limited by the uncertainty in the sky determination. It indicates that deep imaging data of KMTNet is suitable to study the extended faint features of nearby galaxies, such as stellar halos, outer disks, and dwarf companions.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.40 no.3
• /
• pp.27-37
• /
• 2017

As the global uncertainty of manufacturing has increased and the quality problem has become global, the recall has become a fatal risk that determines the durability of the company. In addition, as the convergence of PSS (product-service system) product becomes common due to the development of IT convergence technology, if the function of any part of hardware or software does not operate normally, there will be a problem in the entire function of PSS product. In order to manage the quality of such PSS products in a stable manner, a new approaches is needed to analyze and manage the hardware and software parts at the same time. However, the Fishbone diagram, FTA, and FMEA, which are widely used to interpret the current quality problem, are not suitable for analyzing the quality problem by considering the hardware and software at the same time. In this paper, a quality risk assessment model combining FTA and FMEA based on defect rate to be assessed daily on site to manage quality and fishbone diagram used in group activity to solve defective problem. The proposed FTA-FMEA based risk assessment model considers the system structure characteristics of the defect factors in terms of the relationship between hardware and software, and further recognizes and manages them as risk. In order to evaluate the proposed model, we applied the functions of ITS (intelligent transportation system). It is expected that the proposed model will be more effective in assessing quality risks of PSS products because it evaluates the structural characteristics of products and causes of defects considering hardware and software together.

• Structural Engineering and Mechanics
• /
• v.14 no.2
• /
• pp.171-190
• /
• 2002

Two cases of design are performed for the hyperbolic paraboloid saddle shell (Lin-Scordelis saddle shell) and the hyperbolic cooling tower (Grand Gulf cooling tower) to check the design strength against a consistent design load, therefore to verify the adequacy of the design algorithm. An iterative numerical computational algorithm is developed for combined membrane and flexural forces, which is based on equilibrium consideration for the limit state of reinforcement and cracked concrete. The design algorithm is implemented in a finite element analysis computer program developed by Mahmoud and Gupta. The amount of reinforcement is then determined at the center of each element by an elastic finite element analysis with the design ultimate load. Based on ultimate nonlinear analyses performed with designed saddle shell, the analytically calculated ultimate load exceeded the design ultimate load from 7% to 34% for analyses with various magnitude of tension stiffening. For the cooling tower problem the calculated ultimate load exceeded the design ultimate load from 26% to 63% with similar types of analyses. Since the effective tension stiffening would vary over the life of the shells due to environmental factors, a degree of uncertainty seems inevitable in calculating the actual failure load by means of numerical analysis. Even though the ultimate loads are strongly dependent on the tensile properties of concrete, the calculated ultimate loads are higher than the design ultimate loads for both design cases. For the cases designed, the design algorithm gives a lower bound on the design ultimate load with respect to the lower bound theorem. This shows the adequacy of the design algorithm developed, at least for the shells studied. The presented design algorithm for the combined membrane and flexural forces can be evolved as a general design method for reinforced concrete plates and shells through further studies involving the performance of multiple designs and the analyses of differing shell configurations.

• Geotechnical Engineering
• /
• v.6 no.2
• /
• pp.5-20
• /
• 1990

In the seismic analysis of structures, where the dynamic soil-structure interaction (DSSI) is considred, earthquake input motions as well as dynamic soil properties are random in nature. To take into account the random nature of both the input motions and the dynamic soil properties systematically, a probabilistic analysis of the DSSI subjected to seismic loading is proposed in this paper, The complex response method formulized by the elastic half space theory, the random vibration theory, and the Rosenblueth's two-point estimate method are combined for the proposed probabilistic analysis. The conclusions drawn from this study are as follows ' 1) The uncertainty bands of the earthquake input motions proposed by Kanai-Tajimi as well as those of the dynamic properties are large the coefecients of variation of those parameters tinge from 0.4 to 0.6. 2) The uncertainties of the dynamic soil properties are more sensitive to the structural responses than those of the input motion parameters. 3) The effect of correlations between the input motion parameters and the dynamic soil properties is negligible.

• Journal of the Korea Institute of Building Construction
• /
• v.10 no.2
• /
• pp.75-80
• /
• 2010

With the intensifying of price competition and structural diversifications, the uncertainty of the domestic housing market has been increased. This highlights the importance of the planning stage of construction projects, and the increased need for a higher level of accuracy in approximate estimates. Currently, a number of research and development programs to calculate construction cost at the initial planning stage are being conducted. However, there are few cases in which local characteristics are considered in deriving the results. If local calibration can be conducted during estimates, more accurate cost estimates will be enabled. This could also play a major role in ensuring the success of a project. Therefore, the purpose of this research is to develop a calculation methodology and a model for a local index based on the historical data of public apartment buildings, and to derive a local index that supports accurate construction cost estimates.

• Hwankyungkyoyuk
• /
• v.15 no.1
• /
• pp.68-82
• /
• 2002

My responses to Kim Kyung-Ok's Critique on my critique on the Hungerford approach can be summarized as follows; First, it was argued that possible confusions and misunderstandings around the concept of behavior in REB were mainly caused by Hungerford himself who has used the word in several different ways, from a bunch of overt actions to almost all kinds of responses including cognitive skills, without any clear operational definition of it for more than 20 years. It seems to be needed for future users of the word, 'Behavior' to Prevent unnecessary confusions by providing their operational definition of it. Second, REB is too ambiguous to be a legitimate goal of environmental education and too outcome-oriented to be a meaningful measure for environmental education research. Anyone who accept REB as a goal of EE or a measure for research should clearly suggest procedures and criteria for judging the environmental responsibility of actions under consideration. Third, the Hungerford approach has begun by realizing the limit of a linear traditional behavior change system and has been evolving toward a complex model with dynamic interactions among/between cognitive variables and affective variables. However, it still has one-way structural orientation toward 'Behavior' with no feedbacks. Addition of some feedback processes would make the model more flexible and realistic. Finally, both the Hines model and the Hungeford model were established based on a series of behavioristic studies including three doctoral dissertations equiped with a list of actions which were prejudged to be environmentally responsible by the researchers, not by the learners. What they were primarily interested in was not how mind functions during the learning processes but how learners' behavior can be effectively changed. Considering uncertainty and complexity associated with environmental problems, a great deal of efforts ought to be made toward more context-based and less normative studies applying cognitive psychology and quantitative approaches.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.41 no.4
• /
• pp.417-428
• /
• 2021

Since future maintenance cost estimation of infrastructure involves uncertainty, it is important to make use of a failure prediction model. However, it is difficult for local governments to develop accurate failure prediction models applicable to infrastructure due to a lack of budget and expertise. Therefore, this study estimated the life expectancy of asphalt road pavement of national highways using the Bayesian Markov Mixture Hazard model. In addition, in order to accurately estimate life expectancy, environmental variables such as traffic volume, ESAL (Equivalent Single Axle Loads), SNP (Structural Number of Pavement), meteorological conditions, and de-icing material usage were applied to retain reliability of the estimation results. As a result, life expectancy was estimated from at least 13.09 to 19.61 years by region. By using this approach, it is expected that it will be possible to estimate future maintenance cost considering local failure characteristics.

• Journal of Neurogastroenterology and Motility
• /
• v.24 no.4
• /
• pp.584-592
• /
• 2018

Background/Aims There is uncertainty about how to measure outcomes reported by patients in gastroesophageal reflux disease (GERD). This study was conducted to develop an instrument and to determine of the definition of respondent for a patient reported outcomes to assess the efficacy of a treatment used for GERD treatment. Methods A structural process has developed a self-evaluation questionnaire for GERD (SEQ-GERD); health-related quality of life questionnaire for GERD (GERD-QOL) was translated through cross-cultural validation. Two-week reproducibility was evaluated and construct validity was assessed by correlating the SEQ-GERD with the Patient Assessment of Gastrointestinal Disorders (PAGI-SYM), the reflux disease questionnaire (RDQ), and GERD-QOL. Changes in SEQ-GERD scores were compared to assess the discriminative validity following 4 weeks of proton pump inhibitor administration. Results A total of 83 Korean patients were included (mean age $46{\pm}14$ years, females 61.4%). The internal consistency of the 19-item SEQ-GERD was good (alpha = 0.60-0.94) and the test-retest reliability was high (intra-class correlation coefficient = 0.67-0.95). The SEQ-GERD highly correlated with the GERD domain of the PAGI-SYM (correlation coefficient r = 0.894, P < 0.001), the RDQ-GERD (r = 0.877, P < 0.001), and GERD-QOL (r = -0.536, P < 0.05). SEQ-GERD scores significantly varied according to the overall treatment effectiveness scale of drug responsiveness and significantly decreased after drug treatment (mean differences according to the overall treatment effectiveness scale, P = 0.020). Conclusion This study supports that SEQ-GERD is reliable and valid, and can be used to evaluate the treatment response in patients with GERD.

• International journal of steel structures
• /
• v.18 no.5
• /
• pp.1617-1630
• /
• 2018

The crucial differences between conventional rail with split-type connectors and continuous welded rails are axial stress in the longitudinal direction and stability, as well as other issues generated under the influence of loading effects. Longitudinal stresses generated in continuously welded rails on railway bridges are strongly influenced by the nonlinear behavior of the supporting system comprising sleepers and ballasts. Thus, the track structure interaction cannot be neglected. The rail-support system mentioned above has properties of non-uniform material distribution and uncertainty of construction quality. The linear elastic hypothesis therefore cannot correctly evaluate the stress distribution within the rails. The aim of this study is to apply the nonlinear finite element method using the nonlinear coupling interface between the track and structural model and to illustrate the welded rail behavior under the loading effect and uncertain factors of the ballast. Numerical results of nonlinear finite analysis with a three-dimensional solid and frame element model are presented for a typical track-bridge system. A composite plate girder, modeled by solid and shell elements, is also analyzed to consider the behavior of the welded rail. The analysis result showed buckling under the independent calculations of load cases, including 'temperature change', 'bending of the supporting structure', and 'braking' of the railway vehicle. A parametric study of the load combination method and the loading sequence is also included in this analysis.