• Korean Journal of Child Studies
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• v.34 no.6
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• pp.1-11
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• 2013

The purpose of this study was to investigate the process of counterfactual reasoning which children undergo, based on mental model theory and dual process theory. The subjects were 120 four-year-olds and 120 five-year-olds from Ulsan. Counterfactual reasoning task conditions were created, including task type and content, which were type 1-specific, type 1-general, type 2-specific, type 2-general. There were two stories used for each task condition. Children's counterfactual reasoning score range was 0 to 8. Data were analyzed using SPSS by mean, standard deviation, one sample t-test, repeated measures of Anova. The results of this study were as follows. First, children's counterfactual reasoning was above chance level regardless of the task condition. Second, children's counterfactual reasoning was lowest when type 1-specific or type 2-specific tasks were given, slightly higher when type1-general tasks were given, and the highest when type 2-general tasks were given. There was no significant difference between 4-year-old and 5-year-old children's counterfactual reasoning.

• Journal of Preventive Medicine and Public Health
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• v.55 no.3
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• pp.243-252
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• 2022

Objectives: Very limited previous research has investigated the utility weights of prostate-related diseases in the general population in Korea. The purpose of this study was to calculate the utility of prostate-related health states in the Korean general public using the standard gamble (SG) method. Methods: Seven health states for hypothetical prostate cancers, 1 for benign prostate hyperplasia, and 1 for erectile dysfunction were developed based on patient education material and previous publications. In total, 460 responses from the Korean general population were used to analyze the utility of prostate-related health states. Computer-assisted personal interviews were conducted, and utility values were measured using a visual analogue scale (VAS) and SG. Mean utility values were calculated for each prostate-related health state. Results: The mean utility values of prostate cancer derived from SG ranged from 0.281 (metastatic castration-refractory prostate cancer) to 0.779 (localized prostate cancer requiring prostatectomy). The utility value of benign prostate hyperplasia was 0.871, and that of erectile dysfunction was 0.812. The utility values obtained using the SG method in all conditions were higher than the values obtained by VAS. There were no significant demographic variables affecting utility values in multivariate analysis. Conclusions: Our findings might be useful for economic evaluation and utility calculation of screening and interventions for prostate-related conditions in the general population.

• Bulletin of the Korean Mathematical Society
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• v.41 no.4
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• pp.665-676
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• 2004

In this paper we characterize asymptotic stability via Lyapunov function in general dynamical systems on c-first countable space. We give a family of examples which have first countable but not c-first countable, also c-first countable and locally compact space but not metric space. We obtain several necessary and sufficient conditions for a compact subset M of the phase space X to be asymptotic stability.

• Communications of the Korean Mathematical Society
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• v.15 no.1
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• pp.77-90
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• 2000

In this paper, we will establish the existence theorem of the operator valued function space integral over paths in abstract Wiener space under the general conditions rather than the known conditions.

• 전기의세계
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• v.19 no.2
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• pp.21-23
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• 1970

Necessary conditions of optimal distributed parameter control systems, Hamiltons coanonical equations, welerstress condition, transversality condition and boundary condition are obtained, when the control function is constrained and the performance index takes on the general form. Also it is concluded that the lumped parameter system is the special case of the distributed parameter system.

• Journal of Korea Society of Industrial Information Systems
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• v.12 no.5
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• pp.54-59
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• 2007

We abtain some stability results for a very general differential system using the method of cone valued vector Lyapunov functions and conversely some sufficient conditions for existence of such vector Lyapunov functions.

• Communications of the Korean Mathematical Society
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• v.37 no.2
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• pp.497-502
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• 2022

Existence and uniqueness for fractional differential equations satisfying a general nonlocal initial or boundary condition are proven by means of Schauder's fixed point theorem. The nonlocal condition is given as an integral with respect to a signed measure, and includes the standard initial value condition and multi-point boundary value condition.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.425-429
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• 1992

Point sets in the Euclidean and digital planes are discussed. The local necessary and sufficient conditions are suggested for pointed lattice extraction from these sets are presented. A number of theorems and corollaries are given. The regular and "almost" regular point sets are studied. The results can be used in automatic control of textured textile images by both general and multiprocessing systems.g systems.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.4
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• pp.287-301
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• 2022

Objectives: This study compared the characteristics of the work environment between agricultural and general workers and analyzed the effects of agricultural working characteristics on work-related health problems. Methods: The participants of this study were 2,347 agricultural workers and 48,042 general workers who were selected by applying standardized weights to the raw data of 50,538 respondents from the 6th Korean Working Condition Survey (KWCS). Variables applicable to both worker groups and related to exposure to hazardous risk factors in the working environment, working hours and intensity of work, health problems and work-related status, and satisfaction with the work environment were selected. Chi-square tests and independent sample t-tests were performed to evaluate the differences in the variables between the two groups. Multivariate logistic regression analysis was conducted to analyze the effects of work environment characteristics on work-related health problems. Results: Compared to general workers, agricultural workers were more exposed to hazardous environments, irregular work patterns such as working on Saturday/Sunday, and short repetitive tasks. They reported more work-related and general health problems, including back pain, upper extremity muscle pain, lower extremity muscle pain, and general fatigue. Agricultural workers showed lower satisfaction with their work environment than general workers. Factors affecting one or more work-related health problems included gender, working years, hazardous factors, irregular work pattern, working hours, and labor intensity. Conclusions: Our findings showed that agricultural workers were relatively more vulnerable to safety issues compared to other occupational groups. Therefore, it is necessary to establish standardized safety and health standards and strengthen systematic safety and health management policies and services for agriculture.

• Journal of The Korea Institute of Healthcare Architecture
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• v.3 no.5
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• pp.97-105
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• 1997

According as the medical demands have been high, ward dept, in general Hospital become more specifying. One thing of its sample is Children ward in general Hospitals and Children's medical demand become increasing. Therefore, this study aims to represent the standard for the architectural planning of the children ward in general Hospital. For it, the present conditions and space programs of 4 general Hospitals were investigated, analyzed. And to present children ward's functional programs, plans of the 2 domestic children hospitals and foreign children hospitals were analyzed. Then one children ward in general hospital was selected, architectural remodeing process was performed by the whole those sources.