• Proceedings of the IEEK Conference
• /
• 1998.10a
• /
• pp.183-186
• /
• 1998

In this article, an algorithm for improving the performance of the convolutional decoder for a COFDM receiver using the subchannel information is introduced. The proposed algorithm defines the average amplitude of the received signal at each subchannel as a certainty of the received signal at that subchannel. If the certainty of a subchannel is low, then the received signal of that subchannel is mitigated, and the brach matric of the convolutional decoder is affected by that signal in a relatively small degree. However if the certainty of a subchannel is high, then the signal is enlarged and the branch matric is affected in a relatively large degree. simulations will show the improved BER performance of a COFDM system when the proposed method has been applied.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.39 no.4
• /
• pp.386-392
• /
• 1990

This paper discribes a sonar-based certainty grid, the probabilistic representation of the uncertain and incomplete sensor knowledge, for autonomous mobile robot navigation. We use sonar sensor range data to build a map of the robot's surroundings. This range data provides information about the location of the objects which may exist in front of the sensor. From this information, we can compute the probability of being occupied and that of being empty for each cell. In this paper, a new method using Bayesian formula is introduced, which enables us to overcome some difficulties of the Ad-Hoc formula that has been the only way of updating the grids. This new formula can be applied to other kinds of sensors as well as sonar sensor. The validity of this formula in the real world is verified through simulation and experiment. This paper also shows that a wide angle sensor such as sonar sensor can be used effectively to identify the empty area, and the simultaneous use of multiple sensors and fusion in a certainty grid can improve the quality of the map.

• Journal of the Korean earth science society
• /
• v.27 no.7
• /
• pp.705-714
• /
• 2006

The purpose of this study was to explore the elementary students' perceptions of Earth systems and environmental issues. A survey was conducted to determine the students' perceptions on the following aveas: (1) the concepts of certainty and tangibility, (2) self-reported knowledge level, (3) perceived danger level of selected eight Earth systems and environmental issues, and (4) their primary information source on these issues. Results indicated that ozone hole, acid rain, El $Ni\widetilde{n}o$, and global warming were identified by the students as uncertain and intangible issues. Perceived certainty and perceived tangibility were highly positively correlated with self-reported knowledge compared to other relationships. The results also showed that learning from school was the most frequent information source for environmental issues. The second most frequently used source of information was television among several mass media sources. It is hoped that this study contributes to understanding the elementary school students' perceptions toward the selected Earth systems and environmental issues.

• Hwankyungkyoyuk
• /
• v.13 no.2
• /
• pp.14-23
• /
• 2000

This study was designed to find answers for the two questions that had been raised in the study of Lee and Fortner(2000): 1) How can the appropriateness of classification of environmental issues by perceived certainty and 2) How are perceived certainty, tangibility, significance of environmental issues and willingness to act to solve those problems related to each other\ulcorner A questionnaire consisted of 40 questions was administered to 144 college students. Results of the study revealed that classification through cluster analysis appeared to be more appropriate and credible than classification by mean scores or medians. Four major factors were found to have high positive correlations to each other as hypothesized. These results imply for environmental educations that people's attitude toward and behavior on environmental problems are likely to be more strongly and meaningfully associated with their perceptions of those problems that are subjective and flexible than physical or chemical characteristics of the problems that are frequently considered as objective.

• The Journal of Fisheries Business Administration
• /
• v.39 no.2
• /
• pp.109-123
• /
• 2008

This study is aimed to establish an investment decision model for offshore aquaculture project of rock bream in Korea using a certainty equivalent method (CEM) based on the expected utility theory and to investigate its economic viability under risk and uncertainty. In the analysis with CEM, the effects of risk attitude and risk level on investment and risk premium were examined and the impacts of various risk and uncertainty factors on the investment decision were also assessed. In addition, the outcomes were compared to those evaluated by the traditional net present value (NPV) method. Results show that risk premium grew as the investors became more risk averse and uncertainty level (the variance of NPV) increased. Consequently, the certainty equivalent value was predicted to decrease from the value assessed by the traditional NPV method.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.8 no.2
• /
• pp.87-93
• /
• 2008

In this paper, we propose a hierarchical fuzzy based nutrition evaluation system that can analyze the individuals' nutrition status through the inference results generated by each layer. Moreover, a method to minimize the uncertainty of inference in the evaluated nutrition status is discussed. To show the effect of the uncertainty in fuzzy inference, we compared the results of nutrition evaluation with/without the certainty factor of rules on 132 people over the age of 65. From the experimental results, we can see that the evaluation method with the modified certainty factor provides better reliability than that of the general evaluation method without the certainty factor.

• Asia pacific journal of information systems
• /
• v.29 no.4
• /
• pp.644-672
• /
• 2019

Negative consequences incurred from employees' non-work-related computing (NWRC) have been one of the security-related issues in information intensive organizations. While most studies have focused on the factors that motivate employees to engage in NWRC, this study examines the mediating effect of moral beliefs on the relationship between sanctions and NWRC using a moral beliefs-based model. The research model posits that the formal (i.e., punishment severity and detection certainty) and informal sanctions (subjective norms and descriptive norms) enhance employees' moral beliefs against NWRC intention. From a cross-sectional scenario-based survey involving 176 employees working at banks in Mongolia, our results indicate that moral beliefs fully mediate the relationship between detection certainty/subjective norms and NWRC intention and act as a partial mediator in the relationship between descriptive norms and NWRC. The findings from this study present empirical evidence that both informal and formal sanctions could be an effective deterrent for NWRC intention through employees' moral beliefs.

• Journal of the Korea Convergence Society
• /
• v.5 no.4
• /
• pp.155-161
• /
• 2014

We survey the relation of fuzzy entropy measure and similarity measure. Each measure represents features of data uncertainty and certainty between comparative data group. With the help of one-to-one correspondence characteristics, distance measure and similarity measure have been expressed by the complementary characteristics. We construct similarity measure using distance measure, and verification of usefulness is proved. Furthermore analysis of similarity measure from fuzzy entropy measure is also discussed.

• Journal of the military operations research society of Korea
• /
• v.9 no.1
• /
• pp.15-28
• /
• 1983

In sequential capital allocation processes, the information on the future availability (flexibility) of invested funds provides a decision maker with additional insight into the characteristics of alternatives. The investment decision with consideration of flexibility and profitability results in more wealth accumulation than the decision without considering flexibility does in sequential investment processes. To utilize the information on the flexibility under certainty, the PV/FI decision model is developed.

• 제어로봇시스템학회:학술대회논문집
• /
• 1993.10a
• /
• pp.119-124
• /
• 1993

This paper describes a method of producing maps of an indoor environment with an autonomous mobile robot equipped with sonar array. This method uses the certainty grid suitable for accommodation of inaccurate sensor data and real-time navigation. Each grid contains a certainty vale that indicates the measure of confidence that an obstacle exists within th grid area. The scheduled firing method is used to eliminate the crosstalk between ultrasonic sensors. The effectiveness of the method is verified by a series of experiments.