• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1782-1787
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• 1997

A combined algorithm called APEXS(Alarm Processing and Diagnosis Expert System) for power plants has been developed on the time-based alarm processing with a proper alarm prioritization and a diagnosis with a qualitative model(QM), qualitative interpreter(QI), and a state-transition trees(STT).

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.275-278
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• 1996

This fault diagnosis system consists of qualitative models, qualitative interpreter, and inference engine. Qualitative models are formed by analysis of the relationships between faults and behaviors of sensor trends, which are described by state transition trees. Qualitative interpreter outputs confidence factors with three qualitative quantities which represent the states of sensor trends. And then, the possible faults are detected by inference module which matches the states of trends within a window size with the qualitative models using the well-known min-max operation.

• Korean Journal of Adult Nursing
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• v.27 no.1
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• pp.117-126
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• 2015

Purpose: Korean women, who have come to the forefront at a risk of cancer, have been notable objects for qualitative nursing research in last a couple of decades. Given the imparity and varieties of those findings, this study was aimed to synthesize the impact of cancer diagnosis and its treatment on Korean women's lives using a qualitative meta-synthesis method. Methods: By searching five English-based databases and four Korean databases, 21 qualitative studies on Korean women's particular experiences of cancer diagnosis and treatment since 2000 were included. Using a meta-synthesis process by Sandelowski & Barroso (2007), the selected studies were synthesized for interpretive integration of the findings. Results: The meta-synthesis elicited three themes: detachment from the usualness, awareness of profound desires, and redefinition of every relation. With destructive experiences of a diagnosis and its treatments, Korean women felt apart from their everyday life, daily roles, and even from their own body. They then grasped a strong desire for life and for beauty, and reconfirmed the sense of mission for being a mother. Those changes made them to reconstruct all relations surrounded them. Conclusion: The findings yield a substantive portrait of the given issue, which could be helpful for health care professionals.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.110-115
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• 2004

The hybrid fault diagnosis method based on a combination of the signed digraph (SDG) and the partial least-squares (PLS) has the advantage of improving the diagnosis resolution, accuracy and reliability, compared to those of previous qualitative methods, and of enhancing the ability to diagnose multiple fault. In this study, the method is applied for the multiple fault diagnosis of the Tennessee Eastman challenge process, which is a realistic industrial process for evaluating process contol and monitoring methods. The process is decomposed using the local qualitative relationships of each measured variable. Dynamic PLS (DPLS) model is built to estimate each measured variable, which is then compared with the estimated value in order to diagnose the fault. Through case studies of 15 single faults and 44 double faults, the proposed method demonstrated a good diagnosis capability compared with previous statistical methods.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1328-1333
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• 2006

For fault diagnosis of machines and equipments, knowledge-based method has been used widely but has some limitations for complex systems. These can be covered by model-based method. As one kind of model-based method, Qualitative modeling diagnosis method is developed in this research. The developed method uses output signal only. In this method quantization of the output signal mattes automata which can characterize the flow of the signal pattern to normal and fault respectively. As an example of the qualitative diagnosis method, an electric tool which has faults at gear and bearing were examined in this research. The result shows that the developed method can diagnose the fault clearly for the two fault cases.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.5 s.110
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• pp.495-502
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• 2006

A fault diagnosis method is developed in this study using automaton through quantization of vibration signals for normal and faulty conditions, respectively. Automaton is a kind of qualitative model which describes the system behaviour at the level of abstraction. The system behavior was extracted from the probability of the output sequence of vibration signals. The sequence was made as vibration levels by reconstructing the originally measured vibration signals. As an example, a fault diagnosis for the bearing of ATM machine was done, which detected the bearing fault with confident level compared to any other existing methods of kurtosis or spectrum analysis.

• Imaging Science in Dentistry
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• v.47 no.3
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• pp.189-197
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• 2017

Purpose: To quantify artifacts from different root filling materials in cone-beam computed tomography (CBCT) images acquired using different exposure parameters. Materials and Methods: Fifteen single-rooted teeth were scanned using 8 different exposure protocols with 3 different filling materials and once without filling material as a control group. Artifact quantification was performed by a trained observer who made measurements in the central axial slice of all acquired images in a fixed region of interest using ImageJ. Hyperdense artifacts, hypodense artifacts, and the remaining tooth area were identified, and the percentages of hyperdense and hypodense artifacts, remaining tooth area, and tooth area affected by the artifacts were calculated. Artifacts were analyzed qualitatively by 2 observers using the following scores: absence (0), moderate presence (1), and high presence (2) for hypodense halos, hypodense lines, and hyperdense lines. Two-way ANOVA and the post-hoc Tukey test were used for quantitative and qualitative artifact analysis. The Dunnet test was also used for qualitative analysis. The significance level was set at P<.05. Results: There were no significant interactions among the exposure parameters in the quantitative or qualitative analysis. Significant differences were observed among the studied filling materials in all quantitative analyses. In the qualitative analyses, all materials differed from the control group in terms of hypodense and hyperdense lines (P<.05). Fiberglass posts did not differ statistically from the control group in terms of hypodense halos(P>.05). Conclusion: Different exposure parameters did not affect the objective or subjective observations of artifacts in CBCT images; however, the filling materials used in endodontic restorations did affect both types of assessments.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1995.10b
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• pp.92-97
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• 1995

In medical diagnostic process we are dealing with the preliminary diagnosis based on the interview chart. We will quantify the qualitative information of a patient by dual scaling and establish both prototypes of fuzzy diagnostic sets and the fuzzy linear regressions. Its utility is shown in the diagnosis of headache and CAFDDH.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.15 no.4
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• pp.495-503
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• 2008

Purpose: To date most research related to patients with breast cancer has discriminately investigated the status within or after the treatment although the patients demand holistic nursing care from the time of diagnosis. Thus, the purpose of this study was to investigate the trajectory of breast cancer diagnosis and patients' experiences in the pre-treatment period. Method: This qualitative study used qualitative thematic analysis. Nineteen Korean women who were diagnosed with breast cancer within the last 6 month participated in the study. Individualized interviews were conducted with each participant in a cancer center in K city. The interviews were tape-recorded, transcribed, and analyzed using the thematic analysis process. Results: The overriding theme was "the scattered life in an unforeseen swirl", which illustrates the participants' unexpected crisis with confusion and emotional distress. Two subthemes included "falling into an unavoidable journey", and "staggering in a muddle with urgency". The categories were "unexpected probability", "nagging nodularity", "ominous presentiment", "emotional upheaval", "bad thought intrusion", and "a sense of urgency". Conclusion: Patients in the pre-treatment period encountered utter emotional distress and a sense of urgency after being diagnosed breast cancer. Strategies to develop nursing care for patients in this period and nursing implications are discussed.

• Journal of the Korean Institute of Gas
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• v.4 no.4 s.12
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• pp.42-49
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• 2000

Due to their size and complexity, it is very difficult to make diagnostic system for the whole chemical processes. Therefore, a systematic approach is required to decompose larpge-scale process into sub-processes and then diagnose them. This paper suggests a method for the minimization of knowledge base and flexible diagnosis to be used in qualitative fault diagnosis based on Fault-Effect Tree model. The system can be decomposed for flexible diagnosis, size reduction of knowledge base, and consistent construction of complex knowledge base. The new node, gate-variable, is introduced to connect the cause-effect relationships of each sub-process. For on-line diagnosis, off-line analysis is performed to construct Fault-Effect Trees of gate-variables as well as activation conditions of gate-variables. On-line diagnosis strategy is modified to get the same diagnosis result without system decomposition. The proposed method is illustrated with a fault diagnosis system for a large-scale boiler plant.