• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.2 s.48
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• pp.83-90
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• 2006

In active vibration control of building, controller design considering both control input saturation of controller and parameter uncertainties of building is needed. In our previous research, we proposed a robust saturation controller which guarantees robust stability and control performance of the uncertain linear time-invariant system in the presence of control input saturation. In this paper, the availability of the robust saturation controller for the building with an active mass damper (AMD) system is verified through experimental tests. Experimental tests are carried oui using a two-story building model with a hydraulic-type AMD.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.3-6
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• 2000

The magnetic bearing system are intrinsically unstable, and need the feedback control of electromagnetic forces with measured displacements. So the controller design plays an important role in constructing high performance magnetic bearing system. In case of magnetic bearing system, the order of identified model is high because of unknown dynamics included in closed loop systems - such as sensor dynamics, actuator dynamics - and non-linearity of magnetic bearings itself. In this paper the identification and robust control of flexible rotor supported by magnetic bearing are discussed. We measure and identify overall system that contains not only flexible rotor model but also magnetic bearing and time delay. The structured and unstructured uncertainties are modeled that cover variations of natural frequencies, uncertainties in sensor and actuator gains and unmodeled dynamics. And desired performances are specified with several weighting function. Using augmented system that includes identified model, uncertainties, and weighting functions, μ-synthesis is applied to flexible rotor supported with magnetic bearing. The flexible rotor was spin up over the first flexible critical speed.

• The Korean Journal of Health Service Management
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• v.5 no.1
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• pp.133-145
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• 2011

The purpose of this study is to analyze the influence of external environment, organizational characteristics on informatization level in hospital settings, and to provide suggestions to improve the informatizaiton level of strategic information system of hospitals. In order to achieve study purpose, causal model was developed and empirically tested. Data were collected from 716 managers of 89 hospitals keeping information system in Busan and KyungNam Province using self-administered structured questionnaire. Major results of this study were as follows; First, among hospitals which had information training programs, informatization capacity was significantly higher. Moreover, informatization capacity was significantly varied by ownership type, institutional level, and number of beds of hospitals. Second, environmental uncertainty, intra-industry competition intensity, decision-making concentration, work standardization variables and perceived benefits were found to be significant affecting factors on informatization capacity as a result of path analysis. Third, support of top-management and perceived benefits were found to be significant affecting factors on informatization capability as a result of path analysis. Especially, informatization capability was positively affected by informatization capacity. Finally, perceived benefits was found to be significant affecting factors on informatization competency as a result of path analysis. Especially, informatization competency was positively affected by informatization capability.

• Journal of the Korea Safety Management & Science
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• v.10 no.1
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• pp.11-22
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• 2008

Humans are well-known for being adept at using intuition and expertise in many situations. However, human experts are still susceptible to errors in judgment or execution, and failure to recognize the limits of knowledge. This would happen especially in semi-structured situations, in multi-disciplinary settings, under time or other stress, under uncertainty, or when knowledge is outdated Human errors are caused by cognitive biases, attentional slips/memory lapses, cultural motivations, and missing knowledge. The purpose of this research is to study errors of human experts committed in judgment and the general idea of critiquing systems as corresponding plan. Compared to expert systems, critiquing systems are narrowly focused programs useful in limited situations for collaborating with and supporting experts in their task activities. It supports an expert by detecting the human's errors by deploying various strategies that stimulate humans to improve their performance. A variety of types of critiquing systems has spread through numerous application areas.

• Child Health Nursing Research
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• v.13 no.4
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• pp.454-466
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• 2007

Purpose: To explore the experiences of parenting from the mothers of children with severe CHD and to develop a grounded theory about their experiences. Method: Grounded theory method guided the data collection and analysis. A purposeful sample of 16 mothers of children with severe CHD participated during the period 2003. The data were collected by semi-structured individual interviews. Results: "Raise with dignity" emerged as the core phenomenon. 'Powerlessness' came up as the central concept. The causal conditions working on powerlessness was 'living with a bomb in the heart': uncertainty and the context were 'confronting people's eyes', 'developing child's adaptability'. An intervening condition was 'forming a support system' and consequences for coping with powerlessness were 'overcome' or 'ambivalence' using the strategies for mother's positive personality, care role perception, accepting, acknowledgement, and managing the body and mind. Conclusions: In the results of this study, the mothers of children with severe CHD are continue to struggle with life during children's growth and repeated attacks of disease. They need to be provided with skills to cope with physical and mental problems in rearing the children with expertized information for the entire period of growth.

• Journal of Arbitration Studies
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• v.26 no.3
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• pp.3-26
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• 2016

The preferential Rules of Origin (RoO) govern tariff preferences that are given in accordance with the FTA. However, relatively few studies have been devoted to the procedures in settling disputes that are relevant to RoO under the FTA. This study is a first attempt at analyzing the applicability and the potential improvement in dispute settlement procedures in FTAs targeted at the preferential RoO. By exploring three dispute cases involving the preferential RoO, it is suggested that restrictiveness, complexity, and uncertainty that are inherent in the preferential RoO may trigger political tension and dispute. Forming a panel that is capable of mitigating political tension, facilitating participation and early cooperation of experts and stakeholders, and establishing a well-structured enforcement procedure are essential in dispute settlement procedures to resolve disputes involving cases on RoO. Furthermore, the current dispute settlement procedure that hinders the private sector's access should be changed to one that is more open to private sector entities, such as companies, to facilitate the enforcement of the decision. Given that more improved FTA dispute settlement procedure may guarantee the enforcement and application of the FTA preferential treatment in relation with more politically powerful states and foster genuine free trades, more in-depth studies must be conducted on this topic.

• Journal of Korean Elementary Science Education
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• v.24 no.4
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• pp.426-434
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• 2005

In this study, elementary school students' responses toward a discrepant event about a float-or-sink problem were investigated through semi-structured interviews. Initial participants were 61 fifth-grade students from two elementary schools. After excluding the students who did not possess the target misconception from the results of a preconception test and who were not willing to participate in an interview, 31 students (14 males and 17 females) were finally interviewed by two teacher-interviewers. During the interviews, students were first provided with a hands-on experiment which was the same as the situation in the preconception test, and then they were asked about believability of the discrepant event, inconsistency between the discrepant event and their existing conceptions, and belief change after experiencing the discrepant event. Interviews were audio- and video-taped, and then were transcribed by two interviewers. After analyzing the interview transcriptions, we found four types of students' responses; rejection, uncertainty, peripheral belief change, and belief change. We also found that belief change response type should be classified into three distinctive subtypes; belief decrease, ad-hoc belief change, and analytical-abductive belief change.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.851-861
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• 2021

This study aims to explore the specific risks in family small-medium enterprises (SMEs) and explain how they manage these risks to sustain and expand. In Indonesia, family business composes around 95 percent of all businesses and contributes about 80 percent to the country's economy. SMEs contribute approximately 57.8 percent to the nation's gross domestic product. Risk management poses challenges to the family business's survival, as family members do not take actions on risk. The assessment of risk is difficult and family businesses lack the ability to determine risk management priorities, including risk management review processes to evaluate risk, thus leading to family business failures. Applying the case study approach, in-depth semi-structured interviews were conducted in seven family SMEs comprising fifteen informants. Additionally, a focus group discussion consisting of three experts is conducted to reaffirm the findings from the interviews, observations, and field notes. The research identified the specific risks and how the family owners strategize to safeguard against these risks such as cash flow deficiency, operations dysfunction, cultural frailty, disharmony, transgenerational entrepreneurship failure, political uncertainty, and unprofessionalism. Comprehending these risks and their strategic decisions elucidated in this research could enable the family owners and key non-family professionals to work hand-in-hand to thrive over the family business risks together. Further avenues of research regarding family business risk management are also suggested in this study.

• Journal of Korea Water Resources Association
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• v.54 no.5
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• pp.321-334
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• 2021

A fixed reflectivity-rainfall relationship approach, such as the Marshall-Palmer relationship, for an entire year and different seasons, can be problematic in cases where the relationship varies spatially and temporally throughout a region. From this perspective, this study explores the use of long-term radar reflectivity for South Korea to obtain a nationwide calibrated Z-R relationship and the associated uncertainties within a Bayesian inference framework. A calibrated spatially structured pattern in the parameters exists, particularly for the wet season and parameter for the dry season. A pronounced region of high values during the wet and dry seasons may be partially associated with storm movements in that season. Overall, the radar rainfall fields based on the proposed modeling procedure are similar to the observed rainfall fields. In contrast, the radar rainfall fields obtained from the existing Marshall-Palmer relationship show a systematic underestimation. In the event of high impact weather, it is expected that the value of national radar resources can be improved by establishing an active watershed-level hydrological analysis system.

• The Korean Journal of Rehabilitation Nursing
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• v.2 no.2
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• pp.243-256
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• 1999

The purpose of this study was to identify the degree of self-care activities of stroke patients, the family burden, and the educational needs of primary caregivers. A descriptive survey research was conducted in 97 stroke patients and their respective primary caregivers. Data were collected by the interviews using a structured questionnare from July 26th to August 5th, 1999. NIH stroke status was $12.15{\pm}8.40$, the degree of self-care activities of stroke patients was $26.85{\pm}9.39$. The score of objective burden of primary caregivers was $31.24{\pm}4.81$ and subjective burden was $24.30{\pm}6.99$. The score of the educational needs was $89.78{\pm}9.99$. We present several imformations about clients from these scores as follows: The patients were convalescent and their depentant level of self- care was middle range; The objective burden was higher than the subjective burden; And the educational needs of family caregivers were very high. The Elain Mattis Educational Wants of Family Caregivers of Disabled Adults Questionnaire was used to assess the educational needs of primary caregivers of stroke patients. The results of this research are offered to help nurses understand the feelings of uncertainty about the new and unexpected role that family caregivers face and to help nurses meet the needs of families preparing to care stroke survivors at home.