• Journal of Oriental Neuropsychiatry
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• v.12 no.2
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• pp.185-191
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• 2001

Objectives: This study aimed to evaluate the usefulness as a screening test of Clock Drawing Test(CDT) compared with the standard K-DRS in probably dementia. Methods: The subjects for this study consisted of 19 elderly persons who visited to the outpatient department of Oriental Neuropsychiatry of the Kyunghee Oriental hospital. They received the K-DRS and the Clock Drawing Test. Three observers evaluated them with circle, numbers, hands. Inter-rater reliability of scores from Clock Drawing Test was assessed and Pearson correlation coefficients were used to examined the relationships between scores from Clock Drawing Test and K-DRS. Results: Correlations between individual raters was highly significant (r= .957, .974, and .970, respectively: p<.001). There was stastically significant correlations between K-DRS and CDT scores (r= 0.849, p<.001). Conclusions: The CDT can be rated reliably by observers and correlations between CDT and K-DRS is significantly high. We confirmed the usefulness of CDT as simple, easily administered, low cost, and reliable general screening test for dementia.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.4
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• pp.377-383
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• 2002

To obtain a high performance in a direct vector controlled induction machine, it is essential to obtain the current rotor flux. The accuracy of flux observers for induction machines inherently depends on parameter sensitivity. This paper proposes an analysis method for conventional flux observers using "parameter sensitivity". The "parameter sensitivity" is defined as the ratio of the percentage change in the system transfer function to the percentage change of the parameter variation. We define the ratio between real flux and estimated no as the transfer function, and analyze a parameter sensitivity of this transfer function. Practical verification is presented to conform the capabilities of the proposed analysis method.sed analysis method.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.4
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• pp.299-306
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• 2003

The rotor flux position is needed to perform vector control of induction motor. But rotor speed information is needed to get accurate the rotor flux position. It is difficult to implement the open loop method without speed information or the motor equation only because of noise or the motor parameter error. This paper presents the speed estimator can use the arbitrary rotor flux observer by separating the flux observer and speed estimator and apply the three flux observers proposed by Ohtani, Lorenz and full order flux observer. The validity of speed estimator presented is verified and the performance using the three rotor flux observers is analyzed by the simulation and experiment.

• Korean Journal of Occupational Health Nursing
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• v.9 no.1
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• pp.56-61
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• 2000

This study was done in an attempt to reveal those factors interfering with the observation study. Three trained research assistants collected data by observing the two occupational health nurses working in the small scale enterprises on the 3rd and 10th of February, 1999. The first observation was performed on the 3rd of February without observation guidance. Guidance was given during the second observation on the 10th of February. These data were compared between reporters in nursing services of 'Workplace visiting', 'Health counselling' and 'Blood pressure checking' according to nursing time and frequency. These areas were chosen because these activities were regarded as clearly identifiable by observers in contrast to the other performances. The data showed inconsistency between reporters. However, they were reduced when reporters observed nurses with guidance, although there were still minor differences between data in time and frequency. Discussions were carried out to find possible reasons for these differences. The causes were mainly attributed to the difficulty in workplace conditions to observe, the work specificity of nurses visiting each workplace and the delicate situation between nurses and observers when reporters were travelling in the nurse's car. Therefore, the results suggest that the observation method applied to the nursing service research at small-scale enterprises should be more concerned about the selection of appropriate workplace and operational definition of nursing activity in order to more precisely measure nurses' attitudes.

• Journal of The Korean Digital Architecture Interior Association
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• v.11 no.4
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• pp.67-80
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• 2011

The architectural space is the involuntary place where man lives and experiences, and as a 3 dimensional space through the continuous experience with the concept of 4th dimension of time, it provides the observers with the dramatic space imagery. These kinds of space experiences are experienced mentally and perceptively through the physical elements of inner and outer space of the architectural buildings, and this space imagery is created here by all the space composing elemensts of the building. These space experiences are caused by the changing processes of the space characteristics, and the observers perceive the changes in space characteristics. The present building is going with Eco-Architecture. When 2008 sees the building,,Eco-Architecture design which hits appears. There is a possibility of seeing 16 kind types from that place. And From here examined the spatiality which is expressed. These changing processes of inner and outer space, space versus space, and unit space, which are perceived by the observer. It`s way to help in architectural design and wishes.

• Journal of Ocean Engineering and Technology
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• v.20 no.6 s.73
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• pp.24-34
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• 2006

Hydrodynamic coefficients strongly affect the dynamic performance of an AUV. Thus, it is important to know the true values of these coefficients, in order to accurately simulate the AUV's dynamic performance. Although these coefficients are generally obtained experimentally, such as through the PMM test, the measured values are not completely reliable because of experimental difficulties and errors. Another approach, by which these coefficients can be obtained, is the observer method, in which a model-based estimation algorithm estimates the coefficients. In this paper, the hydrodynamic coefficients are estimated using two nonlinear observers: a sliding mode observer and an extended Kalman filter. Their performances are evaluated in Matlab simulations, by comparing the estimated coefficients obtained from the two observer methods, with the experimental values as determined from the PMM test. A sliding mode controller is constructed for the diving and steering maneuver by using the estimated coefficients. It is demonstrated that the controller, applied with the estimated values, maintains the desired depth and path with sufficient accuracy.

• Imaging Science in Dentistry
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• v.44 no.2
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• pp.137-141
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• 2014

Purpose: This study was performed to investigate the interobserver agreement on the detection of carotid artery calcifications on panoramic radiographs. Materials and Methods: This study consisted of panoramic radiographs acquired from 634 male patients of the age of 50 years or older. Having excluded carotids of no diagnostic quality, 1008 carotids from the panoramic radiographs of the patients were interpreted by two oral and maxillofacial radiologists independently for the presence of carotid artery calcifications. Statistical analysis was used to calculate the interobserver agreement. Results: Interobserver agreement was obtained for 932 carotids (92.4%). Inconsistent interpretation of 76 carotids (7.5%) between the two observers was found. Cohen's kappa value was 0.688 (p<0.001). Conclusion: The probability of a match between the two observers was substantially high.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.2
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• pp.407-414
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• 2007

A sensor fault detection scheme(SFDS) for a class of nonlinear systems that can be represented by Takagi-Sugeno fuzzy model is proposed. Basically, the SFDS may be considered as a multiple observer scheme(MOS) in which the bank of state observers and the detection & isolation logic are included. However, the proposed scheme has two great differences from the conventional MOSs. First, the proposed scheme includes fuzzy fault detection observers(FFDO) that are constructed based on the T-S fuzzy model that provides very good approximation to nonlinear dynamic systems. Secondly, unlike the conventional MOS, the FFDOS are driven not parallelly but sequentially according to the predetermined sequence to avoid the massive computational burden, which is known to be the biggest obstacle to the practical application of the multiple observer based FDI schemes. During the operating time, each FFDO generates the residuals carrying the information of a specified fault, and the corresponding fault detection logic unit performs the logical operations to detect and isolate the fault of interest. The proposed scheme is applied to an inverted pendulum control system for sensor fault detection/isolation. Simulation study shows the practical feasibility of the proposed scheme.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.286-297
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• 2018

We analyzed scientific observer data to identify species composition and catch trends of Korean tuna longline fisheries in the Indian Ocean. The data were collected by Korean scientific observers onboard Korean tuna longline fishing vessels in the Indian Ocean from 2010 to 2015. The observers identified 94 species including 5 tuna, 6 billfish, 11 shark, 7 other fish, 5 seabird and 1 sea turtle. Albacore tuna Thunnus alalunga and southern bluefin tuna Thunnus maccoyii were the dominant tuna species, and swordfish Xiphias gladius were the most commonly captured billfish. During the survey periods, 87 seabirds were incidentally bycaught. Black-browed albatross Diomedea melanophris was the dominant seabird species in bycatch, especially in 2010. Cluster analysis showed difference in the species composition of catches between the eastern and western Indian Ocean.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.12
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• pp.1177-1183
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• 2010

In this paper, a parallel bank of multiple adaptive unknown input observers approach suggested by D.Wang is applied to detect a single fault of control surface actuator and to estimate the actuator position of lock-in-place fault using a small fixed-wing UAV model with eight control surfaces. This paper shows that not only the fault diagnosis algorithm detects and estimates each faults of lock-in-place in 1 second by simulation but also it may be unavailable to isolate among two same-shaped rudders.