• Journal of Korea Society of Industrial Information Systems
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• v.6 no.4
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• pp.54-60
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• 2001

In this thesis, We analyze performance evaluation of one channel B-WLL IF receiver system. Among the item of receiver performance, inter-modulation interference and yield analysis is especially focused. Since inter-modulation interference cause bad influence on system performance due to unwanted third order harmonic located in desired frequency band, third order harmonic causing inter-modulation interference should be efficiently removed. Yield analysis is observing influence on system performance when system element parameter is statistically varied, and in this thesis, system output is observed for LNA parameters. Additionally, Scheme for LNA gain adjustment to reduce inter-modulation interference is proposed by observing variation of third order harmonic output for LNA gain variation.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.5
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• pp.459-466
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• 2014

An index was developed that estimates cardiovascular health degree with easily available physiological information such as survey and noninvasive measurement. The survey score was calculated by utilizing questions related to personal disease history, self-feeling, and management state. The measurement score was calculated using physiological parameters such as blood pressure, accelerated plethysmograph(APG), and heart rate variability(HRV), and augmentation index(AI). In order to evaluate effectiveness of the cardiovascular index and modify weighting factors used in each item, a clinical trial was done in a general hospital. The cardiovascular index showed a clear correlation of 0.685 with the doctor's score on the cardiovascular health degree. The correlation between the self-estimated score and doctor's score was as low as 0.217. The large gap between these two scores demonstrated necessity of more objective tools like the cardiovascular index. The cardiovascular score showed a significant difference between normal persons and patients suffering hypertension or diabetes. (p=0.000).

• Journal of Korean Physical Therapy Science
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• v.15 no.3
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• pp.55-63
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• 2008

Background : The Purposes of this study were to understand difference between free walking and obstacle over walking through the naked eye and motion analysis device, and to review merits of obstacle walking training as item of functional assessment in clinical situations. Methods : All participants were male and performed 3 types of walking methods: free walking, obstacle over walking with low block(height=10cm, width=8cm), and obstacle over walking with high block(height=20cm, width=8cm). All walking were performed 3 trials respectively. Results : In the naked eye, initial contact with toes occurred more than heel strike in obstacle over walking, and the flexion angle of hip and knee were increased in obstacle over walking. On interpretations though motion analysis device, cadence, gait speed and weight accept were significant statistically(p<.05). Cadence and gait speed were decreased, and weight accept duration was increased in obstacle over walking. Rotation among three pelvic motions was significant statistically(p<.05), flexion among three hip motions was significant statistically(p<.05) and flexion among three ankle motions was significant statistically(p<.05). Rotation and flexion among three ankle motions was significant statistically(p<.05). Conclusion : Both the naked eye and interpretations of the device presented many difference between free walking and obstacle over walking. In overcrossing obstacles, many participants appeared walking strategy by perform initial contact with toes. Knee flexion was most significant statistically(p<.05) in obstacle over walking with 20cm block.

• 전자공학회논문지 IE
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• v.47 no.3
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• pp.26-34
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• 2010

In this study, a neuro-fuzzy controller based on the characteristics of fuzzy controlling and structure of artificial neural networks(ANN). This neuro-fuzzy controller has each advantage from fuzzy and ANN, respectively. Plus, it can handle their own shortcomings and parameters in the controller can be tuned by on-line. To verify the proposed controller, it has applied to the AC servo motor which is popular item in robot control field. General PID and fuzzy controller are also applied to the same motor so stability and good characteristic of the proposed controller are compared and proved. Especially, the experiment for variable load is investigated and performance result is proved also.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.2
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• pp.11-18
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• 2002

Psychological and physiological effects of the simulator sickness could be important bias factors for the sensibility evaluation. The purpose of the present study was to clear the differences of psychophysiological responses due to individual sensitivity of simulator sickness. The present experiment tried to investigate the simulator sickness objectively by observing the change of the simulator sickness for the different level of sickness groups (sick and non_sick group). The subjective evaluations using Simulator Sickness Questionnaire (SSQ) and physiological responses were measured every five minutes when they were driving as 60km/h in the driving graphic simulator. Response level of the subjective evaluation for all subjects on the simulator sickness was linearly increased with time for every item, and the response level of sick group was bigger than that of non_sick group. When the analysis on central nervous system was done separately on the sick and the non_sick group, there was significant difference in the parameter $\theta$/total at Fz and Cz. Although the analysis on autonomic nervous system for all subjects showed the increased activation of sympathetic nervous system, there was no significant difference between the sick and non_sick group. In summary, it is necessary to select the subjects who feel less simulator sickness in order to be accurate sensibility evaluation. The parameters to distinguish between the sick and non_sick group were the change on $\theta$/total and subjective evaluation using SSQ.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9A
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• pp.1306-1312
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• 2000

The quality loss of a X-band transmitter has been derived by means of MC simulation. The transmitter as a payload of LEO(Low Earth Orbit) satellite is capable of the down transmission the image data of hundreds Mbps generated from the Electro-Optical Instrument in real time. The parameters such as data asymmetry amplitude unbalance,phase unbalance, wave shaping and channel interference are included in the quality loss simulation Assuming that normally distributed gaussian noise is simply added to the channel, the quality loss of 0.7 dB has been obtained through this simulation based on a 95% confidence interval. The obtained quality loss can be applied to the link budgets as an additional loss item.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.3 s.22
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• pp.73-82
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• 2005

This paper describes shock waveform synthesis methods for a shock response spectnlm over a short time interval with which intereference between parts within a test item is increased to perform a sufficient shock test for damage or malfunction which may be caused by the interference between parts, and a digital filter for obtaining a shock response history required for the shock waveform synthesis and a digital inverse filter for restoration by inversely using the digital filter. The time at which the maximax value occurs in the response history is detected in order to establish a delay time which is one of the parameters in the wavelet, on the condition that the natural frequency of SDOF system with a Q (quality factor) of 10 equals to the wavelet frequency of the zero delay wavelet input. A shock response spectrum over a short time interval and an abrupt change in the acceleration for an instant are illustrated as features of the synthesized waveform.

• Journal of Korean Academy of Nursing
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• v.49 no.1
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• pp.1-13
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• 2019

Purpose: The purpose of this study was to develop and validate the Communication Behavior Scale for nurses caring for people with Dementia (CBS-D). Methods: Based on communication accommodation theory, the initial items were generated through a literature review and interviews with 20 experts. Content and face validity of the initial items were assessed. Data from 486 nurses caring for people with dementia were analyzed using item analysis, exploratory and confirmatory factor analysis, criterion-related validity, and internal consistency. Results: The final scale consisted of 18 items and four factors (discourse response management, interpersonal control, emotional expression, and interpretability) that explained 57.6% of the variance. Confirmatory factor analysis indicated that the theoretical model with 18 items satisfied all goodness-of-fit parameters. Criterion-related validity was shown by the Global Interpersonal Communication Competence Scale (r=.506, p<.001). Cronbach's alpha for the total scale was .88. Conclusion: The CBS-D can be used to measure the communication behavior of nurses caring for people with dementia.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.5
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• pp.145-152
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• 2019

In this study, rebar QTO(Quantity Take-Off) was quickly produced from the BIM model prepared by Revit in the early design phase, and the available premium rates were quantitatively presented. For this purpose, the amount of rebar calculated using the BuilderHub, which specializes in calculating rebar QTO, was analyzed according to various factors such as member type, rebar diameter, building size, item type, and order length, and the effect of each factor on the rebar QTO was determined. In addition, the BIM model generated on Revit was used to establish parameters and processes required to produce rebar QTO, and proposed a rebar premium rate and a stirrup/hoop premium rate based on the BuilderHub output results. Through this study, it is expected that a rapid and efficient comparative evaluation of rebar QTO will be possible according to various structural design alternatives in the early design phase.

• Journal of The Korean Association For Science Education
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• v.25 no.2
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• pp.173-183
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• 2005

In this study, we questioned what assessment types and scoring methods of science performance assessment(SPA) were being used in middle and high school, and how much these SPA scores were reliable(generalizable). To answer these questions, SPA data obtained from the seven schools were classified according to assessment type and scoring method. Based upon this classification, we analyzed the reliability by applying generalizability theory. The result, from the classification of assessment type and scoring method, showed that SPA types of the seven schools were divided into two types: paper-pencil type and task type. Paper-pencil type included answer(content)-restricted essay-type test solely. Task type has two parts: process and outcome assessment. As the results of analyzing scoring methods of the seven schools, there were two cases in the way of scoring methods: one case is scoring all essay-type items and performance tasks by one teacher, the other is scoring assigned performance tasks by two teachers. But the case of scoring assigned essay-type items or the case of cross scoring by two or more teachers were not found. The findings of the reliability analysis are as follows: (1) Effect of essay-type item to SPA score was larger than that of performance task. (2) There was remarkable difference among the seven schools' interaction effect of person and rater in scoring performance tasks. (3) Most of generalizability(reliability) coefficients of SPA for the seven schools were smaller than the acceptable generalizability coefficient(0.80). Therefore, the population of statistical parameters such as number of item, task and rater, should be increased for approaching the acceptable generalizability level.