• Journal of Advanced Marine Engineering and Technology
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• 제20권4호
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• pp.372-372
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• 1996

The torsional vibration of the propulsion shafting system equipped with viscous damper is investigated. The equivalent system is modeled by a two mass softening system with Duffing's oscillator and the vibratory motion is described by non-linear differential equations of second order. The damper casing is fixed at the front-end of crankshaft and the damper's inertia ring floats in viscous silicon fluid inside of the camper casing. The excitation frenquency is proportional to the rotational speed of engine. The steady state response of the equivalent system is analyzed by the computer and for this analyzing, the harmonic balance method is adopted as a non-linear vibration analysis technique. Frequency response curves are obtained for 1st order resonance only. Jump phenomena are explained. The discriminant for the solutions of the steady state response is derived. Both theoretical and measured results of the propulsion shafting system are compared with and evaluated. As a result of comparisions with both data, it was confirmed that Duffing's oscillator can be used in the modeling of the propulsion shafting system attached with viscous damper with non-linear stiffness.

• 전기학회논문지
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• 제65권3호
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• pp.487-492
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• 2016

In this paper, a device for analyzing the pressure distribution during walking was produced by using the pressure sensor on the heel. This device was limited to a frequency band by using the 1st low-pass filter. And an algorithm to analyze the value of the quantity to pressure using a analog to digital converter. It is used by using the threshold voltage of pressure sensor, it is suggested the algorithm. The algorithm is detected the peak which is exceeded the threshold voltage. and thus in accordance, it is detected the number of steps. And the calorie consumption were detected by using it. Also it used an MCU and Bluetooth. And by confirming the data at the LCD of the other MCU, it was to reduce the size of the device. According to this algorithm, it has the advantage that there is no restriction on the activity than when using an imaging device and it is inexpensive than other sensors such as an acceleration sensor or a gyro and it is easy to handle.

• 한국기계가공학회지
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• 제8권3호
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• pp.27-32
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• 2009

In this study, static and dynamic stability estimations on the diecutter with finite element modelling were carried out to be creased and cut away printed sheet exactly. To cut away the sheet exactly, the large force should be pressured on diecutter. And which affects not only the quality of produced sheets but also the stability of diecutter. The analyses with and without the tare of diecutter were carried out with NASTRAN software on applying 400 ton force to its top and moving table respectively. It was known that maximum von-Mises stress of 221 Mpa in diecutter was occurred at the toggle, and it was smaller than the yield stress of 280 Mpa. And maximum deformation of 0.75 mm was occurred at the top table. The natural frequencies of 41, 102, 108, 115, and 134 Hz for the 1st, 2nd, 3rd, 4th and 5th mode, which had been determined by numerical simulation, were not coincided with the max. speeds of motor and moving table of 29 and 2 Hz. And which was verified by vibration test. Therefore it may be estimated that the structure of the diecutter is statically and dynamically stable.

• 간호행정학회지
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• 제10권3호
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• pp.299-310
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• 2004

Purpose : The purpose of this study was to examine the enneagram personality types, nursing professional attitudes and job satisfaction of the nurses. Method: The subjects for this study were 93 nurses who did the enneagram workshop. Demographic characteristics, enneagram personality types, nursing professional attitudes and job satisfaction were measured. The data were analyzed through the SPSS 10.0 window program by were of frequency, percentage, t-test, ANOVA. Result : The highest of nurses' enneagram personality types was type 6 and type 5 and 8 were not existed. The triad of enneagram was consist of head type 40.9%, heart type 39.8%, gut type 19.3% orderly. Nursing professional attitudes and job satisfaction of nurses were positive. Nursing professional attitudes in type 2 were the highest but in type 9 were the lowest. also job satisfaction in type 1 were the highest but in type 2 were the lowest. But statistically nursing professional attitudes and job satisfaction no significant difference according to types of nurses' enneagram. Conclusion : According to the above findings, enneagram will utilize not only instrument for investigation of nurses' personality types but also human resource management program for understanding of nurses. And suggest that the further research is need to identify more variables related to the types of nurses' enneagram for enneagram' utility in nursing organization.

• 한국직업건강간호학회지
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• 제22권4호
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• pp.267-274
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• 2013

Purpose: This study was to assess the prevalence of workplace bullying and the relationship workplace bullying to self-esteem and turnover intention among clinical nurses. Methods: The subjects were 223 clinical nurses at 3 small and medium-sized hospitals in K and B cities. The data were collected from February 1st throughout 28th, 2013. The collected data were analyzed using the SAS program through the frequency, percentage, mean, and Pearson's correlation coefficients. Results: The rate of self-reported bullying in the nursing workplace was 24.6% of respondents. There was a negative correlation between workplace bullying and self-esteem (r=-.39, p<.001). Also there was a positive correlation between workplace bullying and turnover intention (r=.14, p=.031). Conclusion: Prevalence of self-reported bullying is high among small and medium-sized hospitals and is clearly associated with lower levels of self-esteem and higher levels of turnover intention. Therefore, an organizational nursing management program as a monitoring regularly the psychosocial work environment and policies and procedures to prevent and manage workplace bullying is strongly recommended for the promotion of self-esteem and reducing the nurse's intention to leave the organization.

• Child Health Nursing Research
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• 제12권3호
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• pp.351-358
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• 2006

Purpose: This study was attempted to find out the differences of characteristics between potential substance-abuse group and healthy group of middle school students in Busan. Method: The participants were 458 middle school students in Busan. The data were collected from 1st September 2004 to 31th October 2004 using structured questionnaire, and then were analyzed by SPSS-WIN 10.0 program with frequency, percentage, mean, standard deviation and $X^2-test$. Results: 23.6% of the subjects have been smoking, and 16.2% of them have been drinking. 18.6% of the subjects was classified to potential substance-abuse group based on the cut-point suggested by Lee et al.. The characteristics of potential substance-abuse adolescents are that they have religion and siblings, that their parents have divorced, that they don't live with their parents, and that their perceived health state is bad. Conclusion: Based on the findings of this study, It is necessary to develop a substance abuse prevention education program for potential substance-abuse group.

• 기술사
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• 제27권1호
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• pp.5-12
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• 1994

In the high degree information society of the 21st century, along with the social activity becoming much more closer, our life style will also be very much changed. Recognition for obtaining various informations rapidly will be anticipated to enhance and the progress of a mobile communication system is greatly expected. This will enable the system to give and receive ″whenever, wherever, whomever, whatsever information.″ In our country, the car telephone and personal mobile communication services of radio calling etc. are diversified by the telecommunication system reformation and by the introduction of competive principle of the hereafter of 1988. Moreover, in accordance with the tariff, the number of subscrier is rapidly increasing. On the other hand, on the utility side of business, for the realization of a mobile communication which is abundant in functional nature, not only the hitherto voice but also non voice system of data communication is being introduced. The Ministry of Communications of Korea has been expediting the effective utilization of limited frequency band of qusai microwave band etc. as a concrete measures for an ever increasing demand. At the same time, to disseminate and promote a mobile communication most effectively, convenience, economic, and safety nature of the system, and in addition to these, international standardization is considered. For constitution of a new mobile communication, the Ministry has been promoting various policies designed for the digitalization of system, utility extention for home. personal level.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.71-74
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• 2000

Pt/Pb$TiO_3$/$SrTiO_3$/p-Si films were prepared by metallo-organic solution deposition(M0SD) method and investigated its structure and ferroelectric properties. Crystallinity of specimen as a funtions of post annealing temperature and the thickness of $SrTiO_3$(STO) buffer layer was studied using XRD and AFM. Based on C-V and P-E curve, $PbTiO_3$(PTO) capacitors showed good ferroelectric hysteresis arising from the polarization switching properties. When the thickness of ST0 buffer layer between PTO and Si substrate was 260 nrn and the post annealing temperature was $650^{\circ}C$, it was showed that production of the pyrochlore phase due to interdiffusion of Si into FTO was prevented. The dielectric constant of FTO thin films calculated from a maximum Cma in the accumulation region was 180 and the dielectric loss was 0.30 at 100 kHz frequency. The memory window in the C-V curve is 1.6V at a gate voltage of 5V.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.497-502
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• 2005

In mobile phones of multimedia era, microspeakers of high quality sound are essential parts to generate human voice in speaker phone and MP3 song player. In this paper, two types of microspeakers, outer permanent magnet (PM) and combined PM type, are analyzed using electromagnetic, mechanical, acoustical and their coupling analysis. For performance comparison, voice coil diameter is chosen as a design parameter to change excitation position and magnet volume for both types. For combined PM type, sound pressure level (SPL) is improved due to increased PM volume compared to outer PM type. Also, with the decreased voice coil diameter for combined PM type, the 1st resonant mode of the diaphragm is more efficiently excited due to concentrative excitation, resulting in lower and broader frequency range. Therefore, it can be said that the combined PM type microspeakers are more advantageous for high performance microspeaker which are essential for multimedia era.

• 대한조선학회논문집
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• 제53권6호
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• pp.482-493
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• 2016

The identification of modal damping of a segmented hull model with torsional response is difficult task due to the coupling of modal response. This is because the 1st and 2nd torsional vibration modes are closely spaced in frequency domain leading to the situation that the modal decomposition is difficult to achieve by simple band-pass filter. Present study applied several different modal decomposition methods to derive the damping ratio of different modes. The modal decomposition methods considered in this study are simple band-pass filter, Hilbert vibration decomposition, Wavelet transform and proper orthogonal decomposition. Coupled free decay signal obtained from the torsional hammering test on a segmented hull model was processed with four different methods and the derived damping ratios were compared with each other. Discussions also have been made on the pros and cons of the different methodologies.