• Korean Journal of Adult Nursing
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• v.12 no.4
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• pp.629-640
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• 2000

The purpose of this study was to develop and validate the scale to measure dementia patient's caregiver burden of Korea. In the first phase of the study, 15 caregivers of dementia patients were interviewed to provide narrative data from which items were developed. Initially 65 items were generated from the interview data of 15 caregivers. Content validity was judged by two separate panels of experts with 27 professionals and 30 family caregivers. These items were analyzed through the Index of Content Validity and 33 items were selected which met .80 or more of the CVI. This preliminary FCBSD-K was tested with 207 adult caregivers for reliability and construct validity including item analysis and orthogonal(Varimax) factor analysis. Eight items were deleted because of high or low item-item correlation. The result of the second factor analysis produced six factors that coincided with the conceptual framework posed for the scale developed. The six factors were labeled as 'physio social factor' 'emotional factor' 'family cultural factor' 'role obligation' 'guilt feeling' and 'financial & supportive system factor'. The alpha coefficient relating to internal consistency was .9264 for reliability. In conclusion, cultural factor is related to dementia patient's caregiver burden and FCBSD-K was useful in assessing the dementia patient's caregiver burden in Korea.

• Journal of the military operations research society of Korea
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• v.29 no.2
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• pp.13-25
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• 2003

The lack of consideration for statistical properties in Taguchi's three­level linear graphs is rectified. We propose a new set of linear graphs for the three­level orthogonal arrays according to the maximum resolution criterion. In the presence of two­factor interactions however, the serious bias of all the estimated effects as well as the estimated variance shows that these designs should not be employed. The various alternative designs are discussed.

• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.13-16
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• 2000

This paper introduces a more effective usage of the limited OVSF cod in compressed mode which is used during inter-frequency/inter-system handover in UTRA(Universal mobile telecommunications system) Terrestrial Radio Access). The usager is to use dynamic common channel which is shared by several users during the compressed mode.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.116.4-116
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• 2001

We consider a robust configuration problem of inertial sensors for inertial navigation system(INS). Fault detection and isolation(FDI) is necessary to improve reliability of the system. For FDI, there used to be more than three mutually orthogonal sensors and thus we have to consider configuration methods of sensors. Various studies in this area have been done, but the former results did not consider effect of uncertainty(misalignment, scale factor error) to determine the configuration of the sensors. In this paper robust configuration of sensors is proposed through sensitivity analysis. Also total least square(TLS) method ...

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.264-266
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• 2007

Orthogonal Variable Spreading Factor codes are used as channelization codes in WCDMA. In this particular paper, we present a new OVSF codes which is generated from the Jacket Matrices for DS-CDMA systems. The simulations result shows that the purposed OVSF can efficiently reduce the peak values of the correlations than the conventional HOVSF without orthogonality loss. It will be useful to detect the multi-user system under the asynchronous system and save the power of transmission.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.151-154
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• 2000

This paper proposes a novel circuit configuration realizing biquadratic voltage transfer functions using three CCIIs and six passive elements. The circuits realize high-pass, band-pass, low-pass, band-stop and all-pass functions by selecting input voltages. The circuit has low passive sensitivities and permits orthogonal adjustment of quality factor Q and cutoff angular frequency $\omega$$\sub$o/. The effects of non-ideal CCIIs on biquadratic transfer functions are also given.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.1
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• pp.32-39
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• 2009

When adapting the transmitter to the channel state information(CSI), improved transmission is possible compared to the open loop system where no CSI is provided at the transmitter. However, since the perfect channel information is rarely available at the transmitter, the system design based on the partial CSI becomes an important factor. Especially, in mobile environments, the consideration for the outdated CSI should be applied for mitigating the performance degradation. In this paper, we propose a robust adaptive modulation and coding scheme for bit-interleaved coded orthogonal frequency division multiplexing over time-varying channels. With reasonable feedback overhead, the proposed scheme shows the enhanced performance by compensating for the outdated CSI due to Doppler spread. Simulation results confirm that the performance gain is achieved by applying an accurate BER estimation method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.10C
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• pp.965-975
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• 2005

In this paper, we propose and evaluate joint carrier and sampling frequency offset estimation schemes based on the channel estimation sequences in PLCP (Physical Layer Convergence Procedure) preamble for the proper and effcient synchronization of the MB-OFDM WB (Multi-Band Orthogonal Frequency Division Multiplexing Ultra Wide Band) systems which have recently drawn explosive attention for future W-PAN (Wireless Personal Area Network) applications. In the joint estimation schemes, we first estimate the sampling frequency offset, and then estimate the carrier frequency offset using the estimated sampling frequency offset. Moreover, to improve the reliability of the estimated offset values, each process uses a combination scheme based on weighting factors. Simulation results using IEEE 802.15 Task Group 3a UWB channel models reveal that the estimation scheme using the simple weighting factors based on easily-measurable received signal power of each sub-channel shows favorably comparable performance to the ideal scheme using the weighting factors based on the perfectly-estimated frequency response of the channel.

• Current Applied Physics
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• v.18 no.11
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• pp.1403-1409
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• 2018

In the present study, the $SrMoO_4:Eu^{3+}$ phosphors has been synthesized through hydro-thermal co-precipitation method, and single factor and orthogonal experiment method was adopted to find optimal synthesis condition. It is interesting to note that hydro-thermal temperature is a prominent effect on the luminescent intensity of $SrMoO_4:Eu^{3+}$ red phosphor, followed by co-precipitation temperature, calcining time, and the doping amount of $Eu^{3+}$. The optimal synthesis conditions were obtained: hydro-thermal temperature is $145^{\circ}C$, co-precipitation temperature is $35^{\circ}C$, the calcining time is 2.5 h, and the doping amount of activator $Eu^{3+}$ is 25%. Subsequently, the crystalline particle size, phase composition and morphology of the synthesized phosphors were evaluated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results show that these phosphors possess a scheelite-type tetragonal structure, and the particle size is about $0.2{\mu}m$. Spectroscopic investigations of the synthesized phosphors are carried out with the help of photo-luminescence excitation and emission analysis. The studies reveal that $SrMoO_4:Eu^{3+}$ phosphor efficiently convert radiation of 394 nm-592 and 616 nm for red light, and the luminescence intensity of $SrMoO_4:Eu^{3+}$ phosphors is improved. $SrMoO_4:Eu^{3+}$ phosphors may be a potential application for enhancing the efficiency of white LEDs.

• Journal of the Korean Society of Clothing and Textiles
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• v.6 no.2
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• pp.49-55
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• 1982

The purpose of this study was to analyze the factorial structure of the criteria on clothing selection. Data were obtained from 219 housewives in Seoul. 95 likert type questions were selected from the existing questionnaires and from the open end questions. The items were analyzed for discriminating power, followed by the factor analysis. 57 items were subjected to the principal component analysis with orthogonal rotation after extraction of 5 major factors. 47 items were found to be significantly loaded to at least one of the five factors. The factors had the following characteristics: Factor I. The persons scoring high on this factor would invest time and energy in their clothes to achieve their image and individuality. They were interested in clothes, appearance and fashion. Factor II. The persons scoring high on this factor were more concerned about the practicality of clothing, such as ease-of-care, comfort, texture and quality of fabric. They would not select the clothes which soiled easily and would not perform as expected. Factor III. High scores on this factor were associated with the eagerness to get the cloth-ing value for the money. They would make a long plan to buy an expensive clothing and choose a unique clothing regardless of fashion. Factor IV. A high score on this factor was suggestive of modesty. They were willing to buy inconspicuous clothes, such as dark or muted colors, small prints and conservative styles. Factor V. High scores on this factor were characterized by the desire for conformity and approval of their friends. This result may be used to develop an instrument to measure the criteria on clothing selection of consumer.