• Journal of Hospice and Palliative Care
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• v.18 no.3
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• pp.188-195
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• 2015

Purpose: We examined the effects of a well-dying program on nursing students in terms of death preparation, death recognition and perception of well-dying perception. Methods: The design of this study was quasi-experimental and non-synchronized with a non-equivalent control group. The study was conducted with nursing students: 32 in the experimental group and 36 in the control group. The well-dying program was consisted of five sessions: introduction, thinking about meaning of death, organizing things to do before dying, looking back on my life, and leaving a trail of my life. Descriptive analysis, t-test, ${\chi}^2$ test and ANCOVA were used with SPSS 18.0 program to analyze the data. Results: After attending the program, a difference was observed in death preparation of the experimental group (t=2.61, P=0.014). The death recognition (F=154.15, P<0.001) score of the experimental group was significantly higher than the control group. There was no significant difference between the groups in perception of well-dying (F=0.11, P=0.747). Conclusions: The well-dying program helped nursing students build positive death recognition. Therefore, this study is expected to contribute to development of a death education program for nursing students.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.647-654
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• 2016

The aim of this study was to investigate the effects of death education on the attitude toward DNR, fatigue, and quality of sleep for generic care worker. This study followed a nonequivalent control group and a non-synchronized design. This study was performed in a visiting generic care service institution in J city, Chung-Cheong province, Korea between February 15 to May 30, 2016. The study included 43 participants who agreed to participate in this study. They were randomly divided into two groups: 21 participants in the experimental group and 22 in the control group. Participants in the experimental group received death education 2 hours per day, once a week, for a duration of greater than 8 weeks. The effect of treatment was measured using a structured questionnaire on the attitude toward DNR, fatigue, and quality of sleep before and after 8 weeks of intervention. Data were analyzed using t-, chi-square, Fisher Exact- and paired t-tests. The experimental group showed a significantly increased attitude toward DNR (p=0.001) and quality of sleep (P<0.001), whereas significantly decreased attitude toward fatigue (p=0.030) than the control group after 8 weeks of intervention. The death education program was shown to be an effective nursing intervention for generic care workers. Therefore, we can consider the possibility of incorporating death education in the nursing program.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.156-162
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• 2016

This study was conducted to investigate the effects of a death education program on self-esteem, spiritual well-being, and pain in adults. This investigations employed a nonequivalent control group non-synchronized design, and was performed in C hospital located in Chungju, Chungcheongbukdo province, Korea from January 4-13, 2016. The study included 48 participants who agreed to enrolled. Participants were randomly divided into an experimental and a control group of 22 and 26 applicants each. Participants (n=22) in the experimental group participated in the death education program for 2 hours, three times a week for 2 weeks. The effects of treatment were measured using a structured questionnaire to evaluate self-esteem, spiritual well-being, and pain before and after 2 weeks of intervention. Data were analyzed using a t-test, chi-squared test, Fisher's Exact-test and a paired t-test. The experimental group showed significantly increased self-esteem (P<0.002) and spiritual well-being (P<0.015), and significantly reduced pain (P<0.014) compared to the control group after 2 weeks of intervention. Overall, the death education program was shown to be an effective nursing intervention for adults; therefore, of its use in various fields should be considered.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.201-208
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• 2017

Recently, the installation of photovoltaic(PV) systems has been increasing due to the worldwide interest in eco-friendly and abundant solar energy. On the other hand, a PV system has approximately 25% power loss while the energy generated from solar cells is transformed to the power coupling point through a power conversion system (DC/AC). If the output voltage of a string in the PV system is lower than the operating range of the inverter when a part of module in the string has a shadow due to weather conditions, the string is not synchronized and the whole efficiency of output power in a PV system may be reduced significantly. Therefore, to overcome this problem, this paper proposes a novel control method to compensate for the lower voltage by introducing a DC/DC voltage regulator for each string in a PV system, which adopts a concept for MPPT (Maximum Power Point Tracking) control function using the P&O algorithm and adopts constant voltage control method used in an existing inverter. This paper also implements a 2kW DC/DC voltage regulator based on the proposed algorithm and performs a variety of scenario-based experiments. From the simulation result, it was confirmed that the operation efficiency in the proposed method is improved compared to the existing method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.12
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• pp.2349-2356
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• 2008

In this paper, we present the method to effectively extract and classify the EEG caused by only brain activity when a normal subject is in a state of mental activity. We measure the synchronous EEG on the auditory event when a subject who is in a normal state thinks of a specific task, and then shift the baseline and reduce the effect of biological artifacts on the measured EEG. Finally we extract only the mental task signal by averaging method, and then perform the recognition of the extracted mental task signal by computing the AR coefficients. In the experiment, the auditory stimulus is used as an event and the EEG was recorded from the three channel $C_3-A_1$, $C_4-A_2$ and $P_Z-A_1$. After averaging 16 times for each channel output, we extracted the features of specific mental tasks by modeling the output as 12th order AR coefficients. We used total 36th order coefficient as an input parameter of the neural network and measured the training data 50 times per each task. With data not used for training, the rate of task recognition is 34-92 percent on the two tasks, and 38-54 percent on the four tasks.

• Korean Journal of Remote Sensing
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• v.12 no.1
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• pp.1-16
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• 1996

Korea Aerospace Research Institute(KARI) is developing a Korea Multi-Purpose Satellite I(KOMPSAT-I) which accommodates Electro-Optical Camera(EOC), Ocean Color Imager(OCI), Space Physics Sensor(SPS) for cartography, ocean color monitoring, and space environment monitoring respectively. The satellite has the weight of about 500 kg and is operated on the sun synchronized orbit with the altitude of 685km, the orbit period of 98 minutes, and the orbit revisit time of 28days. The satellite will be launched in the third quarter of 1999 and its lifetime is more than 3 years. EOC has cartography mission to provide images for the production of scale maps, including digital elevation models, of Korea from a remote earth view in the KOMPSAT orbit. EOC collects panchromatic imagery with the ground sample distance(GSD) of 6.6m and the swath width of 15km at nadir through the visible spectral band of 510-730 nm. EOC scans the ground track of 800km per orbit by push-broom and body pointed method. OCI mission is worldwide ocean color monitoring for the study of biological oceanography. OCI is a multispectral imager generating 6 color ocean images with and <1km GSD by whisk-broom scanning method. OCI is designed to provide on-orbit spectral band selectability in the spectral range from 400nm to 900nm. The color images are collected through 6 primary spectral bands centered at 443, 490, 510, 555, 670, 865nm or 6 spectral bands selected in the spectral range via ground commands after launch. SPS consists of High Energy Particle Detector(HEPD) and Ionosphere Measurement Sensor(IMS). HEPD has mission to characterize the low altitude high energy particle environment and to study the effects of radiation environment on microelectronics. IMS measures densities and temperature of electrons in the ionosphere and monitors the ionospheric irregularities in KOMPSAT orbit.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.269-275
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• 1999

For the purpose of sweet potato varietal improvement, yulmi, shinyulmi, gunmi, hongmi, and seonmi, whose source and sink are different, were cultivated at different planting densities, and then defoliation at initial stage of tuberous root weight increase on the relation of source and sink was observed as follows. The response of stem and leaf and tuberous root weight by planting density and defoliation rate of sweet potato varieties was different. Stem and leaf weight per m$^2$ increased along with dense planting by the following order; shinyulmi> seonmi> hongmi> gunmi> yulmi. Tuberous root number per m$^2$ was the most at 75$\times$20cm planting density, showing seonmi the most number. The number of stem and leaf and tuberous root increased along with the lowered rate of defoliation. In case of 75$\times$10cm and 75$\times$20cm planting density, tuberous root weight increased by increase of stem and leaf weight up to 50% defoliation and the difference of stem and leaf and tuberous root number was low as defoliation rate increases. The tuberous root and total dry weight matter was the most at 75$\times$20cm planting density. The increase and decrease of source synchronized with those of sink at 75$\times$10cm and 75$\times$20cm, however the relationship occurred less at 75$\times$30cm.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.815-821
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• 2021

This study addresses on the design of performance monitoring system for the time synchronization service of the enhanced long-range navigation (eLoran) system, which has a representative ground-wave radio broadcast system capable of providing positioning, navigation, timing and data (PNT&D) services. The limitations of time-synchronized systems due to the signal vulnerabilities of the global navigation satellite system (GNSS) are explained, and the performance monitoring system for the eLoran timing service as a backup to the GNSS is proposed. The time synchronization service using eLoran system as well as system configurations and the user requirements in the differential Loran (dLoran) system are described to monitor the time synchronization performance. The results of the designed system are presented for long-term operation in the eLoran testbed environment. As the results of time performance monitoring, we were able to verify the time synchronization precision within 43.71 ns without corrections, 22.52 ns with corrections. Based on these results, the eLoran system can be utilized as a precise time synchronization source for GPS timing backup.

• KIPS Transactions on Computer and Communication Systems
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• v.10 no.7
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• pp.191-198
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• 2021

Since the size of training dataset become large and the model is getting deeper to achieve high accuracy in deep learning, the deep neural network training requires a lot of computation and it takes too much time with a single node. Therefore, distributed deep learning is proposed to reduce the training time by distributing computation across multiple nodes. In this study, we propose hybrid allreduce strategy that considers the characteristics of each layer and communication and computational overlapping technique for synchronization of distributed deep learning. Since the convolution layer has fewer parameters than the fully-connected layer as well as it is located at the upper, only short overlapping time is allowed. Thus, butterfly allreduce is used to synchronize the convolution layer. On the other hand, fully-connecter layer is synchronized using ring all-reduce. The empirical experiment results on PyTorch with our proposed scheme shows that the proposed method reduced the training time by up to 33% compared to the baseline PyTorch.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.455-464
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• 2019

The sensorless control based on the flux linkage of PM synchronous motors has excellent position estimation characteristics at low speeds. However, a limitation arises because the integrator of flux estimator is saturated by the DC offset generated during the analog to digital conversion(ADC) process of the measured current. In order to overcome this limitation, HPF with a low cutoff frequency is used. However, the estimation performance is deteriorated (Ed- the verb deteriorate already includes the meaning of 'problem') at high speed due to the low cutoff frequency, and increasing the cutoff frequency of the HPF induces further problems of phase leading and initial starting failure at low speeds. In this paper, the cutoff frequency of HPF was synchronized to the operation frequency of the motor: at low speeds the cutoff frequency was set to low in order to reduce the phase leading of the estimated flux, and at high speeds it was set to high to raise the DC offset removal performance. As a result, the operating range was increased by 200%. Furthermore, a phase compensation algorithm is proposed to reduce the phase leading of the HPF to less than 1.5 degrees over the full operating range. The proposed sensorless control algorithm was verified by experiment with a PM synchronous motor for a washing machine.