• Journal of KIISE
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• v.43 no.7
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• pp.763-772
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• 2016

With the spread of smartphones containing multiple on-board sensors, the market for context aware applications have grown. However, due to the limited power capacity of a smartphone, users feel discontented QoS. Additionally, context aware applications require the utilization of many forms of context and sensing information. If context transition has occurred, types of needed sensors must be changed and each sensor modules need to turn on/off. In addition, excessive sensing has been found when the context decision is ambiguous. In this paper, we focus on power consumption associated with the context transition that occurs during indoor/outdoor detection, modeling the activities of the sensor associated with these contexts. And we suggest a freezing algorithm that reduces power consumption in context transition. We experiment with a commercial application that service is indoor/outdoor location tracking, measure power consumption in context transition with and without the utilization of the proposed method. We find that proposed method reduces power consumption about 20% during context transition.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1199-1202
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• 2008

High mobility bottom gate thin film transistors (TFTs) with an amorphous gallium tin zinc oxide (a-GSZO) channel layer have been produced by rf magnetron cosputtering using a gallium zinc oxide (GZO) and tin (Sn) targets. The effect of the post annealing temperatures ($200^{\circ}C$, $250^{\circ}C$ and $300^{\circ}C$) was evaluated and compared with two series of TFTs produced at room temperature and $150^{\circ}C$ during the channel deposition. From the results it was observed that the effect of pos annealing is crucial for both series of TFTs either for stability as well as for improving the electrical characteristics. The a-GSZO TFTs operate in the enhancement mode (n-type), present a high saturation mobility of $24.6\;cm^2/Vs$, a subthreshold gate swing voltage of 0.38 V/decade, a turn-on voltage of -0.5 V, a threshold voltage of 4.6 V and an $I_{ON}/I_{OFF}$ ratio of $8{\times}10^7$, satisfying all the requirements to be used in active-matrix backplane.

• The Journal of the Acoustical Society of Korea
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• v.16 no.2
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• pp.41-48
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• 1997

This paper proposes the methods for improving the recognition rate of theARS, especially equipped with the speech recognition capability. Telephone speech, which is the input to the ARS, is usually affected by the announcements from the system, channel noise, and channel distortion, thus directly applying the recognition algorithm developed for clean speech to the noisy telephone speech will bring the significant performance degradation. To cope with this problem, this paper proposes three methods: 1)the accurate detection of the inputting instant of the speech in order to immediately turn off the announcements from the system at that instant, 2)the effective end-point detection of the noisy telephone speech on the basis of Teager energy, and 3)the SDCN-based compensation of the channel distortion. Experiments on speaker-independent, noisy telephone speech reveal that the combination of the above three proposed methods provides great improvements on the recognition rate over the conventional method, showing about 77% in contrast to only 23%.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.6 no.2
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• pp.198-210
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• 1999

This study is to investigate sleep patterns of rheumatoid arthritis patients through a survey research. The subjects for this study were 97 patients registered in Hanyang University Hospital Rheumatoid Arthritis Center, and the period of data collection was from July 15, 1998 to August 30, 1998. The research instruments used in this study were the measures of sleep, pain, and fatigue, and SPSSWIN 8.0 Program was used for data analysis. The research results are as follows ; The patients went to bed between 11 and 12 p.m., but many of them found difficulty in falling asleep within 5 minutes. They woke up quite early at around 4 to 6 o'clock in the morning and remained in bed about 1 hour. Only 39 percent of the subjects reported satisfaction with their sleep. Fifty six percent of the subjects took a nap, generally did in the afternoon and 22.7 percent of them napped for half an hour. They suffered sleep disturbance, but their sleep environments were calm and comfortable, and they turn off the light when they went to sleep. As for the quality of sleep, over 50 percent of the subjects reported not being able to sleep deeply, 30 percent of the subjects woke up frequently during sleep, 60 percent experienced frequent arousal after sleep onset. Over 90 subjects slept for 6 to 8 hours. This shows that even though they had rheumatoid arthritis, the patients remained in bed for a sufficient period of time. They also reported waking up or turning frequently during sleep. The sense of fatigue from sleep disturbance scored a relatively high 35.84 points on average against the possible score of 64 points. Behavior for sleep promotion was very active. Sleep disturbance occurred in proportion to the sense of fatigue and pain, and was negatively correlated with quality of sleep. The pain had positive correlations with the illness duration, sleep disturbance and had a negative correlation with the quality of sleep.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.11
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• pp.1243-1253
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• 2007

Recently UHF RFID system has drawn a great deal of attention because of its potential to revolutionize supply chain management. An important characterization of the performance of a RFID system is 'interrogation range', which is defined as the maximum distance between a reader and a tag. Forward-link interrogation range is defined as the maximum distance from which the tag receives just enough power to turn on and back-scatter, and reverse-tink interrogation range is the maximum distance from which the reader can detect this back-scattered signal. A link balance has to be found between the two interrogation ranges. In this paper, the interrogation range equations are formulated in both forward-link and reverse-link and a trade-off between the two values is investigated in order to maximize the interrogation range. As a result, it is observed that the gain of the reader antenna, the isolation of the circulator, and the phase noise of the local oscillator with range correlation effect mainly determine the reverse-link interrogation range.

• Journal of Digital Convergence
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• v.11 no.4
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• pp.229-234
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• 2013

The purpose of this study is to develop a lighting apparatus of the illuminance and color temperature to maximize the ability of the optimal combination of light sources that can be controlled efficiently control device. Finding people comfortable feeling for indoor lighting that can be used in a variety of color temperature illumination area by combining light sensitivity can be realized. Lighting apparatus for fluorescent lamps with different color temperature of 2000K and 8000K, and by varying the quantity of each of the fluorescent lamps, the illuminance of lighting equipment and color temperature through optical simulations were evaluated. By infrared remote control receiver, divided into 5 types of relaxation, conversation, meeting, hospitality, arts and the lighting environment you want to transfer the PC0 ~ PC4 through the parallel port on the mode selected by the user at the receiving end the DC voltage output. EEFL inverter input DC voltage and the DC input voltage, depending on the level of EEFL dimming value (illuminance and color temperature) lighting environment you want to create change while using a PIR sensor EEFL automatically turn off if people do not have was developed so that the power consumption so you can save.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.4
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• pp.331-335
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• 2020

In this study, through the accumulated technologies such as real-time monitoring of power consumption using power line communication (PLC) method, power control, and automatic blocking of standby power, to commercialize them, we developed the hardware design, algorithm, protocol and module along with data transmission using PLC. We conducted the study to develop advanced products. We also proposed cloud-based smart outlet products with a novel type of outlet. These products can measure the internal power consumption through the H/W modules and the modules that control the power of household appliances connected to the smart outlets and smart plugs. Subsequently, they transmit the measurements to the energy saving system server via a communication module. This system can control the terminal device connected to the Gateway (G/W) server through a mobile phone. This will allow the customer to check the power consumption of the building at any given time, to turn the terminal on/off, and to maximize the energy efficiency during the construction of new apartments or multi-family housing in an area.

• Journal of Korean Academy of Nursing Administration
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• v.2 no.2
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• pp.5-16
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• 1996

The purpose of this study is to identify the handwashing knowledge and attitudes of resistered nurses on general wards. Subjects for this study include 182 nurses working in general wards of a hospital in Seoul area. Data were collected by a questionnaire from July 30 to August 10,1996. Statistical analyses were done by the SPSS/PC program. The techniques used in this sudy included frequencies, chi-square test. The results of this study are summarized as follows. 1. 34.6% of the respondents reported that they washed their hand an average of 5 to 7 times during the work day. 2. 38.5% of the respondents reported always washing after each patient contact. Only 9.9% always washed before contact with a patient. 3. 56.6% of the respondents reported a washing time of 10 to 20 seconds, whereas 29.1% washed 21 to 30 seconds. Chi-square tests were employed to determine any differences in handwashing frequency and duration by age, working years, work position. There were no satistically significant differences among the variables. 4. 95.6% of the subjects used water and plain soap during the washing process. The respondents washed the palms of the hands, the backs of their hands and between their fingers(33%). Only 17.6% removed rings before handwashing. Similarly, 11% removed their wristwatch. The majority(96.2%) reported that they used communal textile towel to dry their hands. When asked what method they used to turn off the water faucet after washing, 98.4% reported using direct hand-to-faucet contact. 5. Nursing activities that showed the highest handwashing rates was after wound dressing(22.9%), followed by suctioning(21.4%), injection(21.2%), inserting catheter(18%). 6. Reasons cited for reduced handwashing frequency included being too busy to wash more often(74.7%), no need to wash more often(11.0%) and dry skin caused by frequent handwashing(3.3%). 7. When asked where they obtained their current knowledge of handwashing techniques, they reported professors(73.6%), resisted nurses(14.8%) and supervisor(6.6%). 8. Nursing staff thought that proper handwashing was important factor in decreasing nosocomical infections(72.4%).

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.34-40
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• 2006

This paper proposed power system for new DC 49[V] telecommunication using forward three-phase PWM rectifier power factor and efficiency for improvement of ripple voltage. Proposed power system for DC 48[V] telecommunication that consists of power conversion devices including switch, inductor and condenser were made between each line, in power inverter device of each switch control turn-on in period of continuity time control to get power factor '1' of sine wave current and on-off of switch lessens peak current that was happened and got conversion efficiency 92.1[%] composing in PWM rectifier of forward form instead of general PWM rectifier. Also, harmonic input regulation value(IEC61000-3-2 Class-As) satisfy input current and reduce ripple factor of output voltage in state that distortion of three-phase supply is overlapped each other.

• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.129-141
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• 2008

Portable navigation markets grew up to 95% last year. This study aims to develop a business model for pedestrian-oriented portable navigator for street shoppers. Related previous studies developed successfully the alogrithm for a portable navigator, and the current study seeks for diverse ways to turn this system into a new type of on & off line-based LBS business. The business model proposed in this study adopted two different approaches of benefit yields based on the structural analysis of so-called Wanavi navigation system. One is segmented approach seeking for benefits from each individual system component such as communication network, contents, and platform. The other approach is to run the business by integrating relevant system componts in every possible way to attract customers to this portable navigator. The purpose of this proposal is not limited to activate emerging walking navigator markets, but to aim at creating idealistic free market system where all the shoppers are furnished complete market information to the fullest extent when they go on shopping.