• Journal of electromagnetic engineering and science
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• v.14 no.1
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• pp.1-8
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• 2014

A differential-cascode CMOS power amplifier (PA) with a supply modulator for envelope tracking (ET) has been implemented by 0.18 ${\mu}m$ RF CMOS technology. The loss at the output is minimized by implementing the output transformer on a FR-4 printed circuit board (PCB). The CMOS PA utilizes the $2^{nd}$ harmonic short at the input to enhance the linearity. The measurement was done by the 10MHz bandwidth 16QAM 6.88 dB peak-to-average power ratio long-term evolution (LTE) signal at 1.85 GHz. The ET operation of the CMOS PA with the supply modulator enhances the power-added efficiency (PAE) by 2.5, to 10% over the stand-alone CMOS PA for the LTE signal. The ET PA achieves a PAE of 36.5% and an $ACLR_{E-UTRA}$ of -32.7 dBc at an average output power of 27 dBm.

• Biomedical Science Letters
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• v.25 no.2
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• pp.149-158
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• 2019

The objective of this study was to evaluate the effects of thoracic mobilization (TM) on the angle of thoracic kyphosis, and static and dynamic balances by application period. The subjects of this study were 18 adult males and females (${\geq}20years\; old$) who had the angle of thoracic kyphosis equal to or higher than $40^{\circ}$. A pre-test was conducted for all subjects and TM was carried out. Data were collected before the intervention, 3 weeks after the intervention, and 6 weeks after the intervention. It was measured three times per measurement and mean values were used for the analysis. The results of this study showed that the angle of thoracic kyphosis significantly (P<.05) decreased after applying TM. However, the migration area ($mm^2$) of the center of pressure (COP) in the static balance did not vary significantly. In the case of the dynamic balance, when eyes were open, the migration area ($mm^2$) of the COP significantly (P<.05) decreased after 3 weeks. When eyes were open, the migration area ($mm^2$) of the COP significantly (P<.05) decreased after 3 weeks and 6 weeks. Therefore, an intervention for improving the human body alignment and balance should be applied for a long-term, rather than a short-term, in order to be effective.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.3
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• pp.197-206
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• 2021

We compared two typical ensemble time scale algorithms; AT1 and Kalman filter. Four commercial atomic clocks composed of two hydrogen masers and two cesium atomic clocks provided measurement data to the algorithms. The allocation of relative weights to the clocks is important to generate a stable ensemble time. A 30 day-average-weight model, which was obtained from the average Allan variance of each clock, was applied to the AT1 algorithm. For the reduced Kalman filter (Kred) algorithm, we gave the same weights to the two hydrogen masers. We also compared the frequency stabilities of the outcome from the algorithms when the frequency offsets and/or the frequency drift offsets estimated by the algorithms were corrected or not corrected by the KRISS-made primary frequency standard, KRISS-F1. We found that the Kred algorithm is more effective to generate a stable ensemble time scale in the long-term, and the algorithm also generates much enhanced short-term stability when the frequency offset is used for the calculation of the Allan deviation instead of the phase offset.

• Journal of Korean Academy of Nursing
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• v.34 no.7
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• pp.1277-1287
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• 2004

Purpose: This study was to evaluate the effects of a short term comprehensive life style modification program on glycemic metabolism, lipid metabolism and body composition in type 2 diabetes mellitus patients. Method: A nonequivalent control group with a pre post test was designed. Data collection was done from October 2003 to June, 2004 at a hospital. Glycemic metabolism was measured by a.c., p.c. and $HbA_{1}c$, and lipid metabolism was measured by cholesterol, HDL cholesterol, LDL cholesterol and triglycerides. Body Composition was measured by body weight, body mass index, waist, measurement waist per hip ratio, body fat, muscle weight and abdominal fat tissue(intra abdominal distance). The Experimental group, which was composed of 29 participants, was educated based on a life style modification protocol at a weekly meeting for 12 weeks and carried out exercise, diet along individual parameters and self monitoring, while 24 participants in the control group received only diet education. Result: 1. The experimental group showed a significant lower a.c.(t=2.11, p=.04) and $HbA_{1}c$(t=2.65, p=.01) compared to those of the control group. 2. The experimental group showed a significant lower LDL than the results of the control group(t=2.42, p=.02). 3. The experimental group showed a significant lower weight(t=3.09, p=.00), BMI(t=3.01, p=.00), body fat(t=2.94, p=.01) and abdominal fat tissue(t=3.05, p=.01) than those of the control group. Conclusion: The results provided evidence for the effectiveness of a short term comprehensive life style modification program composed of exercise, diet, support, self efficacy elevation and self monitoring in type 2 diabetes mellitus.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.9
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• pp.457-464
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• 2017

Indoor air quality analysis is conducted to understand abnormal atmospheric phenomena and the external factor affecting indoor air quality. By recording indoor air quality measurements periodically, we are able to observe patterns in air quality. However, it difficult to predict the number of potential parameters, set parameters for a given observation and find the coefficients. Moreover, the results are time-dependent. Thus to address these issues, we introduce a microchip capable of periodically recording indoor air quality and a model that estimates atmospheric changes based on time series data.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.1
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• pp.41-46
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• 2006

Ubiquitous location based services, offer helpful services anytime and anywhere by using real-time location information of objects based on ubiquitous network. Particularly, autonomous mobile robots can be a solution for various applications related to ubiquitous location based services, e.g. in hospitals, for cleaning, at airports or railway stations. However, a meaningful and still unsolved problem for most applications is to develop a robust and cheap positioning system. A typical example of position measurements is dead reckoning that is well known for providing a good short-term accuracy, being inexpensive and allowing very high sampling rates. However, the measurement always has some accumulated errors because the fundamental idea of dead reckoning is the integration of incremental motion information over time. The other hand, a localization system using RFID offers absolute position of robots regardless of elapsed time. We construct an absolute positioning system based on RFID and investigate how localization technique can be enhanced by RFID through experiment to measure the location of a mobile robot. Tags are placed on the floor at 5cm intervals in the shape of square in an arbitrary space and the accuracy of position measurement is investigated . To reduce the error and the variation of error, a weighting function based on Gaussian function is used. Different weighting values are applied to position data of tags since weighting values follow Gaussian function.

• Journal of Environmental Analysis, Health and Toxicology
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• v.21 no.4
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• pp.209-219
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• 2018

In the areas of RoHS, WEEE, ELV and REACH, reinforcement of environmental regulations against harmful substances is a global trend not only in EC but also in all over the world. In the fields of Korea's major export products such as material parts, electrical and electronic products and automobile parts, we are responding to these regulations consistently. To develop reference material for analyzing lead and cadmium in paints, the candidate materials were produced through the screening process which separated shapes and sizes. To secure the traceability of the candidate materials produced, the characteristics and uncertainties are estimated by ICP-AES analysis using the primary reference material. The short-term and long-term stabilities also are evaluated in parallel. In order to calculate the final certification value of the candidate material, the verification were carried out by the performance evaluation through the comparison among the KOLAS (Korea Laboratory Accreditation Scheme) laboratories, and the CRM was produced in accordance with ISO Guide 35. The certified values and uncertainties of Pb and Cd of the final paint standard, determined according to the joint analysis among laboratories, are Pb [($191.4{\pm}3.1$) mg/kg, ($944.1{\pm}5.6$) mg/kg] and Cd [($45.0{\pm}2.6$) mg/kg, ($225.5{\pm}3.5$) mg/kg]. These standard materials were developed to enhance the reliability of measurement analysis, including the validity and traceability of measurement results. Also it is expected that the CRM will be used as QCM (quality control material) for the product design and the process monitoring, so that regulation and management of hazardous heavy metals can be systematically implemented.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.524-527
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• 1997

Conventional target tracking algorithms based on the linear estimation techniques perform quite efficiently when the target motion does not involve maneuvers. Target maneuvers involving short term accelerations, however, cause a bias in the measurement sequence. Accurate compensation for the bias requires processing more samples of which adds to the computational complexity. The primary motivation for employing a neural network for this task comes from the efficiency with which more features can be as inputs for bias compensation. A system architecture that efficiently integrates the fusion capabilities of a trained multilayer neural net with the tracking performance of a Kalman filter is described. The parallel processing capability of a properly trained neural network can permit fast processing of features to yield correct acceleration estimates and hence can take the burden off the primary Kalman filter which still provides the target position and velocity estimates.

• Journal of Korean Academy of Nursing
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• v.36 no.7
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• pp.1164-1174
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• 2006

Purpose: This study was conducted to identify the effects of a PMS nutritional education program for college nursing students. Method: Subjects consisted of nursing students(experimental group: 19, control group: 27). The experimental group participated in a PMS nutritional education program for 8 weeks (including group and individual involvement). Data was collected before and after the education, and measurement tools were premenstrual symptoms, PMS knowledge, and self health behavior. Results: After the intervention, the experimental group showed a significant increase in PMS knowledge(Z=6.32, p=.000) and self health behavior(t=3.00, p=.004) compared to the control group. After the intervention the experimental group showed a significant increase in PMS knowledge(Z=-4.64, p=.000) and self health behavior(t=-3.04, p=.005) than before the intervention. Conclusions: These results suggest that the short term effects of a PMS nutritional education program for nursing students was proven useful and the program should be applied to PMS nutrition education for PMS clients as well as health professionals.

• Journal of the Korean Magnetic Resonance Society
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• v.21 no.1
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• pp.26-30
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• 2017

Dynamic properties of proteins can present key information on protein-ligand and protein-protein interaction. Despite their usefulness, the properties of protein dynamics have not been obtained easily due to protein stability and short-term measurement. Here, it is shown that combined method for analysis of dynamical properties. It utilizes predicted order parameter and NMR relaxation data such as $T_1$, $T_2$, and heteronuclear NOE. The suggested method could be used to know the flexibility of protein roughly without precise dynamical parameters such as order parameters through model-free analysis.