• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.10
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• pp.202-208
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• 2012

Fetal heart rate monitoring is important information to assess fetal well-being. Non-invasive fetal ECG (electrocardiography) can be derived from maternal abdominal signal. And various promising signal processing methods have been introduced to extract fetal ECG from mother's composite abdominal signal. However, non-invasive fetal ECG monitoring still has not been widely used in clinical practice due to insufficient reliable measurement and difficulty of signal processing. In application of signal processing method to extract fetal ECG, it might be lower signal to noise ratio due to time varying white Gaussian noise. In this paper, time varying Kalman smoother is proposed to remove white noise in fetal ECG and its feasibility is confirmed. Wiener process was set as Kalman system model and covariance matrix was modified according to white Gaussian noise level. Modified error covariance matrix changed Kalman gain and degree of smoothness. Optimal covariance matrix according to various amplitude in Gaussian white noise was extracted by 5 channel fetal ECG model, and feasibility of proposed method could be confirmed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.10
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• pp.45-52
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• 2008

We investigated the design of an RF-powered, wireless temperature sensor tag chip using $0.18-{\mu}m$ CMOS technology. The transponder generates its own power supply from small incident RF signal using Schottky diodes in voltage multiplier. Ambient temperature is measured using a new low-power temperature-to-voltage converter, and an 8-bit single-slope ADC converts the measured voltage to digital data. ASK demodulator and digital control are combined to identify unique transponder (ID) sent by base station for multi-transponder applications. The measurement of the temperature sensor tag chip showed a resolution of $0.64^{\circ}C/LSB$ in the range from $20^{\circ}C$ to $100^{\circ}C$, which is suitable for environmental temperature monitoring. The chip size is $1.1{\times}0.34mm^2$, and operates at clock frequency of 100 kHz while consuming $64{\mu}W$ power. The temperature sensor required a -11 dBm RF input power, supported a conversion rate of 12.5 k-samples/sec, and a maximum error of $0.5^{\circ}C$.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.5
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• pp.40-49
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• 2008

A Frequency synthesizer for mobile-DTV applications is implemented using $0.18{\mu}m$ CMOS process with 1.8V supply. PMOS transistors are chosen for VCO core to reduce phase noise. The measurement result of VCO frequency range is 800MHz-1.67GHz using switchable inductors, capacitors and varactors. We use varactor bias technique for the improvement of VCO gain linearity, and the number of varactor biasing are minimized as two. VCO gain deterioration is also improved by using the varactor switching technique. The VCO gain and interval of VCO gain are maintained as low and improved using the VCO frequency calibration block. The sigma-delta modulator for fractional divider is designed by the co-simualtion method for accuracy and efficiency improvement. The VCO, PFD, CP and LF are verified by Cadence Spectre, and the sigma-delta modulator is simulated using Matlab Simulink, ModelSim and HSPICE. The power consumption of the frequency synthesizer is 18mW, and the VCO has 52.1% tuning range according to the VCO maximum output frequency. The VCO phase noise is lower than -100dBc/Hz at 1MHz at 1MHz offset for 1GHz, 1.5GHz, and 2GHz output frequencies.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.9
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• pp.68-73
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• 2013

In this paper, we proposed a readout circuit of pulse waveform and rate for a U-health system to monitor health condition. For long-time operation without replacing or charging a battery, either pulse waveform or pulse rate is selected as the output data of the proposed readout circuit according to health condition of a user. The proposed readout circuit consists of a simple digital logic discriminator and a dual-mode ADC which operates in the ADC mode or in the count mode. Firstly, the readout circuit counts pulse rate for 4 seconds in the count mode using the dual-mode ADC. Health condition is examined after the counted pulse rate is accumulated for 1 minute in the discriminator. If the pulse rate is out of the preset normal range, the dual-mode ADC operates in the ADC mode where pulse waveform is converted into 10-bit digital data with the sampling frequency of 1 kHz. These data are stored in a buffer and transmitted by 620 kbps to an external monitor through a RF transmitter. The data transmission period of the RF transmitter depends on the operation mode. It is generally 1 minute in the normal situation or 1 ms in the emergency situation. The proposed readout circuit was designed with $0.11{\mu}m$ process technology. The chip area is $460{\times}800{\mu}m^2$. According to measurement, the power consumption is $161.8{\mu}W$ in the count mode and $507.3{\mu}W$ in the ADC mode with the operating voltage of 1 V.

• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.69-78
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• 2004

In this study, the back analysis program was developed by applying the genetic algorithm, one of artificial intelligence fields, to the direct method. The optimization process which has influence on the efficiency of the direct method was modulated with genetic algorithm. On conditions that the displacement computed by forward analysis for a certain rock mass model was the same as the displacement measured at the tunnel section, back analysis was executed to verify the validity of the program. Usefulness of the program was confirmed by comparing relative errors calculated by back analysis, which is carried out under the same rock mass conditions as analysis model of Gens et at (1987), one of back analysis case in the past. We estimated the total displacement occurring by tunnelling with the crown settlement and convergence measured at the working faces in three tunnel sites of Kyungbu Express railway. Those data measured at the working face are used for back analysis as the input data after confidence test. As the results of the back analysis, we comprehended the tendency of tunnel behaviors with comparing the respective deformation characteristics obtained by the measurement at the working face and by back analysis. Also the usefulness and applicability of the back analysis program developed in this study were verified.

• The Journal of the Korea Contents Association
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• v.7 no.12
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• pp.139-144
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• 2007

Radiotherapy which is the most effective for orbit lymphoma has been used increasingly due to the increase of orbit or ocular adnexal tumor patients. Curative effects and convalescence have been being more satisfied thanks to remarkable development of cancer chemotherapy and medical treatments, but side effects such as cataract, dry eye and retinopathy still break out. Thus, in this study, a Lens Shielding Device (LSD hereafter) was designed to prevent occurring of cataract due to radiation therapy for orbit lymphoma and its efficacy through dosimetry were evaluated. And in this paper, its manufacturing process was also explained. LSD is composed of a cover body covering the lens and a side fixing part supporting the cover body. To measure radiation, the patient therapy conditions were simulated and the measurement of the radiation was conducted with Thermo Luminescence Detector (TLD) and Markus chamber. The average TLD value was 5.7% and the TLD value and Markus chamber value were acquired as 4.2% and 5.1% respectively at 6 mm depth where zero lens center was located. Only 1.5Gy ($300Gy{\times}\;5%$) or 5% of total 30Gy with 9 MeV electron beam is estimated to affect on patient's lens. That is smaller dose than the threshold value of cataract (2GY) or the value (5Gy) that was reported to cause cataract in clinical conditions. Thus, these findings suggest that LSD be very useful for prevention of cataract during radiotherapy for malignant lymphoma of orbit and ocular adnexa. Furthermore, it might be possible to reduce patient's discomfort caused by alien substances and to make it easier to fix the device with customized manufacturing manners.

• Journal of Distribution Science
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• v.14 no.7
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• pp.91-100
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• 2016

Purpose - Recently actively growing franchise systems distribution channel system in which franchise headquarter compared with franchise occupies an important place in distribution channel. Due to this, franchise and franchise headquarter are interdependent on task and in this situation the goal they go after, motivation and objective are probably inconsistent. If so, possibility to participate goal setting process or operating activity of opposite side is becoming bigger and in the end conflict may generate. The purpose of this study is to examine the role of the supervisor's attitude and expertise as moderating factors in the relationship between goal-incongruity/coercive power/role-incongruity and the conflict perceived by franchisee. Research design, data and methodology - This study was intended to verify how the supervisor's attitude and expertise as moderating factors in the relationship between goal-incongruity/coercive power/role-incongruity and the conflict perceived by franchisee. In order to achieve the purpose of this study, some study models and hypotheses have been established through theoretical examinations. Then, using these scales, the researcher completed the questionnaire survey. To test our hypotheses, the survey was conducted from March 9, 2016 for 20 days by random sampling, The study was implemented through a descriptive survey method using a self-administered questionnaire. A survey of 124 restaurant franchisee across Seoul and Gyeonggi Province was performed. A total of 124 completed responses were analyzed. In this study, I used SPSS 22.0 to analyze data and did frequency analysis to see demographic, and general features of the respondents; also did exploratory factor analysis to examine the validity of the items of measurement. Factor analysis was first calculated at a minimum, the number of factors, principal component analysis used when variables are committed to maximising the information with (principle component analysis) and the rotation of factors were angry about the great variable factors than 1.0 by applying Varimax rotation. In addition, I used the value of Cronbach's (Alpha) to examine the reliance of questionnaire items, final analysis the reliability factor can be found both high reliability hayeoteumeuro exceeds over 0.6 and did Multiple regression analysis to test hypothesis and also did hierarchical regression analysis to examine moderating effect. Results - To analyze the proposed model, according to the analysis result, it was found that the influence of goal-incongruity, coercive power, and role-incongruity on the perceived conflict of franchisee is moderated by the supervisor's attitude and expertise. That is, the more the supervisor's attitude and expertise were positive, the more the conflicts of the goal-incongruity, coercive power, and role-incongruity were decreased. It also confirmed previous research's finding that goal-incongruity, coercive power, and role-incongruity positively influence on the conflict. Conclusions - According to the results of this research which reduces the conflict of franchise from the in consistent goal; coercive power, and inconsistent role of superiors, it provides very important implications for franchise headquarter which has franchise system and also give them some suggestion about how to recruit superiors and what kind of training may be fit for the superiors.

• Journal of Distribution Science
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• v.17 no.8
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• pp.107-118
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• 2019

Purpose - The present study examines the effect of service employees' experienced customer incivility through their emotional exhaustion. We identified service employees' emotion regulation ability as a boundary condition (i.e., moderating variable) that decreased the positive relationship between service employees' experienced customer incivility and their emotional exhaustion. Furthermore, we also investigated the negative relationship between service employees' experienced customer incivility and their service performance via emotional exhaustion. Research design, data, and methodology - Drawing on AET (affective event theory) and COR (conservation of resources) theory, we developed three research hypotheses (i.e., mediation, moderation, and moderated mediation). Online panel survey data from 552 frontline employees at several service organizations (e.g., department stores, retail stores, hotels, restaurants, airlines, banking, insurance company, and etc) in South Korea were examined. To assess two types of validity (i.e., convergent and discriminant validity) and reliability of measurement model, we employed the CFA (confirmatory factor analysis) using M-plus 8.2 software. Internal consistency also was tested by Cronbach' α. In addition, we employed the SPSS PROCESS MACRO 2.16, which was recommended by Hayes (2013, 2015), to estimate mediation, moderation, and moderated mediation effects. Results - As predicted, the negative relationship between service employees' experienced customer incivility and their service performance was mediated by emotional exhaustion. Furthermore, service employees' emotion regulation ability also played a significant moderating role of the relationship between service employees' experienced customer incivility and emotional exhaustion, such that this relationship was less pronounced when service employees had a high level of their emotion regulation ability than when thir emotion regulation ability was low. Service employees' emotion regulation ability further moderated this mediation effect of service employees' experienced customer incivility on service performance through emotional exhaustion. These findings have theoretical implications for employees' experienced customer incivility and emotion regulation ability research and provide managerial implications for practitioners. Conclusions - This study empirically elaborated the previous model of service employees' experienced customer incivility and personal resource (e.g., emotion regulation ability) literature by presenting the findings that service employees' experienced customer incivility influences their service performance via emotional exhaustion and that emotion regulation ability effectively reduces this negative effect.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.354-360
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• 2020

This study examined the factors for sorting miscellaneous cereal crops using a rice-sorting device by analyzing the physical characteristics according to the moisture content. The initial moisture contents of miscellaneous cereal were 16.3, 19.8, and 16.5%, respectively. The samples were used in the experiment after drying to five levels. The width, length, and area of the samples increased with increasing moisture content except for the roundness, and all the prediction models were developed with a first-order linear equation. The bulk density of Italian millet and sorghum increased with increasing moisture content, whereas the bulk density of common millet was unaffected by the change in moisture content. The terminal velocity of the samples increased with increasing moisture content, and a first-order linear equation was used to develop the prediction models. The measured physical properties of the miscellaneous cereal crops based on the changes in the moisture content could be expressed using a first-order experimental model equation. Therefore, the rice-sorting device could be applied to the terminal velocity, but the other device applying the geometrical characteristics and bulk density was required to change the design of the process depending on the type of grain.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.11a
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• pp.147-153
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• 2002

Due to the growth of population and industrial development at the coastal cities, there has been much increase in necessity to effective control of the wastes into the coastal water and river. The amount of disposal at those waters has been increased rapidly and it is necessary for us to track of it in order to keep the water clean. The investigation and research related to the water quality in this region have been conducted continuously but the systematic survey of the disposed wastes at the bottom was neglected and/or minor. In this study we surveyed the status of disposed waste distribution at the bottom coastal water and river from the scanned images. The intensity of sound received by the side scan sonar tow vehicle from the sea floor provides information as to the general distribution and characteristics of the superficial wastes. The port and starboard side scanned images produced from a transducer borne on a tow fish connected by tow cable to a tug boat have the area with width of 22m∼112m, and band of 44m∼224m. All data are displayed in real-time on a high-resolution color display (1280 ${\times}$ 1024 pixels) together with position information by DGPS. From the field measurement and analysis of the recorded images, we could draw the location and distribution of bottom disposals. Furthermore, we made a database system which might be fundamental for planning the waste reception and process control system.