• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.8 s.350
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• pp.6-12
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• 2006

Recently, according to the rapid development of mobile system, the development of relative mobile components has been required, and especially, with the miniaturization of mobile component, the complex with nearby components has been progressed. In this paper, multi-output VC-TCXO (Voltage Controlled-Temperature Compensated Crystal Oscillator) for WCDMA integrates the additional CMOS inverter, so it can be the normal clipped sinewave output and additional CMOS output, and also it can be satisfied the VC-TCXO's requirements for WCDMA system. And the important characteristics of reference oscillator, like phase noise and frequency short term stability, are satisfied with WCDMA(UMTS) system's requirement In this paper, however, 25MHz is used for reference frequency, similarly and practically, we think that it can be used from 10MHz to 40MHz.

• The Korean Journal of Pain
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• v.10 no.2
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• pp.179-184
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• 1997

Background: Ketorolac($Tarasyn^{(R)}$) is a non-steroidal anti-inflammatory drug(NSAID) which has shown to be an effective postoperative analgesic available parenterally, and when combined with morphine can reduce its requirement. The analgesic efficacy and adverse effects of continuous infusion of ketorolac added to morphine IV PCA was evaluated in 60 women after abdominal hysterectomy. Methods: Patients were assigned to receive either morphine intravenous(IV) bolus followed by morphine IV patient controlled analgesia(PCA), or ketorolac 30mg IV and continuous IV infusion at 4.0mg/hr in combination with the above regimen. The authors evaluated PCA morphine used, pain assessment(verbal pain intensity score and visual analogue scale) and side effects at 2, 4, 6 and 24hrs during pain control. Results: Continuous infusion of ketorolac decreased the PCA morphine usage significantly(30.4 ---> 19.6 mg : p=0.007) at 24hrs postoperatively. Significant differences were seen favoring ketorolac infusion in pain intensity and visual analogue scale both at rest and during movement. There were no differences in incidences of deep sedation, nausea & vomiting. But the ketorolac group they complained of dizziness more than morphine only group. Little pruritus was recorded in either groups. Conclusions: The authors conclude continuous IV infusion of ketorolac in conjunction with morphine PCA provide effective analgesia after low abdominal surgery.

• The Korean Journal of Pain
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• v.8 no.2
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• pp.244-250
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• 1995

Many clinical and laboratory experiments have been developed to prevent or decrease post-operative pain. One of these methods is pre-operative administration of opioid. Recently there have been differing and debatable results reported of pre-operative treatment for post-operative pain management. It was our study to determine whether pre-operative epidural fentanyl prevented central facilitation or wind up of spinal cord from nociceptive afferent input through c-fibers. We evaluated the effect of epidural fentanyl 50 mcg 10 minutes before operation and 10 minutes before the end of surgery. 28 parturient women for Cesarean Section were randomly allocated to receive the epidural fentanyl either at 10 minutes before operation (Group 1, n=14) or 10 minutes before the end of surgery (Group 2, n=14). All of the 28 parturient women were anesthetized with epidural block using (22 ml of) 2% lidocaine supplemented with light general anesthesia ($N_2O$ 2 L/min-$O_2$, 2 L/min), we controlled post-operative pain with epidural PCA(patient controlled analgesia) infusion of meperidine and 0.07% bupivacaine. The action duration of epidural fentanyl from the end of surgery to the first requirement of analgesics with epidural PCA were not significantly different between the two groups. No significant differences between two groups were observed in VAS pain score at 1, 2, 3, 6, 12, 24, and 48 hours after the operation. The number of self administration of narcotics with PCA during 48 hours after surgery were the same between the two groups. The hourly infusion rates of demerol were the same. Pre-operative administration of fentanyl was not clinically effective compared to administration just before the end of surgery for postoperative pain control.

• Clinical and Experimental Reproductive Medicine
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• v.22 no.2
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• pp.123-130
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• 1995

Many types of medication regimens have been used for controlled ovarian hyperstimulation for assisted reproductive technique(ART). Questions are now being raised regarding how to lower the escalating costs of assisted reproduction and decrease the extent of patient discomfort and disruption of life style without sacrificing success rates. In this investigation, from January 1994 through August 1994 patients presenting to the Chung-Ang university hospital, infertility clinic were offered the option of the clomiphene citrate (CC)/single Human Menopausal Gonadotropin(HMG) combination and conventional GnRH-agonist combination method. 60 patients (78 cycles) were given CC/single HMG combination as a study group, and 78 patients (102 cycles) were given conventional GnRH-a combined ultrashort protocol as a control group for IVF-ET program and the resulting number of oocyte retrieved, embryo produced, and pregnancy initiated were compared. There were no differences between the two groups in mean age, serum $E_2$, LH and FSH level on menstrual cycle day 2. HMG requirement was 2 ampules in study group and $24.2{\pm}6.8$ ampules in control group. On the day of HCG injection, serum LH and FSH levels were not significantly different, but serum $E_2$, was significantly higher in control group(p<0.001). There was relatively well endometrial quality in control group but not significant compare to study group. In control group, numbers of retrieved oocyte and transferred embryo were significantly more than study group(p<0.001). Fertilization rate was not significantly different in the two groups and pregnancy rates were 20.2% in study group 28.4% in control group(p<0.001). CC/single HMG protocol for IVF-ET is less expensive than GnRH-a combined ultrashort protocol and minimizes patients discomfort. In addition, CC/single HMG protocol produces acceptable pregnancy rate and represents an attractive alternative to select patients undergoing IVF-ET.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.7
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• pp.784-790
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• 2012

In this paper, an all-digital CMOS ultra-wideband(UWB) pulse generator for high band(6~10 GHz) frequency range is presented. The pulse generator is designed and implemented with extremely low power and low complexity. It is designed to meet the FCC spectral mask requirement by using Gaussian pulse shaping circuit and control the center frequency by using CMOS delay line with shunt capacitor. Measurement results show that the center frequency can be controlled from 4.5 GHz to 7.5 GHz and pulse width is 1.5 ns and pulse amplitude is 310 mV peak to peak at 10 MHz pulse repetition frequency(PRF). The circuit is implemented in 0.13 um CMOS process with a core area of only $182{\times}65um^2$ and dissipates the average power of 11.4 mW at an output buffer with 1.5-V supply voltage. However, the core consumes only 0.26 mW except for output buffer.

• The Korean Journal of Pain
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• v.20 no.2
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• pp.123-129
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• 2007

Background: Postoperative pruritus following the administration of epidural narcotics is a very common and undesirable side effect. Therefore, we evaluated the use of a combination of naloxone and sufentanil via patient controlled epidural analgesia to determine if the incidence of pruritus was decreased when compared to the use of sufentanil alone. Methods: Patients scheduled for subtotal gastrectomy under general anesthesia were enrolled in a prospective, double-blinded and randomized trial. All patients received a $20{\mu}g$ epidural bolus of sufentanil in 5 ml of 0.2% ropivacaine. Following administration of the epidural, patients in the sufentanyl group (S) received a continuous epidural comprised of sufentanil ($0.75{\mu}g/ml$) in 0.2% ropivacaine, whereas patients in the naloxone group (N) received an epidural infusion comprised of naloxone ($4{\mu}g/ml$) and sufentanil ($0.75{\mu}g/ml$) in 0.2% ropivacaine. The infusion rate, demand dose and lockout interval were 5 ml/hr, 0.5 ml and 15 minutes respectively. Next, the occurrence of postoperative analgesia and side effects were evaluated by blinded observers. Results: The incidence of pruritus (47.4% versus 20.0%, P = 0.013) and nausea (42 .1 % versus 20.0%, P = 0.043) were lower in group N than in group S. In addition, there were no significant differences observed in the visual analogue scale, the incidence of vomiting or the incidence of sedation. Furthermore, epidural infusion of naloxone at $0.25-0.4{\mu}g/kg/hr$ did not affect the requirement for postoperative sufentanil. Conclusions: Epidural naloxone reduces epidural sufentanil induced pruritus and nausea without reversing its analgesic effects.

• The Korean Journal of Pain
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• v.33 no.1
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• pp.40-47
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• 2020

Background: Duloxetine is an antidepressant that is also useful in chronic neuropathic and central origin pain. In this study, the role of duloxetine in decreasing acute postoperative pain after lumbar canal stenosis surgery is explored. Methods: In this single center, triple blinded, and placebo-controlled trial, 96 patients were randomized for statistical analysis. The intervention group received oral duloxetine 30 mg once a day (OD) for 2 days before surgery, 60 mg OD from the day of surgery to the postoperative second day and 30 mg OD for the next 2 days (a total duration of 7 days). A placebo capsule was given in the other group for a similar time and schedule. The same standard perioperative analgesia protocols were followed in both groups. Results: Total morphine consumption up to 24 hours was significantly decreased in the duloxetine group (P < 0.01). The time to the first analgesia requirement was similar in both groups but the time to the second and third dose of rescue analgesia increased significantly in the duloxetine group. The time to ambulation was decreased significantly (P < 0.01) in the duloxetine group as compared to the placebo group. Pain scores remained similar during most of the time interval. No significant difference was observed in the complication rate and patient satisfaction score recorded. Conclusions: Duloxetine reduces postoperative pain after lumbar canal stenosis surgery with no increase in adverse effects.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.9
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• pp.1-6
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• 2019

Preterm children require a controlled environment that is as close as possible to that inside the womb. Incubators are well equipped to fulfill this requirement; however, they are cumbersome and expensive, thereby restricting their portability and availability in less developed and rural areas. This research comprises the development and system validation of a portable incubator. The system consists of a collapsible baby enclosure that can be stowed inside the system base when not in use. The enclosure is made from acrylic such that it is easy to clean and allows unhindered visual observation of the occupant while being robust enough to withstand transit conditions. The system can be powered either by a mains supply or a 12-VDC automobile power supply. Additionally, it has an onboard battery to ensure a continuous supply during transit. A Peltier plate controlled using a microcontroller ensures the desired enclosure temperature irrespective of the ambient temperature. Built-in sensor probes can measure the skin temperature, pulse rate, blood oxygenation level, and ECG of the infant and display them on the system screen. The system function is validated by testing its peak power consumption and the heating and cooling performances of the environment control system.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.260-263
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• 2003

This paper has developed the computer integration manufacturing system and Internet based tele-operations. The functions of CIMS include production planing, material requirement planning, work order generation, process control, quality control, shipping planning, warehouse and inventory management and material cost accounting.[1] In this paper focuses on the automatic warehouse control and inventory management by developing the information system as well as the Internet-based integration. The system overview is divided into three parts, the mechanical system, the computer and developed software to control and manage the information and the communication system. The mechanical system consists of the warehouse machine and forklift mobile robot controlled by programmable logic controller (PLC). The computer works on many functions such as control station interfaces with PLC, managing database and inventory, and Internet server to broadcast the inventory database to users via World Wide Web and monitoring the operation on web camera. Our scheme the inventory database can be checked easily anywhere and anytime when the users connect to the Internet. In this article, the lead-time and inventory level can be reduced therefore the holding cost and operating time is also decreased.

• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.227-230
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• 2003

In this paper, a full bridge edge-resonant zero voltage mode based soft-switching PWM DC-DC power converter with a high frequency center tapped transformer link stage is presented from a practical point of view. The power MOSFETS operating as synchronous rectifier devices are implemented in the rectifier center tapped stage to reduce conduction power losses and also to extend the transformer primary side power MOSFETS ZVS commutation area from the rated to zero-load without a requirement of a magnetizing current. The steady-state operation of this phase-shift PWM controlled power converter is described in comparison with a conventional ZVS phase-shift PWM DC-DC converter using the diodes rectifier. Moreover, the experimental results of the switching power losses analysis are evaluated and discussed in this paper. The practical effectiveness of the ZVS phase-shift PWM DC-DC power converter treated here is actually proved by using 2.5kW-32kHz breadboard circuit. An actual efficiency of this converter is estimated in experiment and is achieved as 97$\%$ at maximum.