• Journal of Dental Anesthesia and Pain Medicine
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• 제19권3호
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• pp.151-158
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• 2019

Background: This study aimed to examine whether the combination of low-dose ketamine and propofol in deep sedation is clinically useful in controlling the behavior in intellectually disabled patients who are typically extremely noncooperative during dental procedures. Methods: A total of 107 extremely noncooperative intellectually disabled adult patients were analyzed. In all patients, deep sedation was performed using either propofol alone (group P) or using a combination of propofol and 0.2 mg/kg or 0.4 mg/kg ketamine (groups PK0.2 and PK0.4, respectively). The procedures were performed in the order of insertion of nasal cannula into the nostril, attachment of mouth gag, and mouth cleaning and scaling. The frequency of patient movement during the procedures, mean arterial pressure, heart rate, peripheral oxygen saturation, recovery time, discharge time, and postoperative nausea and vomiting were examined. Results: The three groups were significantly different only in the frequency of patient movement upon stimulation during single intravenous injection of propofol and scaling. Conclusion: For propofol deep sedation, in contrast to intravenous injection of propofol alone, prior intravenous injection of low-dose ketamine (0.4 mg/kg) is clinically useful because it neither affects recovery, nor causes side effects and can suppress patient movement and vascular pain during procedures.

• 센서학회지
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• 제28권4호
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• pp.240-245
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• 2019

Phase interpolation is widely adopted in frequency synthesizers and clock-and-data recovery systems to produce an intermediate phase from two existing phases. The intermediate phase is typically generated by combining two input phases with different weights. Unfortunately, this results in non-uniform phase steps. Alternatively, the intermediate phase can be generated by successive approximation, where the interpolated phase at each approximation stage is obtained using the same weight for the two intermediate phases. As a proof of concept, this study presents a 2-GHz 8-bit successive approximation digital-to-phase converter that is designed using 65-nm CMOS technology. The converter receives an 8-phase clock signal as input, and the most significant bit (MSB) section selects four phases to create two sinusoidal waveforms using a harmonic rejection filter. The remaining least significant bit (LSB) section applies the successive approximation to generate the required intermediate phase. Monte-Carlo simulations show that the proposed converter exhibits 0.46-LSB integral nonlinearity and 0.31-LSB differential nonlinearity with a power consumption of 3.12 mW from a 1.2-V supply voltage.

• 한국운동역학회지
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• 제22권2호
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• pp.219-228
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• 2012

The purpose of this study was to investigate how induced fatigue of the ankle joint muscles affects the capability and recovery of postural control during single-leg stance in healthy adults. The study population included 22 randomly recruited men and women. Postural control was performed on single-leg stance with eyes open. Ankle joint muscle was fatigued by repeated heel raises. According to the results of this study, for the anteroposterior variables, both men and women showed significantly increased center of mass velocity and decreased center of pressure 95% edge frequency immediately after fatigue. For the mediolateral variables, both men and women showed significantly increased center of mass velocity and decreased center of pressure 95% edge frequency immediately after fatigue. For the total variables, both men and women showed significantly increased center of mass averaged-velocity immediately after fatigue, and also, the center of pressure 95% confidence ellipse area significantly increased in women. Postural control variables were not significantly different for men and women at any time (Pre, P0, P10, and P20). In conclusion, the gender does not affect the capability and recovery after induced fatigue of ankle joint muscles. The effect of fatigue found for the anteroposterior and the mediolateral variables in both men and women. Furthermore ankle joint muscle fatigue led to change of postural control strategy from an ankle joint strategy towards a hip joint strategy. These changes are believed to damage postural control. The ankle joint muscle recovered from fatigue within 20 min during single-leg stance.

• 전자공학회논문지SC
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• 제46권1호
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• pp.68-75
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• 2009

본 논문에서는 이중 보간 방식을 기반으로 1/4-rate 클록을 이용하는 효율적인 CDR을 제안하였다. 제안한 CDR은 다채널 송수신기에서 다중 위상 클록을 이용하여 클록 주파수를 줄일 경우 필요한 클록의 수가 증가하여 이들 클록을 공급할 때 소모되는 전력과 하드웨어적 부담이 증가한다는 단점을 극복하는 것을 목표로 설계되었다. 이를 위해 1/2-rate 클록 방식과 동일한 공급 클록 수를 유지하면서 각각의 복원부에서 추가로 필요한 클록을 플립플롭을 이용하지 않고 인버터만으로 생성하였다. 이로 인해 보다 높은 전송률의 요구 시 장애 요인 중 하나인 클록 생성기의 주파수를 낮추어 고속 전송을 가능케 하였으며, 공급 클록의 수를 증가시키지 않고 1/4-rate 주파수의 클록을 이용함으로써 CDR을 저전력화하였다.

• Annals of Clinical Neurophysiology
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• 제16권2호
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• pp.62-69
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• 2014

Background: Neuromodulation therapy has been used to an adjunctive treatment promoting motor recovery in stroke patients. The objective of the study was to determine the effect of repetitive transcranial magnetic stimulation (rTMS) on neurobehavioral recovery and evoked potentials in rats with middle cerebral artery occlusion. Methods: Seventy Sprague-Daley rats were induced permanent middle cerebral artery occlusion (MCAO) stroke model and successful stroke rats (n=56) assigned to the rTMS (n=28) and sham (n=28) group. The 10 Hz, high frequency rTMS gave on ipsilesional forepaw motor cortex during 2 weeks in rTMS group. The somatosensory evoked potential (SSEP) and motor evoked potential (MEP) were used to evaluate the electrophysiological changes. Behavioral function of the stroke rat was evaluated by the Rota rod and Garcia test. Results: Forty rats ($N_{rTMS}=20;\;N_{sham}=20$) completed all experimental course. The rTMS group showed better performance than sham group in Rota rod test and Garcia test at day 11 (p<0.05) but not day 18 (p>0.05). The amplitude of MEP and SSEP in rTMS group was larger than sham group at day 18 (p<0.05). Conclusions: These data confirm that the high frequency rTMS on ipsilesional cerebral motor cortex can help the early recovery of motor performance in permanent middle cerebral artery stroke model and it may simultaneously associate with changes in neurophysiological activity in brain.

• 한국정보통신학회논문지
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• 제2권3호
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• pp.317-323
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• 1998

동기는 유선 통신뿐만 아니라 무선 통신에서도 중요한 요소이다. 특히 GPS에서 사용하는 대역확산 통신방식에 있어서는 더욱 중요하다. 50(Synchronous Oscillator)는 동기, 동조, 필터, 증폭, 분주를 하나의 과정으로 처리할 수 있는 회로망이며 입력 신호가 없을 때에는 $w_0$ 에서 자주 발진하는 발진기이지만 SO는 추적 대역폭 내에서 위상이 $180^{\circ}$ 바뀐다. 따라서 이를 해결하기 위하여 CPSO를 사용하였으며 CPSO(Coherent Phase Synchronous Oscillator)는 SO에2개의 외부 루프를 첨가함으로서 구성되며 CPSO는 높은 잡음 제거능력과 빠른 획득시간의 SO 특성을 유지하는 동안 더 넓은 추적범위와 zero offset의 위상 응답을 가지게 되며 입출력 신호의 위상이 일치하게 된다. 본 논문에서는 이러한 성질을 이용하여 CPSO를 GPS(Global Positioning System)의 데이터 추출회로에 적용하였으며 우수한 데이터 추출능력을 확인하였다.

• 운동영양학회지
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• 제16권1호
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• pp.43-50
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• 2012

This study was designed to investigate the effect of vibratory stimulation on recovery of muscle function from delayed onset muscle soreness (DOMS). Volunteers performed 3 set of 70 % maximal voluntary eccentric muscle contraction and induced DOMS. volunteers were allocated to one of three treatment group after DOMS : group I (control), group II (ultrasound), group III (vibration). Maximal Voluntary Isometric Contraction (MVIC), Visual Analog Scale (VAS), Range Of Motion (ROM), Root Mean Square (RMS), Median frequency (MDF), Blood Serum Creatine Kinase (CK), Lactic dehydrogenase (LDH) were recorded at baseline, and 24, 48, 72 hours post-exercise. In MVIC measurement, there was a statistically significant difference in group III compared to group I (p < .05). In VAS measurements, there were a statistically significant difference in group II and III compared to group I (p < .05). In ROM measurement, there was a statistically difference in group II and III compared to group I (p < .05). In Muscle Volume with Ultrasonography measurement, there was no statistically significant difference in any groups (p > .05). In RMS and MDF measurement, there were a statistically significant difference in group II and III compared to group I (p < .05). In Blood samples of CK and LDH measurements, There were no statistically significant difference in any groups (p > .05). From the above result, Vibratory stimulation had a positive effect on recovery of muscle function from delayed onset muscle soreness. Further studies should be undertaken to ascertain the more effectiveness of vibratory stimulation and may be a promising treatment modality.

• Clinical and Experimental Pediatrics
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• 제53권4호
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• pp.554-559
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• 2010

목 적: 편두통의 형태별로 topiramate의 치료효과의 차이를 연구하였다. 방 법: 2005년 1월 1일부터 2008년 6월 30일까지 본 병원 소아청소년과에서 편두통으로 처음 진단하여 topiramate를 처방하여 치료했던 환자 38명을 대상으로 하였다. Topiramate의 치료효과는 최초의 월당 두통발생횟수에 대한 치료 후 월당 두통발생횟수로 완쾌, 개선, 그리고 무효의 세 가지로 판정하였으며 치료 완료 후 1년이 경과한 후의 상태를 완치, 감소, 그리고 지속으로 구분하여 조사하였다. 결 과: 전조 편두통은 84.6%가 완쾌되었고, 1례가 개선, 나머지 1례에서 효과가 없었다. 무 전조 편두통은 47.1%가 완쾌되었고 29.4%가 개선되었으며, 23.5%에서 효과가 없었다. 개연적 편두통의 경우 완쾌와 개선이 각각 20%이었으며 60%에서 효과가 없었다. 이밖에 1례의 무 두통 전조 환자는 완쾌되었고, 소아기 양성 돌발성 현훈은 2례 중 1례는 완쾌를 보였고, 1례는 효과가 없었다. 전체적으로 topiramate 투여 후 평균 57.9%가 쾌유하였고, 18.4%에서 개선되었으며, 그리고 23.7%에서는 효과가 없었다. 편두통의 종류별로는 전조 편두통이 무 전조 편두통에 비해 좋은 치료결과를 보였다. 또한 전조 편두통은 개연적 편두통에 비해서도 치료성적이 좋았다. 그러나 무 전조 편두통과 개연적 편두통은 치료성적의 차이가 없었다. 결 론: Topiramate가 소아 청소년의 전조증세가 있었던 편두통에서 좋은 치료효과를 보였으며, 또한 무 전조 편두통에서도 비교적 좋은 효과를 보였으나 개연적 편두통에서의 그 효과가 불투명하였다. 치료 후의 장기적 경과에서는 대체적으로 관해상태가 지속하였다.

• 대한인간공학회지
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• 제14권1호
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• pp.9-23
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• 1995

The objectives of the study were twofole: (1) to investigate effects of rhythmic contraction and sustained contraction methods on recovery rate of isometric endurance capacity and (2) to compare aptterns of muscle recruitment of both arms observed during each contraction period. In the experiment, each of two subjects performed five successive rhythmic or sustained isometric contractions at 50% MVC with both arms to the point of fatigue, which was the failure to maintain the required tension. In making the contractions, the subjects stood erect with upper arms held at an angle of approximately 90 .deg. to the forearm. The interval between the successive contractions was kept constant at 3, 7, 20, or 40 minutes. Regardless of the contraction methods, the recovery rate was least at the shortest interval and was highest at the longest interval. However, a statistical analysis showed that the recovery rates for the rhythmic contractions were significantly lower than those for the sustained contractions throughout 4 different intervals. Furthermore, as the frequency of the rhythmic contractions per min, increased 4 to 6 times, the recovery rate of isometric endurance capacity decreased. From an EMG anglysis, recruitment pattern of the muscules of both arms was found to be common between two different contraction methods. The biceps muxcles of the upper arms played a major role in exerting 50% MVC, while the brachioradialis muscles of the forearms acted as synergists. As the contraction proceeded, the role of the biceps muscles as a prime mover lessened due to the fatigue. Then, the brachioradialis muscles exerted more strength to sustain 50% MVC. The implications of these finding were discussed.

• 한국산업보건학회지
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• 제25권2호
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• pp.156-165
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• 2015

Objectives: The purpose of this study was to investigate the possible effects of a gasoline vapor recovery system on personal exposure levels of gasoline vapor constituents including benzene, toluene, ethyl benzene, xylene(BTEX), and methyl tert-butyl ether(MTBE) among gas station workers in a metropolitan area. Methods: Thirty-one gas station workers at ten gas stations in a metropolitan area were selected as subjects for this study. Test method PV2028 as recommended in the OSHA process was used for sampling and analysis. Results: The personal exposure levels of benzene, toluene, ethyl benzene, xylene, MTBE and gasoline vapor in the gas station workers were $0.0018{\pm}0.0069ppm$, $0.0077{\pm}0.0137ppm$, $0.0002{\pm}0.0008ppm$, $0.0016{\pm}0.0084ppm$, $0.2619{\pm}0.3340ppm$, and $1.4940{\pm}1.7984ppm$, respectively. After adjustment for refueling frequency and volume, personal exposure levelswere higher in the gas stations where gasoline vapor recovery systems(Stage II) were not installed, but the results were not statistically significant. Gasoline vapor concentrations showed a positive correlation to the level of MTBE, a gasoline additive. Conclusions: Vapor recovery systems(Stage II) were effective not only in reducing emissions of air pollutants, but also in reducing exposure to hazardous substances among gas station workers. In addition, acorrelation between gasoline vapors and MTBE concentration was confirmed.