척수강내 Bupivavacain에 첨가한 소량의 Neostigmin의 진통효과와 부작용

소금영,정종달,김병철,유벙식,안태훈,김훈정,임경준 조선대학교 2000 The Medical Journal of Chosun University Vol.25 No.2

Background : Spinal cholinergic receptor has been shown to have a antinociceptive action, an effect that can be mimicked by spinal cholinesterase inhibitor. Intrathecal injection of neostigmine cause analgesia and adverse effect in a dose-dependent pattern in the patients. The purpose of this study was to determine whether small doses of intrathecal neostigmine (10, 25 and 50 ㎍) produce analgesia and any side effects. Method : After getting informed consents, 60 patients scheduled for orthopedic surgery of lower extremities under spinal anesthesia were randomly assigned to one of four groups. Using dose-ranging design, patients received either normal saline or neostigmine l0, 25 or 50 ㎍ in a 1-㎎ solution of 5% glucose in normal saline with heavy bupivacaine 12 ㎎. Heart rate, blood pressure, degree of motor and sensory block were recorded. The assessment of postoperative analgesia included time to first rescue, total number of rescue medication and pain score on visual analog scale (VAS) at 1, 3, 6, 9, 12, 24 hour. Nausea and vomiting were assessed by using the visual analog scale at 24 hr postperatively and the incidence of them was recorded postoperatively. Result : There were no significant differences among the four groups in characteristics of spinal blocks. Compared to saline, neostigmine groups significantly prolonged time to first rescue medication and decreased total number of rescue medication and pain visual analog scale score, but incidence of nausea and 24hr nausea VAS score were not increased in neostigmine group compared to control group. Conclusion : These data in patients injected intrathecal neostigmine suggest that analgesia may occur at doses less than neostigmine 50 ㎍ and neostigmine 50㎍ has a better analgesia effect with fewer side effects than other doses for postoperative analgesia.

Fast Acquisition Method for GPS L1/L2C Software Receivers

Keum-Cheol Kwon,Duk-Sun Shim 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

GPS modernization program offers a new civil signal on L2 band, which together with the legacy L1 C/A drives the development of dual frequency receivers for civil applications. The acquisition of L2C takes much time comparing with that of L1 signal. Under the assumption that the GPS signal is strong enough for detection this paper suggests a fast acquisition method for the dual L1/L2C GPS signals for software receivers and compares the performance with that of other methods.

New Material for a Super Resolution Disc

( Keum Cheol Kwak ),( Sun Hee Kim ),( Chang Ho Lee ),( Ki Chang Song ) 정보저장시스템학회 2007 정보저장시스템학회논문집 Vol.3 No.2

Rapid Acquisition of CM and CL Code for GPS L2C Software Receivers

Keum-Cheol Kwon,Duk-Sun Shim 대한전기학회 2011 Journal of Electrical Engineering & Technology Vol.6 No.5

The GPS modernization program offered a new civil signal on the L2 band, and the first modernized GPS Block IIR satellite was launched in September 2005. Currently, eight GPS Block IIRM satellites and two Block IIF satellites transmit L2C signal. The L2C signal contains two codes of CM and CL that are much longer than the L1 C/A code. Thus, the acquisition of the CM and CL codes takes more time compared with that of L1 C/A code. Under the assumption that the L2C signal is strong enough for detection, this paper suggests rapid acquisition methods for the GPS L2C signals for software receivers and compares its performance with that of other methods.

Performance Analysis of Direct GNSS Spoofing Detection with Accelerometers for Constant Velocity

Keum-Cheol Kwon,Duk-Sun Shim 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.8

Global navigation satellite systems (GNSSs) are gaining importance as their main applications in localization and navigation particularly for future autonomous vehicle navigation. A drawback of GNSS for spoofing is the simple structure of the GNSS signal and its weak strength on the Earth’s surface. These conditions can expose civilian users to GNSS spoofing attacks with the potential to cause significant damage. There are many approaches to detecting GNSS spoofing; one category uses independent sensors, such as inertial sensors. Inertial sensors are typically used as tightly coupled GNSS/INS (inertial navigation system) integration to provide consistency checks for position, velocity, or other parameters. However, in this study, a direct consistency check of the acceleration itself is used to detect spoofing and provide the probability density function (PDF) of a proposed decision variable for a constant-velocity case. The proposed decision variable compares the accelerations of the GNSS and accelerometers for the constant-velocity case. The performance of the proposed spoofing detection method is analyzed based on the detection probability of GNSS spoofing.

A comparison of retentive strength of implant cement depending on various methods of removing provisional cement from implant abutment

Keum, Eun-Cheol,Shin, Soo-Yeon The Korean Academy of Prosthodonitics 2013 The Journal of Advanced Prosthodontics Vol.5 No.3

PURPOSE. This study evaluated the effectiveness of various methods for removing provisional cement from implant abutments, and what effect these methods have on the retention of prosthesis during the definitive cementation. MATERIALS AND METHODS. Forty implant fixture analogues and abutments were embedded in resin blocks. Forty cast crowns were fabricated and divided into 4 groups each containing 10 implants. Group A was cemented directly with the definitive cement (Cem-Implant). The remainder were cemented with provisional cement (Temp-Bond NE), and classified according to the method for cleaning the abutments. Group B used a plastic curette and wet gauze, Group C used a rubber cup and pumice, and Group D used an airborne particle abrasion technique. The abutments were observed using a stereomicroscope after removing the provisional cement. The tensile bond strength was measured after the definitive cementation. Statistical analysis was performed using one-way analysis of variance test (${\alpha}$=.05). RESULTS. Group B clearly showed provisional cement remaining, whereas the other groups showed almost no cement. Groups A and B showed a relatively smooth surface. More roughness was observed in Group C, and apparent roughness was noted in Group D. The tensile bond strength tests revealed Group D to have significantly the highest tensile bond strength followed in order by Groups C, A and B. CONCLUSION. A plastic curette and wet gauze alone cannot effectively remove the residual provisional cement on the abutment. The definitive retention increased when the abutments were treated with rubber cup/pumice or airborne particle abraded to remove the provisional cement.

Experimental Study of Spatial and Temporal Dynamics in Double Phase Conjugation

Kwak, Keum-Cheol,Yu, Yong-Hun,Lim, Tong-Kun,Lee, Dae-Eun,Son, Jung-Young Optical Society of Korea 1999 Current Optics and Photonics Vol.3 No.2

Spatial and temporal dynamics arising in a photorefractive crystal(BaTiO3) during the process of double phase conjugation was studied experimentally. We studied the dynamical effects caused by the buildup of the diffraction grating and turn on of phase conjugated beams, as well as the spatial effects caused by the finite transverse coupling of beams and the propagation direction of beams. We observed conical emission in DPCM. We believe that various temporal and spatial instabilities are due to movement of the nonlinear grating. For a real beam coupling and constructive interaction of interference fringes in the crystal, we observed steady, periodic, irregular temporal behavior. And, by the calculation of the correlation index, we found that the spatial correlation decreased as the transverse interaction region was increased.

항법좌표계 수평가속도 측정값에 대한 GPS 기만검출 영역

권금철(Keum-Cheol Kwon),심덕선(Duk-Sun Shim) 대한전기학회 2018 대한전기학회 학술대회 논문집 Vol.2018 No.-

의사위성을 이용한 광역보정정보 전송시스템에 대한 실시간 시험

권금철(Keum-Cheol Kwon),심덕선(Duk-Sun Shim) 대한전자공학회 2015 전자공학회논문지 Vol.52 No.6

본 논문에서는 의사위성을 이용하여 실시간 광역보정정보 시스템 구축 및 전송 실험에 대한 내용을 다루고 있다. 실험을 위하여 의사위성을 제작하고 중앙처리국과 의사위성간 광역보정정보 송수신을 위한 서버/클라이언트 프로그램을 구현하여 데모시스템을 구축하였다. 그리고 소프트웨어 GPS 수신기와 하드웨어 GPS 수신기, 일반 자동차 네비이션을 이용하여 광역 보정정보 시스템 성능을 확인하였다. 그 결과로 중앙처리국과 클라이언트간 보정정보 전송후 의사위성을 이용하여 신호를 방사한 결과 이상없이 보정정보가 전송되는 것과 보정정보를 이용한 결과 사용자 위치 에러가 감소되는 것을 확인할 수 있었다. This paper presents the real-time experiments of WA-DGNSS transmission system using a pseudolite and shows the performance of WA-DGNSS. We implement a server/client program to receive the WA-DGNSS data from the master station, and fabricate a pseudolite to transmit the WA-DGNSS data to users. The performance of the WA-DGNSS transmission system is tested by software and hardware GPS receivers, respectively. The experiments show that the WA-DGNSS data is well transmitted to GPS receivers without errors and thus WA-DGNSS works well.

GPS 소프트웨어 수신기에 대한 GPS 의사위성의 영향 분석

권금철 ( Keum Cheol Kwon ),장윤재 ( Yoon Jae Jang ),양철관 ( Cheol Kwan Yang ),심덕선 ( Duk Sun Shim ) 한국항행학회 2012 韓國航行學會論文誌 Vol.16 No.4

이 논문은 의사위성 신호에 대한 GPS 소프트웨어 수신기의 성능을 분석하고자 한다. 의사위성이 계속 켜져 있을 경우와 펄싱이 주어졌을 경우에 대해서, 의사위성의 신호세기와 의사위성과 수신기 사이의 거리에 따라 의사위성이 GPS 소프트웨어 수신기에 미치는 영향을 알아본다. This paper considers the performance of the non-participating GPS software receivers under the presence of GPS pseudolite(PL). For the continuous PL signal and pulsed PL signal, the impact of PL signals on the GPS software receivers is investigated according to the signal strength of the PL and the distance between the PL and the GPS receiver.