미추마취에서 가온한 국소마취제가 작용발현에 미치는 변화

한상보,정태호,박정환,정수진,이지아 대한마취과학회 1997 Korean Journal of Anesthesiology Vol.33 No.6

Background : One of the main disadvantages of caudal block is the long latent period before a satisfactory blockade is obtained. Many investigators have used various preparations of local anesthetic solutions to improve the speed of onset. This study was performed to evaluate the effectiveness of prewarming of lidocaine HCl for caudal block. Methods : Fifty healthy young patients(ASA I) were allocated into two groups, A and B. In group A, the local anesthetic solution were injected at room temperature(25oC), while in group B, they were injected at 37oC. All the caudal block were performed using 2% lidocaine HCl 20 ml with fentanyl 100ug and epinephrine 1:200,000. The onset time was defined as the period from completion of injection until the patient first noticed loss of sensation to pin-prick on perianal region. Assessment of sensory loss was made at 15 seconds interval. We have compared the onset of sensory blockade between groups. The duration of analgesia and any significant side effects were also recorded. Results : The onset of sensory blockade was significantly faster in group B(3.5±0.5 minutes) than group A(6.2±0.9 minutes). The duration of analgesia were not significantly changed between groups. Side effects of urinary retention, pruritus and nausea were noted between both groups but the difference was not significant. Conclusions : We have found that the onset time was 44% faster with warm lidocaine-fentanyl mixture(37oC) than with the room temperature(25oC). The improved clinical usefulness was achieved with no increase in side effects. The technique is a safe and effective method to reduce the latency of onset. (Korean J Anesthesiol 1997; 33: 1098∼1102)

PPF 제어기법을 이용한 다중 모드 강제 진동의 능동 진동 제어

한상보,곽문규,윤신일 한국소음진동공학회 1997 소음 진동 Vol.7 No.6

This paper presents active vibration control scheme of multi-mode forced vibration using piezocetamic sensors and actuators. The control scheme adopted is the Positive Position Feedback (PPF) control. Among various vibration control techniques. PPF control technique makes use of generalized displacement measurements to accomplish the vibration suppression. Two independent controllers are implemented to control the first and the second modes of the beam under external excitation. Experimental results for various damping ratios and feedback gains of the PPF controllers are compared with respect to the contorl efficiency. The results indicate that steady state vibration under wide band excitation can be controlled effectively when multiple sets of PZT sensors and actuators were used with PPF control technique.

충격 해머의 感度補正

한상보 한국소음진동공학회 1991 소음 진동 Vol.1 No.2

The impact hammer is extensively used in experimental modal analysis as a means to provide force over a broad range of frequencies. The hammer mass and the impact head are often changed to achieve a desired impact time duration with its corresponding input frequency spectrum, these mass changes affect the performance and sensitivity of the force transducer employed to measure the impact force. Both a mathematical model describing the effects of impact head and hammer mass on the performance of the force transducer and experimental verification of this model are presented here.

복합재료내의 계면 접착 특성에 따른 지능형 구조물의 진동제어에 관한 연구

한상보,박종만,차진훈 한국소음진동공학회 1998 소음 진동 Vol.8 No.6

The success of controllability of smart structures depends on the quality of the bonding along the interface between the main structure and the attached sensing and acuating elements. Generally, the analysis procedures neglect the effect of the interfacial bond layer or assume that this bond layer behaves like viscoelastic material. Three different bond layers. two modified epoxy adhesives, and one isocyanate adhesive were prepared for their toughness and moduli. Bond layer of the chosen adhesive provides an almost perfect bonding condition between the composite structure and the PZT while bended significantly like arrow-shape. The perfect bonding condition is tested by considering various material properties of the bond layers. and based on this perfect bonding condition, the effects of the interfacial bond layer on the dynamic behavior and controllability of the test structure is experimentally studied. Once the perfect bonding condition is achieved. dynamic effects of the bond layer itself on the dynamic characteristics of the main structure is negligible. but the contribution of the attached PZT elements on the stiffness of the multi-layered structure becomes significant when the thickness of the bond layer increased.

구조물-가진기 상호작용에 의한 공진주파수 변동에 대한 해석

한상보,Han, Sang-Bo 대한기계학회 1996 大韓機械學會論文集A Vol.20 No.7

The purpose of this paper is to investigate the influence of the exciter attached for the measurement of natural frequencies when extracting the frequency response functions of the test structure in experimental modal analysis. The procedure is first to model the attached exciter as an additional degree of freedom system and next to verify the suggested model by experimentally extracting the natural frequencies of the test structure with various values of exciter mass, stinger stiffness and attachment position of the exciter on the test structure. It is concluded that as additional degree of freedom system which includes the natural frequency of the exciter itself and axial stiffness of stinger should be considered to quantatively define the coupling effects of structure-exciter interaction on the measured natural frequencies. It is not the mass of the exciter itself but the coupling effect of the additional degree of freedom mass-spring system consisting of exciter body and armature coil that characterizes the natural frequency deviation. Therefore, when the natural frequency of this additional mass-spring system is outside of the test frequency range, the coupling effect of structure-exciter interaction can be minimized.

지표면의 반사특성을 고려한 환경소음 예측

한상보 한국소음진동공학회 2001 소음 진동 Vol.11 No.2

The analytical model of the ground wave can be used for the prediction of the noise level from a source above a plain and homogeneous ground surface with no obstacles nearby. Sound propagation along the surface of the ground can be affected by the roughness of the ground surface and the direction of the wind. The effects of the ground surface and the wind can be formulated in terms of the ground coefficient and the noise source parameter. Upward and downward conditions can also be addressed by considering the direction of the wind. The ground coefficient and the noise source parameter are estimated using the measured noise levels of two points under particular environmental condition, and the noise levels of arbitrary points under the same environmental condition can be estimated. The proposed method can be utilized to estimate the noise level of specific noise environment and its validity was confirmed with the results of actual field measurement.

복합 적층 강판의 감쇠 특성에 대한 연구

한상보 경남대학교 신소재연구소 1996 論文集 Vol.7 No.-

구조용 강판의 제진 능력을 향상시키기 위하여 인성이 증가된 에폭시 수지, 도포형 아크릴 공중합체 에멀젼, 그리고 판형의 이소탁틱폴리프로필렌 등을 사용하여 강판과 고분자수지 적층판을 제작하고 각판의 표면 전단강도 시험과 진동실험을 통하여 감쇠의 상대적인 크기를 비교하였다. 세 수지들 중에서 에폭시 수지를 사용한 경우가 표면 전단강도의 값이 가장 큰 것으로 나타났으며, 이는 에폭시 수지 자체의 뛰어난 접착성과 적절한 인성의 조절에 기인되어 바람직한 제진 특성을 줄 수 있을 것으로 생각된다. 아미노-실란 결합제로 처리하고 에폭시 수지를 사용한 제진 강판의 경우에서 표면 전단강도의 값이 건조한 경우와 젖은 경우 미처리 보다 모두 크게 나타났다. 감쇠계수의 측정 결과 아크릴 공중합체 에밀죤을 사용한 시편이 현대 상용화되고 있는 일본 제품 보다 뛰어난 제진 및 방음 성능을 가지고 있음을 확인하였다. 또한, 에폭시/철 분말 제품은 이종 재료들 간의 접착 문제만 해결하면 넓은 주파수 영역에 걸쳐서 우수한 제진 및 방음 성능을 발휘할 것이라는 사실을 알 수 있었다. Steel/polymer laminates using three different types of polymer. i.e., modified epoxy, acryl copolymer emulsion, and isotactic polypropylene(1PP) were prepared, and their lap shear strength and relative dampimg coefficients were compared. Among them, the toughened epoxy showed the highest lap shear strength value. This is due to the excellent adhesive ability of epoxy resin itself and the appropriate control of toughness. This also provides desirable damping properties of the steel plates. In epoxy based steel laminates treated with amino silane coupling agent. lap shear strength appeared higher than the untreated one under both dry and wet conditions. Since the interface between steel surface and epoxy resin is relatively tough, this can cantribute to improve the interfacial bonding by mechanical interlocking. With respect to the damping factors, the acryl copolymer emulsion showed better damping capability than commercially available Japanese steel plates. In addition, it was found that the laminates with iron powder can be used for improving structural and acoustic damping properties for wide band of frequency range if the bonding problem between different materials was solved.

“인공지능 기술과 AI기반 스마트 팩토리 연구개발 동향” 특집을 내면서

한상보 한국조명·전기설비학회 2020 조명.전기설비 Vol.34 No.4

진동응답 계측결과를 이용한 기진력의 추정

한상보 대한기계학회 1995 대한기계학회논문집 Vol.19 No.1

It is attempted to estimate excitation force of a linear vibratory system using measured vibration responses. The excitation force is estimated from the relationship between the vibration response and system characteristic matrices which are extracted from both the mathematical model of the system and actual response in contrast to the usual approach of inverting the frequency response matrices. This extraction scheme is based on the fact that the vibration response can be expressed in term of linear combination of frequency domain modal vectors defined as mutually orthonormal basis vectors in frequency domain. The extracted frequency domain basis vectors are very stable in computational manipulation. It is found that the estimated excitation force is in good agreement with actually measured force except at the natural frequencies the structure, which is the common feature still to be overcome by the research efforts in this area. From the results of this paper, this disagreement is considered to come from the discrepancy between the model and actual value of the mass, damping and stiffness of the structure.

Effect of Oxygen for Diamond Film Synthesis with C-Hexane in Microwave Plasma Enhanced CVD Process

한상보 대한전기학회 2012 Journal of Electrical Engineering & Technology Vol.7 No.6

The purpose of this paper is to decide the optimum synthesis conditions of polycrystalline diamond films according to the ratio of gas mixture. Diamond films were deposited with cyclo-hexane as a carbon precursor by the microwave plasma enhanced chemical vapor deposition process. The optimum oxygen ratio to cyclo-hexane was reached about 125 % under the fixed 0.3% c-hexane in hydrogen. Oxygen plays a role in etching the graphitic components of carbon sp2 bond effectively. By OES measurement, the best synthesis conditions found out about 12.5 % and 15.75 %, which is the emission intensity ratios of CH(B-X) and Hβ on Hα, respectively. Also, the electron temperature was similar about 5,000 to 5,200 K in this work.