Air-coupled 트랜스듀서를 이용한 배관에서의 유도초음파 모드 규명

김현묵,박익근,김용권,장경영,조용상,조윤호 한국비파괴검사학회 2004 학술대회 논문집 Vol.- No.-

발전설비의 중요한 요소인 배관의 효율적인 비파괴검사를 위해, comb 트랜스듀서를 이용하여 유도초음파를 발생하고 ACT(air-coupled transducer)를 적용하여 비접촉으로 수신하였다. comb 트랜스듀서의 요소간격과 이론적인 분산선도로부터 발생가능 한 모드가 예측되었다. 또한 예측된 모드를 수신하기 위해 각 모드의 이론적인 음속을 이용하여 ACT의 수신 각도를 결정하였다. 수신모드의 특성을 규명하기 위해 웨이블릿 변환과 2D-FFT를 이용한 시간-주파수해석을 수행하여 이론적인 분산선도와 비교하였다. 수신된 모드는 이론적으로 예측된 모드와 일치하는 것으로 나타났다.

위암환자의 복강내에 투여한 Mitomycin C-Carbon Particle의 Mitomycin 용출에 관한 연구

노승무,조영훈,정경수,오정연,김진향,양준묵,강대영,송규상,조준식,최선웅,이진호,민병무,김용백,김창식,박근성,인현빈,정현용,김학용 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Locoregional recurrence is the most common type of recurrence in surgical operation of gastric adenocarcinoma, and peritoneal dissemination is one of the most difficult problems in advanced gastric adenocarcinoma treatment. Because the peritoneal cavity is the most common site of the first recurrence after gastric cancer resection, intraperitoneal chemotherpy seems a logical choice for cancer chemotherapy. The Mitomycin C(MMC) adsorbed by the activated charcoal particles(CH) is relatively released when the drug concentration surrounding the carbon particles becomes low in the peritoneum of the peritoneal cavity. For the intraperitoneal chemotherapy on the advanced gastric adenocarcnoma, mitomycin C adsorbed on activated carbon particles was administered in the peritoneal cavity just before abdominal wall closure. The closed drainage tubes were inserted in the peritoneal cavity and clamped for tuo hours after completion of operation. MMC concentrations were serially measured in peritoneal fluid, plasma and urine at 2hour, 48 hour, 72 hour and 168 hour following its administration in order to study the efficacy of the MMC-CH as a drug delivery system. There were minimal toxicities in born marrow, liver, and gastrointestinal system after intraperitoneal MMC-CH administration. The data of this study suggested that MMC-CH may have a somewhat more beneficial effect than surgery alone when administered in optimal dose and schedules, but the MMC concentration of the peritoneal fluid was not sufficient to eradicate remnant cancer cells, and effective duration of maintenance was only below 24 hours in the peritoneal fluid and plasma.

근거리 무선통신용 블루투스 베이스밴드 시스템 설계 및 구현

백은창,조현묵 국립7개대학공동논문집간행위원회 2001 공업기술연구 Vol.1 No.-

In this paper, it is designed and verified the baseband system that performs various protocol functions of specification of the Bluetooth system. In order to verify the developed circuits, various baseband functions are tested by using the ModelSim simulator. The developed circuits operate at 4㎒ main clock. Test suite includes hop selection function, generation of the sync word, error correction(l/3 rate FEC, 2/3 rate FEC), HEC generation/checking, CRC generation/checking, data whitening/dewhitening and packet trans/reception procedure, etc. As a result of the simulation, it is verified that the developed baseband system conform to the specification of the Bluetooth system. Also, the developed function blocks synthesized by using the Synopsys tool. The synthesized top level circuit has 136 cells and 3,362 μ㎡ cell area. Design of Encryption and CVSD function block and implementation of FPGA chip deserve future study for better Bluetooth baseband system.

Self-biased Super MOS 복합회로를 응용한 공정검출회로

徐範洙,趙鉉默 국립7개대학공동논문집간행위원회 2005 공업기술연구 Vol.5 No.-

A new process detection circuit is proposed. The proposed process detection circuit compares a long channel MOS TR (L > 0.4um) to a short channel MOS TR which uses lowest feature size of the process. The circuit generates the differential current proportional to the deviation of carrier mobilities according to the process variation. This method keep the two TR's drain voltage same by implementing the feedback using a high gain OPAMP. This paper also shows the new design of the simple high gain self-biased rail-to-rail OPAMP using a proposed self-biased super MOS composite circuit. The gain of designed OPAMP is measured over 100dB with 0.2~1.6V wide range CMR in single stage. Finally, the proposed process detection circuit is applied to a differential VCO. The VCO showed that the proposed process detection circuit compensates the process corners successfully and ensures the wide rage operation.

만성 승모판 패쇄부전증 환자에서의 안지오텐신 전환효소 억제제의 장기 투여 효과

김대희,이명묵,이해영,조현재,박승정,서재빈,서정원,양한모,윤창환,조상호,이준희,김용진,김명아,손대원,오병희,박영배 대한순환기학회 2004 Korean Circulation Journal Vol.34 No.2

Air-coupled 트랜스듀서를 이용한 발전설비 배관에서의 유도초음파 모드 규명

박익근,김현묵,김용권,송원준,조용상,장경영,조윤호 한국비파괴검사학회 2004 한국비파괴검사학회지 Vol.24 No.4

발전설비의 중요한 요소인 배관의 효율적인 비파괴검사를 위해, 배관내에 유도초음파를 comb 트랜스듀서를 이용하여 발생시켰으며, 유도초음파를 비접촉 방식으로 수신하기 위해 ACT(air-coupled transducer)를 적용하였다. comb 트랜스듀서의 요소간격과 이론적인 분산선도로부터 발생가능 한 유도초음파 모드가 예측되었다. 또한 예측된 모드를 수신하기 위해 각 모드의 이론적인 위상속도를 이용하여 ACT의 수신 각도를 결정하였다. 수신모드의 특성을 규명하기 위해 웨이블릿 변환과 2D-FFT를 이용한 시간-주파수해석을 수행하여 이론적인 분산선도와 비교한 결과, 수신된 모드는 이론적으로 예측된 모드와 일치하는 것으로 나타났다. In order to inspect the piping effectively, one of the important components in the facility of power plants, the ultrasonic guided wave was generated by a comb transducer and was received in a non-contact fashion by using an air-coupled transducer. The guided wave modes that can be generated by the comb transducer in piping are predicted from the theoretical dispersion curves and the element spacing of a comb transducer. Moreover, to receive the specific modes, the receiving angle of the air-coupled transducer is calculated from Snell's law between the phase velocities of guided waves and the sound velocity of air. The guided wave modes obtained in experiments are identified from the result of time-frequency analysis such as wavelet transform and two-dimensional fast Fourier transform.

Rat의 복강에 삽입한 Filorouracil-Polyglycolic acid제형의 Fluorouracil용출에 관한 연구

노승무,정경수,오정연,김진향,양준묵,강대영,송규상,최정목,최선웅,이진호,조준식,민병무,김용백,김창식,박근성,김승영,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

A common form of relapse in adenocarcinoma of the stomach is intraperitioneal dissemination, in fact, among gastric adenocarcinoma patients who have undergone surgery intended to cure, approximately 50% of the patients develope initial recurrence in the peritoneal cavity regardless of the anatomic site of the primary tumor within the stomach. The efficacy of systemic postoperative chemotherapy to prevent peritoneal recurrence of gastrric adenocarcinoma is not satisfactory. There is still a great need for improved therapeutic strategies on the disseminated microscopic disease and small miliary nodules remaining on the peritoneal surface or lymphatics after operation. The authers have made fluorouracil-polyglycolic acid composite disks(Fu-PGA disks) with fluorouracil and biodegradable polymer: polyglycolic acid for more effective intraperitoneal chemotherapy. We inserted the Fu-PGA disk(s) in the peritoneal cavity of rat and pharmacokinetic study was performed to measure fluorouracil concentration in the peritoneal fluid, plasma, liver, kidney and heart tissue at 24 hour, 72 hour and 168 hour after insertion of Fu-PGA disk(s). Myelosuppressive action of this composite also was determined following its administration. The data of this study suggested that Fu-PGA composite will be a new device releasing drugs in a controlled manner and having targetability to peritoneum, and this device will be improving the efficacy of intraperitoneal chemotherapy for gastric adenocarcinoma.

생체분해성 고분자를 이용한 사시수술용 제형개발 및 효용성에 대한 연구

민병무,김용백,김승영,김창식,박근성,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

A new device, muscle clamping system was developed to facilitate exact quatifying technique A strabismus surgery, and reduce the risk of complications. The device is composed of a lower fixing body with three jaws and an upper supporting body. They are used to clip an extraocular muscle and fix it to the sclera with a single bite. Superior rectus recession on 16 rabbit eyes were performed with this new device. Conjunctival injection, muscle adhesion strength, and light microscopic findings were examined at 1, 2, 4 and 8 weeks postoperatively. The Conjunctival injection were minimal, adhesion power ranged from 420 to 600 gram gravity, which is sufficient in withstand the normal pull of human extraocular muscle. In microscopic exam, some Inflammatory cells and fibrosis were found. The new device was technically easy, fast, and accurate, so it may be useful in stabismus surgery.

Rat의 복강에 삽입한 Fluorouracil-Polyglycolic acid 제형의 Fluorouracil 용출에 관한 연구

노승무,정경수,오정연,김진향,양준묵,강대영,송규상,최정목,최선웅,이진호,조준식,민병무,김용백,김창식,박근성,김승영,김학용,인현빈 忠南大學校 癌共同硏究所 1998 癌共同硏究所 硏究誌 Vol.2 No.1

A common form of relapse in adenocarcinoma of the stomach is intraperitoneal dissemination, in fact, among gastric adenocarcinoma patients who have undergone surgery intended to cure, approximately 50% of the patients develope initial recurrence in the peritoneal cavity regardless of the anatomic site of the primary tumor within the stomach. The efficacy of systemic postoperative chemotherapy to prevent peritoneal recurrence of gastrric adcnocarcinoma is not satisfactory. There is still a great need for improved therapeutic strategies on the disseminated microscopic disease and small miliary nodules remaining on the peritoneal surface or lymphatics after operation. The authers have made fluorouracil-polyglycolic acid composite disks(Fu-PGA disks) with fluorouracil and biodegradable polymer: polyglycolic acid for more effective intraperitoneal chemotherapy. We inserted the Fu-PGA disk(s) in the peritoneal cavity of rat and pharmacokinetic study was performed to measure fluorouracil concentration in the peritoneal fluid, plasma, liver, kidney and heart tissue at 24 hour, 72 hour and 168 hour after insertion of Fu-PGA disk(s). Myelosuppressive action of this composite also was determined following its administration. The data of this study suggested that Fu-PGA composite will be a new device releasing drugs in a controlled manner and having targetability to peritoneum, and this device will be improving the efficacy of intraperitoneal chemotherapy for gastric adenocarcinoma.

생체분해성 망막압정을 이용한 망막고정에 대한 실험적 연구

김용백,민병무,김창식,박근성,김승영,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

Biodegradable retinal fixation devices obtain mechnical fixation of the retina with desirable chorioretinal scarring and with the potential for local, sustained release of antimetabolites and steroids to inhibit proliferative vitreoretinopathy. We manufactured a biodegradable retinal tack with barb that was designed in order to prevent intrusion from implantation of retinal tacks. This study was carried to evaluate the efficacy for retinal fixation and the capability for sustained release of drugs with a newly designed biodegradable retinal tack Biodegradable retinal tacks were made of polymers of glycolic acids and were designed with barbs in a shape to prevent the disinsertion. Biodegradale retinal tacks are divided into 3 parts, a conical portion that is inserted into the sclera, a cylinder portion that remains in the vitreous, and a neck portion between the pin and the cylinder. The tapered conical end was manufactured to allow easy insertion through the retina and choroid into the sclera. A cylinder portion was manufactured with a tapered angle that fixes firmly into the orifice of 19 gauge spinal needle. A neck portion, 0.4 mm in diameter, was designed to prevent disinsertion from following implantation of retinal tack. The applicator was a 19 gauge spinal needle and its orifice was prepared to 15°angle to accept the tapered cylinder portion of the retinal tack. The retinal tacks, secured in the needles, were passed through the formed vitreous and inserted into the retina, choroid, and sclera and were released by pushing the internal needle, usually within 2-3mm of the medullary ray of the posterior rabbit retina A retinal tack was placed in each of 8 pigmented rabbit eyes. Slit-lamp biomicroscopy, indirect ophthalmoscopy and fundus photography were performed periodically from 1 day to 8 weeks after surgery. Eight eyes were enucleated and studied by light microscopy at 8 weeks. Biomicroscopic evaluation of the animals revealed edemas adjacent to the retinal surfaces immediately after insertion of the biodegradable retinal tacks in all the animals. These edemas disappeared after 1 week. The first noticeable change in the size of retinal tacks was shown after 2weeks. The size of the retinal tacks gradually got smaller, decreasing to about one-half at 4 weeks and about one-third at 8 weeks. All retinal tacks remained in inserted places without any movement for an 8 week period. On light microscopy, epiretinal proliferations were seen to extend into the vitreous cavity. Cellular capsules that lined the inner aspect of the scleral defect caused by tack insertion were found. However the adjacent retina had a normal cytologic appearance and architecture in all specimens. We manufactured a biodegradable retinal tack that is designed to prevent intrusion from implantation of retinal tacks. All biodegradable retinal tacks reduce in size with time, but no retinal tacks extruded from the inserted place. The newly designed biodegradable retinal tack can be used for retinal fixation and may be used as a vehicle for the introduction of pharmacologic agents to prevent the cellular events that promote proliferative vitreoretinopathy.