능·수동 듀얼(Dual) 모드 GPS 안테나를 위한 0.13㎛ CMOS 고주파 프론트-엔드(RF Front-end)

정춘식,이승민,김영진,Jung, Cheun-Sik,Lee, Seung-Min,Kim, Young-Jin 한국항행학회 2009 韓國航行學會論文誌 Vol.13 No.1

본 논문은 1P8M CMOS $0.13{\mu}m$ 공정을 이용하여 GPS응용에 적합한 프론트-엔드(front-end)를 구현하였다. 저잡음 증폭기(LNA)는 능동 안테나와 수동 안테나를 지원하기 위해 높은 전압이득과 낮은 잡음지수(Noise Figure)의 LNA1모드와 낮은 이득과 높은 입력 3차 교차점(IIP3: 3rd Input Intercept Point)의 LNA2모드로 동작한다. 두 LNA의 측정된 성능은 1.2 V의 공급전압에서 각각 3.2/2 mA의 전류를 이용하여 16.4/13.8 dB 이득과, 1.4/1.68 dB NF, 그리고 -8/-4.4 dBm의 IIP3값을 갖는다. 쿼드 하향주파수 혼합기(quadrature downconversion 혼합기)는 트랜스임피던스 증폭기(transimpedance amplifier)와 가변저항을 이용하여 27.5 dB에서 41 dB의 변환이득을 갖는다. 프론트-엔드는 LNA1모드 동작 시 6.6 mW의 전력을 소모하여 39.8 dB의 변환이득, 2.2 dB의 잡음지수와 -33.4 dBm의 IIP3의 성능을 갖는다. The CMOS RF front-end for Global Positioning System(GPS)are implemented in 1P8M CMOS $0.13{\mu}m$ process. The LNAs consist of LNA1 with high gain and low NF, and LNA2 with low gain and high IIP3 for supporting operation with active and passive antenna. the measured performances of both LNAs are 16.4/13.8 dB gain, 1.4/1.68 dB NF, and -8/-4.4 dBm IIP3 with 3.2/2 mA form 1.2 V supply, respectively. The quadrature downconversion mixer is followed by transimpedance amplifier with gain controllability from 27.5 to 41 dB. The front-end performances in LNA1 mode are 39.8 dB conversion gain, 2.2 dB NF, and -33.4 dBm IIP3 with 6.6 mW power consumption.

Effect of Butanol Fraction of Panax ginseng Head on Gastric Lesion and Ulcer

정춘식 대한약학회 2002 Archives of Pharmacal Research Vol.25 No.1

인삼노두 추출물의 위염 및 위궤양에 대한 효과

정춘식,정기화,이은방 德成女子大學校 藥學硏究所 1997 藥學論文誌 Vol.8 No.1

In a preliminary screening of plant extracts for the antigastritic and antiulcer actions in rats. the extracts of head of Panax ginseng Radix showed positive activity in HCI·ethanol-induced gastric lesion. Among the systematic fractions of hexane. chloroform. butanol and water. the most potent butanol fraction reduced significantly HCI ethanol-induced gastric lesion at the oral dose of 500 mg/kg. In pylorus ligated rats. hexane and butanol fraction showed decreases in the volume of gastric secretion and acid output. of which effects were stronger in butanol fraction Further assays with butanol fraction disclosed that in significantly suppressed the aspirin-induced and Shay ulcer. The butanol fraction at the intraduodenal colse of 500 mg/kg showed significant stimulation of mucus secretion.

감돈탈장에 대한 전복막외 접근법에 의한 서혜부 탈장교정술

정춘식,이정은,조용걸,유상화,정규영,김승한,이동근 대한내시경복강경외과학회 2010 Journal of Minimally Invasive Surgery Vol.13 No.2

Purpose: Laparoscopic herniorrhaphy (LH) has an advantage for evaluating the viability of incarcerated bowel. In this retrospective study, we aimed to review the data for use of the TEP technique in treating incarcerated hernias in order to document the feasibility of the laparoscopic procedure. Methods: During a 2-year period from January 2008 to December 2009, one surgeon (C.S) at our institution operated on 27 patients with acutely (n=3) or chronically (n=24)incarcerated hernia. Incarcerated hernias were divided into acute or chronic types arbitrarily, based on who had symptoms of acute abdominal pain and signs of intestinal obstruction. For acute cases, the TEP procedure was done following laparoscopic transperitoneal evaluation to assess viability of the incarcerated bowel. Results: All patients except one having a femoral hernia were male. Mean age was 41 years old (range, 25∼75). No case converted from a laparoscopic to an open procedure. Two acute incarcerated cases contained a segment of small bowel and the other contained small bowel and omentum. All acute cases were operated on successfully on an emergency basis by laparoscopic TEP repair. All chronic cases contained omentum without bowel. In one case of acute and seven cases of chronic type, a small inguinal incision was made to reduce hernia contents. No recurrence was noticed at a mean of 13months of follow-up. Conclusion: If there is no entrapment of bowel in chronic incarcerated cases, the TEP procedure will be satisfactory. It may be reasonable, however, to evaluate viability of bowel transperitoneally before doing a TEP procedure in acute cases.

LDPC 부호에 의한 UEP 효과 분석

정춘식,주언경 대한전기학회 2011 정보 및 제어 심포지엄 논문집 Vol.2011 No.4

Steptozotocin 유발 당뇨 흰쥐에서 Tabebuia avellandae의 항당뇨 효과

정춘식,정기화 德成女子大學校 藥學硏究所 1997 藥學論文誌 Vol.8 No.1

Hypoglycemic effect of Tabebuia avellandae was investigated in the streptozotocin(STZ)-induced diabetic rats. Diabetes was induced in male Sprague-Dawley rats by injections of STZ(45 mg/kg, i.v.). Rats weighing 200-250g were divided into 6 groups:normal, STZ-control, hexane fr., CHCI_3 fr., BuOH fr. and H_2O fr. gourp. Normal and STZ-control rats received 3% tween 80 only. Four groups of diabetic rats were administered orally at doses of 100, 400, 300 and 400 mg/kg/day of hexane, CHCI_3, BuOH and H_2O fr. respectively. Fractions were administered orally to the rats for 7 days after STZ injection. All rats were anesthetized with ether, blood samples were taken by cardiac puncture for clinical chemistry and the rats were killed by exsanguination. Liver, kidney, heart and spleen were removed, weighed and analyzed. We measured glucose, protein, cholesterol and triglyceride levels in the plasma and glycogen, cholesterol and triglyceride levels in liver. The extent of blood glucose decrement in rats administered H_2O fraction was greater than that in the STZ-control rats. The serum cholesterol and triglyceride levels were significantly lowered by administration of H_2O fraction compared with those of STZ-control group. Treatment of rats with Tabebuia avellandae fractions caused decreases in STZ-induced elevation of cholesterol and triglyceride. Liver triglyceride level was significantly lowered hexane and BuOH fraction group compared with STZ-control group. These results suggest that H_2O fraction of Tabebuia avellandae has the hypoglycemic action against STZ-induced diabetic rats.

Comparison of Long-term Clinical Outcomes according to the Change in the Rectocele Depth between Transanal and Transvaginal Repairs for a Symptomatic Rectocele

정춘식,Sang Hwa Yu,Jeong Eun Lee,Dong Keun Lee 대한대장항문학회 2012 Annals of Coloproctolgy Vol.28 No.3

Purpose: This study was aimed to compare the results of a transanal repair with those of a transvaginal levatorplasty and to determine the long-term clinical outcomes according to the change in the depth of the rectocele after the procedure. Methods: Of 50 women who underwent a rectocele repair from March 2005 to February 2007, 26 women (group A) received a transanal repair, and 24 (group B) received a transvaginal repair with or without levatorplasty. At 12 months after the procedures, 45 (group A/B, 22/23 women) among the 50 women completed physiologic studies, including anal manometry and defecography, and clinical-outcome measurements. The variations of the clinical outcomes with changes in the depth of the rectocele were also evaluated in 42 women (group A/B, 20/22) at the median follow-up of 50 months. Results: On the defecographic findings, the postoperative depth of the rectocele decreased significantly in both groups (group A vs. B, 1.91 ± 0.20 vs. 2.25 ± 0.46, P = 0.040). At 12 months after surgery, 17 women in each group (group A/B,77/75%) reported improvement of their symptoms. However, only 11 and 13 women (group A/B, 55/59%) of groups A and B, respectively, maintained their improvement at the median follow-up of 50 months. Better results were reported in patients with a greater change in the depth of their rectocele (≥4 cm) after the procedure (P = 0.001)Conclusion: In both procedures, clinical outcomes might become progressively worse as the length of the follow-up is increased. Purpose: This study was aimed to compare the results of a transanal repair with those of a transvaginal levatorplasty and to determine the long-term clinical outcomes according to the change in the depth of the rectocele after the procedure. Methods: Of 50 women who underwent a rectocele repair from March 2005 to February 2007, 26 women (group A) received a transanal repair, and 24 (group B) received a transvaginal repair with or without levatorplasty. At 12 months after the procedures, 45 (group A/B, 22/23 women) among the 50 women completed physiologic studies, including anal manometry and defecography, and clinical-outcome measurements. The variations of the clinical outcomes with changes in the depth of the rectocele were also evaluated in 42 women (group A/B, 20/22) at the median follow-up of 50 months. Results: On the defecographic findings, the postoperative depth of the rectocele decreased significantly in both groups (group A vs. B, 1.91 ± 0.20 vs. 2.25 ± 0.46, P = 0.040). At 12 months after surgery, 17 women in each group (group A/B,77/75%) reported improvement of their symptoms. However, only 11 and 13 women (group A/B, 55/59%) of groups A and B, respectively, maintained their improvement at the median follow-up of 50 months. Better results were reported in patients with a greater change in the depth of their rectocele (≥4 cm) after the procedure (P = 0.001)Conclusion: In both procedures, clinical outcomes might become progressively worse as the length of the follow-up is increased.

흰주 위조직에 대한 노두 추출물 및 분획물의 항지질과산화작용

정춘식 德成女子大學校 藥學硏究所 1996 藥學論文誌 Vol.7 No.1

In a preliminary screening of plant extracts for the antigastric and antiulcer action in rats, the extracts of Panax ginseng Radix showed positive activity in HCl·ethanol-induced gastric lesion. Panax ginseng Radix was extracted with methanol and fractionated systemically with hexane, chloroform and butanol. The chloroform and butanol fraction reduced significantly HCl·ethanol-induced gastric lesion at the dose of 150 and 500㎎/㎏, p.o, respectively. On the gastric secretion in pylorus ligated rats, hexane and butanol fraction decreased the volume of gastric secretion and acid output. It also significantly suppressed the aspirin-induced and Shay's ulcer. The butanol fraction at the i.d. dose of 500㎎/㎏ showed significant inhibition in absolute ethanol induced gastric lesion which was more potent than 150㎎/㎏ of cimetidine and had significant stimulation of mucus secretion. These results might suggest that the butanol fraction of Panax ginseng Radix had inhibitory action in gastric lesion and ulceration through inhibition of gastric acid secretion and stimulation of mucin secretion in the stomach of rats.

두릅나무 根皮抽出物의 藥理學的 硏究

정춘식,김재완 德成女子大學校 藥學硏究所 1991 藥學論文誌 Vol.2 No.1

The plant of Aralia elata (Araliaceae) is described to be used for treatment of diabetes, gastritis, neuralgegia and rheumatoid arthritis in oriental medicinal books. This study is concerned with the effect on the gastritis and ulcer in rats and some general pharmacological action in rats. It was observed that the methanol extract of the rootbark of Aralia elata showed effectiveness in gastritis and pain in rats. From the result obtained that the methanol extract exhibited antigastritic activity. Thus, It was fractionated into hexane, chloroform, ethylacetate and butanol, and further bioassays for the fractions resulted in potent activity in the butanol fraction. The fraction elicited analgesic effect by inhibition of writhing syndrome induced by acetic acid and by increment of pain-threshold in inflamed tail of mice. The fraction showed inhibition of HCl · ethanol and absolute ethanol induced gastritis and inhibition of Shay ulcer in rats. It also exhibited inhibition of gastric secretion in rats. The fraction showed low acute toxicity, i.e., the minimum lethal dose was more than 5000 ㎎/㎏ in oral administration in rats and LD_50 was 740 ㎎/㎏ given subcutaneous by in rats.

두릅나무 根皮抽出物의 藥理學的 硏九

정춘식 덕성여자대학 약학부 1992 약운 Vol.12 No.-