2005년도 소아 서혜부 탈장치료 경향

김성민,김대연,김상윤,김성철,김우기,김재억,김재천,박귀원,서정민,송영택,오정탁,이남혁,이두선,전용순,정상영,정을삼,최금자,최순옥,한석주,허영수,홍정,최승훈,Kim, Seong-Min,Kim, Dae-Yeon,Kim, Sang-Yoon,Kim, Seong-Chul,Kim, Woo-Ki,Kim, Jae-Eok,Kim, Jae-Chun,Park, Kwi-Won 대한소아외과학회 2006 소아외과 Vol.12 No.2

Inguinal hernia is the most common disease treated by the pediatric surgeon. There are several controversial aspects of management 1)the optimal timing of surgical repair, especially for preterm babies, 2)contralateral groin exploration during repair of a clinically unilateral hernia, 3)use of laparoscope in contralateral groin exploration, 4)timing of surgical repair of cord hydrocele, 5)perioperative pain control, 6)perioperative management of anemia. In this survey, we attempted to determine the approach of members of KAPS to these aspects of hernia treatment. A questionnaire by e-mail or FAX was sent to all members. The content of the questionnaire were adapted from the "American Academy of Pediatrics (AAP) Section on Surgery hernia survey revisited (J Pediatr Surg 40, 1009-1014, 2005)". For full-term male baby, most surgeons (85.7 %) perform an elective operation as soon as diagnosis was made. For reducible hernia found in ex-preterm infants already discharged from the neonatal intensive care unit (NICU), 76.2 % of surgeons performed an elective repair under general anesthesia (85.8 %). 42.9 % of the surgeons performed the repair just before discharge. For same-day surgery for the ex-premature baby, the opinion was evenly divided. For an inguinal hernia with a contralateral undescended testis in a preterm baby, 61.9 % of surgeons choose to 'wait and see' until 12 month of age. The most important consideration in deciding the timing of surgery of inguinal hernia in preterm baby was the existence of bronchopulmonary dysplasia (82.4 %), episode of apnea/bradycardia on home monitoring (70.6 %). Most surgeons do not explore the contralateral groin during unilateral hernia repair. Laparoscope has not been tried. Most surgeons do not give perioperative analgesics or blood transfusion.

매개변수 보정 전문가시스템을 이용한 HSPF 모형의 수문 매개변수 보정 및 적용성 평가

김성민,김상민,Kim, Sung Min,Kim, Sang Min 한국농공학회 2013 한국농공학회논문집 Vol.55 No.4

The purpose of this study was to evaluate the applicability of the HSPEXP expert system for the calibration of the Hydrological Simulation Program - Fortran (HSPF) for the study watershed. HSPEXP offers advice to the modeler, suggesting parameter changes that might result in better representation of a river basin and provides explanations supporting the recommended parameter changes. The study watershed, Sancheong, is located within the Nakdong River Basin and having the size of $1,072.4km^2$. Input data for the HSPF model were obtained from the landuse map, digital elevation map, meteorological data and others. Water flow data from 2006 to 2008 were used for calibration and from 2009 to 2010 were for validation. Using the HSPEXP expert system, hydrological parameters were adjusted based on total volume, then low flows, storm flows, and finally seasonal flows. For the calibration and validation period, all the HSPEXP model performance criteria were satisfied.

상장간막동맥 증후군의 복강경 수술 및 3차원재건 복부 전산화단층촬영 영상을 이용한 추적관찰 -1예보고-

김성민,김성훈,권인규,김명준,형우진,최승훈,Kim, Seong-Min,Kim, Sung-Hoon,Kwon, In-Kyou,Kim, Myoung-Joon,Hyoung, Woo-Jin,Choi, Seung-Hoon 대한소아외과학회 2005 소아외과 Vol.11 No.2

Superior mesenteric artery (SMA) syndrome is a rare disorder caused by extrinsic compression of the third portion of the duodenum by the SMA. The operative treatment of choice is bypassing the obstructed duodenal segment by duodenojejunostomy. We report one case of SMA syndrome treated by laparoscopic duodenojejunostomy and followed up by 3D-reconstructive CT scan. A fifteen-year-old boy with intermittent vomiting and weight loss was admitted. Ultrasonography showed narrowing of the distance between the SMA and aorta. Hypotonic duodenography showed dilatation of duodenal third portion and barium stasis. On 3Dreconstructive CT scan, the angle between SMA and aorta was $37^{\circ}$. The postoperative course was uneventful. Three months later, he had gained 3 kg of weight and the angle between SMA and aorta increased to $38-39^{\circ}$ on 3D reconstructive CT scan. Laparoscopic duodenojejunostomy for bypassing the obstructive duodenum in SMA syndrome is a feasible and safe method.

남강댐유역 내 주요 하천관측지점의 홍수유출량 추정을 위한 단위도 모형 비교연구

김성민,김성재,김상민,Kim, Sung-Min,Kim, Sung-Jae,Kim, Sang-Min 한국농공학회 2012 한국농공학회논문집 Vol.54 No.3

In this study, three different unit hydrograph methods (NRCS, Snyder and Clark) in the HEC-HMS were compared to find better fit with the observed data in the Namgang-Dam watershed. The Sancheong, Shinan, and Changchon in Namgang-Dam watershed were selected as the study watersheds. The input data for HEC-HMS were calculated land use, digital elevation map, stream, and watershed map provided by WAter Management Information System (WAMIS). Sixty six storms from 2004 to 2011 were selected for model calibration and validation. Three unit hydrograph methods were compared with the observed data in terms of simulated runoff volume, and peak runoff for the selected storms. The results showed that the coefficient of determination ($R^2$) for the peak runoff was 0.8295~0.9999 and root mean square error (RMSE) was 0.029~0.086 mm/day for calibration stages. In the model validation, $R^2$ for the peak runoff was 0.9061~0.9916 and RMSE was 0.030~0.088 mm/day which were more accurate than calibrated data. Analysis of variance showed that there was no significant difference among the three unit hydrograph methods.

크라온에테르를 이용한 탈륨(I) 이온 선택성 전극

김성민,정성욱,김진은,김재상,Sung Min Kim,Sung Uk Jung,Jineun Kim,Jae Sang Kim 대한화학회 1993 대한화학회지 Vol.37 No.8

Tl$^+$이온 센서로서 크라운 에테르 B15C5와 DB18C6를 중성운반체로 한 PVC 액체막 이온 선택성 전극을 제작하였다. 막용매로는 DOA, NPPE 및 NPOE를 사용하였으며 친유성 염, KTClPB의 농도를 변화시킨 여러가지 조성의 막을 시험하였다. B15C5와 DB18C6 막 전극의 감응전위는 농도범위, 10$^{-1}$∼10$^{-5}$M에서 직선으로 나타났으며 최대 기울기는 전극에 따라서 40∼55 mV/decade였다. 선택계수는 분리용액법으로 결정하였으며 알카리금속 이온, 알칼리토금속 이온 및 일부 전이금속 이온에 대하여 좋은 선택성을 나타냈다. 제작된 액체막 전극은 Ph > 3 에서 안정한 감응전위를 보였다. Poly(vinyl chloride)(PVC) membrane electrodes based on the lipophilic neutral carrier, dibenzo-18-crown-6(DB18C6) and benzo-15-crown-5 (B15C5) as the active sensors for Tl$^+$ ion have been prepared and tested in different content of the potassium tetrakis(4-chlorophenyl)borate (KTClPB) as lipophilic salt. Dioctyl adipate (DOA), 2-nitrophenyl phenyl ether (NPPE) and o-nitrophenyl actyl ether (NPOE) were used as plasticizing solvent mediators. Electrodes exhibited good linear responses of 40∼55 mV decade$^{-1}$ for Tl$^+$ ion within the concentration ranges 10$^{-1}$∼10$^{-5}$M TlNO$_3$. Selectivity coefficients of interfering ions (alkali metal, alkaline earth metal and some transition metal ions) for Tl$^+$-ISE were determined by separate solution method and were sufficiently small for most of them. These crown ether type ion-selective electrodes are suitable for use with aqueous solution at pH > 3.

모래분사법과 불투명 도재의 도포방법이 도재용착주조관의 전단결합강도에 미치는 영향

김성민,최성민,정인성,Kim, Sung-Min,Choi, Sung-Min,Chung, In-Sung 대한치과기공학회 2011 대한치과기공학회지 Vol.33 No.4

Purpose: This study was investigated the bonding strength of two kinds of Ni-Cr alloy with respect to the condition of surface treatment. Methods: The surface treatment was performed on the two kinds of Ni-Cr alloy (B alloy and R alloy) specimens, which were sandblasted with $50{\mu}m$, $110{\mu}m$, and $250{\mu}m$ aluminium oxide and were treated with opaque application (paste and wash opaque). The roughness on the surfaces of the specimens was observed. The metal-ceramic interfaces were analyzed with EPMA in order to ionic diffusion, and the shear test was performed. Results: The BA250 specimen, which has higher surface roughness, showed the highest bonding strength in B specimens. In R specimens, the bonding strength of RA110 specimen was the highest. Conclusion: B specimen formed a mechanical bond between metal-ceramic interfaces; however, in the case of R specimen, a chemical bond was formed between that interfaces. There was no significant statistical difference between the bonding strengths of two types of specimens (p>0.05).

S-DMB와 2.4/5 GHz WLAN 신호 수신을 위한 이중 광대역 다이폴형 안테나의 설계 및 구현

김성민,양운근,Kim, Sung-Min,Yang, Woon-Geun 한국전자파학회 2006 한국전자파학회논문지 Vol.17 No.11

본 논문에서는 S-DMB(Satellite Digital Multimedia Broadcasting)와 2.4/5 GHz WLAN(Wireless Local Area Network) 신호 수신을 위한 이중 광대역 다이폴형 안테나를 설계 및 구현하였다. 제안된 안테나는 기존 모노폴형 이중 대역 안테나를 기본으로 하여 평면형 광대역 다이폴 형태로서 $8{\times}33.8{\times}1.68mm^3$ 크기로 구현되었다. 안테나는 1.6 mm 두께의 FR4 기판위에 인쇄되어 있는 형태로 중심부에 낮은 주파수 대역에서 동작하는 다이폴 형태의 안테나와 높은 주파수에서 공진 특성을 가지는 두 개의 대칭 구조로 구성된 공진 소자로 되어 있다. 또한 전산 모의 실험으로 각 주파수 대역에서 안테나의 표면에 전류가 밀집되는 곳을 확인하였다. 전류가 밀집된 부분의 길이를 조정함으로서 각 주파수 대역에서 독립적으로 공진 주파수를 변화시킬 수 있었다. 그리고 입력 임피 던스 대역폭$(VSWR\leq2)$이 2 GHz 대역에서 362 MHz(14.23 %), 5 GHz 대 역 에서 1188 MHz(22.13 %)로 광대역 특성을 나타내었다. 측정된 안테나의 최대 이득은 2 GHz 대역에서 4.33 dBi이고 5 GHz 대역에서 5.48 dBi로서 이득 면에서 개선되었다. 제작된 안테나는 전 방향성의 양호한 방사 패턴 특성을 갖는다. In this paper, we designed and implemented a dual wideband dipole type antenna for the reception of S-DMB (Satellite Digital Multimedia Broadcasting) and 2.4/5 GHz WLAN(Wireless Local Area Network) signals. The proposed antenna based on conventional monopole type dual band antenna was implemented as planar wideband dipole type antenna with the volume of $8{\times}33.8{\times}1.68mm^3$. The proposed antenna is printed type on FR4 substrate of 1.6 mm thick and composed of a dipole type antenna for low frequency band and two symmetric structured resonance elements for high frequency band. We confirmed antenna area with dense surface current for each frequency band with simulation. By varying the length of the antenna area with dense surface current, we could vary resonance frequency of each frequency band separately. Impedance bandwidths$(VSWR{\leq}2)$ are 362 MHz(14.23 %) for 2 GHz band and 1188 MHz(22.13, %) for 5 GHz band which show wideband characteristic. Measured maximum gains were 4.33 dBi for 2 GHz band and 5.48 dBi for 5 GHz band which showed improved performance. And the implemented antenna has a good omni-directional radiation pattern characteristic.

평판 가까이에 놓인 타원형 실린더 주위 유동에 관한 연구

김성민,이상준,Kim, Seong-Min,Lee, Sang-Jun 대한기계학회 1996 大韓機械學會論文集B Vol.20 No.8

Flow characteristics and aerodynamic forces acting on an elliptic cylinder placed in a plane boundary layer were investigated experimentally. Four cylinder models with axis ratio(major axis to minor axis, AR=A/B) of 1, 2, 3, and 4 having the same equivalent diameter were used in this experiment. The Reynolds number based on the equivalent diameter $D_e$(=20mm) was 13,000. In the case of circular cylinder, regular vortex shedding occurs for the cylinder gaps larger than G/B=0.3 and is not almost related to the boundary layer thickness. But, for the elliptic cylinders, the vortex shedding frequency is increased with increasing the gap ratio (G/B) and the axis ratio (AR) of elliptic cylinders. The maximum drag coefficient acting on a circular cylinder is mainly affected by the boundary layer thickness. But, the elliptic cylinders(AR$\geq$2), except for the smaller gap G/B<0.2, show a nearly constant drag coefficient which is much smaller than that of a circular cylinder. The base pressure on the flat plate decreases with increasing the axis ratio(AR) of the elliptic cylinder. In the case of a circular cylinder, the base pressure has the minimum value at the gap ratio G/B=0.4, but it occurs at G/D=2 for elliptic cylinders. The mean velocity of the cylinder wake is quickly recovered at a small cylinder height ratio(H/$\delta$), but the turbulent intensity is rapidly recovered at a large cylinder height ratio(H/$\delta$). The effective wake region in the plane boundary layer is shrinkaged with increasing the axis ratio(AR) of elliptic cylinder. And the drag coefficient and streamwise turbulent intensity of the elliptic cylinder with AR=4 are less than half of those for the circular cylinder(AR=1).

H.264/AVC의 $4{\times}4$ DCT기반 워터마크에 따른 영상왜곡과 비트율 변화에 대한 연구

김성민,원치선,Kim, Sung-Min,Won, Chee-Sun 대한전자공학회 2005 電子工學會論文誌-SP (Signal processing) Vol.42 No.5

지금까지 적용되었던 MPEG(Motion Picture Expert Group)기반의 워터마크(watermark) 기법들은 새로운 압축 표준 H.264/AVC의 달라진 부호화 방식으로 인하여 H.264/AVC에 그대로 적용되기에는 많은 문제점을 가지고 있다. 본 논문에서는 이전의 압축표준에 사용되었던 DCT(Discrete Cosine Transform)기반의 워터마크 기법이 H.264/AVC에 적용 되었을 때 발생 할 수 있는 문제를 분석하였으며, 그 결과를 영상왜곡 및 비트율(bit-rate) 변화의 측면에서 연구 하였다. 기존의 MPEG-2 사용 되었던 DCT기반 워터마크 기법들이 H.264/AVC에 적용되었을 때 H.264/AVC 부호화의 큰 특징인 인트라(intra) 부호화 및 CAVLC(Context Adaptive Variable Length Coding)의 영향으로 인하여 PSNR은 모든 QP(Quantization Parameter)에 대하여 평균 28.17 dB 감소 되었으며, 비트율은 모든 QP에 대하여 평균 56.71 % 증가 하였다. There are some problems in directly applying the conventional MPEG bit-stream based watermarking schemes to the bit-stream of a new compression standard, H.264/AVC. In this paper we analyze the effects of the conventional DCT-based watermarking scheme to H.264/AVC, especially in terms of image distortions and bit-rate changes. It turns out that the intra-frame prediction md CAVLC of H.264/AVC with the watermarking worsen the image distortions and bit-rate changes. The experiment results show on average 28.17dB decrease in PSNR and 56.71% increase in bit-rate over all QPs.

기관 식도루가 없는 식도폐쇄증 환자의 치료경험

김성민,최승훈,김성훈,권인규,한석주,오정탁,Kim, Seong-Min,Choi, Seung-Hoon,Kim, Sung-Hoon,Kwon, In-Kyu,Han, Seok-Joo,Oh, Jung-Tak 대한소아외과학회 2005 소아외과 Vol.11 No.2

Esophageal atresia without tracheoesophageal fistula accounts for 7-11 % of all types of esophageal atresia and is very difficult to treat. In our hospital from 1990 to 2005, we operated upon 40 patients with esophageal atresia, and 6 had pure atresia. The preoperative characteristics, operative findings and post operative course of the six patients with pure atresia were analysed. Immediate gastrostomy was performed in all 6 patients. One patient had simultaneous cervical esophagostomy. Esophageal reconstruction procedures were transhiatal gastric pull up in 3 patients, esophagocologastrostomy utilizing left colon in 1, and transthoracic esophagoseophagostomy with esophageal bougination in 2. Postoperative complications were pneumonia, anastomosis leakage, and gastroesophageal reflux symptom. Conservative management was effective in all patients. A larger series of cases would be required to demonstrate the most effective treatment for this particular anomalous condition. 1990년 1월부터 2005년 5월까지 연세대학교 의과대학 세브란스 병원 소아외과에서 기관식도루가 없는 식도폐쇄증으로 진단받고 수술을 시행받은 6예의 환자의 수술전후 임상상을 검토하였다. 이들의 빈도는 같은 기간동안 수술받은 식도폐쇄증 환자의 약 15 %였으며, 이들 6예 모두에서 단계적인 수술로 상부식도와 하부식도를 연결하는 수술을 성공적으로 시행하였으며(위전위법 3명, 대장전위법 1명, 자가식도 단단문합 2명), 수술 후 추적관찰시 양호한 소견을 보였다. 식도의 부우지 확장을 수차례 시행한 후 식도단단문합이 가능한 환자는 이 방법이 가장 좋을 것으로 생각되며, 자가식도의 1차적인 단단문합이 성공하기 위한 수술전식도 부우지확장의 적절한 횟수와 정도에 대한 연구가 되어야 할 것이다. 타 장기를 이용한 식도재건술 후에 발생할 수 있는 수술직후의 폐렴, 문합부 누출이나 식도 협착, 위식도 역류증상 등에 대하여서도 그 빈도를 줄일 수 있는 수술방법에 대한 지속적인 연구가 필요할 것으로 생각된다.