• Geomechanics and Engineering
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• 제8권1호
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• pp.81-95
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• 2015

The permeability behavior of Ariake clays has been investigated by constant rate of strain (CRS) consolidation tests with vertical or radial drainage. Three types of Ariake clays, namely undisturbed Ariake clay samples from the Saga plain, Japan (aged Ariake clay), clay deposit in shallow seabed of the Ariake Sea (young Ariake clay) and reconstituted Ariake clay samples using the soil sampled from the Saga plain, were tested. The test results indicate that the deduced permeability in the horizontal direction ($k_h$) is generally larger than that in the vertical direction ($k_v$). Under odometer condition, the permeability ratio ($k_h/k_v$) increases with the vertical strain. It is also found that the development of the permeability anisotropy is influenced by the inter-particle bonds and clay content of the sample. The aged Ariake clay has stronger initial inter-particle bonds than the young and reconstituted Ariake clays, resulting in slower increase of $k_h/k_v$ with the vertical strain. The young Ariake clay has higher clay content than the reconstituted Ariake clay, resulting in higher values of $k_h/k_v$. The microstructure of the samples before and after the consolidation test has been examined qualitatively by scanning electron microscopy (SEM) image and semi-quantitatively by mercury intrusion porosimetry (MIP) tests. The SEM images indicate that there are more cut edges of platy clay particles on a vertical plane (with respect to the deposition direction) and there are more faces of platy clay particles on a horizontal plane. This tendency increases with the increase of one-dimensional (1D) deformation. MIP test results show that using a sample with a larger vertical surface area has a larger cumulative intruded pore volume, i.e., mercury can be intruded into the sample more easily from the horizontal direction (vertical plane) under the same pressure. Therefore, the permeability anisotropy of Ariake clays is the result of the anisotropic microstructure of the clay samples.

• 한국산학기술학회논문지
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• 제15권6호
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• pp.3983-3989
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• 2014

도시화로 인한 도심유역 내 강우유출양상이 개발이전과 다른 양상을 보이므로, 도심유역 내 강우유출량을 저감하기 위해 집중형 유출 저감 시설이 시행되어왔다. 그러나 시설의 한계점 때문에 분산형 유출 저감 시설인 저영향개발(Low Impact Development; LID)의 계획 및 적용이 활발하게 진행되고 있다. 본 연구에서는 대표적인 LID 요소기술을 대상으로 공간적 분포에 따른 유출특성을 분석하였다. 대상유역은 동일한 유역 및 우수배수 특성을 지닌 5개의 소유역으로 구성하였고, 대표적인 LID 요소기술로 선정된 옥상녹화와 투수성 포장의 적용위치 및 개수에 따른 2개의 시나리오에 대한 유출특성을 분석하였다. SWMM 모형적용 결과, 적용 소유역 1개당 옥상녹화의 경우 총 유출량은 11.07%, 첨두 유출량은 3.42% 저감되었으며, 투수성포장의 경우 총 유출량은 18.09%, 첨두 유출량은 17.94% 저감되었다. 이와 같은 감소율은 적용 LID의 위치에 상관없이 일정하였고, 적용 LID의 개수에 따라 정비례하게 증가하였다. 옥상녹화와 투수성 포장에서 유출특성 저감률의 발생 차이는 각 방법의 매개변수인 수리전도도의 영향 때문인 것으로 판단된다.

• 대한환경공학회지
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• 제38권3호
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• pp.117-127
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• 2016

새만금유역을 대상으로 수질개선을 위한 다양한 방법을 검토하고 환경유지용수 확보에 따른 수질개선 효과를 평가하였다. 만경강과 동진강의 환경유지용수 확보를 위해 강변저류지설치, 저수지증고, 신규댐 건설, 용수 취배수체계 조정, 용담댐, 섬진강댐 물 이용체계를 조정하는 방안을 선정하였다. 환경유지용수 확보 가능한 방안에 따른 시나리오 구성을 통해 수질개선효과를 예측하기 위하여 유역모형 SWAT과 수질모델 QUAL2K를 연계하여 BOD와 T-P항목에 대해 수질변화를 모의하였다. 시나리오 적용을 통한 모의 결과 총량관리단위유역말단인 만경B 지점의 경우 관개기 BOD 수질개선율은 28.70%, T-P의 수질개선율은 17.09%로 나타났고, 비관개기BOD 수질개선율은 28.51%, T-P의 수질개선율은 28.68%로 나타났다. 동진 A 지점의 경우 관개기 BOD 수질개선율은 14.39%, T-P 수질개선율은 14.59%, 비관개기 BOD 수질개선율은 15.54%, T-P 수질 개선율은 19.46 %로 나타나 환경유지용수가 수질개선에 효과가 있는 것으로 분석되었고 특히, 비관개기 수질개선에 효과가 크다는 것을 알 수 있었다.

• Journal of Chest Surgery
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• 제32권2호
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• pp.171-174
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• 1999

배경: 다한증은 젊은 나이에 0.6%에서 1%까지 보고되고 있으며 최근 흉강 내시경 기구의 발전으로 2 mm 내시경에 의한 다한증 치료가 가능하게 되어 수술 후 통증이나 상처에 대한 걱정 없이 수술을 시행할 수 있게되었고 또한 보상성 다한증등의 합병증을 최소한으로 줄일 수 있는 수술방법이 필요하게 되었다. 대상 및 방법: 연세대학교 의과대학 영동세브란스병원 훙부외과에서는 1997년 9월부터 1998년 2월까지 89례의 다한증 환자에서 2 mm 흉강경을 이용한 89례의 흉부교감 신경절 절단술(sympathicotomy)을 시행하였으며 모든 환자에서 추적 가능하였으며 평균수술시간은 30분이었으며 평균입원기간은 1일이었다. 결과: 수술후 보상성 다한증은 57례(64.0%)에서 나타났으며 생활에 불편한 정도의 보상성 다한증은 14례(15.7%) 였다. 보상성 다한증의 발생율은 일반적인 수술방법과 큰 차이가 없었으나 다한증의 정도는 훨씬 줄어드는 양상을 보였다. 수술의 만족도는 96.6%에서 만족한다고 하였으며 3.4%에서 만족하지 못한다고 하였다. 2 mm 흉강경을 이용한 T2 흉부교감 신경절 절단술(sympathicotomy)은 다한증의 치료를 위한 치료방법으로 매우 간편하고 효과적인 치료방법으로 생각되어지며 신경의 재 성장에 의한 재발등의 결과를 확인하기 위해 장기 추적관찰이 필요하리라고 생각된다. 결론: 본 연세대학교 영동세브란스 병원에서는 1997년 9월부터 1998년 2월까지 2 mm흉강경을 이용하여 T2 sympathicotomy를 시행하여 다한증치료를 하였기에 임상 고찰과 함께 보고하는 바이다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.315-315
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• 2017

In Japan, more than 80 % of soybean growing area is converted fields and excess water is one of the major problems in soybean production. For example, recent study (Yoshifuji et al., 2016) suggested that in the fields of shallow groundwater level (GWL) (< 1m depth), rising GWL even in a short period (e.g. 1 day) causes inhibition of soybean growth. Thus it becomes more and more important to predict GWL and soil moisture in detail. In addition to conventional surface drainage and underdrain, FOEAS (Farm Oriented Enhancing Aquatic System), which is expected to control GWL in fields adequately, has been developed recently. In this study we attempted to predict GWL and soil moisture condition at the converted field with FOEAS in Biwa lake reclamation area, Shiga prefecture, near the center of the main island of Japan. Two dimensional HYDRUS model (Simuinek et al., 1999) based on common Richards' equation, was used for the calculation of soil water movement. The calculation domain was considered to be 10 and 5 meter in horizontal and vertical direction, respectively, with two layers, i.e. 20cm-thick of plowed layer and underlying subsoil layer. The center of main underdrain (10 cm in diameter) was assumed to be 5 meter from the both ends of the domain and 10-60cm depth from the surface in accordance with the field experiment. The hydraulic parameters of the soil was estimated with the digital soil map in "Soil information web viewer" and Agricultural soil-profile physical properties database, Japan (SolphyJ) (Kato and Nishimura, 2016). Hourly rainfall depth and daily potential evapo-transpiration rate data were given as the upper boundary condition (B.C.). For the bottom B.C., constant upward flux, which meant the inflow flux to the field from outside, was given. Seepage face condition was employed for the surrounding of the underdrain. Initial condition was employed as GWL=60cm. Then we compared the simulated and observed results of volumetric water content at depth of 15cm and GWL. While the model described the variation of GWL well, it tended to overestimate the soil moisture through the growing period. Judging from the field condition, and observed data of soil moisture and GWL, consideration of soil structure (e.g. cracks and clods) in determination of soil hydraulic parameters at the plowed layer may improve the simulation results of soil moisture.

• Tuberculosis and Respiratory Diseases
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• 제40권5호
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• pp.468-473
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• 1993

연구배경 : 최근의 비디오 영상기술, 내시경 수술기구 및 내시경 수술기법의 눈부신 발달에 힘입어 흉강경의 영역이 단순한 늑막질환 진단에서 여러가지 흉부질환의 치료 방법으로 넓어졌다. 비디오 흉강경 수술(VATS) 방법은 3년전에 개발된 새롭고 가히 매력적이라 할 만한 흉부질환 수술방법으로 서울대학교병원에서도 1992년 7월에 도입하여서 비록 짧은 기간이지만 여러가지 임상경험을 하였기에 그 결과를 분석한다. 방법 : 1992년 7월부터 1993년 4월까지 10개월간 30명 환자에게 31예의 비디오 흉강경 수술을 시행하였다. 폐기포 절제술이 18명(19예), 종격동 종양 절제술이 4예, 폐실질 폐조직 생검 3예, 늑막생검 3예, 늑막종괴제거술 1예 그리고 늑막심낭창형성술 1예였다. 결과 : 사망예는 없으며 8예의 합병증이 발생하였다. 장기간공기누출이 3예, 장기간 늑막액 유출이 2예, 기흉재발 1예, 호너씨 증후군 1예, 애성 1예였다. 31예 모두 비디오흉강경 자체로 수술을 완료하였다. 합병증이 없었던 자연기흉 환자들의 술후 입원기간은 5일정도로 평상적인 개흉술로 수술받은 환자보다 입원기간이 약간 짧았다. 결론 : 비록 비디오 흉강경 수술은 초기단계라서 비교적 술후 합병증 빈도가 높았지만 이러한 술식이 통증감소, 입원기간단축, 빠른 회복, 미용적으로 우수한 작은 수술 상처 등의 여러가지 장점을 갖고 있어 환자들에게 매우 유익하다고 확신한다. 비디오 흉강경수술의 영역은 앞으로 흉곽내 여러가지 질환의 진단과 치료에 사용되고 심지어 심장병질환에도 응용될 것이라 생각된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권5호
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• pp.355-364
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• 2011

Introduction: This study evaluated nerve recovery through retrospective study of patients with lingual nerve damage. Patients and Methods: The patients who visited Seoul National University Dental Hospital for an injury to the lingual nerve from April 1988 to August 2009 were enrolled in this study (n=41). The relevance of various factors including the causes of damage, age, etc. was analyzed by the subjective improvement based upon questionnaires and the clinical records. The evaluation variants were a subjective assessment and neurosensory examination composed of the direction, contact threshold, two-point discrimination, pin prick, thermal discrimination and current perception threshold. Results: The causes of lingual nerve damage were an extraction of the lower third molar (75.6%), local anesthesia (9.7%), incision and drainage (4.88%), trauma (2.44%). The evaluation of subjective prognosis exhibited no difference in sensory improvement depending on the cause, age and gender. Based upon the subjective evaluation, 44.7% of patients showed sensory improvement. The first hospital visit from injury was shorter in the group showing subjective improvement (3.41 months) than those showing no improvement (5.24 months) (P=0.301). Thirty six out of 41 patients were treated with only conservative therapy and 5 patients were treated by surgical intervention. Neurosensory examinations revealed improvement, although not statistically significant, and the degree was higher in the subjectively improved group. The contact threshold discrimination showed the highest correlation with subjective improvement (P=0.069). Most of the sensory recovery was gained within 12 months and the degree of improvement at the tip of the tongue was higher than that of the dorsum (P<0.001). Conclusion: The damaged lingual nerve improved at a rate of 44.7% and mostly within 12 months after the incident. There was no difference between the subjective prognosis and neurosensory examination depending on the cause of damage, age and gender, whereas the contact threshold discrimination was the best variant that reflected the subjective prognosis statistically.

• 대한족부족관절학회지
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• 제10권2호
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• pp.213-217
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• 2006

Purpose: To evaluate the clinical and radiological results of tibio-talo-calcaneal arthrodesis using ipsilateral distal fibula buttress which had advantages of extended operative field and release of contracted soft tissue. Materials and Methods: We retrospectively reviewed 4 postraumatic compartment syndrome, 2 residual poliomyelitis, 1 posttraumatic osteoarthritis with subtalar joint infection and 1 posttarumatic sciatic nerve palsy patients who underwent a tibio-talo-calcaneal arthrodesis from April, 1996 to March, 2002. Each of the cases was notable for a severe rigid equinovarus, persistent pus drainage of calcaneal area and paralytic foot. The mean duration of follow up was 18 months (range, $13{\sim}42$ months). The pain, function and alignment were evaluated by the modified ankle hindfoot scale of the American Orthopaedic Foot and Ankle Society (AOFAS) and patients satisfaction clinically. The radiological union were evaluated by plain AP and lateral radiographs. Results: The AOFAS score improved from 58 points (range, $47{\sim}78$) preoperatively to 82 (range, $60{\sim}89$) postoperatively. Patents satisfaction checked at 12 months after operation had favorable results (excellent and good 80%). Union rate was 100% radiographically and the mean duration of union was 12.5 weeks (range $8{\sim}22$ weeks). There was 2 cases of superficial pin tract infection and one protrusion of screw. Conclusion: Tibio-talo-calcaneal arthrodesis using ipsilateral distal fibula buttress was good modality of arthrodesis which provides wide operative field and release of contracted soft tissue in some cases of contracted foot.

• Archives of Plastic Surgery
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• 제36권4호
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• pp.432-436
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• 2009

Purpose: Negative pressure therapy has been used in various conditions to promote wound healing. It has also been used to secure a skin graft by improving microcirculation and improving tight adhesion between the graft and the recipient bed. To reduce post burn scar contracture and improve aesthetical result, many types of dermal substitutes have been invented and used widely. The goal of this study was evaluate usefulness of the VAC (Kinetic concepts Inc., San Antonio, TX) in improving the take rate and time to incorporation of Integra$^{(R)}$ in reconstruction of burn scar contracture. Methods: A retrospective study was performed from October, 2006 to December, 2008. The VAC was utilized for 11 patients. The average patient's age was 19.7 years (range 5 - 27) and average surface area was $785cm^2$ (range 24 - 1600). The burn scars were excised deep into normal subcutaneous tissue to achieve complete release of the scar, Integra$^{(R)}$ was sutured in place with skin staple와 Steri - strip$^{(R)}$. Then slit incisions were made on silicone sheet only with No.11 blade for effective drainage. The VAC was used as a bolster dressing over Integra$^{(R)}$. Negative - Pressure ranging from 100 to 125 mm Hg was applied to black polyurethane foam sponge trimmed to the appropriate wound size. An occlusive seal over the black polyurethane foam sponge was maintained by a combination of the occlusive dressing, OP - site$^{(R)}$. The VAC dressing changes were performed every 3 or 4 days until adequate incorporation was obtained. The neodermis appeared slightly yellow to orange color. When the Integra$^{(R)}$ deemed clinically incorporated, The VAC was removed and take was estimated with visual inspection. Very thin STSG(0.006 ~ 0.008 inches) was performed after silicone sheet removal. Result: The mean time for clinically assessed incorporation of Integra$^{(R)}$ was 10.00 days (range 9 - 12). The mean dressing change was 3.5 times until take was obtained. In All patients, Integra$^{(R)}$ had successful incorporation in tissue without serious complications. Conclusion: Integra$^{(R)}$ in combination with Vacuum - Assisted Closure(VAC) may be incorporated earlier than conventional dressing method.

• Journal of Chest Surgery
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• 제12권3호
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• pp.281-288
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• 1979

For years, physicians and anatomists have been interested in the heart that has one functioning ventricle. Various terms have been suggested for this entity including single ventricle, common ventricle, double-inlet left ventricle, cor biatriatum triloculare, and primitive ventricle. In this report, the term "single ventricle" is utilized as suggested by Van Praagh, and is defined as that congenital cardiac anomaly in which a common or separate atrioventricular valves open into a ventricular chamber from which both great arterial trunks emerge. An outlet chamber, or infundibulum, may or may not be present and give rise to the origin of either of the great arteries. This definition excludes the entity of mitral and tricuspid atresia. An 11 year old cyanotic boy was admitted chief complaints of exertional dyspnea and frequent upper respiratory infection since 2 weeks after birth. He was diagnosed as inoperable cyanotic congenital heart disease, and remained without any corrective treatment up to his age of 11 year when he suffered from aggravation of symptoms and signs of congestive heart failure for 2 months before this admission. On 22nd of May 1979, he was admitted for total corrective operation under the impression of tricuspid atresia suggested by a pediatrician. Physical check revealed deep cyanosis with finger and toe clubbing, and grade V systolic ejection murmur with single second heart sound was audible at the left 3rd intercostal space. Development was moderate in height [135 cm] and weight[28Kg]. Routine lab findings were normal except increased hemoglobin [21.1gm%], hematocrit [64 %], and left axis deviation with left ventricular hypertrophy on EKG. Cardiac catheterization and angiography revealed 1-transposition of aorta, pulmonic valvular stenosis, double inlet of a single ventricle with d-loop, and normal atriovisceral relationship [Type III C solitus according to the classification of Van Praagh]. At operation, longitudinal incision at the outflow tract of right ventricle in between the right coronary artery and its branch [LAD from RCA] revealed high far anterior aortic valve which had fibrous continuity with mitral annulus, and pulmonic valve was stenotic up to 4 mm in diameter positioned posterolaterally to the aorta. Ventricular septum was totally defective, and one markedly hypertrophied moderator band originated from crista supraventricularis was connected down to the imaginary septum of the ventricular cavity as a pseudoseptum of the ventricle. Size of the defect was 3X3 cm2 in total. Patch closure of the defect with a Teflon felt of 3.5 x 4 cm2 was done with interrupted multiple sutures after cut off of the moderator band, which was resutured to the artificial septum after reconstruction of the ventricular septum. Pulmonic valvotomy was done from 4 mm to 11 mm in diameter thru another pulmonary arteriotomy incision, and right ventriculotomy wound was closed reconstructing the right ventricular outflow tract with pericardial autograft of 3 x 4 cm2. Atrial septal defect of 2 cm in diameter was closed with 3-0 Erdeck suture, and atrial wall was sutured also when rectal temperature reached from 24`C to 35.5`C. Complete A-V block was managed with temporary external pacemaker with a pacing rate of 110/min. thru myocardial wire, and arterial blood pressure of 80/50 mmHg was maintained with Isuprel or Dopamine dripping under the CVP of 25-cm saline. Consciousness was recovered one hour after the operation when his blood pressure reached 100 /70 mmHg, but vital signs were not stable, and bleeding from the pericardial drainage and complete anuria were persisted until his heart could not capture the pacemaker impulse, and patient died of low output syndrome 320 min after the operation.