• 한국대기환경학회지
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• 제28권3호
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• pp.233-248
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• 2012

The national emission from energy sector accounted for 84.7% of all domestic emissions in 2007. Of the energy-use emissions, the emission from mobile source as one of key categories accounted for 19.4% and further the road transport emission occupied the most dominant portion in the category. The road transport emissions can be estimated on the basis of either the fuel consumed (Tier 1) or the distance travelled by the vehicle types and road types (higher Tiers). The latter approach must be suitable for simultaneously estimating $CO_2$, $CH_4$, and $N_2O$ emissions in local administrative districts. The objective of this study was to estimate 31 municipal GHG emissions from road transportation in Gyeonggi Province, Korea. In 2008, the municipalities were consisted of 2,014 towns expressed as Dong and Ri, the smallest administrative district unit. Since mobile sources are moving across other city and province borders, the emission estimated by fuel sold is in fact impossible to ensure consistency between neighbouring cities and provinces. On the other hand, the emission estimated by distance travelled is also impossible to acquire key activity data such as traffic volume, vehicle type and model, and road type in small towns. To solve the problem, we applied a hierarchical cluster analysis to separate town-by-town road patterns (clusters) based on a priori activity information including traffic volume, population, area, and branch road length obtained from small 151 towns. After identifying 10 road patterns, a rule building expert system was developed by visual basic application (VBA) to assort various unknown road patterns into one of 10 known patterns. The expert system was self-verified with original reference information and then objects in each homogeneous pattern were used to regress traffic volume based on the variables of population, area, and branch road length. The program was then applied to assign all the unknown towns into a known pattern and to automatically estimate traffic volumes by regression equations for each town. Further VKT (vehicle kilometer travelled) for each vehicle type in each town was calculated to be mapped by GIS (geological information system) and road transport emission on the corresponding road section was estimated by multiplying emission factors for each vehicle type. Finally all emissions from local branch roads in Gyeonggi Province could be estimated by summing up emissions from 1,902 towns where road information was registered. As a result of the study, the GHG average emission rate by the branch road transport was 6,101 kilotons of $CO_2$ equivalent per year (kt-$CO_2$ Eq/yr) and the total emissions from both main and branch roads was 24,152 kt-$CO_2$ Eq/yr in Gyeonggi Province. The ratio of branch roads emission to the total was 0.28 in 2008.

• 한국작물학회지
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• 제37권4호
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• pp.361-371
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• 1992

본 시험은 벼의 수량성을 증가시킬 수 있는 새로운 초형으로서 소얼ㆍ수중형품종이 잠재수량성을 다얼ㆍ수수형품종과 비교, 평가하기 위하여 국제미작연구소(IRRI)에서 1988년에 수행되었다. 공시품종은 소얼ㆍ수중형인 1R25588과 다얼ㆍ수수형인 IR58이었으며, 이들은 분얼능력과 이삭의 크기는 현저한 차이가 있었으나 다른 특성은 비슷하였다. 1. 소비조건(질소 0 '||'&'||'amp; 100kg / ha)에서는 재식밀도에 관계없이 IR255888과 IR58 사이에 수량차이가 없었으나, 다비밀식조건(질소, 150 '||'&'||'amp; 200kg / ha, 재식거리 10$\times$10cm)에서는 소얼ㆍ수중형인 IR2588이 다얼ㆍ수수형인 IR58보다 유의적으로 수량이 많았다. 최고수량은 질소 150kg /ha, 재식밀도 10$\times$10cm 그리고 주당묘수 2묘식 처리구에서 나타났으며 IR255888과 IR58이 각각 7.10과 6.60 t /ha이었다. 이는 소얼ㆍ수중형인 IR255888이 다얼ㆍ수수형인 IR58보다 수량성이 높다는 것을 나타내었으며, 또한 벼의 잠재수량을 보다 높일 수 있는 이상적인 초형이 '소얼ㆍ강간ㆍ수중형'이라는 결과를 뒷받침하고 있다. 2. 다비밀식 상태에서 IR255888이 IR58보다 높은 수량성을 나타내었으며, 이는 주로 소얼ㆍ수중형 초형인 IR255888의 수당영화수 IR58보다 많았기 때문이었다. 3. 단위면적당 수수는 IR58이 IR255888보다 많았고 수당영화수는 IR255888이 IR58보다 많았는데, 수량을 가장 잘 나타내는 단위면적당 영화수는 IR2588이 IR58보다 많았다. 4. 임실비율은 두 품종간에 차이가 없었느+CY42나, 천립중은 IR255888이 IR58보다 무거웠다. 5. IR255888과 IR58간에 엽면적지수는 서로 비슷하였으나 총건물 생산량은 특히 다비밀식 상태에서 IR255888이 IR58보다 많은 경향을 나타내었다. 분얼당 엽면적과 건물중은 IR255888이 IR58 보다 월등히 많았는데, 이는 많은 sink(수당영화수)를 채울수 있는 source로서 광합성 작용과 동화산물의 축적에 크게 기여할 것이다. 6. IR255888과 IR58 모두 분얼당 엽면적 및 건물중은 수당영화수와 정의 상관관계를 나타내었는데, 소얼성품종의 상관관계가 다얼성품종보다 높았다. 또한, IR255888에서는 분얼당 엽면적 및 건물중이 천립중과 유의적인 상관관계가 있었으나 IR58에서는 관계가 없었다. 7. 수량을 감소시키는 요인 중에 하나인 주내경쟁 정도는 소얼성품종이 다얼품종보다 적었다. 또한, 다비밀도 상태에서는 다수확을 위한 주당 묘수가 적정 재식밀도에서의 주당 묘수보다 적었다.

• 한국초지조사료학회지
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• 제4권1호
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• pp.35-40
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• 1983

낙엽(落葉)퇴적물의 종류(種類)가 겉뿌린 초종(草種)의 발아(發芽), 정착(定着), 목초율(牧草率) 및 수량(收量)에 미치는 영향(影響)을 구명(究明)코저 리기다 소나무, 굴참나무, 물오리나무 및 일본잎갈나무의 낙엽(落葉)을 공시(供試)하여 시험(試驗)한 결과(結果)는 다음과 같다. 1. Petri dish 내(內)에서의 발아율(發芽率)은 낙엽종류(落葉種類) 및 초종(草種)에 따라 영향을 받았고, 특히 소나무 낙엽(落葉)침출액은 ladino clover와 timothy 같은 소립종(小粒種)의 발아(發芽)를 억제하였다. 2. Pot내(內)에서의 정착율(定着率)은 ladino clover와 timothy가 소나무 침출액(浸出液)에 의해 약간 감소되었을 뿐 기타 초종간(草種間)에는 상대적으로 감소 경향은 없었다. 3. 소립종(小粒種)인 ladino clover와 timothy 및 무거운 red clover는 낙엽간극내(落葉間隙內)에 종자(種子)가 쉽게 침투되어 정착율(定着率)이 높았다. 4. 일본잎갈나무의 퇴적층에서 모든 초종(草種)의 정착율(定着率)은 심하게 감소되었는데 이것은 수분(水分) 보존력(保存力)이 낮기 때문인 것으로 본다. 5. 초장(草長) 및 근장(根長)은 낙엽종류(落葉種類) 및 초종(草種)에 따라 차이(差異)가 있었다. 6. 굴참나무 수림내(樹林內)에서 겉뿌림 목초(牧草)의 정착율(定着率)은 지표처리(地表處理)에 따라 화입(火入) 36%, 제경(蹄瓊) 46%, 갈퀴 37%, 및 무처리(無處理) 31%였다. 7. 목초율(牧草率)은 지표처리(地表處理)에 따라서 화입(火入) 57.8%, 제경(蹄耕) 70.9%, 갈퀴 59.6% 및 무처리(無處理) 54.0%였다. 8. 지표처리(地表處理)로써 제경(蹄耕)은 겉뿌림시(時) 기존식생(植生)을 억압할 뿐 아니라 토양(土壤)과 종자(種子)가 잘 밀착(密着)할 수 있어 효과가 컸다. 9. 건물수량(乾物收量)은 제경처리(蹄耕處理)가 가장 높았으나(P<0.05) 다른 처리간(處理間)의 수량(收量) 차이(差異)는 크기 않았다. 이상의 결과를 종합할 때 경사산지(傾斜山地) 및 임간지내(林間地內)에서의 겉뿌림 초지조성(草地造成)은 낙엽(落葉)퇴적물 위에 직접 겉뿌림하는 조성방법(造成方法)도 중요(重要)한 의미(意味)를 내포한다.

• 한국농공학회지
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• 제13권2호
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• pp.2262-2275
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• 1971

조사대상은 전라북도 관내 토지개량 조합 저수지 14개소와 전라남도관내 토지개량 조합저수지 20개소에 대하여 저수량 및 토사매몰량을 실측조사하고 또한 두 도내에 산재하여 있는 소류지 3,347개소에 대하여는 해당 시군에 비치된 대장에 의하여 조사하였다. 그 결과를 요약하면 다음과 같다. 1. 저수지 유역의 임상이 저수지 설치당시에는 대부분 산림이 울창하여 양호하였든 것이 8.15 해방과 6.25동란으로 주민들의 도벌과 남벌로 인하여 거의 황폐되었으며 또 유역내의 토사유출과 저수지내에 유사침전이 심하게 되어 유역면적 1ha당 연평균 $10.63m^3$의 토사침적을 보게 되었다. 2. 이 결과는 평균 27.5%의 저수량 감소를 초래하게 된 것이다. 특히 소류지는 계획당시에는 단위 저수량이 평균 0.19hm로 판명되었는데 이는 원래부터 저수량이 부족한데다가 다년간의 토사 매몰로 인하여 더욱 부족하게 되었다. 3. 평소의 유지관리 상황이 매우 소홀하여서 제방누수 산지 불임부의 누수 통관누수 등이 있는데도 불구하고 개보수를 하지 않고 방치한 곳도 있다. 4. 한발시에 준설한 곳도 있기는 하나 그 준설토사를 저수지 안에 쌓두어 환원된 예도 있었다. 5. 일반농민이 용수를 낭비하는 경향이 많었다. 이상과 같은 실정이므로 수자원 보완책으로서 다음과 같은 방안을 채택할 것을 당국에 건의하는 바이다. (1) 벼가 생육기별로 요구하는 최소한의 용수량만을 관계하는 절수재배를 여행한 것. (2) 용수가 극히 부족한 지방에서는 답토양의 수분을 70% 정도로 유지시키도록 수일간에 한번씩 소량으로 관계하는 계획관개를 실행한 것. (3) 지하수 복류수를 최대한 이용할 수 있도록 지구안에 관정을 굴착할 것. (4) 지구안에 보가 설치되어 있는 곳에서는 집수정을 병설하여 한발시에는 복류수를 양수하여 관개에 이용할 것. (5) 저수지 유역내의 산림은 이를 일체 보안림에 편입시켜서 조림 사방 야계등 공사를 우선적으로 실시하여 수원함양에 주력할 것. (6) 못자리는 집단식을 채택하고 묘대용수는 자체 해경을 원칙으로 할 것. (7) 매몰된 토사는 될 수록 준설하여 계획 저수량을 확보한다. (8) 하천이 저수지로 흘러들어가는 어구에는 웨이어를 설치하여 유입토사를 사전에 처리할 것. (9) 물넘이의 표고는 입지 조건에 따라 자동식 구조로하여 올리되 홍수위는 올리지 않고 홍수시에는 수위가 강하되어 재방을 덧쌓거나 용지매수를 하지 않고서도 저수량을 증대하는 방안을 모색할 것.

• Radiation Oncology Journal
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• 제6권1호
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• pp.63-73
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• 1988

One hundred fifty-four patients with the carcinoma of the uterine cervix were studied retrospectively to assess the result and impact of treatment at Department of Radiation Oncology, Korea University, Hae-Wha Hospital from Feb 1981 through Dec. 1986. Prior to radiotherapy, the patients were evaluated and staged by recommendation of FIGO including physical examination, pelvic examination, cystoscopy, rectosigmoidoscopy, chest X-ray, IVP. Ba enema. Also, an additional pelvic CT scan was obtained for some of the patients. The patients were treated by radiotherapy alone or adjuvant postoperative irradiation; in case of radiation therapy only, whole pelvic irradiation was given with Co-60 teletherapy unit via AP and PA parallel opposing fields or 4-oblique fields, 180 cGy per day, 5 days per week and intracavitary insertion was performed. In satges Ia, Ib, and IIa with small primary lesion, external irradiation was initially given to pelvis up to $2,000\~3,000\;cGy/2frac{1}{2}\;-3frac{1}{2}$ weeks and then intracavitary insertion was performed using Fletcher-Mini-Declos Applicator with cesium-137 cources and followed by external irradiation of $1,000\~2,000\;cGy/1frac{1}{2}\;-2frac{1}{2}$weeks via AP and PA parallel opposing fields with midline shield to spare of bladder and rectum. However, if the primary lesion is large, external irradiation was given without midline shield. More than stages IIb, the patients were treated by external beam irradiation up to 5,400cGy/30f for 6 weeks via 4-oblique portals and at the dose of 5,040cGy/28f the field was cut 5cm from the top margin for spare of small bowel, and followed by intracavitary irradiation, If there was residual tumor an additional dose of $900\~l,200cGy/5\~7f$ was given to parametrium and/or residual tumor area. Total dose of radiation to A and B-point were as follows; A-point; In early stages, Ia, Ib, IIa; $8,000\~9,000$ B-point $5,000\~6,000 cGy$ A-point; In advanced stages IIb, IIIa, IIIb; $9,000\~10,000$ B-point $60,000\~7,000cGy$ The results were obtained and as fellows; 1 The patients distribution according to FIGO staging system were stage Ia 6, Ib 27, IIa 28, IIb 54, IIIa 12, IIIb 18, and stage IVa 9. 2. Value of CT scan were demonstration of cervix tumor mass, parametrial and pelvic side wall tumor spread, pelvic and inguinal lymph nodes metastases, and hydronephrosis. Three dimensional quantitative demonstration of tumor volume is also important in planning radiation therapy. Another advantage of CT scan was detection of recurrent tumor after radiation or surgery. 3. Local control rate of tumor according to the size was $91.3\%$ for less than 5cm in size and $44.6\%$ in tumor over 5cm (p<0.0068). 4. Thirty out of 50 recurrent sites has locoregional failures and 17 cases has distant metastases. And the para-aortic lymph nodes were the most common site for distant metastases. 5. The most common complication was temporal rectal bleeding which was controlled most by conservative management. However, 4 patients required for endoscopic cauterization. 6. The 5-year survival rates showed; stage la and Ib $95\%,\;stage\;IIa\;81\%\;stage\;lIb\;67\%,\;stage\;IIIa\;37.7\%,\;stage\;IIIb\;23\%$ and 3-year survival rate of stage IVa showed $11.6%$, retrospectively.

• Journal of Trauma and Injury
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• 제23권2호
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• pp.107-112
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• 2010

Purpose: Recently, the change to a more complex social structure has led to an increased frequency of traumas due to violence, accident and so on. In addition, the severity of the traumas and the frequency of penetrating injuries have also increased. Traumas to cervical and abdominal areas, what are commonly seen by general surgeons, can have mild to fatal consequences because in these areas, various organs that are vital to sustaining life are located. The exact location and characteristics of the injury are vital to treating patients with the trauma to these areas. Thus, with this background in mind, we studied, compared, and analyzed clinical manifestations of patients who were admitted to Wonju Christian hospital for penetrating injuries inflicted by themselves or others. Methods: We selected and performed a retrospective study of 64 patients who had been admitted to Wonju Christian Hospital from January 2005 to December 2009 and who had cervical or abdominal penetrating injuries clearly inflicted by themselves or others. Results: There were 51 male (79.7%) and 13 female (20.3%) patients, and the number of male patients was more dominant in this study, having a sex ratio of 3.9 to 1. The range of ages was between 20 and 86 years, and mean age was 43.2 years. There were 5 self-inflicted cervical injuries, and 19 self-inflicted abdominal injuries, making the total number of self-inflicted injury 24. Cervical and abdominal injuries caused by others were found in 11 and 29 patients, respectively. The most common area involved in self-inflicted injuries to the abdomen was the epigastric area, nine cases, and the right-side zone II was the most commonly involved area. On the other hand, in injuries inflicted by others, the left upper quadrant of the abdomen was the most common site of the injury, 14 cases. In the neck, the left-side zone II was the most injured site. In cases of self-inflicted neck injury, jugular vein damage and cervical muscle damage without deep organ injury were observed in two cases each, making them the most common. In cases with abdominal injuries, seven cases had limited abdominal wall injury, making it the most common injury. The most common deep organ injury was small bowel wounds, five cases. In patients with injuries caused by others, six had cervical muscle damage, making it the most common injury found in that area. In the abdomen, small bowel injury was found to be the most common injury, being evidenced in 13 cases. In self-inflicted injuries, a statistical analysis discovered that the total duration of admission and the number of patients admitted to the intensive care unit were significantly shorter and smaller, retrospectively, than in the patient group that had injuries caused by others. No statistically significant difference was found when the injury sequels were compared between the self-inflicted-injury and the injury-inflicted-by-others groups. Conclusion: This study revealed that, in self-inflicted abdominal injuries, injuries limited to the abdominal wall were found to be the most common, and in injuries to the cervical area inflicted by others, injuries restricted to the cervical muscle were found to be the most common. As a whole, the total duration of admission and the ICU admission time were significantly shorter in cases of self-inflicted injury. Especially, in cases of self inflicted injuries, abdominal injuries generally had a limited degree of injury. Thus, in our consideration, accurate injury assessment and an ideal treatment plan are necessary to treat these patients, and minimally invasive equipment, such as laparoscope, should be used. Also, further studies that persistently utilize aggressive surgical observations, such as abdominal ultrasound and computed tomography, for patients with penetrating injuries are needed.

• Nuclear Medicine and Molecular Imaging
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• 제43권5호
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• pp.421-428
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• 2009

목적: 악성 종양 환자의 F-18 FDG PET/CT에서 우연히 발견된 부신 종양의 특성에 대해 알아보고 양성 및 악성 부신 종양을 감별하는 데 있어서 F-18 FDG PET/CT의 진단 능력에 대해 평가해 보았다. 대상 및 방법. 2005년 3월부터 2008년 8월까지 시행한 F-18 FDG PET/CT에서 우연히 부신 종양이 발견된 75명의 악성 종양 환자들(89개의 부신 종양)을 대상으로 하였다. 평균 연령은 $60.8{\pm}10.2$(35-87)세였으며, 남자는 46명, 여자는 29명이었다. 정량 분석을 위해 89개의 부신 종양의 장경(cm), HU, SUVmax, SUVratio를 각각 측정하였다. 부신 종양의 SUVmax를 간의 8번 분절의 SUVmax인 SUVliver로 나눈 값을 SUVratio로 하였다. 부신 종양은 조직학적 확진, 방사선학적 평가(HU<0: 양성), 임상적 판단에 따라 최종 진단하였다. 결과: 양성과 악성 부신 종양을 감별하는데 크기, HU, SUVmax, SUVratio의 4가지 변수는 모두 유의한 차이가 있었다(p<0.05). 그리고, SUVratio가 가장 정확도가 높았다. SUVratio는 cut-off value 1.0에서 민감도 90.9%, 특이도 75.6%를 보였다. 1.5 cm 크기 이하의 작은 부신 종양에서는 양성과 악성 부신 종양을 감별하는데 SUVratio만 통계적으로 유의한 차이가 있었다(p<0.05). SUVratio는 cut-off value 1.0에서 민감도 80.0%, 특이도 86.4%를 보였다. 결론: 악성 종양 환자에서 우연히 발견된 부신 종양을 양성과 악성으로 감별 진단하는데 있어서 정량 분석을 통해 F-18 FDG PET/CT가 비조영증강(nonenhanced) CT에 비해서 더 정확한 정보를 제공할 수 있다고 생각된다.

• 한국농공학회지
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• 제24권4호
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• pp.57-68
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• 1982

The paddy fiels slope located in Kangweon province Hwyongsung gun Gonggeun myon Shinchonri was considerably steep and so it was impossible to economically consolidate the field up to date. But for the porpose of farm mechanization, the field (32. 27ha) was consolidated by the auther under the assitance of the Ministry of Agriculture and Fishery and,;the Administration of Kangweon province. This paddy field consolidation was caused by the treatise on "Land-consolidation methods for farm mechanization in the steep-sloped paddy field", of which the auther is the same. The constrution was carried out from September, 1981 to April, 1982. During the 4esign and construction, some Peculiarities were found and discussed. That is, in design, besides the common condititions for a design, some special conditions were considered and written below; (1) The ranges of field slope in this design were 1/100-1/30. (2) Long sides of the land readjustment blocks must be arranged abreast contour line, and so they make the amount of cutting and banking decreased so as to take the maximum advantage of the configuration of the field. (3) In design, the main principles of dividing blocks were written below; i) First of all, long side of a block should be drawn straight abreast a contour line. ii) Long side of a block should arrange abreast contour line and make its length 100-150m, if not, l)reak the side in order to make a bended rectangle. iii) Length of a short side should be determinded within differences of elevation (0.6 -1. 2m) between the two adjacent blocks toward the normal to a contour line. iv) Length of a short side should be above 15m and the ratio of long and short side should be slso kept 1: (4-6). v) A new field surface leveling was determinded from the elevation which produce the least amount of cuttingand banking within the range of 0.6-1. 2m diffe rences of elevation between the two adjacent blocks. vi) In the course of dividing blocks with the same width along the line which was normal to a contour line, all blocks connot keep their shape in a retangle because of steep slope of the field and so on, and so it was also necessory to make some non-retanglar and small blocks such as a trianglar or trapezoidal shape, which was impossible to use some of farm machinery. But because this non-rectanglar and small blocks were divided, larger and many rectanglar blocks can be divided and construction cost can also be lowered. According to the conditions discussed above, the paddy field consolidation project designed and constructed. And the results of this study were obtained as below; (1) Three-forth of total cost of this paddy field consolidation was not construction cost, and these cost consist of land grading (1/4), road and canal construction cost (1/4) and the other cost (1/4) such as surveying or materials and 56 on. (2) The steeper the land slope, the greater cost was assigned for road and canal construction, and than land grading. (3) Curtailment of the road and canal construction cost depended on simplificating their strutures. (4) In the case of the land slopes were low, the land grading cost was high by 1: 1.4 in comparison with the road and canal construction cost, and conversely when the slops were steep, the road and canal construction cost was high by 1 : 5 in compa- rison with the land grading cost. (5) The densities of irrigation canal, drainage canal and trunk and branch road were 150. Sm/ha, 60. im/ha and 17. 4m/ha respectively. The density of irrigation canal of the area was high by 2 times in comparison with the average one of Kangweon Province, and the others were nearly the same. (6) Most farmers (above 85%) knew the effects of paddy field consolidation. The effects are; 1) Improvement of irrigation 2) Improvement of farm management 3) Improvement of transportarion 4) farm mechanization and 5) grouping of the scattered land. And the more farm modernization was accomplished by these projects, the more farmers wanted to live in their land. (7) In spite of the very steep sloped paddy field, the diminution rate of the net farm land caused by consolidation was 7.7% which was nearly the same as the one of Chulweon plain of Kangweon province. Land grading cost was 971, OOOwon/ha which was rather cheap by 13.2% than the one of Ghulweon plain, and unit construction cost was 5, 341, OOOwon/ha (included soil addition) which was also nearly the same as the one of Chulweon plain and FNFIA (The federation of national farmland improvement association).

• 농업과학연구
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• 제10권1호
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• pp.129-134
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• 1983

목초(牧草) 수확기(收穫機)의 설계(設計) 및 목초(牧草)의 처리가공(處理加工)의 기초자료(基礎資料)로서 기여(寄與)하고저 6개(個) 종류(種類)의 목초(牧草)-reed canarygrass, alfalfa, red clover, orchardgrass, meadow fescue 및 birdsfoot trefoil-을 공시건초(供試乾草)로 사용(使用)하여 자연건조(自然乾燥)에 따른 함수율변화(含水率變化)와 전단(剪斷) 각변화(角變化)가 전단력(剪斷力) 및 전단(剪斷) energy에 미치는 영향(影響)을 포함(包含)한 목초(牧草)의 전단특성(剪斷特性)을 측정분석(測定分析)한 결과(結果)는 다음과 같다. 1. 건초(牧草)의 linear density는 직경(直徑)의 증가(增加)에 따라 증가(增加)하는 경향(傾向)이었으며 그 증가율(增加率)은 red clover에서 가장 컷다. 2. 전단면적(剪斷面積)의 증가(增加)에 따른 전단력(剪斷力)의 증가율(增加率)은 alfalfa에서 가장 큰 값을 나타냈고 meadow fescue에서 가장 작은 값을 나타냈다. 3. 전단면적(剪斷面積)의 증가(增加)에 따른 전단(剪斷) energy의 증가율(增加率)은 reed canarygrass, red clover 및 alfalfa에서 컷고 birdsfoot trefoil, orchardgrass 및 meadow fescue는 작은 값을 나타냈다. 4. 함수율(含水率)이 전단특성(剪斷特性)에 미치는 영향(影響)은 비교적 컷으며 reed canarygrass 및 red clover는 약 40% 함수율(含水率)에서 전단력(剪斷力) 및 전단(剪斷) energy가 최대치(最大値)를 나타냈으며 반면(反面) meadow fescue 및 orchardgrass는 감소초기(減少初期)인 약 70% 부근(部近)에서 최소치(最小値)를 나타냈다. 5. 전단각(剪斷角)이 $90^{\circ}$에서 $70^{\circ}$, $50^{\circ}$로 감소(減少)할때 전단력(剪斷力)도 감소(減少)하였다.

• 대한치과보철학회지
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• 제49권4호
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• pp.316-323
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• 2011

연구 목적: 본 연구의 목적은 치과용 임플란트 나사산 디자인이 변연골 응력에 미치는 영향에 정량적인 분석을 하고자 한다. 연구 재료 및 방법: 외경 4.1 mm (경부직경 3.5 mm), 매식부 길이 10 m인 표준형 ITI 임플란트 시스템(ITI Dental Implant System; Straumann AG, Waldenburg, Switzerland)을 기본모델(대조모델)로 채택하고, 그 몸체의 나사산은 다른 임플란트 시스템에 채택되고 있는 삼각형, 사각형, buttres형 디자인을 가지는 가상의 해석모델을 4종 만들었다. 해석모델은 나사산 형태와 크기에 따라 (1) 모델 A (작은 삼각형 나사산), (2) 모델 B (큰 삼각형 나사산), (3) 모델 C (buttres형 나사산), 및 (4) 모델 D (사각형 나사산)로 구분하였다. 유한요소 모델링과 해석에는 NISA II/DISPLAY III (Engineering Mechanics Research Corporation, Troy, MI, USA) 프로그램을 사용하였다. Mesh 구성에는 NKTP type 34형 solid 요소(4각형 축대칭 요소, 요소당 절점수 8개)를 사용하여 임플란트 장축과 평행한 축대칭 하중은 물론 장축과 경사각을 갖는 비축대칭 하중조건을 모두 해석할 수 있도록 하였다. 임플란트의 표면으로부터 각각 0.2, 0.4, 0.6, 0.8, 1.0 mm 떨어진 위치에 5개의 응력관찰점(stress monitoring point)을 설정 하여 기록된 응력 값으로부터 회귀분석을 통하여 변연골 응력 최대값(peak stress)을 정량화하였다. 해석에 사용한 하중 조건은 2가지로, 임플란트 축에 평행한 수직하중 100 N과 임플란트 축과 $30^{\circ}$를 이루는 경사력 100 N 조건이었다. 결과: 임플란트 경부와 접하고 있는 인접 변연골에 응력집중현상이 보이고 있었으며, 그 양상은 임플란트 나사산 디자인과 무관하게 거의 유사하게 관찰되었다. 수직력 100 N 조건에서 산출된 변연골 최대응력값은 대조모델과 실험모델 A, B, C, D에서 7.84, 6.45, 5.96, 6.85, 5.39 MPa이었고, 경사력 조건에서는 각각 29.18, 26.45, 25.12, 27.37, 23.58 MPa이었다. 결론: 임플란트 나사산의 디자인은 변연골의 응력에 영향을 미치는 중요한 요소이다.