연령증가에 따른 혈압요소들의 좌심실비대 및 관동맥질환과의 관련성

박재석,박창규,박미영,박재형,김용현,나진오,신성희,서순용,홍순준,박성미,임홍의,김응주,서홍석,오동주,노영무 대한순환기학회 2004 Korean Circulation Journal Vol.34 No.2

슬관절 내측부 인대 손상의 보존적 치료

임홍철,심재학,남혁우,왕준호,노영진 대한스포츠의학회 2000 대한스포츠의학회지 Vol.18 No.2

Purpose : The medial collateral ligament injury is the most common injury of the knee. Recently Non-operative treatment has been preferred than operative treatment and most of patients have satisfactory clinical results after non-operative treatment. But a few patients have continuous instability after non-operative treatment, so the purpose of this study is to fine out the cause of persistent symptom. Methods and Materlals : We performed a retrospective study of one hundred thirty seven patients with medial collateral ligament injury treated non-operative from January 1990 to December 1997. W divided patients into two groups: isolated medial collateral ligament injury (groupⅠ): medial collateral ligament injury with concomitant anterior cruciate ligament injury (groupⅡ) and we analysed MRI finding, valgus instability, and Lysholm knee score. Result : At the follow up, three of group Ⅰ, five of group Ⅱ had persistent grade Ⅲ valgus instability. In group Ⅰ, we could find two case of rupture of the proper of medial collateral ligament with inward inversion and one case of concomitant posteromedial compartment injury. We could find the proper rupture of medial collateral ligament with inversion inward in two patients, the injury of posteromedial compartment in one patient. Two patients of group Ⅱ with grade Ⅲ valgus instability had anterior instability with laxity of grafted tendon after anterior cruciate ligament reconstruction. Conclusion : Most of isolated injury of the medial collateral ligament heals wthout operative intervention. But in case of rupture of the proper portion of medial collateral ligament with inversion inward or concomitant injury of posteromedial compartment, we should consider the operative treatment of medial collateral ligament. In case of medial collateral ligament injury with anterior cruciate ligament, it would better to consider the delicate reconstruction of anterior cruciate ligament.

한국어의 특성을 고려한 용례 검색 시스템

홍금원,임재수,서희철,임해창 고려대학교 컴퓨터과학기술연구소 2001 JOURNAL OF COMPUTER SCIENCE & ENGINEERING TECHNOLO Vol.3 No.-

본 논문에서는 한국어의 특성을 고려한 용례 검색 시스템을 제안한다. 제안된 시스템은 직접 용례 검색과 색인 기반 용례 검색을 제공한다. 직접 용례 검색에서는 원시 말뭉치에서 한글 음절 단위의 검색뿐만 아니라 한글 자소 단위의 검색이 가능하며, 색인 기반 용례 검색에서는 어절, 형태소, 그리고 체계화된 품사정보를 이용한 검색이 가능하다. 검색속도 및 색인된 파일의 크기는 실험을 통하여 최적화 한다. 사용자는 검색된 용례로부터 연산 및 정렬 과정을 거쳐서 보다 정확하게 선별된 용례를 얻을 수 있다. 본 시스템을 통해 얻어진 용례 정보는 사전 편찬 등의 한국어 연구의 기초 자료로 활용할 수 있으며, 말뭉치를 기반으로 한 다양한 분야에서 활용할 수 있을 것이다. In this paper, we propose the concordance system considering the characteristics of Korean. The proposed system provides two kinds of retrieval method: direct access retrieval and index based retrieval. In direct access retrieval method, it is possible to retrieve examples using grapheme-based query as well as syllable based query. In index-based retrieval method, it is possible to retrieve examples using eojeol, morpheme, or part-of-speech. The speed of the system and the size of the indexed file is optimized through several experiments. Users can acquire the exact and selective examples from previously retrieved items by filtering and/or sorting. The linguistic information acquired by the system can be utilized as basic data for Korean Linguistic research such as lexicography and it can be used in various application fields based on corpus.

乳牛의 血液性狀과 泌乳量에 關한 硏究

林貞澤,金宇權,李載洪,韓邦根 全南大學校農漁村開發硏究所 1982 農業科學技術硏究 Vol.17 No.2

國內에서 飼育되고 있는 Holstein種의 血液成分値 그리고 血液成分値와 泌乳量과의 相關關係등을 檢討할 目的으로 全南地域에서 飼育되고 있는 外觀上 健康하다고 認定된 Holstein種 870餘頭를 對象으로 血液成分値를 調査檢討 하였고 한편 産乳量을 調査하여 血液成分値와 産乳量과의 關係를 檢討하여 다음과 같은 結論을 얻었다. 1. 平均 RBC數는 5.97(3.20~9.96)×10 6/㎕이었으나 成牝牛의 平均 RBC數는 6.06(3.20~9.74)×10 6/㎕이었으며 年齡別 平均 RBC數에서 1年牛가 5.19×l0 6/㎕로 特히 낮았다. 2. 平均 Hb量은 9.61(5.3-18.4)g/100ml 이었으나 成牝牛의 平均 Hb量은 9.42(5.3-18.4)g/100ml 이었으며 年齡別 平均 Hb量에서 2年牛가 8.97g/100ml로 特히 낮았다. 3. 平均 PCV値는 31.10(19~5)ml/100ml이었으며 成牝牛의 平均 PCV値는 31.04(19~55)ml/100ml 이었으며 年齡別 平均 PCV値에서 2年牛가 29.84ml/100ml로 가장 낮았다. 4. 平均 MCV値는 52.09(23.77~86.57) fl이었으나 成牝牛의 平均 MCV値는 51.22(29.77~86.57)fl 이었으며 1年未滿牛의 55.64fl 및 1年牛의 57.63fl 등 송아지에서 더 높았다. 5. 平均 MCH値는 16.10(8.21~28.96)pg 이었으며 成牝牛의 平均 MCH値는 15.54(8.21~28.96)pg 이었으며 1年未滿牛의 18.41pg 및 1年牛의 19.17pg 등 송아지에서 더 높았다. 6. 平均 MCHC値는 30.90(17.35~53.75)g/100ml 이었으나 成牝牛의 平均 MCHC値는 30.35(17.35~53.57)g/100ml 이었으며 1年未滿牛의 33.27g/100ml 등 송아지에서 더 높았다. 7. 貧血牛는 大部分이 大赤血球性이며 高血色素性이었으나 小赤血球性(MCV 37.15fl)이며 低血色素性(MCH 12.35pg)인 個體, 大赤血球性이며 低血色素性(MCHC 24.21g/100ml)인 個體 그리고 小赤血球性(MCV 35.71fl)이며 高血色素性(MCHC 40.83g/100ml)을 나타낸 個體도 發見되었다. 8. 平均 WBC數는 10.186(3,200~31,600)㎕ 이었고 成牝牛의 平均 WBC數는 10,408(3,200~31,600)㎕으로 어느 年齡層에서나 높은 値이었으나 2年牛가 12,647/㎕로 特히 높았다. 9. WBC鑑別計數의 平均値는 淋巴球가 66.95(36~91), 單核球가 3.08(0~12), 好中球가 25.69(2~54), 好酸球가 3.84(0~18) 그리고 好鹽基球가 0.44(0~5)%이었으나 成牝牛의 平均値는 淋巴球가 65.87(36~86), 單核球가 3.15(0~9), 好中球가 25.84(6~53), 好酸球가 4.73(0~15) 그리고 好鹽基球가 0.4(0~2)% 이었다. 10. 淋巴球는 1年牛를 頂点으로 年齡의 增加에 따라서 減少하고 있었으나 好中球는 1年牛가 가장 낮았으며 年齡의 增加에 따라서 增加하여 淋巴球와는 負의 相關關係를 나타냈고 單核球와 好酸球는 高齡牛에서 若干 높은 傾向이 있었다. 11. 平均血小板數는 252,429(93,000~964,000)/㎕이었으나 成牝牛의 平均血小板數는 245,658(110,000~570,000)/㎕이었으며 年齡別特徵은 認定할 수 없었다. 12. 平均血淸TP量은 6.88(4.10~10.20)g/100ml이었으나 成牝牛의 平均血淸TP量은 7.35(5.10~10.20)g/100ml이었으며 年齡의 增加에 따라서 점점 增加하는 傾向이 있었다. 13. 平均血淸Alb量은 3.43(2.00~4.40)g/100ml이었으나 成牝牛의 平均血淸Alb量은 3.51(2.00~4.40)g/100ml이었으며 1年未滿牛의 3.33g/100ml 및 1年牛의 3.31g/100ml등 송아지에서 若干 더 낮은 傾向이 있었으나 그 外는 거의 비슷하였다. 14. 平均血淸Glb量은 3.45(1.10~7.15)g/100ml이었으나 成牝牛의 平均血淸Glb量은 3.84(1.40~7.15)g/100ml이었으며 年齡의 增加에 따라서 점점 增加하는 傾向이 있었다. 15. 平均血淸A/G比는 0.99(0.40~3.33)이었으나 成牝牛의 平均血淸A/G比는 0.91(0.43~2.64)이었으며 年齡의 增加에 따라서 점점 減少하는 傾向이 있었다. 16. 平均血淸 cholesterol量은 145.65(44.0~336.0)mg/100ml이었으나 成牝牛의 平均血淸cholesterol量은 180.93(46.4~336.0)mg/100ml이었으며 年齡의 增加에 따라서 增加하여 4年牛를 頂点으로 다시 下向하는 傾向을 나타내고 있었다. 17. 平均血淸 glucose量은 46.00(27.0~96.0)mg/100ml이었으나 成牝牛의 平均血淸glucose量은 39.61(27.0~65.0)mg/100ml이었다. 血淸 glucose量은 全般的으로 낮은 値이었으나 年齡別 平均血淸glucose量에서 1年未滿牛가 58.07(39.7~96.0)mg/100ml로 가장 높았으며 特히 어린 송아지에서 높았다. 18. 平均血淸Mg量은 2.68(0.20~8.60)mg/100ml이었으나 成牝牛의 平均血淸Mg量은 2.72(0.20~8.46)mg/100ml이었으며 年齡別 平均血淸Mg量에서 7年以上牛가 2.27mg/100ml로 特히 낮았으며 老齡牛에서 Mg의 減少가 顯著하였다. 19. 平均血淸Ca量은 4.36(3.16~8.40)mEq/L이었고 成牝牛의 平均血淸Ca量도 4.37(3.16~8.40)mEq/L로 全般的으로 낮은 量이었으며 年齡別 特徵은 認定할 수 없었다. 20. 平均血淸P量은 6.27(3.10~9.78)mg/100ml이었으나 成牝牛의 平均血淸P量은 5.92(3.10~9.78)mg/100ml이었으며 年齡別 平均血淸P量에서 1年未滿牛가 7.50(4.70~9.40)mg/100ml로 特히 높았다. 21. 平均血淸Ca/P比는 1.39(0.68~2.64)이었으나 成牝牛의 平均血淸Ca/P比는1.48(0.68~2.64)로 全般的으로 낮은 値이었으며 年齡別 平均血淸Ca/P比에서 1年未滿牛가 1.21(0.83~1.93)로 가장 낮았다. 22. 平均血淸K量은 4.94(3.5~6.7)mEq/L이었으나 成牝牛의 平均血淸K量은4.84(3.5~6.2)mEq/L이었으며 年齡別 血淸K量에서 1年未滿牛가 5.22(4.0~6.7)mEq/L로 特히 높았으며 그外는 거의 비슷하였다. 23. 平均血淸Na量은 138.43(123~157)mEq/L이었으나 成牝牛의 平均血淸Na量은137.32(123~157)mEq/L이었으며 1年未滿牛의 139.74mEq/L 및 1年牛의 140.16mEq/L등 송아지에서 더 높았다. 24. 平均血淸Cl量은 99.96(84.6~123.0)mEq/L이었고 成牝牛의 平均血淸Cl量도 100.09(84.6~123.0)mEq/L로 年齡別差異点은 발견할수 없었다. 25. 平均血淸Na/K比는 28.02(21.49~37.14)이었으나 成牝牛의 平均血淸Na/K比에서 1年未滿牛가 26.77(21.49~35.00)로 特히 낮았다. 26. RBC數, Hb數, PCV値, MCH 및 MCHC는 모두 15~20kg群에서 第一 높았고 20~25kg群, 25kg以上 群으로 갈수록 낮아지는 傾向을 보였다. 卽 赤血球系 檢査値와 産乳量과는 負의 相關關係에 있는 것으로 보아진다. 27. WBC數와 産乳量과는 負의 相關關係가 있는 것으로 보아지며 血小板數와 産乳量과는 特別한 關係를 認定할 수 없었다. 28. WBC鑑別系數와 産乳量과의 相關에서는 淋巴球는 負의 相關關係에 있는 것으로 보아지며 好中球는 淋巴球와는 反對로 正의 相關關係에 있는 것으로 보아진다. 한편 單核球와 好酸球는 産乳量增加에 따라서 增加하는 傾向이 있었다. 29. 血淸TP量 및 血淸Glb量은 産乳量增加에 따라서 增加하는 傾向이 있었으며 血淸Alb量 및 血淸A/G比는 産乳量增加에 따라서 減少하는 傾向이 있었다. 30. 血淸glucose量과 産乳量과는 負의 相關關係에 있는 것으로 보아지며 血淸cholesterol量은 産乳量增加에 따라서 增加하는 傾向이 있었다. 31. 血淸Mg量은 産乳量이 가장 많은 25kg以上群에서 特히 낮았으며 血淸Ca 및 P量은 産乳量增加에 따라서 增加하는 傾向이 있었으나 血淸Ca/P比는 産乳量增加에 따라서 減少하는 傾向이 있었다. 32. 血淸Na量 및 血淸Na/K比는 産乳量과는 正의 相關關係에 있는 것으로 보아지며 血淸K量은 産乳量增加에 따라서 減少하는 傾向이 있었고 血淸Cl量과 産乳量과는 特別한 關係를 認定할 수 없었다. This work was conducted to determine the composition of the blood of Holstein cattle in Korea and the relationships between the blood composition and milk production. Blood samples were taken from 870 healthy cattle in Chonnam province. Milk yield was recorded, and the results obtained in this study are summarized as follows: 1. Mean red blood cell(RBC) count was 5.97(3.20~9.96)×10 6/㎕, whereas the RBC count of adult cows was 6.06(3.20~9.74)×10 6/㎕. The RBC count between age groups appeared to be especially lower in the age group of 1 year(5.19×l0 6/㎕) than in the other age groups. 2. Mean hemoglobin(Hb)content was 9.61(5.3-18.4)g/100ml, whereas the Hb content of adult cows was 9.42(5.3-18.4)g/100ml. The Hb content between age groups appeared to be especially lower in the age group of 2 years(8.97g/100ml) than in the other age groups. 3. Mean packed cell volume(PCV) was 31.10(19-5)ml/100ml. The PCV between age groups was lowest in the age group of 2 years(29.84ml/100ml). 4. Mean corpuscular volume(MCV) was 52.09(23.77-86.57) fl. whereas the MCV of adult cows 51.22(29.77-6.57) fl. Mean corpuscular hemoglobin(MCH) was 16.10(8.21-28.96) pg, whereas the MCH of adult cows was 15.54(8.21-28.96) pg. Mean corpuscular hemoglobin concentration(MCHC) was 30.90(17.35-53.57)g/100ml, whereas MCHC of adult cows was 30.35(17.35-53.57)g/100ml. The MCV, MCH and MCHC appeared to be higher in the calves and heifers than in the adult cows. 5. Most anemic cattle showed macrocytic, hyperchromic anemia. Various types of anemia were detected; microcytic(MCV 37.15 fl) hypochromic(MCH 12.35.pg); macrocytic hypochromic(MCHC 24.21g/100ml); microcyticfMCV 35.71 fl)hyperchromic(MCHC 40.83g/100ml). 6. Mean white blood cell(WBC) count was 10,186(3,200-31,600)/ l, which was high compared with other results. The WBC count between age groups appeared to be especially higher in the age group of 2 years(12, 647/yu.e) than in the other age groups. 7. Mean differential WBC count was lymphocyte 66.95(36-91), monocyte 3.08(0-12), neutrophil 25.69(2-54), eosinophil 3.84(0-18) and basophil 0.44(0-5%), respectively, while in the adult cows, it was lymphocyte 65.87(36-86), monocyte 3.15(0-9), neutrophil 25.84(6-53), eosinophil 4.73(0-15) and basophil 0.41(0-2)%, respectively. Lymphocyte count increased up to 1 year of age and thereafter it decreased with age, whereas the reverse was the case with neutrophil count. There was a negative correlation between lymphocyte and neutrophil counts. Monocyte and eosinophil counts tended to be slightly higher in the older age groups. 8. Mean platelet count was 252,429(93,000-964,000)/㎕; no differences were found in the platelet count between age groups. 9. Mean serum total protein(TP) content was 6.88(4.10-10.20)g/100ml, while the TP content of adult cows was 7.35(5.10-10.20)g/100ml. The TP content tended to increase with age. 10. Mean serum aIbumin(Alb) content was 3.43(2.00-4.40)g/l00ml, while the Alb content of adult cows was 3.51(2.00-4.40)g/100ml. The Alb content appeared to be lower in the calves and heifers than in the adult cows. 11. Mean serum globulin(GIb) content was 3.45(1.10-7.15)g/100ml, while the Gib content of adult cows was 3.84(1.40-7.15g)/100ml. The Gib conienc tended to increase with age. 12. Mean serum .albumin: globuIin(A/G) ratio was 0.99(0.40-3.33), while the A/G ratio of adult cows was 0.91(0.43-2.64). The A/G ratio tended to decrease with age. 13. Mean serum cholesterol concentration was 145.65(44.0-336.0)mg/100ml, whereas the scrum cholesterol concentration of adult cows was 180.93(46.4-336.0)mg/100ml. The serum cholesterol concentration increased up to 4 years of age and thereafter it decreased with age. 14. Mean serum glucose concentration was 46.00(27.0-96.0)mg/100ml, whereas the serum glucose concentration of adult cows was 39.61(27.0-65.0)mg/100ml, which was low compared with other results. The serum glucose concentration between age groups appeared to be especially higher in the age group of less than 1 year(58.07mg/100ml) than in the other age groups. 15. Mean serum magnesium(Mg) concentration was 2.68(0.20-8.60)mg/100ml, whereas the Mg concentration of adult cows was 2.72(0.20-8.46)mg/100ml. The Mg concentration between age groups appeared to be especially lower in the age group of more than 7 years(2.27mg/100ml) than in the other age groups. Decreased Mg concentration was shown in older cows. 16. Mean serum calcium(Ca) concentration was 4.36(3.16-8.40)mEq/L, which was low compared with other results. No differences were found in the Ca concentration between age groups. 17. Mean serum inorganic phosphate(P) concentration was 6.27(3.10-9.78)mg/100ml, whereas the P concentration of adult cows was 5.92(3.10-9.78)mg/100ml. The P concentration between age groups appeared to be especially higher in the age group of less than 1 year(7.50mg/100ml) than in the other age groups. 18. Mean serum calcium: inorganic phosphate(Ca/P) ratio was 1.39(0.68--2.64). The Ca/P ratio of adult cows was 1.48(0.68-2.64), which was lower compared with other results. The Ca/P ratio between age groups was lowest in the age group of less than 1 year(1.21). 19. Mean serum potassium(K) concentration was 4.94(3.5-6.7)mEq/L> whereas the K concentration of adult cows was 4-84(3.5-6.2)mEq/L. The K concentration between age groups appeared to be especially higher in rhe age group of less than 1 year(5.22mEq/L) than =n the other age groups. 20. Mean serum sodiurn(Na) concentration was 138.413(123-157)mEq/L> whereas the Na concentration of adult cows was 137.32(123-157)mEq/L. The Na concentration between age groups appeared to be higher in the calves and heifers than in the adult cows. 21. Mean serum chloride concentration was 99.96(84.6-123.0)mEq/L; no differences were found between age groups in the scrum chloride concentration. 22. Mean serum sodium: potassium(Na/K) ratio was 28.02(21.49-37.14), whereas it was 28.37(22.00-37.14) in the adult cows. The Na/K ratio between age groups appeared to be especially lower in the age group of less than 1 year(26.77) than in the other age groups. 23. The values of RBC count, Hb content, PCV, MCH and MCHC increased up to 15-20kg milk yielding group and thereafter they tended to decrease with higher milk yielding groups. In other words, there was a negative correlation between the values of erythrocytic series and milk production. 24. The leukocyte and lymphocyte count were a negative correlation with milk yield, while the neutrophil count was a positive correlation wirh milk yield. The monocyte and eosinophil count tended to increase as milk production increased. No relationships were found between the platelet count and milk production. 25. The serum total protein and globulin content tended to increase as milk production increased, while the reverse was the case with serum albumin content and A/G ratio. 26. The serum glucose concentration was a negative correlation with milk yield. The Serum cholesterol concentration tended to increase as milk production increased. 27. The serum calcium and inorganic phosphate concentration tended to increase as milk production increased, while the opposite was the case with Ca/P ratio. The serum magnesium concentration was especially lower in the highest milk yielding group than in the other milk yielding groups. 28. The serum sodium concentration and the Na/K ratio tended to increase as milk production increased. In other words, there was a positive correlation with milk yield. The serum potassium concentration tended to decrease as milk production increased. No relationships were found between the serum chloride concentration and milk production.

활성탄을 이용한 낙동강 상수원수의 수처리 효과

임영성,강관호,이홍재,서동철,허종수,손보균,조주식 한국환경농학회 2002 한국환경농학회지 Vol.21 No.3

상수원수를 보다 효과적으로 처리함으로서 양질의 수돗물을 공급하기 위한 기초자료를 얻고자 낙동강 상수원수를 대상으로 활성탄처리에 의한 공탐체류시간 및 활성탄 여층 깊이에 따른 수처리 효율과 생물활성탄으로서의 이용 가능성을 조사한 결과는 다음과 같다. 공탑체류시간(EBCT)에 따른 수처리 효율은 EBCT가 증가할수록 증가되었으나 운전시간이 경과함에 따라 활성탄 흡착능력은 감소되어 처리효율도 서서히 감소하였다. 활성탄 여층깊이에 따른 pH 변화는 활성탄 층 깊이에 따라 거의 없었으며, D0는 활성탄 층 깊이가 깊을수록 서서히 감소하였다. KMnO^4 소비량, UV254 흡광물질 DOC 및 THMFP 처리효율은 활성만 표층으로부터 하부로 내려갈수록 증가하였으며, 운전시간이 경과할수록 활성탄 상층부에 형성되어 있던 흡착대파 하부로 이동하였다. DOC의 상당 부분이 활성탄여과지에 서식하는 미생물 작용에 의해 분해 제거되는 것으로 나타났으며, 운전개시 126일 후의 BAC에서 활성탄 표층으로 부터깊이 20 cm 부근에 미생물이 1.1*10^7 cell/cm^3 이상 존재하는 것으로 관찰되어 생물활성탄 조건을 만족시키고 있었다. This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using mated carbon process. For raw water, Nakdong river was used. From the activated carbon adsorption experiment, the following results were obtained. The efficiency of water treatment enhanced with increase in empty bed contact time. Variation of pH was not detected to the bed depth, but DO content gradually decreased with the bed depth, Removal efficiency of KMnO₄ consumption, UV254 absorption, DOC and THMFP also were increased by increasing in the bed depth. Transition of adsorption zone from upper parts of the bed to the lower parts were detected as treatment periods increased. Large portion of DOCs were degraded and removed by the microbes growing on the surface of activated carbons. Cell numbers of microbes were estimated over 1.1 × 10 exp(7) cell/㎤ at the depth of 20 ㎝ from the surface 126 days after starting operation. The results shown that the activated carbon filter was successfully acted as a biofilm filter.

낙동강 상수원수의 오존처리 효과 : II. 회분식 오존처리에 의한 휘발성유기화합물 및 조류제거 효과 II. Removal of VOCs and Algae in Raw Water by Conducting Batch Test of Ozonation Experiments

임영식,이홍재,이도진,허종수,손보균,조주식 한국환경과학회 2002 한국환경과학회지 Vol.11 No.12

This study was carried out to evaluate the pollutant removal efficiencies of the advanced drinking water treatment using ozonation process. For raw water, Nakdong River was used. By conducting batch test of ozonation efficiencies of the ozonation were 94 to 92%, respectively. Removal efficiencies of single VOC compound or mixed VOC compounds in the raw water were 80% to 90% by the ozonation with 2 mg/ℓ dosage and 10 minutes contact time. Removal efficiencies of ABS by the ozonation with 1 mg/ℓ, 3 mg/ℓ dosage and 20 minutes contact time were 83% to 96%, respectively. Almost 67% of chlorophyll-a at the concentration of 38.㎍/ℓ was removed by ozonation at ozone dosage of 1mg/ℓ for 20 min. considering the efficiency of ozone utilization and water treatment, the most effective ozonation could be obtained with high ozone dosage and short and short contact time.

卒業定員制 實施 以後의 被學事警告者의 實態에 關한 調査硏究 : Focusing on the BNU Students of Academic Years 1981 and 1982 釜山大學校 1981, 1982學年度 入學生을 中心으로

林再澤,鄭弘燮 釜山大學校 學生生活硏究所 1982 硏究報 Vol.18 No.1

The present study is an attempt to find some informations of the under-graduate students who were probated or dismissed by BNU for unsatisfactory academic reasons since the Graduation Quota Policy. The variables considered in this research were several life backgrounds, college entrance examination score, attitudinal characteristics, and personality of the students. The subjects were 1961 students (1330 freshmen and 631 sophmores) who were probated or dismissed by the BNU regulations for Spring and Fall semesters of Academic Year 1981 and Spring semester of Academic Year 1982. The Groduation Quota Policy refers to a new educational system in which, out of 130% of college entrees, only 100% of the students are supposed to be given bacelers degree, whereas the rest of students (30%) are supposed to drop out of college programs since the Academic Year 1981 in case of every College and University in Korea. According to the implementation of this policy. students with a cumulative undergraduate course average below 1.8, or two or more grade F for two or more times before the graduation of the college are removed their name from the register by the school. The life backgrounds and the attitudinal characteristics of the subject were measured on the questionaries which were established by the Student Guidance Center at BNU, and their Personality Characteristics were measured on the Standardized Personality Diagnostic Test by Sang Ro Lee et al. These data including the subjects' college Enterance examination scores were collected at the beginning of the subjects' college entrance. As a reference, we constrasted some variables of the subjects with those of the other equivalent students including the subjects at BNU. The major findings are as follows: 1) The students who were probated or dismissed for unsatisfactory academic reasons after implementation of Grduation Quota System relatively increased more than those before the implementation of Graduation Quota System, that is, 11.7% to 1.8%, 11.2% to 1.9%, and 10.3% to 0.8% at Spring and Fall semesters of Academic Year 1981 and Spring semester of the Academic Year 1982 respectively. 2) By the analysis of data in terms of the place of residence family atmosphere, and socio-economic status, there were no significant difference between the distribution of the subjects and that of the other equivalent general students. But the propotion of the rural subjects were significantly higher that of urban subjects on the .005 level of significance. 3) There were no significant differences between the distribution of the subjects and that of the other general students according to the liberal high schools and the specialized high schools including commercial, technical, agricultural schools. 4) The less college entrance examination scores the subjects earned, the higher proportion of them were probated or dismissed by BNU concerned for unsatisfactory academic performance reasons. 5) There were a little significant relations between college entrance examination score and the subjects involved. That is, the subjects who have earned less college entrance examination scores appeared more dominant in the order of humannities, physical sciences, social sciences, engineering, and arts area. 6) Students who earned the college entrance examination scores under the lower 30 percentile in each department were equal to 41.9% of all the probated and dismissed students. and the propotion of the subjects who were higher than 20 percentile of college entrance examination score distribution of the whole students each department appeared 9.8 percent of the total subjects. 7) Where were no significant differences between the distribution of the subjects and that of the other general students in terms of types of perception of the social problems, levels of satisfaoften with their areas of study, level of interest in circle activities, and personality traits

염수분무 환경에서 알루미늄-크롬 용융도금강판의 부식생성물이 내식성에 미치는 영향

임병문,홍승현,정재인,최장현,정원섭 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.10

The effect of corrosion products of hot-dip Al-Cr steel sheet on the corrosion resistance were investigated. The results of XRD and XPS measurements showed that there was not found a hydroxide type corrosion product on the surface of aluminized steel after salt spray test(SST) but there was found some cracks in the surface layer which accelerates corrosion during SST. In Al-Cr coated steel case, the main phase of the corrosion products after salt spray test was found to be Al(OH)₃. The polalization curves of aluminized steel after SST shows that there was no passivation layer. For the Al coated layer, a porosity in the Al-oxide film on the surface layer leads to preferential corrosion. After the Al coated layer was completely removed, the Al_(5)Fe₂layer was selectively corroded and then, the steel substrate was exposed to the electrolyte. However, the polalization curves of Al-Cr coated steel after SST shows that the passivation layer was formed, which could increase the corrosion resistance of Al-Cr coated steel. In case of the Al-Cr coated layer, the densely covered hydroxide layer of Al(OH)₃and the intermetallic compound layer of Al_(13)Cr₂became a barrier against further corrosion after the Al layer was removed. In this case, corrosion was not proceeded even through the same current density. The densely covered hydroxide of Al(OH)₃and the intermetallic compound layer of Al_(13)Cr₂were considered to be one of the reasons of high corrosion resistance for Al-Cr coating.

알루미늄-크롬 용융도금강판의 미세조직과 집합조직에 미치는 크롬의 영향

임병문,홍승현,정재인,최장현,정원섭 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.10

Microstructure and texture changes of aluminized coatings on steel sheets having Cr ranging from 0.0% to 1.0% in the coated layer were investigated. The surface morphology of the Al-Cr coated steel is not influenced by the increase of Cr contents in the coated layer. While the coated layer of aluminized steel consisted of two phases of Al and Al_(5)Fe₂, the aluminized coating layer containing Cr was composed of three phases of Al, Al_(13)Cr₂, and Al_(13)Fe₄+Al_(5)Fe₂. The surface layer was Al, the middle layer was Al_(13)Cr₂, and the interfacial layer between the coating and the steel substrate was Al_(13)Fe₄and Al_(5)Fe₂. The texture of the aluminized coating without Cr was characterized as a {001} fiber texture which major orientation was {001}<110>. As the Cr content in the aluminized layer was increased to 1.0%, the texture of the aluminized coating was not changed but the intensity of the {001} fiber texture was increased. The major orientation in the {001} fiber texture was changed from the rotated cube orientation of the aluminized coating with 0.1%Cr to the cube orientation of the aluminized coating with 1.0%Cr.

골재생산과 관련한 터널작업에서 효율적인 심빼기 발파공법

임한욱,김재홍,조영동 강원대학교 부설 석재복합신소재 제품연구센터 2000 석재연 논문집 Vol.5 No.-

실린더 컷 심빼기 공법은 일반적으로 터널단면에 관계없이 널리 쓰이는 방법이다. 본 연구에서는 종래의 실린더 컷 공법을 개선한 새로운 방법을 제안하였다. 제안한 방법의 특징은 발파당 굴진장을 증대시킬수 있는데 이를 요약하면 다음과 같다. 발파당 굴진장은 평균 3.8m 이상으로 종래의 심빼기 바법 경우 천공장의 90~95% 인데 비하여 제안한 방법은 천공장의 99.5%까지 가능하다. 또한 비장약량은 1.363에서 1.297 kg/㎥로 약 5%가, 비천공장은 2.393에서 2.130 kg/㎥로 약 8%가 감소되었다. 이외에 발파진동, 비산거리, 파쇄입도면에서도 종래 방법보다 양호함을 확인하였다. The cylindrical cut is most frequently used in tunnelling regardless of their dimensions. In this study the new parallel cut is proposed to raise advance per round, which is considered to be an elevation of the traditional cylinder cuts. The main results of this study are as follows; The average advances per rounds in new cuts can reach 99.5% of drilling length. That of traditional cylinder cuts are known approximately 90~95%; Specific charge weight is approximately reduced 5%(1.363→1.297 kg/㎥); Specific drilling rate is also reduced 8% compared to that of cylinder cut(2.393→2.130 kg/㎥); Vibrations, fly rock, and fragmentation produced by the new blast are to be proved superior to those of the traditional cylinder cuts.