소포제를 이용한 초속경 LMC의 특성 개선연구

윤경구,김성환,정원경,권혁찬 강원대학교 부설 석재복합신소재 제품연구센터 2003 석재연 논문집 Vol.8 No.-

본 논문은 콘크리트 배합시 발생하는 과도한 기포 발생 문제점을 해결하기 위하여 최적의 소포제 종류 및 혼입률 범위를 산정하여 초속경 라텍스개질 콘크리트 성능을 개선하는 것이다. 초속경 라텍스개질 콘크리트 실험은 2종류의 소포제 A, C와 혼입률 0, 1, 2, 3%을 주요 변수로 하여 공기량 시험, 압축강도 및 휨강도 시험을 수행하였다. 또한, 내구성 평가를 위하여 염소이온 투과실험도 수행하였다. 초속경 라텍스 개질 콘크리트의 공기량시험 결과 소포제 종류에 상관없이 소포제 혼입률 1%이상 첨가시 공기량은 50%이상 감소하였다. 또한, 소포제 첨가에 의한 기포 발생량 감소에 의해서 압축강도의 증진을 이루었다. 초속경 라텍스개질 콘크리트 실험은 A, C 소포제로 선정하여 실험을 수행하였다. 초속경 라텍스개질 콘크리트의 강도 특성에서는 A 소포제 혼입률 1%에서 압축강도 235kgf/㎠ , 휨강도는 조기 교통개방에 요구되는 휨강도 기준 45kgf/㎠를 초과하는 49kgf/㎠를 나타내었다. The purpose of this study was to remove the excessive air foaming which was produced in mixing the RSLMC(latex-modified concrete with rapid-setting cement) by choosing the best antifoam agent type and the optimized quantity for performance improved RSLMC. The main experimental variables such as antifiamer types(A, C), antifoamer contents(0, 1, 2, 3%), and latex contents(15%). Air content test and compressive, flexural tests were carried out to measure the improved properties of RSLMC. the rapid chloride permeability was carried out to estimate a durability of RSLMC. The results of RSLMC showed that the decrease of 50% air content was obtained by admixturing a antifoam agent by 1%. Two kinds and the optimized quantities of antifoam agent were selected for using in RSLMC. The results of RSLMC were obtained at a latex content of 15% and a antifoam agent quantity of 1% with antifoamer A type. The compressive strength and flexural strength at 3 hours after RSLMC placement were 235kgf/㎠ and 49kgf/㎠, respectively, which exceeded the flexural strength criterion of 45kgf/㎠ in order to open the RSLMC placed to traffic.

주혈관이 하나만 남은 하퇴부 연부조직 결손 환자에서 비복혈관(sural vessel)을 수혜혈관으로 한 유리피판 전이

변재경,하범준,현원석,김재중,신명수 大韓成形外科學會 1999 Archives of Plastic Surgery Vol.26 No.3

Free flaps have been widely used in lower leg reconstruction. However, in cases with extensive injury to the vessels as well as to the bone and soft tissues, and having only one intact major vessel in the lower leg(single vessel leg), careful selection of recipient vessels for the free flap transfer is mandatory for preventing further vascular compromise of the distal lower leg. The sural artery and its vena comitantes are frequently protected form externally harmful forces by the bulky surrounding gastrocnemius muscle and can be used as recipient vessles for free flaps without any detrimental influence on the vascularity of the distal lower leg. In our department, three latissimus dorsi muscle free flap were transferred with sural vessels as recipient vessels in the reconstruction of the single vessel legs. Except for one case of flap failure due to serious infection at the microvascular anastomoses site, all the other cases were successfully reconstructed without any necrosis of the gastrocnemius muscle or the distal leg. In addition, the sural vessels were easily accessed in any patient position and their caliber was similar to that of the vascular pedicles of the donor muscle flaps. In conclusion, the sural vessels can be another useful option in selecting recipient vessels for free flap transfer in the reconstruction of the single vessel leg.

특1급 호텔과 특2급 호텔 간 호텔정보시스템 품질 비교

이병원,윤병섭,이경구 대한경영학회 2003 大韓經營學會誌 Vol.16 No.7

The purpose of this study is to analyse the critical differences of the hotel information system's EDP(electronic data processing) internal control and quality between 1st 5star hotels and 2nd 5star hotels. This paper examines the relationships of the hotel information system's internal control and quality with that of user satisfactions. This study sets out the research model of influencing factors and the performance of the hotel information system through theoretical studies based on Management Information Systems, and then empirically tests hypotheses related to the model. The model was tested by multiple regression analysis using SPSS 10.0 on a sample of 618 respondents who have worked with the hotel information system in 5star hotels. The major results of this study are as follows: First, differences between 1st 5star hotels and 2nd 5star hotels are statistically significant influences on EDP internal control. Second, information quality, system quality and service quality of 1st 5star hotels are more statistically significant influences on the hotel information system's quality than that of 2nd 5star hotels. Third, EDP internal control has a statistically significant influence on the hotel information system's quality. The study's findings also indicate that EDP internal control of hotel information system affects differently on the quality of hotel information system according to grade of hotels.

콘크리트 鋪裝의 初期計測을 통한 初期擧動 特性分析

정원경,김동호,권혁찬,윤경구 강원대학교 산업기술연구소 2003 産業技術硏究 Vol.23 No.A

The purpose of this paper is to analysis of initial behavior of concrete pavement with initial measurement strain gauge for concrete pavement at field, and to investigate the field test results for field applicability testing. The early-age behaviors of concrete pavement slabs were measured using the strain gauges. From the slab depths and positions, the outputs from each gauges were recorded at initial curing period The initial measurement of concrete pavement and check of crack at the joint were performed. the results could be summarized as follows. From the results of concrete strength, compressive strength and flexural strength were showed 271kgf/㎝', 43kgf/㎝' respectively. From the tests of early-age strain measurement, it was found that the strain varied at the maximum value of 150μ ε and early1 behavior of concrete slab was showed a tensile strain However. for long-term was showed a compressive strain due to dry-shrinkage.

라덱스 혼입률에 따른 철근콘크리트의 휨파괴 거동특성

정원경,김동호,이주형,임홍범,윤경구 江原大學校 産業技術硏究所 2002 産業技術硏究 Vol.22 No.A

Reinforced concrete(R/C) is commonly used to structures because they have many merits that compressive strength, economy and so on. However, reinforced concrete has a crack at the tensile section which is due to the relatively lower tensile strength than its compressive strength. Latex modified concrete(LMC) has higher tensile and flexural strength than the ordinary portland cement, due to the interconnections of hydrated cement and aggregates by a film of latex particles. The purpose of this study was to investigate the flexural behavior of reinforced concrete beam with latex modified concrete, having the main experimental variables such as concrete types(ordinary portland cement concrete, latex modified concrete), latex contents(0%, 15%), flexural steel ratios(0.012, 0.0235), and with/without shear reinforcement. The beam of LMC showed considerably higher initial cracking loads and ductility than that of OPC, but, similar to ultimate strength and deflection. This might be attributed to the interlocking of hydrated cement and aggregates by a film of latex particles, water retention due to hydrophobic, and colloidal properties of the latexes resulting in reduced water evaporation. The beam with latex modified concrete could be adopted at field for controlling and reducing the tensile crack due to its higher tensile strength.

국립 디지털도서관 조경설계

김도경,최원만,박지순 경희대학교 디자인연구원 2005 예술· 디자인학연구 Vol.9 No.2

This winning landscape design was presented to a national design competition for the master plan of new Digital Library on the existing National Library of Korea. The site is located at San 60-1, Banpo-Bong, Seocho-Gu, Seoul and has an area of 142,233㎡. The judging criteria for landscape design set by the client could be articulated as follows: an environment friendly design and a landscape design harmonizing existing facilities with new digital library. In this design, we first tried to respect its existing setting and context, a library in a city park environment, Also the design required an interpretation of the meaning of 'digital library' and its relationship with 'old' library.

콘크리트 공극 분석을 위한 평면간격계수의 제안

정원경,최성용,김성환,윤경구 江原大學校 産業技術硏究所 2005 産業技術硏究 Vol.25 No.A

Air void systems in hardened concrete has an important influence on concrete durability such as freeze-thaw resistance, water permeability, surface scaling resistance. Linear traverse method and point count method described at ASTM are the routine analysis of the air void system that have been widely used to estimate the spacing factor in hardened concrete. Recently, many concretes often have a spacing factor higher than the generally accepted 200-250㎛ limit for the usual range of air contents. This study is proposed to estimate the plane spacing factor by calculation of simplicity. The plane spacing factor need two parameters that are air content and numbers of air voids in the hardened concrete. Those obtained from the standard air-void system analysis of the ASTM C 457. The equation is valid for all values of paste-to-air ratio because the estimation of paste content is unnecessary at the using ASTM C 457. The plane spacing factor yields a similar estimate of the standard spacing factor.

대유행 인플루엔자(H1N1 2009) 급성호흡곤란증후군에 대한 체외막 산소화 장치의 조기적용 1예

이경학,이길수,오원섭,유숙원,천성빈,이승준 대한감염학회 2010 감염과 화학요법 Vol.42 No.2

Despite advanced technologies in intensive care, pandemic influenza (H1N1 2009) can rapidly progress to acute respiratory distress syndrome (ARDS) and cause death in a small subset of patients. Extracorporeal membrane oxygenation (ECMO) is expected to provide adequate gas exchange, to reduce ventilator-induced lung injury and, eventually, to improve outcome in these patients. A previously healthy, young female received mechanically ventilatory support because of rapidly progressive respiratory failure caused by 2009 H1N1 influenza. As she failed to respond to high ventilatory support, ECMO was instituted at 6 hours after admission. We describe detailed course of case and literature review on ECMO, helping physicians make a decision to initiate ECMO in patients with influenza-related ARDS.

젠더와 교육 : 무엇이 문제인가

조경원 신라대학교 여성문제연구소 2006 젠더와 사회 Vol.17 No.-

經濟作物 主産團地에서의 灌漑實態와 適正灌水를 위한 諸要因 究明에 關한 硏究

李庚熙,金始源,金鍾天 建國大學校附設 農業資源開發硏究所 1982 論文集 Vol.7 No.-

우리나라 經濟作物 主産地에서의 土壤水分管理의 合理化를 위하여 栽培團地內의 土性, 圃場內의 土壤水分含量의 變化狀態, 각 作物의 蒸散量, 그리고 실제 農家에서의 灌水에 대한 關心度의와 灌水實態를 調査하였고, 이것을 基礎로 하여 주요 作物에 대한 施策에 參考가 될 資料를 얻었기에 이에 그 結果를 報告하는 것이다. 1) 平澤地域의 배추 圃場은 대체적으로 砂質土壤으로 灌水의 必要性이 대단히 컸다. 특히, 栽培期間中에 143.4mm의 降水量이 있었으나 적어도 6回에 걸쳐 139.9mm의 灌水가 더 되어야 適正水分을 維持할 수 있는 상태였다. 戶當 배추 栽培面積은 平均 2,130坪으로 경영 규모도 큰 편이며, 用水源도 여러 종류로 많이 갖고는 있었으나 스프링 쿨러를 이용하는 農家는 1,23%에 불과하였으며 灌水時期 決定을 科學的으로 하지 못하고 있었다. 그리고 揚水機의 確保數가 적으며 너무 小型이었다. 2) 瑞山地域의 마늘 栽培團地의 土性은 대부분 砂質 및 砂質壤土로서 排水는 잘 되는 곳을 擇하고 있었으나 灌水施設은 대단히 적은 상태였다. 地下水位 70∼80cm의 곳에서는 適正水分 維持가 容易하였으나 그 외에는 적어도 9回에 걸쳐 428.4mm의 灌水가 더 되어야 한다. 즉, 마늘 栽培期間中 565.6mm의 降雨가 순조롭게 있어야 하며 이보다 적을 때는 灌水로 補充되어야 한다. 戶當 마늘 栽培面積은 약 300∼1,500坪으로 마늘로서는 규모가 비교적 큰 편이었으며, 61.3%의 農家가 灌水를 하고는 있었으나 灌水 回數가 2∼3回 밖에 안 되어 불충분하였으며 用水源은 대부분 地下水를 이용하고 있었다. 스프링 쿨러를 이용하는 農家는 3.5%에 불과하였고 70.2%가 호스관수를 하고 있었다. 揚水機도 3馬力이 36.8%로 아주 小型인 것이 대부분이었다. 3) 忠州地域의 고추 栽培團地의 土性은 砂質壤土가 39.6%로 排水가 容易한 편이었다. 비닐멀칭을 하였으나 蒸發量 313mm에 대하여 降水量 199.5mm로 乾燥의 害를 받고 있었다. 499.5mm의 灌水가 있어야 하는데 降水量이 199.5mm 밖에 안 되며 이것도 集中的으로 내렸기 때문에 期間中에 300mm의 灌水가 要求되었다. 즉, 灌水間斷日數 10日, 1回 30mm의 灌水가 要求되었다. 戶當 고추 栽倍規模는 약 1,800坪으로 큰 편이었으며, 灌水를 한 農家는 56.3%로 많은 편인데 1回 灌水가 44.4%로 가장 많았으며 2回가 18.5%로 灌水回數가 적어 건조의 害가 많은 편이었으나 멀칭 栽倍로 피해는 감소되었다. 멀칭 재배이기 때문에 스프링 쿨러는 전혀 사용하지 않았으며 도랑관개가 14.8%로 많은 편이었다. 用水源은 냇물이 主였으며 用水源이 가까운 곳에서만 灌水가 실시되고 있었다. 4) 大關嶺 高冷地에서의 감자 栽倍에 있어 栽倍期間 중 降水量은 5mm 이상의 것이 20回나 되었기 때문에 適濕狀態가 유지되었다. 그럼에도 불구하고 降雨가 集中的으로 있었기 때문에 場所에 따라서는 水分不足狀態가 심하여 77日間의 生育期間 중 後期에 pF 2.5 이상이 15日이나 나타나는 곳도 있었다. 灌水에 대하여서는 관심도 없었고 施設의 준비도 전혀 없는 상태였다. 5) 忠州地域의 담배 圃場은 대체적으로 砂質이 많은 土壤으로 많은 灌水를 要하는 狀態였다. 1日 平均 降水量 5.4mm이었으나 集中降雨期間을 除外하면 1日 平均 2.6mm 降雨에 蒸發量 3.8mm로 水分不足狀態으나 비닐멀칭처리로 심한 乾燥의 害는 없었다. 즉, pF 2.3 이상은 期間中에 나타나지 않았다. 이는 담배의 蒸散量이 2.8mm로 적은 데에도 원인이 있는 것으로 생각된다. 멀칭栽倍로 灌水 回數는 적어서 1∼2回가 대부분이었으며 하천 가까이의 圃場에서만 실시 되었다. 6) 大邱地方의 사과園 土壤은 砂土 및 砂壤土가 90%이었고, 栽倍農家의 93%가 灌水를 하고 있으며 年間5∼7回를 灌水하는 農家가 68%로 가장 많았다. 大邱地方의 砂壤土 사과園에서 實施한 試驗結果로는 土壤水分測定器로 14.7cmHg(pF 2.3)가 灌水할 適期라고 推定되었고 1回 灌水量은 最低 40mm(40T/10a) 정도로 하고 7∼10日 間隔으로 實施함이 適合할 것으로 推定되었다. 7) 배에 대한 壤土에서의 試驗結果 土壤水分測定器로 14.7cmHg(pF 2.3)가 灌水의 適時이며 1回 灌水量은 最低 40mm(40T/10a) 정도로 하고 10∼14日 間隔으로 實施함이 適合할 것으로 推定되었다. 8) 大田地方의 砂質土에서 實施한 포도園에 대한 試驗結果 土壤水分測定器로 14.7cmHg(pF 2.3)가 灌水의 適時이며 灌水量은 最低 30mm(30T/10a)로 하고 10日 間隔으로 實施함이 適合할 것으로 推定되었다. 9) 平澤地方의 배 栽倍農家 중 59%가 無灌水로 栽倍하고 있었는데 그 중 75%는 灌水를 希望하고 있고, 大田地方의 포도 栽倍農家 중 87%가 無灌水로 栽倍하고 있으며 그 중 90%가 灌水를 希望하고 있으나 與件未備로 못하고 있는 實情이었다. 10) 調査 대상의 모든 栽倍團地에서 대부분이 肉感을 통해서 灌水時期를 決定하고 있는데 좀더 科學的인 方法으로 하기 위하여는 土壤水分測定器를 供給하여 灌水時期와 灌水量을 決定할 수 있도록 조치함이 必要할 것으로 생각된다. 11) 현재 一般的으로 灌水施設은 미약하나 施設을 갖추려고 하는 農家가 많으므로 栽培規模에 대한 適切한 揚水機의 普及이 政策的인 次元에서 이루어져야 할 것이다. For proper management of watering system in Korea, soil texture, change in soil moisture in the field, and amount of transpiration for eight crops cultivated in eight region were measured. Farmer's interest on watering and the present status of watering were surveyed. The following results were obtained. 1. At the region of Pyung-taek, the soils for Chinese cabbage was generally sandy loam, which requires large amount of watering. The precipitation during the cultivation period was 143.4mm and at least the additional 139.9mm watering in the 6 days interval was necessary for the optimal growth. Average cultivation areas of one household was 6901.2m², the sources of water were various. Only 1.23% of farmers was using sprinkler, and the number of pump was short and the type was too small. 2. At the region of Seo-san, the soil for garlic cultivation was sandy or sandy loam. The site was well drained, but had bad facilities. The area of which watertable was 70-80cm had adequate moisture condition. The other area required 428.4mm watering in the 9 days interval, i.e. during the garlic cultivation the 565.6mm precipitation is necessary. Average cultivation area per household was about 3240m². The 61.3% of farmer was watering the garlic field 2 to 3 times throughout the cultivation period, which was not enough. The source of water was mostly from the underground, the 3.5% used sprinkler system and the 70.2% the house, the 36.8% used the pump less than 3 HP. 3. At the region of Chung-ju, 39.6% of soil for red-pepper cultivation was sandy loam and well drained type. The precipitation 199.5mm during cultivation period resulted drought injury as the evaporation reached 313mm even with polyethylene film mulching. Total 499.5mm i.e. 30mm watering at 10 days interval for 100 days and the natural precipitation 199.5mm was required. Average cultivation area of red-pepper per household was 5832m². The 56.3% of farmers was watering; the 44.4% once only and the 18.5% twice. No sprinkler was used because of polyethylene mulching. The 14.8% used furrow irrigation. The source of water was from the stream near the field, which was most of the case. 4. At the region of Dae-gwan-ryeong, in most field there was no water shortage. In some fields since the precipitation occurred in a short period of time, and the precipitation more than 5mm for one time occurred on 20 occasion, the potato suffered water shortage during 77 days of cultivation period. In the field pF value more than 2.5 was recorded for 15days at the end of the cultivation period. No irrigation was done at the region of Dae-gwan-ryeong. 5. At the region of Chung-ju the soil for tabacco was sandy and required watering. Average precipitation per day was 5.4mm, but the precipitation was 2.6mm while the evaporation was 3.8mm when the concentrated precipitating period was excluded. The shortage of water was prevented by polyethylene film mulching and partly by the low transpiration of tabacco 2.8mm per day. The watering was done once or twice only at the field of tobacco near the stream. 6. At the region of Dae-gu the 90% soil for apple farm was sandy or sandy loam. The 93% farmer watered and the 68%, 5 to 7 times per year. It was estimated that the soil water condition which required watering was 14.7cm Hg(pF 2.3) by tensiometer, and the proper amount of watering at one time was at least 40mm(40T/10a) and that the interval. 7 to 10 days. 7. At the region of Pyung-taek pear farm, It was estimated that the soil water condition which required watering was 14.7cm Hg(pF 2.3), and that the amount of watering at one time was 40mm(40T/10a) and that the interval, 10-14 days. 8. At the region of Dae-jeon the sandy soil for grape required watering at least 30mm at one time in 10 days interval when the soil moisture condition reached 14.7 cm Hg(pF 2.3). 9. 59% of pear grower at Pyung-taek used no irrigation, but the 75% of them were interested in watering. Similarly 87% of grape grower at Dae-jun had no watering system, but the 90% of them were interested in watering, if they could. 10. In all the region surveyed the timing of watering was decided by each farmer's subjective experience. It is necessary that the timing and the amount of watering should decided by some objective method such as tensiometer. 11. Generally in the most farms, watering facilities were illequiped, or none. Since many farmers were intended to have the facilities, proper size of water pumps which fits to their cultivation area should be supplied nationally.