• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
• /
• pp.193-194
• /
• 2010

콘크리트 표면도장을 고려한 염소이온 침투해석 프로그램을 개발하고, 이를 사용하여 내구수명 연장 효과를 분석하였다. 해석결과에 의하면 표면도장은 가능한 초기에 실시하는 것이 효과적이었다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2007년도 춘계학술대회 논문집
• /
• pp.535-536
• /
• 2007

• 한국토양비료학회지
• /
• 제49권2호
• /
• pp.115-124
• /
• 2016

The objectives of this study were to evaluate the soil fertility about plastic film house, upland, and orchard in Gyeongbuk Province, Korea. The surface chemical properties of soil samples were investigated every 4 year from 2000 year at upland, 2001 year at orchard, and 2002 year at plastic film house. During 12 year's monitoring, mean soil pH was increased by 0.7 and 0.8 pH unit from pH 5.7 in upland and orchard, respectively, 0.5 pH unit from pH 6.5 in plastic film house. About 50% of all the field samples occupied within the recommended pH range (pH 6-7). Although soil organic matter (SOM) was gradually increased by about $10g\;kg^{-1}$ for 12 years, 40% of orchard, 49% of plastic film house, and 77% of upland soil samples were still below the 3% SOM. The mean concentration of available phosphate for 12 years in upland, orchard, and plastic film house were 530, 600, and $760mg\;kg^{-1}$, respectively. The relative frequencies exceeding the recommended available phosphate range ($300-550mg\;kg^{-1}$) were 43%, 53%, and 66% at upland, orchard, and plastic film house soils, respectively. $NH_4OAc$ exchangeable $K^+$ of upland, orchard, and plastic film house in the last soil test were 0.8, 0.9, and $1.6cmol_c\;kg^{-1}$, respectively. The relative frequencies above the recommended K level were 56% and 70% of orchard and plastic film house soil samples, respectively. The levels of crop nutrients except exchangeable Ca and Mg in upland soil were tended to increase gradually in the three fields. Exchangeable Mg, EC, available phosphate, organic matter and soil pH could be used as principle components to differentiate the chemical properties of three land fields. This analysis revealed that the soil fertility was affected by cropping method and field management, although additional research is needed to assess the importance of management on soil chemical properties and many fields indicate an opportunity for improvement in fertilizer management.

• 한국토양비료학회지
• /
• 제46권5호
• /
• pp.327-332
• /
• 2013

This survey was conducted to obtain basic data about organic matter such as BOD (Biochemical Oxygen Demand), COD (Chemical Oxygen Demand), DOC (Dissolved Organic Carbon) and TOC (Total Organic Carbon) in agricultural water in Gyeongnam province. BOD and COD are currently used for water quality indices, but adoption of TOC is being suggested. The surface water samples were collected at 39 locations in Gyeongnam province in April, July and October. Average concentrations of BOD, COD, DOC and TOC were 1.6, 3.3, 5.3 and $5.7mg\;L^{-1}$, respectively. In July, average concentrations of BOD and COD were 2.4 and $3.9mg\;L^{-1}$, respectively, showing these values were higher than other months. Average concentrations of TOC in April, July and October were 4.8, 7.4 and $4.8mg\;L^{-1}$, respectively. This suggested that the highest value of TOC was in July. Average decomposition efficiencies for BOD-C/TOC and COD-C/TOC were 11.4 and 23.9%, respectively. Correlation coefficient of TOC and DOC was higher by 0.995, whereas that of TOC and COD was lower by 0.763. Especially, TOC and DOC were highly related than others.

• 콘크리트학회지
• /
• 제6권5호
• /
• pp.140-148
• /
• 1994

R/C 라멘골조에 있어서 수직부재(기둥, 벽등)에 수평부재(보, 슬라브등)의 콘크리트 강도보다 1.4배가 넘는 강도의 콘크리트를 분리타설할 경우 ACI 318R-89 R10.13.1은 수직부재에 타설한 콘크리트가 수평부재로 2ft(60cm)이상의 내민길이를 확보하도록 규정하고 있다. 이에 따라 본 연구는 이규정을 그대로 적용하기에 앞서 실험적인 검증을 통한 구조적인 안전성을 확보하기 위하여 고강도 콘크리트 내민길이, 콘크리트 압축강도 등을 주요변수로 하여 총 6개의 실험체를 제작하여 실험 및 분석하였다. 실험결과 압축강도 및 내민 길이의 증가에 따라 각 실험체의 연성능력은 증가하는 것으로 나타났으며 R/C 라멘골조에 고강도 콘크리트와 보통강도 콘크리트를 분리타설할 경우 균열발생상황, 접합부에서의 거동 등을 고려할 때 고강도 콘크리트의 내민길이는 2h(h=보의 전체춤) 정도를 확보하여야 할 것으로 보여진다.

• 한국CDE학회논문집
• /
• 제4권3호
• /
• pp.269-283
• /
• 1999

Surface/surface intersection is a common and important problem in geometric modeling and CAD/CAM. Several methods have been used to approach this problem. All possible intersection curves can be obtained by using the subdivision algorithm, while it requires a great deal of memory and is somewhat inefficient. The tracing algorithm is much faster than the subdivision algorithm, and can find points on the intersection curve sequentially. But, the tracing algorithm has some problems in the intersection curves on surface boundaries. In this paper, an Improved tracing algorithm that includes some ideas such as a new trace-terminating condition for the intersection curves on surface boundaries, detecting closed intersections and extension for composite surfaces is suggested. This algorithm consists of three step: generating state points for curve tracing, tracing intersection curves and sorting pieces of the intersection curves. The results of this algorithm and comparisons to the 'DESIGNBASE' and 'ACIS' system are presented.

• Clinics in Shoulder and Elbow
• /
• 제20권3호
• /
• pp.147-152
• /
• 2017

Background: To evaluate the clinical and functional outcomes of arthroscopic-assisted reduction and percutaneous screw fixation for glenoid fractures with scapular extension, and investigate the radiologic and clinical benefits from the results. Methods: We evaluated patients treated with arthroscopic-assisted reduction and percutaneous screw fixation for glenoid fractures with scapular extension from November 2008 to September 2015. Fractures with displacement exceeding one-fourth of the anterior-articular surface or more than one-third of the posterior-articular surface in radiographic images were treated by surgery. Clinical assessment was conducted based on range of motion, Rowe score, and Constant score of injured arm and uninjured arm at last follow-up. Results: Fifteen patients with Ideberg classification grade III, IV, and V glenoid fracture who underwent arthroscopic-assisted reduction using percutaneous screw fixation were retrospectively enrolled. There were no differences in clinical outcomes at final follow-up compared to uninjured arm. Bone union was seen in all cases within five months, and the average time to bone union was 15.2 weeks. Ankylosis in one case was observed as a postoperative complication, but the symptoms improved in response to physical therapy for six months. There was no failure of fixation and neurovascular complication. Conclusions: We identified acceptable results upon radiological and clinical assessment for the arthroscopic-assisted reduction and percutaneous fixation. For this reason, we believe the method is favorable for the treatment of Ideberg type III, IV, and V glenoid fractures. Restoration of the articular surface is considered to be more important than reduction of fractures reduction of the scapula body.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1992년도 가을 학술발표회 논문집
• /
• pp.185-190
• /
• 1992

ACI318-89 Recommended that when the specified compressive strength of concrete in a column is greater than1.4 times that specified for a floor system, top surface of the column concrete shall extend 2ft(600mm)into the slab from the face of column to avoid unexpected brittle failure. The major variables are extension distance, flexural strength ratio(Mr), and shear reinforcement ratio(Vs). Test results are as follows ; (1) The failure modes of specimens under cyclic loading were concentrated at critical region from beam-column joint face. (2) Ductility index($\mu$f) were increased with increasing of shear confinement ratio and flexural strength ratio. (3)The specimens with 2ft extension distance showed more ductility than the specimens with 1ft extension distance.

• KIEE International Transactions on Electrophysics and Applications
• /
• 제5C권2호
• /
• pp.49-53
• /
• 2005

The current drive in a MOSFET is limited by the intrinsic channel resistance. All other parasitic elements in a device structure perform significant functions leading to degradation in the device performance. These other resistances must be less than 10$\%$-20$\%$ of the channel resistance. To meet the necessary requirements, the methodology of separation and quantification of those resistances should be investigated. In this paper, we developed an extraction method for the resistances using calibrated TCAD simulation. The resistance of the extension region is also partially determined by the formation of a surface accumulation region that gathers below the gate in the tail region of the extension profile. This resistance is strongly affected by the abruptness of the extension profile because the steeper the profile is, the shorter this accumulation region will be.

• 복식
• /
• 제67권3호
• /
• pp.81-98
• /
• 2017

The purpose of this study is to provide basic information for the development of pants patterns with a high level of fit and comfort through calculating surface variations of lower body parts by movement, grouping them into factors, and analyzing how their surface variations link to one another. The achieved results will help determine essential elements for constructing pants patterns, such as key measurements of lower body parts, the amount of ease values and selection of fabrics, which should be taken into consideration for allowing better movement in clothing. The study required lower body 3D scanning of women for analysis, and 13 women between the ages of 20-24 participated in the scanning, which was done by using Artec Eva 3D scanner. Their scanned data were digitalized and converted to measure the values of their lower body surface length and girth in pre-determined positions such as walking, stair climbing and sitting on a chair. These measurements have been statistically analyzed through SPSS 21.0 to obtain the average amounts and rates of extension for each of the measurement item. Some of the highlighted study results are as follows: The surface length and girth measurements were grouped into 4 factors based on their average extension rates. The results from correlation analysis between measurement items within each factor demonstrated that common items linked to all the changes in the values of other items in the three movements. But in most cases, items were not always correlated with each other for different movements. The results also showed that there were correlations between girth measurements, length measurements, and girth and length measurements. Therefore, key measurements for daily pants should be determined within reasonable estimations between relevant measurement items, while the measurements for work pants, which often withstand certain postures or repetitive movements, may require measurement items that are appro priate for, and closely related to, certain movements or tasks.