근래 국내 초고층 주상복합 건물에는 철근콘크리트구조가 보편적으로 적용되는데, 이러한 철근콘크리트 초고층 주상복합 건물은 시공 시점에 따라 구조적인 문제가 발생할 수 있다. 따라서, 시공 중인 철근콘크리트 초고층 주상복합 건물에 대하여, 시공 시점별 구조 안전성 및 횡력저항성능을 검토하고자 한다. 이를 위해, 예제 모델로 탑상형의 초고층 주상복합 60층 건물을 선정했고, 기존의 범용구조해석 프로그램을 사용하여 구조해석을 수행하였다. 각 시공 시점별 10층, 20층, 30층, 40층, 50층, 60층 완료모델과 60층 완공단계 모델의 구조성능을 비교하였다. 구조성능 비교를 위해 이 모델들의 고유치해석을 수행하였으며, 횡력저항성능과 부재별 단면성능을 검토하였다. 횡력저항성능 검토를 위해 횡변위비와 층간변위비를 검토했고, 부재별 단면성능 검토는 완공단계에 대한 설계강도비와 시공단계의 설계강도비를 비교하여 부재안전성을 검토하였다. 이 연구를 통해, 시공 중인 철근콘크리트 초고층 건물의 구조 안전성을 검토하고 시공단계에 적합한 구조해석 및 설계하중의 가이드라인을 제시하고자 한다.
The importance of genetic resource preservation has been highlighted in the literature as a means of maintaining genetic diversity. Investigations for hematologic values and the differential count of white blood cell count (WBC) for Korean indigenous cattle (KIC) and endangered indigenous cattle (EIC) are rarely performed. Therefore, the objective of this study was to investigate the hematologic values of total 40 EIC (White, Black, Mini cattle) and 35 KIC as control by analysis of hematologic characteristics. As a result, the mean values of RBC and platelet of EIC were significantly decreased by age (p<0.05). The mean values of RBC, HCT, MCV and MCHC between EIC and KIC of the same age (2 ~3 years) showed the statistical significance (p<0.05). Also, in the WBC of EIC, the mean values were decreased according to the age from 13.9×103/μL~12.7×103/μL under 1 year to 9.1×103/μL~11.5×103/μL over 2 years respectively. In the differential count of WBC of EIC (White, Black, Mini cattle), it showed generally the rates of 40.2%, 52.2%, 49.0% lymphocyte and 27.2%, 33.9%, 32.0% segmented neutrophil from 2~3 years respectively. Result of this study will be used for establishing reference range for blood analysis in EIC such as white, black and mini cattle. This study reported hematological values which could serve as baseline information for comparison in conditions of nutrient deficiency, physiological and health status of endangered Korean native cattle. In addition, this study provides a valuable resource for further investigations of the preservation of rare genetic stocks underlying traits of interest in cattle.
When designing Water Distribution System (WDS), determination of life cycle for WDS needs to be preceded. And designer should conduct comprehensive design including maintenance and management strategies based on the determined life cycle. However, there are only a few studies carried out until now, and criteria to determine life cycle of WDS are insufficient. Therefore, methodology to determine life cycle of WDS is introduced in this study by using Life Cycle Energy Analysis (LCEA). LCEA adapts energy as an environmental impact criterion and calculates all required energy through the whole life cycle. The model is build up based on the LCEA methodology and model itself can simulate the aging and breakage of pipes through the target life cycle. In addition the hydraulic analysis program EPANET2.0 is linked to developed model to analyze hydraulic factors. Developed model is applied to two WDSs which are A WDS and B WDS. Model runs for 1yr to maximum 100yr target life cycle for both WDSs to check the energy tendency as well as to determine optimal life cycle. Results show that 40yr and 54yr as optimal life cycle for each WDS, and tendency shows the effective energy is keep changing according to the target life cycle. Introduced methodology is expected to use as an alternative option for determining life cycle of WDS.
The purpose of this study is to identify ways of remodeling from the traditional hanok to the modern local governmental facility in 1910s. Analysing architectural drawings in the National Archives of Korea, 58 hanok remodeling cases of 52 facilities were verified like the provincial office, county office, county court from 1907 to 1910s. Using hanok as the local governmental building, exterior walls were all changed to the scaled-wooden wall like one of western-wooden building in 1910s and the western-style entrance was set. Change of the plan caused by remodeling interior walls had an intention of the centralized closed plan. Remodeled semi-outer corridor using the space of the eave became changed to the inner corridor with expansion of space. Expansion of hanok for spatial demand was in three ways. First was the expansion towards the eave space, second was direct extension from hanok, and last was the use of external corridor to the new building. Using the eave space was simple but had limitation of space, it was planed with other expansion ways. The way of direct extension was usually used than the one with the corridor, because it was more economical way.
The aim of this study was to carry out the comparative analysis of the brushing force following various brushing techniques bytoothbrush mounted pressure sensing unit. The study group consisted of 10 dental hygienist participants. The brushing forces (on buccal area of each first molar) were monitored on 8 different kinds of brushing techniques; Fones, Bass, Rolling, Scrub, Charters, stillman, Modified bass and Modified stillman. In Bass, Charters, Fones and Scrub method, force distributions showed a small gap of maximum and minimum value (Max/Min) while a big difference was noted in Modified bass, Modified stillman, Rolling and Stillman methods. Especially, the biggest difference of Max/Min value was observed in the area of lower left first molar. In conclusion, highly delicate manual skill is needed in showing big error range of force distribution. It means that careful force needs to be focused during toothbrushing instruction when a delicate manual skill was carried out.
PURPOSES : Before-and-after studies of red light cameras were conducted with the aim of reducing the number of side right-angle collisions. Three different methods were used for the before-and-after studies, and the analysis results were compared.
METHODS: This research used the naive before-and-after method, the comparison-group method, and the empirical Bayes method to study the effects of red light cameras on side-angle collisions. The results of the three before-and-after methods were compared and interpreted in terms of safety indications at signalized intersections.
RESULTS: The research results showed that side right-angle collisions can be reduced by installing red light cameras at signalized intersections. All three methods guarantee safety improvements of 25~30% on average. With regard to the results of each method, the naive before-and-after method, the comparison-group method, and the empirical Bayes method showed safety improvements of 25.6%, 27.8%, and 29.7%, respectively.
CONCLUSIONS: It was concluded that red light cameras are an effective countermeasure to improve intersection safety. In particular, by installing red light cameras, side right-angle collisions can be reduced by up to approximately 25~30%.
PURPOSES : Although signalized intersections have been considered the best way to control traffic volume in urban areas for several decades, roundabouts are currently being discussed as an alternative way to control traffic volume, especially when traffic is light. Because a roundabout’s efficiency depends on the load geometry as well as the traffic volume, design guidelines for roundabouts are recommended only if the incoming traffic volume is very low. It is rare to substitute a roundabout for an existing signalized intersection in urban areas. This study aims to estimate the benefits from the transformation of an existing signalized intersection into a roundabout in an urban area. When there is a more moderate volume of traffic, roundabouts can be effectively used by optimizing signals located at an approaching roadway.
METHODS : The methodologies of this paper are as follows: First, a signalized intersection was analyzed to determine the traffic characteristics. Second, the signalized intersection was transformed into a roundabout using VISSIM microscopic traffic simulation. Then, we estimated and analyzed the effects and the performance of the roundabout. In addition, we adjusted a method to improve the benefits of the transformation via the optimization of signals located at an approaching road to control the incoming traffic volume.
RESULTS : The results of this research are as follows: The signal-optimized roundabout improved delays compared with the signalized intersection during the morning peak hour, non-peak hour, and evening peak hour by 1.78%, 12.45%, and 12.72%, respectively.
CONCLUSIONS : According to the simulation results of each scenarios, the signal-optimized roundabout had less delay time than the signalized intersection. If optimized signal control algorithms are installed in roundabouts in the future, this will lead to more efficient traffic management.
PURPOSES: The purpose of this study is to investigate the relationship between the crack propagation depth through a slab and crack width movement in continuously reinforced concrete slab systems (CRCSs).
METHODS : The crack width movements in continuously reinforced concrete pavement (CRCP) and continuously reinforced concrete railway track (CRCT) were measured in the field for different crack spacings. In addition, the crack width movements in both CRCP and CRCT were simulated using finite element models of CRCP and CRCT. The crack width movements, depending on the unit temperature change, were obtained from both the field tests and numerical analysis models..
RESULTS: The experimental analysis results show that the magnitudes of the crack width movements in CRCSs were related to not only the crack spacing, but also the crack propagation depth. In CRCP, the magnitudes of the crack width movements were more closely related to the crack propagation depths. In CRCT, the crack width movements were similar for different cracks since most were through cracks. If the numerical analysis was performed to predict the crack width movements by assuming that the crack propagates completely through the slab depth, the predicted crack width movements were similar to the actual ones in CRCT, but those may be overestimated in CRCP.
CONCLUSIONS: The magnitudes of the crack width movements in CRCSs were mainly affected by the crack propagation depths through the slabs.
PURPOSES : In this study, an image analysis method is used to evaluate the pore structure characteristics and permeability of hybrid concrete.
METHODS: The binder weight of hybrid concrete is set to 400 kg/m3, 370kg/m3, and 350 kg/m3, and for each value of binder weight, the pore structure and permeability of concrete mixture is evaluated. The permeability of hybrid concrete is evaluated using a rapid chloride penetration test(RCPT).
RESULTS : The concrete pore structure characteristics of hybrid concrete reveals that as the binder weight is reduced, the entrained air is reduced and the entrapped air is increased. The permeability of the hybrid concrete for all values was measured to be below 1000 C, which indicates a "Very Low" level of permeability relative to the evaluation standard of KS F 2711. Additionally, as the binder weight is decreased, there is a significant increase in the permeability of chloride ions.
CONCLUSIONS : In this study, the pore structure characteristics of hybrid concrete at different binder weights shows that as the binder weight is reduced, the entrained air is reduced and the entrapped air is increased. Consequently, chloride ion penetration resistance of the hybrid concrete is diminished. As a result, it is expected that this will reduce the concrete’s durability.
PURPOSES: The purpose of this study is to analyze the service life of expressway pavement based on both traffic volumes and use of deicing chemicals.
METHODS: A database was built using expressway rehabilitation history information from over the last decade. In order to estimate the service life of expressway pavement, various analysis methods were considered, and a decision was made to perform analysis using a method based on an accumulated rehabilitation ratio. The service life of expressway pavement was then analyzed by classifying the scale of traffic volume and extent of de-icing chemicals used.
RESULTS: The service life of PMA and SMA ranged from 7.8 to 10.6 years and from 9.9 to 12.0 years, respectively. The service life of JCP ranged from 16.0 to 22.2 years, and the service life of CRCP was 33.5 years on average. Results of assessing service life according to traffic volumes and de-icing chemicals showed that the lower the traffic volumes were, the greater the service life of PMA and JCP, and the less that de-icing chemicals were applied, the greater the service life of JCP.
CONCLUSIONS : The dependence of expressway pavement service life on traffic volumes and de-icing chemicals makes it possible to apply LCCA for regional maintenance plans and cost-effective selection of expressway pavement type.
2009 개정 한문과 교육과정에서 학습 요소로 제시된 유의어는 언어생활이 아닌, 한문의 언어적 특성에 기반한 것이다. 그러나 학교 문법의 측면에서 유의어 목록과 유의어 간의 의미 차이 등은 아직 학계에 보고된 바 없다. 본 연구에서는 유의어에 대한 분석 방법론 등을 검토하여 타당한 이론적 기준을 만든 뒤, 이를 근거로 하여 학교 현장의 교수학습에 적합한 유의어 목록을 선정하였다. 또한 선정된 모든 유의어에 대해 각각의 의미 차이를 명확히 기술함으로써 유의 관계에 있는 단어간의 ‘同’과 ‘異’가 분명히 드러날 수 있도록 하였으며 교과서 글감을 위주로 전형적인 예문을 함께 제시함으로써 유의어 학습 목표를 효과적으로 달성하고자 하였다.
한자는 형 음 의의 세가지 요소로 구성되어있다. 그중 자형은 한자의 본체이다. 그러므로 자형을 분석할 때 먼저 한자의 자형구조를 파악해야만 한다. 필획, 부건, 정자 세부분으로 구성되어있는 한자는 구조를 분석할 때 가장 핵심적인 것이 부건이다. 그러므로 한자의 부건을 분석할 때 자형구조를 인식하는 것이 가장 좋은 방법중의 하나이다. 허신의 육서법이 세상에 나온이후 줄곧 한자의 구조를 분석하는 것으로 사용되었다. 현대에 와서 많은 학자들이 육서의 한계점을 인식하고 많은 한자구조방법론을 내놓았다. 현재 한자의 형체구조이론중 가장 대표성을 지닌 세 가지는 육서와 구석규의 삼서설과 왕녕의 한자구형학설이다. 본 논문은 한자구형학 이론을 이용하여 한국의 교육용 기초한자 1800자의 부건을 분석하고자 한다. 부건분석의 결과로 아래와 같은 결과를 도출해내었다. 부건분석후 表意, 標示, 表形, 示音, 記號의 다섯 가지 부건을 도출해냈다. 1차 부건 분해 결과로 중학교 교육용 한자는 직접부건 489개, 고등학교교육용기초한자 554개를 분석했다. 그중 중복된 부건은 모두 291개로 1800자 교육용기초한자의 직접부건은 모두 752개이다. 중학교 교육용 기초한자의 기초부건은 335개이고 고등학교 교육용 기초한자의 기초부건은 356개로 그중 중복되는 기초구건은 228개이므로, 교육용 기초한자 1800자의 기초부건은 모두 463개이다. 한국 교육용 기초한자의 구형모델은 모두 7개로 모든 기능영합성자, 會義 합성자, 音義합성자 ,標義합성자, 形義합성자, 義記합성자, 聲記합성자이다. 구형의 이치적근거를 보유하고 있는 상황은 중학교 교육용 기초한자는 87.33%, 고등학교 교육용 기초한자는 89.1%로 평균수치는 88.22%이다. 교육용 기초한자의 분석결과는 중국의 상용한자와 비교하여, 새로운 한자교육 방법론의 인식은 물론 중국어와 한자의 학습자에게 현대한자의 새로운 한자 학습 방법론을 익히게 할 수 있을 뿐 아니라 한국의 한자규범화 및 교육용 기초한자 선정에도 많은 도움을 줄 것으로 기대된다.
In this study, in order to improve the efficiency of n-type monocrystalline solar cells with an Alu cell structure, we investigate the effect of the amount of Al paste in thin n-type monocrystalline wafers with thicknesses of 120 μm, 130 μm, 140 μm. Formation of the Al doped p+ layer and wafer bowing occurred from the formation process of the Al back electrode was analyzed. Changing the amount of Al paste increased the thickness of the Al doped p+ layer, and sheet resistivity decreased; however, wafer bowing increased due to the thermal expansion coefficient between the Al paste and the c-Si wafer. With the application of 5.34 mg/cm2 of Al paste, wafer bowing in a thickness of 140 μm reached a maximum of 2.9 mm and wafer bowing in a thickness of 120 μm reached a maximum of 4 mm. The study’s results suggest that when considering uniformity and thickness of an Al doped p+ layer, sheet resistivity, and wafer bowing, the appropriate amount of Al paste for formation of the Al back electrode is 4.72 mg/cm2 in a wafer with a thickness of 120 μm.
This study suggested comprehensive structural characterization methods for the commercial blue light emitting diodes(LEDs). By using the Z-contrast intensity profile of Cs-corrected high-angle annular dark field scanning transmission electron microscope(HAADF-STEM) images from a commercial lateral GaN-based blue light emitting diode, we obtained important structural information on the epilayer structure of the LED, which would have beendifficult to obtain by conventional analysis. This method was simple but very powerful to obtain structural and chemical information on epi-structures in a nanometer-scale resolution. One of the examples was that we could determine whether the barrier in the multi-quantum well(MQW) was GaN or InGaN. Plan-view TEM observations were performed from the commercial blue LED to characterize the threading dislocations(TDs) and the related V-pit defects. Each TD observed in the region with the total LED epilayer structure including the MQW showed V-pit defects for almost of TDs independent of the TD types: edge-, screw-, mixed TDs. The total TD density from the region with the total LED epilayer structure including the MQW was about 3.6 × 108 cm−2 with a relative ratio of Edge- : Screw- :Mixed-TD portion as 80%: 7%: 13%. However, in the mesa etched region without the MQW total TD density was about 2.5 × 108 cm−2 with a relative ratio of Edge- : Screw- :Mixed TD portion of 86%: 5%: 9 %. The higher TD density in the total LED epilayer structure implied new generation of TDs mostly from the MQW region.
Base isolation is considered as a seismic protective system in the design of next generation Nuclear Power Plants (NPPs). If seismic isolation devices are installed in nuclear power plants then the safety under a seismic load of the power plant may be improved. However, with respect to some equipment, seismic risk may increase because displacement may become greater than before the installation of a seismic isolation device. Therefore, it is estimated to be necessary to select equipment in which the seismic risk increases due to an increase in the displacement by the installation of a seismic isolation device, and to perform research on the seismic performance of each piece of equipment. In this study, modified NRC-BNL benchmark models were used for seismic analysis. The numerical models include representations of isolation devices. In order to validate the numerical piping system model and to define the failure mode, a quasi-static loading test was conducted on the piping components before the analysis procedures. The fragility analysis was performed by using the results of the inelastic seismic response analysis. Inelastic seismic response analysis was carried out by using the shell finite element model of a piping system considering internal pressure. The implicit method was used for the direct integration time history analysis. In addition, the collapse load point was used for the failure mode for the fragility analysis.
This study was carried out to analyze water suspension in the water supply system through fault tree analysis. And quantitative factors was evaluated to minimize water suspension. Consequently the aim of this study is to build optimal planning by analyzing scenarios for water suspension.Accordingly the fault tree model makes it possible to estimate risks for water suspension, current risks is 92.23 m3/day. The result of scenario analysis by pipe replacement, risks for water suspension was reduced 7.02 m3/day when replacing WD4 pipe. As a result of scenario analysis by water district connections, the amount of risk reduction is maximized when it is connecting to network pipe of D Zone. Therefore, connecting to network pipe for D Zone would be optimal to reduce risk for water suspension.
It is known that sewer problems are the major causes of road cave-in. The objective of this study is to analyze the risk of road cave-in due to storm sewer laterals. We investigated 174 storm sewer laterals using a zoom camera at O-dong area in Seoul. The causes of road cave-in were classified into five cases: breakage of rigid pipe, deformation of flexible pipe, out of pipeline alignment, changing pipe material or changing pipe diameter, and a poor linkage between lateral and sewer. In addition, all defects were sorted into five grades based on the severity rating at storm sewer laterals. In this study, the most fragile pipe materials were found to be concrete pipe and polyethylene pipe, which recorded 2.3 and 1.69 defect rates. With regard to the causes of road cave-in, deformation of flexible pipe has a large influence on road cave-in at present. On a long-term basis, the two causes, out of pipeline alignment and a poor linkage between lateral and sewer, could have more influence on road cave-in.
To perform long-term sewer monitoring, It is important to understand the nature of the wastewater flow that occurs at the point on early stage of the monitor and to prevent in advance a problem which may caused. We can infer the flow properties and external factors by analyzing the scatter graph obtained from the measured data flow rate monitoring data since an field external factor affecting the sewage flow is reflected in the flow rate monitoring data. In this study, Selecting the three points having various external factors, and we Inferred the sewer flow characteristics from depth-velocity scatter graph and determined the analysis equation for the dry-weather flow rate data. At the‘point 1’expected non-pressure flow, we were able to see the drawdown effect caused by the free fall in the manhole section. At the‘point 2’, existed weir and sediments, there was backwater effect caused by them, and each of size calculated from the scatter graph analysis were 400 mm and 130 mm. At the‘Point 3’, there is specific flow pattern that is coming from flood wave propagation generated by the pump station at upstream. In common, adequate equations to explain the dry weather flow data are flume equation and modified manning equation(SS method), and the equations had compatibility for explaining the data because all of R2 values are over 0.95.
목 적: 기존의 콘택트렌즈 분석기에서 1매의 렌즈를 삭제하여 시스템을 간소화하고, 수차를 감소시켜 콘택트렌즈 표면의 선명한 상을 얻는 저가격 고성능의 광학계를 최적화 설계하였다. 방 법: 기존의 콘택트렌즈 분석기의 광학적 성능 분석과 최적화 설계에 사용한 파장은 프라운호퍼 C, d, F선(0.656 ㎛, 0.587 ㎛, 0.486 ㎛)이며 기준파장은 d선으로 하였다. Full field는 object height를 5 mm로 설정하였다. 참고모델의 광학적 성능 분석과 분석기의 최적화 설계에는 Zemax 14.2 설계 프로그램을 사용하였다. 결 과: 최적화 설계한 콘택트렌즈 분석기는 기존의 콘택트렌즈 분석기보다 Spot diagram RMS radius는 42.51% 성능이 향상되었다. 상질에 영향을 주는 구면수차는 96.96%, 비점수차는 68.39%, 종 방향 색수차는 39.29%, 횡 방향 색수차는 95.97% 향상되었고, 상면만곡과 왜곡수차는 각각 82.09%와 66.05%로 수차 성능이 향상되었다. 결 론: 기존의 콘택트렌즈 분석기보다 적은 수차와 적은 렌즈 매수를 갖는 새로운 광학계를 설계하였다. 설계한 콘택트렌즈 분석기는 저가격, 고성능의 성능 최적화가 이루어졌다고 볼 수 있다.