• Earthquakes and Structures
• /
• v.16 no.1
• /
• pp.41-54
• /
• 2019

Reinforced Concrete (RC) shear walls are widely used in Nuclear power plants as effective lateral force resisting elements of the structure and these may experience nonlinear behavior for higher earthquake demand. Short shear walls of aspect ratio less than 1.5 generally experience combined shear flexure interaction. This paper presents the results of the displacement-controlled experiments performed on six RC short shear walls with varying aspect ratios (1, 1.25 and 1.5) for monotonic and reversed quasi-static cyclic loading. Simulation of the shear walls is then carried out by Finite element modeling and also by macro modeling considering the coupled shear and flexure behaviour. The shear response is estimated by softened truss theory using the concrete model given by Vecchio and Collins (1994) with a modification in softening part of the model and flexure response is estimated using moment curvature relationship. The accuracy of modeling is validated by comparing the simulated response with experimental one. Moreover, based on the experimental work a multi-linear hysteretic model is proposed for short shear walls. Finally ultimate load, drift, ductility, stiffness reduction and failure pattern of the shear walls are studied in details and hysteretic energy dissipation along with damage index are evaluated.

• Asia-Pacific Journal of Business
• /
• v.11 no.3
• /
• pp.79-93
• /
• 2020

Purpose - The purpose of this study analyzes the effect of psychological safety on innovative behavior mediated by job crafting. Design/methodology/approach - This study collected 221 survey data from employees in Korea. Collected data were analyzed using SPSS 25.0 and Macro Process. The multiple regression analysis and bootstrap analysis were hired in order to analyze the data. Findings - First, psychological safety had a significant effect on innovation behavior. Second, job crafting proved a mediating effect in the relationship between psychological safety and innovation behavior. In other words, it has been demonstrated empirically that task crafting, cognitive crafting, and relational crafting, which are sub-elements of job crafting, play a mediating role in the relationship between psychological safety and innovative behavior. Research implications or Originality - This study expanded the study of Job Crafting in that it revealed the mediating role of Job Crafting in the relationship of psychological safety and innovative behavior. Second, this study has novelty in that it has established a sense of psychological safety as an independent variable that promotes innovative behavior, and that it has examined each other's structural relationship by adding a variable called Job Crafting.

• Journal of the Korea Institute of Building Construction
• /
• v.20 no.6
• /
• pp.577-584
• /
• 2020

Construction automation and robotics have been widely adopted in the construction industry as a promising solution to such issues like a shortage of skilled labor and the difficulties workers face in harsh working environments. The analysis of the knowledge structure and its evolution from the existing articles helps identify essential knowledge elements and possible future research directions. This study attempts to (1) construct keyword networks from the papers published in the International Symposium on Automation and Robotics in Construction (ISARC), (2) investigate how keywords and keyword communities are associated with each other, and (3) examine the changes in the crucial keywords over time. Through cluster analysis, 79 keywords were categorized into four groups (BIM, Building construction, Sensing, and GPS as representative keywords) with similar structural positions. Research trends show that research themes related to Infrastructure, Construction equipment, and 3D have consistently received a large amount of attention, regardless of geographical region. Research on as-built status model utilization through BIM and Laser scanning and improving Energy performance is taking place more frequently. In contrast, research studies related to problem-solving based on Neural networks are not as common as previously. This study provides useful insights into the construction automation field, at both the macro and micro levels.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.35 no.12
• /
• pp.115-125
• /
• 2019

Most of construction at urban area is now undertaking a redevelopment because currently the most of city is full. But the research about the collision of urban tissue at urban redevelopment area are very limited and there are many issues at urban redevelopment area. So the purpose of this study is to analyze the collision between different urban tissue at urban redevelopment area and suggest proper method for urban redevelopment. The area inside of four main gates, especially Chung Jin, Gong pyeong, Mu gyo- Da dong district are selected to analyze because the area inside of these gates is the oldest urban redevelopment area and each of them has a different redeveloped method. And current status of research area's urban tissue and collision situation are analyzed by macro and micro scale of view. The results of this study were as follows; Ignoring the timeline of the urban redevelopment process can be a major issue in collision between urban tissue. Therefore, the consideration of intermediate stage of redevelopment process is needed by making public area, a temporal use of vacant lot and changing architectural elements can make a harmony between different urban tissue.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2022.10a
• /
• pp.162-162
• /
• 2022

This study was carried out to investigate the effects of nitrogen, phosphorus, potassium (three main macro elements of fertilizer) on growth, yield and mineral contents of Platycodon grandiflorum for. duplux and to obtain the basic data of the proper fertilizer application for increasing the yield of P. grandiflorum for. duplux. Plant height showed significantly good results in all fertilization treatments compared to non fertilizer group (the control, T0), and in particular, the highest was 85.7 cm in the complete group (T4). Chlorophyll content showed a high amount in the range of 20.7 to 23.8 against all fertilization treatment groups, except for non fertilizer (T0) and non nitrogen (T1). The fresh weight of roots were higher quantity than other fertilization treatments in the complete group 55.8 g (T4). The mineral nutrient content ofNa, Mg, Cu and Al of the roots of P. grandiflorum for. duplux from T1 group showed the lowest amount compared to other groups. In addition, P from T2 group, Mn from T3 group and Ca, Fe, Zn from T4 group also exhibited the lowest mineral content compared to other groups respectively.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.44 no.6
• /
• pp.177-187
• /
• 2016

This study started with the question, "Is the cost of landscape construction work in residential areas measured by public enterprises, 'in response to the needs of consumers?" The study analyzed whether the landscape construction expenditure is being introduced at an appropriate ratio according to the value the residents have regarding landscape elements. Following this, research was conducted for the purpose of providing basic data for improving the efficiency of formulating apartment landscape construction costs in the future. This research proceeded based on a questionnaire survey of residents of apartments, and the content of the questionnaire used frequency analysis and descriptive statistics research methods. To take a look at a comparative analysis of value recognition, in particular, a comparative analysis was performed based on the actual input cost based on the ratio of landscape elements by layer. Conclusions were found as follows: First, the degree of interest in the apartment landscape of the tenants was high, and the value of the landscape was high but realistic satisfaction appeared comparatively low. Second, the awareness of residents' values regarding landscape elements appeared to give "plantings" more value than "facilities". Thirdly, as a result of a mutual comparison between the values recognized by the resident regarding landscape elements and the construction input fee, depending on the landscape elements, it appeared that there is a difference in the ratio of up to 52 times from 1.25. Fourth, the fact that there is a difference in the relative proportion of value recognition and inputting construction cost indicates that it is not possible to respond to the needs of tenants during the construction cost development process. It also shows that the utility of inputting construction costs is low. Therefore, a macro-level examination such as reflecting the existing inflation rate is necessary to develop the efficient landscape construction cost of apartment such as the awareness of the value of the residents regarding landscape elements, out of the customary construction cost formulation method based on the microscopic dimensions of the consumer side.

• Korean Journal of Soil Science and Fertilizer
• /
• v.12 no.4
• /
• pp.215-220
• /
• 1980

This is a review of the theory and practical uses of the $Hom{\grave{e}}s$' systematic variations in the fertilizer experiments. General characteristics of the method are as follows : 1 ) It could be recommended as a reasonable met hod for fertilizer experiments in order to improve the weak points in the conventional methods. 2 ) This met hod is a determination of the total amount of nutrients and the relative proportion of each nutrient in the total. 3 ) Concerning of the high yields of crops this met hod should be adapted for the systematic fertilization. 4 ) This is an usable method not only for the macro- but also micro elements investigations.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.43 no.9 s.351
• /
• pp.1-9
• /
• 2006

In the System-on-Chip(SoC) design, the global wires are critical parts for the performance. Therefore, the global wires need to be pipelined using flip-flops or latches. Since the timing constraint of the latch is more flexible than it of the flip-flop, the latch-based design can provide a better solution for the clock period. Retiming is an optimizing technique which repositions memory elements in the circuits to reduce the clock period. Traditionally, retiming is used on gate-level netlist, but retiming for SoC is used on macro-level netlist. In this paper, we extend the previous work of retiming for SoC using flip-flops to retiming for SoC using single-phase clocked latches. In this paper we propose a MILP for retiming for SoC using single-phase clocked latches, and apply the fixpoint computation to solve it. Experimental results show that retiming for SoC using latches reduces the clock period of circuits by average 10 percent compared with retiming for SoC using flip-flops.

• Structural Engineering and Mechanics
• /
• v.55 no.3
• /
• pp.555-581
• /
• 2015

Triangular pyramid and Quadrangular pyramid elements for partial double-layer spherical reticulated shells of pyramidal system are investigated in the present study. Macro programs for six typical partial double-layer spherical reticulated shells of pyramidal system are compiled by using the ANSYS Parametric Design Language (APDL). Internal force analysis of six spherical reticulated shells is carried out. Distribution regularity of the stress and displacement are studied. A shape optimization program is proposed by adopting the sequence two-stage algorithm (RDQA) in FORTRAN environment based on the characteristics of partial double-layer spherical reticulated shells of pyramidal system and the ideas of discrete variable optimization design. Shape optimization is achieved by considering the objective function of the minimum total steel consumption, global and locality constraints. The shape optimization of six spherical reticulated shells is calculated with the span of 30m~120m and rise to span ratio of 1/7~1/3. The variations of the total steel consumption along with the span and rise to span ratio are discussed with contrast to the results of shape optimization. The optimal combination of main design parameters for six spherical reticulated shells is investigated, i.e., the number of the optimal grids. The results show that: (1) The Kiewitt and Geodesic partial double-layer spherical reticulated shells of triangular pyramidal system should be preferentially adopted in large and medium-span structures. The range of rise to span ratio is from 1/6 to 1/5. (2) The Ribbed and Schwedler partial double-layer spherical reticulated shells of quadrangular pyramidal system should be preferentially adopted in small-span structures. The rise to span ratio should be 1/4. (3) Grids of the six spherical reticulated shells can be optimized after shape optimization and the total steel consumption is optimized to be the least.

• Transactions on Electrical and Electronic Materials
• /
• v.14 no.3
• /
• pp.160-163
• /
• 2013

We investigated the effect of light intensity and wavelength of a solar cell device by using photoconductive atomic force microscopy (PC-AFM). The $POCl_3$ diffusion doping process was used to produce a p-n junction solar cell device based on a Poly-Si wafer and the electrical properties of prepared solar cells were measured using a solar cell simulator system. The measured open circuit voltage ($V_{oc}$) is 0.59 V and the short circuit current ($I_{sc}$) is 48.5 mA. Also, the values of the fill factors and efficiencies of the devices are 0.7% and approximately 13.6%, respectively. In addition, PC-AFM, a recent notable method for nano-scale characterization of photovoltaic elements, was used for direct measurements of photoelectric characteristics in local instead of large areas. The effects of changes in the intensity and wavelength of light shining on the element on the photoelectric characteristics were observed. Results obtained through PC-AFM were compared with the electric/optical characteristics data obtained through a solar simulator. The voltage ($V_{PC-AFM}$) at which the current was 0 A in the I-V characteristic curves increased sharply up to 1.8 $mW/cm^2$, peaking and slowly falling as light intensity increased. Here, $V_{PC-AFM}$ at 1.8 $mW/cm^2$ was 0.29 V, which corresponds to 59% of the average $V_{oc}$ value, as measured with the solar simulator. Also, while light wavelength was increased from 300 nm to 1,100 nm, the external quantum efficiency (EQE) and results from PC-AFM showed similar trends at the macro scale, but returned different results in several sections, indicating the need for detailed analysis and improvement in the future.