• Title/Summary/Keyword: form tie

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Online Tie Formation in Enterprise Social Media

  • Yongsuk Kim;Gerald C. (Jerry) Kane
    • Asia pacific journal of information systems
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    • v.29 no.3
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    • pp.382-406
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    • 2019
  • We study the antecedents to tie formation on an (Facebook-like) enterprise social media platform implemented to support cross-boundary connections. Research has produced mixed findings regarding the role of social media in cultivating bridging vs. closed networks. We examine the tie formation patterns of 1,386 enterprise social media users over a two-year period. Specifically, we observe who became (or chose not s become) "friends" with whom at the dyadic level and relate the decisions to various mechanisms that affect one's network to expand, constrain, or bridge. Using logistic and OLS regressions, we find that users tend to form ties via reciprocity and transitivity (with friends of friends), both of which help expand one's network. We also find strong networking tendency toward functional and hierarchical homophily (same business unit and same rank, respectively), which is likely to constrain one's network (closed network structure). We find that one's participation in various online interest groups is likely to open one's network (bridging network structure) while no evidence found for preferential attachment. Overall, we find that enterprise social media offers features, some of which are likely to foster bridging while others foster closed networks via different mechanisms.

Prediction of Failure Strength of Reinforced Concrete Deep Beams using Two-dimensional Grid Strut-Tie Model Method (2차원 격자 스트럿-타이 모델 방법에 의한 철근콘크리트 깊은 보의 파괴강도 예측)

  • Yun, Young Mook;Kwon, Sang Hyok;Chae, Hyun Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.4
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    • pp.605-615
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    • 2016
  • It is difficult to form a rational strut-tie model that represents a true load transfer mechanism of structural concrete with disturbed stressed region(s). To overcome the difficulty and handle numerous load cases with just one strut-tie model, a two-dimensional grid strut-tie model method was proposed previously. However, the validity of the method was not fully examined, although the incorporated basic concepts and new methods regarding the effective strength of concrete strut, load carrying capacity of struts and ties, and geometrical compatibility of grid strut-tie model were explained in detail. In this study, for accurate strength analysis and reliable design of reinforced concrete deep beams, the appropriateness of the two-dimensional grid strut-tie model method is verified. For this, the failure strength of 237 reinforced concrete deep beams, tested to shear failure, is predicted by the two-dimensional grid strut-tie model method, and the results are compared with those obtained by the sectional shear design methods and conventional strut-tie model methods of current design codes.

Dual Monopolies of New Durables and Their Ancillaries: Exclusive Supply Contracts

  • Flath, David
    • Asian Journal of Innovation and Policy
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    • v.7 no.1
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    • pp.207-234
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    • 2018
  • A manufacturer of a durable good typically purchases supplies, including parts for assembly - that are also useful for repairs - from independent "original equipment suppliers" with which it contracts. The manufacturer is a branded monopolist of its final assembled product. To put into effect also a monopoly of the replacement parts, it must stipulate in its arrangements with independent suppliers of the parts that they not supply such patented parts to any other buyer. Durable good owners would then only be able to obtain their requirements of replacement parts from the same company that supplied the durable. This would amount to a tie-in of replacement parts to the direct purchase of new durables. And that describes the apparently widespread practice of automobile manufacturers in India, as exposed in a recent case before the Competition Commission of India (Samsher Kataria v Honda Siel Cars India Limited and others). Here, I will argue that such tie-in enabled automotive manufacturers to more fully appropriate consumer surplus, which induced them to lower the price of new cars, sell more cars and also sell more repair parts. The tie-in expanded the auto parts industry and promoted new entry. The main restraint on expansion of India's automotive manufacturing is not monopoly. It is government protection in the form of tariffs on automobiles and auto parts.

Practical Application of Strut-and-tie model (스트럿-타이 모델의 실용화)

  • Hong, Sung-Gul
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.979-984
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    • 2008
  • This paper discusses how to use basic strut-and-tie models(STM) for practical application. Construction of STM starts with drawing of load paths with equilibrium conditions. Understanding of structural systems including form active systems, vector active systems, and section active systems help us select appropriate systems for possible STM. Simple circular fans can be employed for load paths from concentrated forces to distributed forces. Strength of struts depends on configuration of their nodal zones which meet tension ties and effective compressive strength. The effective compressive strength of struts are assumed to be mainly influenced by transverse strain.

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MOBA based design of FOPID-SSSC for load frequency control of interconnected multi-area power systems

  • Falehi, Ali Darvish
    • Smart Structures and Systems
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    • v.22 no.1
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    • pp.81-94
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    • 2018
  • Automatic Generation Control (AGC) has functionally controlled the interchange power flow in order to suppress the dynamic oscillations of frequency and tie-line power deviations as a perturbation occurs in the interconnected multi-area power system. Furthermore, Flexible AC Transmission Systems (FACTS) can effectively assist AGC to more enhance the dynamic stability of power system. So, Static Synchronous Series Compensator (SSSC), one of the well-known FACTS devices, is here applied to accurately control and regulate the load frequency of multi-area multi-source interconnected power system. The research and efforts made in this regard have caused to introduce the Fractional Order Proportional Integral Derivative (FOPID) based SSSC, to alleviate both the most significant issues in multi-area interconnected power systems i.e., frequency and tie-line power deviations. Due to multi-objective nature of aforementioned problem, suppression of the frequency and tie-line power deviations is formularized in the form of a multi-object problem. Considering the high performance of Multi Objective Bees Algorithm (MOBA) in solution of the non-linear objectives, it has been utilized to appropriately unravel the optimization problem. To verify and validate the dynamic performance of self-defined FOPID-SSSC, it has been thoroughly evaluated in three different multi-area interconnected power systems. Meanwhile, the dynamic performance of FOPID-SSSC has been accurately compared with a conventional controller based SSSC while the power systems are affected by different Step Load Perturbations (SLPs). Eventually, the simulation results of all three power systems have transparently demonstrated the dynamic performance of FOPID-SSSC to significantly suppress the frequency and tie-line power deviations as compared to conventional controller based SSSC.

Experimental and numerical studies on cyclic behavior of continuous-tenon joints in column-and-tie timber construction

  • Qi, Liangjie;Xue, Jianyang;Xu, Dan
    • Structural Engineering and Mechanics
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    • v.75 no.5
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    • pp.529-540
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    • 2020
  • The mechanical properties of timber construction have drawn more attention after the 2013 Lushan earthquake. A strong desire to preserve this ancient architectural styles has sprung up in recent years, especially for residential buildings of the mountainous areas. In the column-and-tie timber construction, continuous-tenon joints are the most common structural form to connect the chuanfang (similar to the beam in conventional structures) and the column. To study the cyclic performance of the continuous-tenon joints in column-and-tie timber construction, the reversed lateral cyclic loading tests were carried out on three 3/4 scale specimens with different section heights of the chuanfang. The mechanical behavior was assessed by studying the ultimate bending capacity, deformation ductility and energy dissipation capacity. Test results showed that the slippage of chuanfang occurred when the specimens entered the plastic stage, and the slippage degree increased with the increase of the section height of chuanfang. An obvious plastic deformation of the chuanfang occurred due to the mutual squeezing between the column and chuanfang. A significant pinching was observed on the bending moment-rotation curves, and it was more pronounced as the section height of chuanfang increased. The further numerical investigations showed that the flexural capacity and initial stiffness of the continuous-tenon joints increased with the increase of friction coefficient between the chuanfang and the column, and a more obvious increasing of bending moment occurred after the material yielding. The compressive strength perpendicular to grain of the material played a more significant role in the ultimate bending capacity of continuous-tenon joints than the compressive strength parallel to grain.

Experimental Study on the Shear Strength of Form Tie Connector Linked by Stud Coupler (스터드 커플러로 연결된 폼타이 연결재의 전단내력에 관한 실험 연구)

  • Seo, Soo-Yeon;Kim, Seoung-Soo;Yoon, Yong-Dae;Ha, Gee-Joo
    • Journal of the Korea Concrete Institute
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    • v.20 no.5
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    • pp.573-581
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    • 2008
  • In general, conventional sheeting H-pile is often used as a temporary member installed upon construction of outer retaining wall at basement floor. In CBW (composite basement wall), R/C basement wall is combined with H-Pile and resists lateral soil pressure together. This paper presents an experimental results of push out shear test of CBW with stud coupler as shear connectors to combine H-Pile with R/C wall six specimens with different diameter of FT (form tie) and arrangement of shear connectors were tested to evaluate the shear capacity of the composite wall. Test results showed that shear strength increased with diameter of FT. The shear strength of shear connector in CBW could be suitably predicted by using the previous equations codified in the codes. Best correlation, especially, was found when the calculation result by the formula in AISC 360-05 was compared to test one.

Differences across countries in the impact of developers' collaboration characteristics on performance : Focused on weak tie theory (국가별 오픈소스 소프트웨어 개발자의 네트워크 특성이 개방형 협업 성과에 미치는 영향 : 약한 연결 이론을 중심으로)

  • Lee, Saerom;Baek, Hyunmi;Lee, Uijun
    • The Journal of Information Systems
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    • v.29 no.2
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    • pp.149-171
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    • 2020
  • Purpose With the advent of the 4th Industrial Revolution, related technologies such as IoT, big data, and artificial intelligence technologies are developing through not only specific companies but also a number of unspecified developers called open collaboration. For this reason, it is important to understand the nature of the collaboration that leads to successful open collaboration. Design/methodology/approach We focused the relationship between the collaboration characteristics and collaboration performance of developers who participating in open source software development, which is a representative open collaboration. Specifically, we create the country-specific network and draw the individual developers characteristics from the network such as collaboration scope and collaboration intensity. We compare and analyze the characteristics of developers across countries and explore whether there are differences between indicators. We develop a Web crawler for GitHub, a representative OSSD development site, and collected data of developers who located at China, Japan, Korea, the United States, and Canada. Findings China showed the characteristics of cooperation suitable for the form of weak tie theory, and consistent results were not drawn from other countries. This study confirmed the necessity of exploratory research on collaboration characteristics by country considering that there are differences in open collaboration characteristics or software development environments by country.

Development of a Man's Fashion Goods Design using a Traditional Bat Pattern -Focusing on the Tessellation Arrangement and Color-Scheme of the Klimt's Painting- (전통 박쥐문양을 활용한 남성 패션상품 디자인 개발 - 테셀레이션 배치법 및 클림트 작품의 색채 활용을 중심으로 -)

  • Lim, Byungsoo;Cho, Jeansuk
    • Journal of Fashion Business
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    • v.17 no.2
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    • pp.95-116
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    • 2013
  • The purpose of this study is to link traditional patterns to man's fashion goods design. Of all the traditional patterns, the bat pattern was chosen for use during the development of a man's fashion goods design as like as neck-tie, pocketchief and scarf. This study is based upon document searches, including research papers. Thought these searches, it investigates the form of traditional bat patterns, tessellation which can be found easily in the Islamic culture as well as in tile and carpet patterns and a modern painting by Gustav Klimt(1862-1918). Based on this investigation, the study attempt to modernize the bat pattern and apply the neck-tie, pocketchief and scarf. The design procedure includes three sub-processes: selection, arrangement and color-scheme. In conclusion, six designs of man's fashion goods were created by using one of Korea's traditional patterns - the bat pattern. Therefore, this study offer invaluable suggestions for multifaced research on how to come up with design concepts which apply Korea's traditional patterns to Man's fashion goods design.

Shear strength prediction of PRC coupling beams with low span-to-depth ratio

  • Tian, Jianbo;Shen, Dandan;Li, Shen;Jian, Zheng;Liu, Yunhe;Ren, Wengeng
    • Earthquakes and Structures
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    • v.16 no.6
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    • pp.757-769
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    • 2019
  • The seismic performance of a coupled shear wall system is governed by the shear resistances of its coupling beams. The plate-reinforced composite (PRC) coupling beam is a newly developed form of coupling beam that exhibits high deformation and energy dissipation capacities. In this study, the shear capacity of plate-reinforced composite coupling beams was investigated. The shear strengths of PRC coupling beams with low span-to-depth ratios were calculated using a softened strut-and-tie model. In addition, a shear mechanical model and calculating method were established in combination with a multi-strip model. Furthermore, a simplified formula was proposed to calculate the shear strengths of PRC coupling beams with low span-to-depth ratios. An analytical model was proposed based on the force mechanism of the composite coupling beam and was proven to exhibit adequate accuracy when compared with the available test results. The comparative results indicated that the new shear model exhibited more reasonable assessment accuracy and higher reliability. This method included a definite mechanical model and reasonably reflected the failure mechanisms of PRC coupling beams with low span-to-depth ratios not exceeding 2.5.