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A Survey on Spectrum Sharing in Cognitive Radio Networks

  • Xu, Tangwen;Li, Zhenshuang;Ge, Jianhua;Ding, Haiyang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.11
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    • pp.3751-3774
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    • 2014
  • With the rapid development of wireless communication, the confliction between the scarce frequency resources and the low spectral efficiency caused by the stationary spectrum sharing strategies seriously restricts the evolution of the future mobile communication. For this purpose, cognitive radio (CR) emerges as one of the most promising inventions which can overcome the spectrum shortage. As the key technology and main objective of CR, spectrum sharing can make full use of the limited spectrum, alleviate the scarcity of frequency resources and improve the system utilities, playing thereby an important role in improving the system performance of cognitive radio networks (CRNs). In this survey, the spectrum sharing in CRNs is discussed in terms of the sharing process, mainstream sharing technologies and spectrum sharing models. In particular, comparisons of different spectrum sharing strategies are concluded, as well as that of different spectrum sensing schemes in sharing procedure. Moreover, some application examples of the spectrum sharing in CRNs, such as smart grid, public safety, cellular network and medical body area networks are also introduced. In addition, our previous related works are presented and the open research issues in the field of spectrum sharing are stated as well.

Static vulnerability of existing R.C. buildings in Italy: a case study

  • Maria, Polese;Gerardo M., Verderame;Gaetano, Manfredi
    • Structural Engineering and Mechanics
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    • v.39 no.4
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    • pp.599-620
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    • 2011
  • The investigation on possible causes of failures related to documented collapses is a complicated issue, primarily due to the scarcity and inadequacy of information available. Although several studies have tried to understand which are the inherent structural deficiencies or circumstances associated to failure of the main structural elements in a reinforced concrete frame, to the authors knowledge a uniform approach for the evaluation building static vulnerability, does not exist yet. This paper investigates, by means of a detailed case study, the potential failure mechanisms of an existing reinforced concrete building. The linear elastic analysis for the three-dimensional building model gives an insight on the working conditions of the structural elements, demonstrating the relevance of a number of structural faults that could sensibly lower the structure's safety margin. Next, the building's bearing capacity is studied by means of parametric nonlinear analysis performed at the element's level. It is seen that, depending on material properties, concrete strength and steel yield stress, the failure hierarchy could be dominated by either brittle or ductile mechanisms.

Mislocalization of TORC1 to Lysosomes Caused by KIF11 Inhibition Leads to Aberrant TORC1 Activity

  • Jang, Yoon-Gu;Choi, Yujin;Jun, Kyoungho;Chung, Jongkyeong
    • Molecules and Cells
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    • v.43 no.8
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    • pp.705-717
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    • 2020
  • While the growth factors like insulin initiate a signaling cascade to induce conformational changes in the mechanistic target of rapamycin complex 1 (mTORC1), amino acids cause the complex to localize to the site of activation, the lysosome. The precise mechanism of how mTORC1 moves in and out of the lysosome is yet to be elucidated in detail. Here we report that microtubules and the motor protein KIF11 are required for the proper dissociation of mTORC1 from the lysosome upon amino acid scarcity. When microtubules are disrupted or KIF11 is knocked down, we observe that mTORC1 localizes to the lysosome even in the amino acid-starved situation where it should be dispersed in the cytosol, causing an elevated mTORC1 activity. Moreover, in the mechanistic perspective, we discover that mTORC1 interacts with KIF11 on the motor domain of KIF11, enabling the complex to move out of the lysosome along microtubules. Our results suggest not only a novel way of the regulation regarding amino acid availability for mTORC1, but also a new role of KIF11 and microtubules in mTOR signaling.

Low-Temperature Plasma Enhanced Chemical Vapor Deposition Process for Growth of Graphene on Copper

  • Ma, Yifei;Jang, Hae-Gyu;Chae, Hui-Yeop
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.433-433
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    • 2013
  • Graphene, $sp^2$-hybridized 2-Dimension carbon material, has drawn enormous attention due to its desirable performance of excellent properties. Graphene can be applied for many electronic devices such as field-effect transistors (FETs), touch screen, solar cells. Furthermore, indium tin oxide (ITO) is commercially used and sets the standard for transparent electrode. However, ITO has certain limitations, such as increasing cost due to indium scarcity, instability in acid and basic environments, high surface roughness and brittle. Due to those reasons, graphene will be a perfect substitute as a transparent electrode. We report the graphene synthesized by inductive coupled plasma enhanced chemical vapor deposition (ICP-PECVD) process on Cu substrate. The growth was carried out using low temperature at $400^{\circ}C$ rather than typical chemical vapor deposition (CVD) process at $1,000^{\circ}C$ The low-temperature process has advantage of low cost and also low melting point materials will be available to synthesize graphene as substrate, but the drawback is low quality. To improve the quality, the factor affect the quality of graphene was be investigated by changing the plasma power, the flow rate of precursors, the scenario of precursors. Then, graphene film's quality was investigated with Raman spectroscopy and sheet resistance and optical emission spectroscopy.

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Effects of Financial Rewards, Parents and Peers, and Benefits and Costs on Choosing Accounting Career: A Global Perspective

  • KONG, Yusheng;NIMA NGAPEY, Jonathan Dior;QALATI, Sikandar Ali
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.157-167
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    • 2020
  • One of the concerns that have received substantial interest in the accounting field, in particular, in accounting education, is the increasing scarcity and demand for professional accountants around the globe. This study aims to investigate the effects of financial rewards (FR), parents' and peers' influence (PPIF), and benefits and cost (BCE) on students' intention to pursue a career in accounting. A quantitative, convenient random sampling approach was used, and an online survey was conducted to collect data from students studying in China. A total of 311 valid responses were used for model testing based on the theory of reasoned action and the theory of planned behavior. The findings of the study include the positive effects of FR, PPIF, and BCE on accounting career choice (ACC). This study illustrates that FR is the most dominant factor (β=0.479) for influencing ACC. Furthermore, the used factor explained 70% variation in ACC. The results of the study have implications both for accounting firms and universities whether offering or not offering accounting as a major. This study provides a global perspective, which keeps this study unique from other studies. And in this study, the Partial Least Square Structural Equation Modeling (PLS-SEM) has been used which is randomly used in accounting research.

Study on Seismic Resistant Safety of Seismic Isolation Design for Bridge using L.R.B. (L.R.B.를 이용한 면진설계의 내지진 안전성 연구)

  • Lee, Chol-Hee;Shin, Jae-In
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.2
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    • pp.121-126
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    • 2002
  • Due to few earthquakes in our country, one generally has thought to be safe from earthquakes. However, severe earthquakes occurred in Dangsan and Hyogohyeon which one had regarded as the zone that had not been risky for earthquakes, so that so many people died and a lot of buildings and bridges were destroyed. This event surprised our country and we undertook preparation for earthquakes on the full scale. The concept of seismic design was induced in the country which was poor in it for the scarcity of recognition and insufficiency of funds. Recently, many specialists are enforcing the provisions of seismic design. Therefore, this study introduces the method which combines PC-LEADeR( design program for L.R.B.) with LUSAS(linear elastic analysis) and performs the seismic isolation design more elaborately and simply. It verifies the propriety of that method, and it also examine the factors that affect the response of the bridges. Seismic isolation design for bridge using L.R.B. provides both economical efficiency and superior seismic performance. Second, the results between by the method proposed and by time history analysis have 20% error at the maximum. That is, the method proposed very appropriate.

Encapsulated Islet Transplantation: Strategies and Clinical Trials

  • Buder, Brian;Alexander, Michael;Krishnan, Rahul;Chapman, David W.;Lakey, Jonathan R.T.
    • IMMUNE NETWORK
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    • v.13 no.6
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    • pp.235-239
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    • 2013
  • Encapsulation of tissue has been an area of intense research with a myriad number of therapeutic applications as diverse as cancer, tissue regeneration, and diabetes. In the case of diabetes, transplantation of pancreatic islets of Langerhans containing insulin-producing beta cells has shown promise toward a cure. However, anti-rejection therapy that is needed to sustain the transplanted tissue has numerous adverse effects, and the islets might still be damaged by immune processes. Furthermore, the profound scarcity of healthy human donor organs restricts the availability of islets for transplant. Islet encapsulation allows the protection of this tissue without the use of toxic medications, while also expanding the donor pool to include animal sources. Before the widespread application of this therapy, there are still issues that need to be resolved. There are many materials that can be used, differing shapes and sizes of capsules, and varied sources of islets to name a few variables that need to be considered. In this review, the current options for capsule generation, past animal and human studies, and future directions in this area of research are discussed.

A Study on the Consciousness of Dental Technicians about the Courses of Dental Technology Dept., Junior College, Korea (한국(韓國) 치과기공사(齒科技工士)들의 전문대학(專門大學) 치기공과(齒技工科) 교육(敎育)에 대한 의식구조(意識構造) 조사(調査) 연구(硏究))

  • Choi, Un-Jea
    • Journal of Technologic Dentistry
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    • v.19 no.1
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    • pp.63-89
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    • 1997
  • This survey aimed at the analysis of the consciousness of the dental technicians on the college education ; 205 dental technicians who graduated the relavant school answered. Following is the result of the analysis with its ststistcal number. 1. About the time when they chose their major, 84 people(41.1%) answered the prepartion period for the college. And, 74(36.1%) said that they applied on their own thought to their major. The reason why they chose it was first the prosperity expected in the near future, 93(45.4%) replied. 2. 161(78.5%) were satisfied with their college days. On the other hand, the most regretful one those days, 69(33.7%) answered, was the scarcity of the study seminar. 3. About the exercise courses, 120(58.6%) showed dissatisfaction, and 66(32.3%) people of the dissatisfied pointed out the lack of the instruments. 4. The suitable number in a class, 124(60.5%) supported, is 20 heads. The appropriate period of education was said three years by 71(34.6%), four years 53(25.9%) and the extension to the graduate school by 41(20.0%) 5. About the tips for the professors, 147(71.7%) proposed they would research and lecture further more. To the college administration, 116(56.5%) suggested it should accomo-data enough instruments for practicing.

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Adaptation Experiences of Male Students in Nursing Education Programs: A Meta-synthesis Study (간호학과 남학생의 학과 적응에 관한 질적 메타합성 연구)

  • Son, Haeng-Mi;Oh, Seieun;Jang, Hye-Young
    • The Journal of Korean Academic Society of Nursing Education
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    • v.24 no.4
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    • pp.391-405
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    • 2018
  • Purpose: The purpose of this study was to integrate and synthesize findings from qualitative studies exploring male students' experiences of adapting to nursing education programs so as to obtain further understanding of the phenomenon. Methods: The meta-synthesis process was primarily guided by Noblit and Hare's approach, which consists of four stages including searching, appraisal of an individual study's quality, data extraction for analysis, and meta-synthesizing the results. Results: Findings from the literature reviewed were synthesized into six themes: 1) extraordinary choice based on job stability and gender scarcity; 2) unexpected feeling of marginalization as minority far apart from the mainstream; 3) assimilation and negotiation for relational adaptation through perspective shift; 4) fortifying the vision and identity as nursing students by meaning making for adapting to the nursing major; 5) mutual support among colleague male students; and 6) serving in the military as way of hiding out and achieving maturation. Conclusion: The findings illustrate that nursing education programs need practical changes promoting male students' adaptation to the program itself as well as preparation to be a professional nurse in the future.

Artification in Flagship Stores of Luxury Fashion Brands (럭셔리 패션 브랜드의 플래그쉽 스토어에 나타난 예술화)

  • Hwang, Jin-Ju;Yim, Eun-Hyuk
    • Fashion & Textile Research Journal
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    • v.22 no.4
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    • pp.413-431
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    • 2020
  • Luxury fashion brands have begun to aggressively introduce art to justify inherent values such as tradition, craftsmanship, and exclusivity that make it difficult for luxury brands to uphold awe-inspiring atmosphere. Artification refers to a process in which non-artistic factors are transformed into art or artistic category under the influence of artistic thoughts or actions. In addition, the consumption space provided by brands have become important as the importance of substantial shopping experience has increased. Especially, since the artification is actively utilized in flagship stores in the communication interface with consumers. This study uses a literature review and case studies to typify and derive the meaning of the method for artification at a flagship store that effectively conveys brand identity and value. The types of artification at a luxury fashion brand flagship store are divided into pursuing brand permanency and maintaining brand exclusivity that also provides a new value of permanency like a work of art to a luxury fashion brand. Basic values, such as scarcity are declining, reviving and justifying the value threatened by the popularization of luxury.