2,202 research outputs found
Revisiting small-world network models: Exploring technical realizations and the equivalence of the Newman-Watts and Harary models
We address the relatively less known facts on the equivalence and technical
realizations surrounding two network models showing the "small-world" property,
namely the Newman-Watts and the Harary models. We provide the most accurate (in
terms of faithfulness to the original literature) versions of these models to
clarify the deviation from them existing in their variants adopted in one of
the most popular network analysis packages. The difference in technical
realizations of those models could be conceived as minor details, but we
discover significantly notable changes caused by the possibly inadvertent
modification. For the Harary model, the stochasticity in the original
formulation allows a much wider range of the clustering coefficient and the
average shortest path length. For the Newman-Watts model, due to the
drastically different degree distributions, the clustering coefficient can also
be affected, which is verified by our higher-order analytic derivation. During
the process, we discover the equivalence of the Newman-Watts (better known in
the network science or physics community) and the Harary (better known in the
graph theory or mathematics community) models under a specific condition of
restricted parity in variables, which would bridge the two relatively
independently developed models in different fields. Our result highlights the
importance of each detailed step in constructing network models and the
possibility of deeply related models, even if they might initially appear
distinct in terms of the time period or the academic disciplines from which
they emerged.Comment: 11 pages, 5 figures, 1 table, to appear in J. Korean Phys. So
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Power-saving method for wireless sensor network
A power saving method of the present invention is provide for a wireless sensor network including a plurality of sensor nodes each transiting between a power saving mode and a transmit/receive mode, determines whether or not there is no transmit or receive data, enters the power saving mode if there is no transmit or receive data, and controls power consumption on the basis of signal-to-noise ratios in the power saving mode. In the power saving method of the present invention, it is possible to minimize the power consumption regardless of nodes density and without an adverse effect on the connectivity of the network, since the sojourn times of the sleep and idle states are determined adaptive to the interference level from neighboring nodes.Board of Regents, University of Texas Syste
Mathematical vibration modeling for an electrostatic precipitator system
The rapping acceleration of collecting plates in electrostatic precipitator system determines the dust- rapping performance of electromagnetic vibration exciter. To maximize the acceleration, the resonance phenomena needs to be driven by matching the mechanical natural frequency of the electrostatic precipitator system and the input frequency of electric current which energizes the electromagnetic vibrator. In this paper, the dust collecting plates and the electromagnetic vibration exciter in electrostatic precipitator system are vibration-modeled mathematically to characterize the resonance frequency. The effective mass and stiffness for each mode of the collecting plates are calculated using finite elements analysis and the natural frequency are computed by the method of least error square. In addition, the effective mass and stiffness of the exciter are computed. Then, the whole electrostatic precipitator system is analyzed. A frequency response analysis based on a sine sweep signal experiment is performed on a prototype for verification of calculated theoretical resonance frequency
Reinforcing effects of methamphetamine in an animal model of Attention-Deficit/Hyperactivity Disorder-the Spontaneously Hypertensive Rat
Substrains of the Spontaneously Hypertensive rat (SHR), a putative animal model of Attention-Deficit/Hyperactivity Disorder (ADHD), have demonstrated increased sensitivity to many drugs of abuse, including psychostimulants. Therefore, it was suggested that studies in SHR may help elucidate ADHD and comorbidity with substance use disorder (SUD). However, the drug intake profile of the SHR in the most relevant animal model of drug addiction, the self-administration (SA) test, and its response on the conditioned place preference (CPP) paradigm are not yet determined. In the present study, we employed SA and CPP tests to investigate the reinforcing effects of the psychostimulant methamphetamine in an SHR substrain obtained from Charles River, Japan (SHR/NCrlCrlj). Concurrent tests were also performed in Wistar rats, the strain representing "normal" heterogeneous population. To address if the presence of ADHD behaviors further increases sensitivity to the rewarding effect of methamphetamine during adolescence, a critical period for the onset of drug abuse, CPP tests were especially conducted in adolescent Wistar and SHR/NCrlCrlj. We found that the SHR/NCrlCrlj also acquired methamphetamine SA and CPP, indicating reinforcing effects of methamphetamine in this ADHD animal model. However, we did not observe increased responsiveness of the SHR/NCrlCrlj to methamphetamine in both SA and CPP assays. This indicates that the reinforcing effects of methamphetamine may be similar in strains and that the SHR/NCrlCrlj may not adequately model ADHD and increased sensitivity to methamphetamine
Happiness Education: International Use of Floating Signifiers in Education Policy // ํ๋ณต๊ต์ก: ๊ต์ก์ ์ฑ ์์์ ๋ถ์ ๊ธฐํ์ ์๋์ ์ธ์ด ์ค์ฉ
Over the past decade, the concept of โhappinessโ has been promoted by global agencies and national education authorities as a solution to the social problems of high teenager suicide rates, school bullying, and increasing socioeconomic polarization. This article considers โHEP: Happiness Education Policyโ in Korea, which was initiated by conservative Park Geun-hye administration (2013-2017) and partly succeeded by the subsequent progressive Moon Jae-in administration (2017-2022). The analysis reveals that the definitional ambiguity of happiness education has opened a space for multiple ascriptions of meanings, particularly those that are in line with the Park administrationโs political and economic visions of โcreative economyโ. It also demonstrates that policies introduced as part of the HEP, such as the Free Semester initiative, have continued to be promoted and even expanded by Moon administration (2017-2022) despite their replacement of the signifier โhappinessโ by โinnovationโ and โfutureโ. Therefore, this study suggests happiness education and, more lately, future education as good examples of โfloating signifiersโ; that is, by lacking a clear referent, they minimize political objections and legitimate the introduction and continuation of contested reforms. //
๋ณธ ์ฐ๊ตฌ๋ ์ ์ฑ
์ ์ด ๋ฐ ์ฐจ์ฉ ์ด๋ก ์ ๊ทผ๊ฑฐํ์ฌ ๋ฐ๊ทผํ ์ ๋ถ์ โ๊ฟ๊ณผ ๋ผ๋ฅผ ํค์ฐ๋ ํ๋ณต๊ต์ก ์ ์ค์ฌ์ผ๋ก ์ ์ฑ
๋ช
์นญ๊ณผ ๊ด๋ จ๋ ์ธ์ด์ ์๋์ ์ค์ฉ ํ์์ ๋ํด ๋ถ์ํ์๋ค.
ํ๋ณต๊ต์ก์ ๊ฒฝ์ฐ OECD๊ฐ ์ธ๋์ ์ ํ(humanitarian turn)์ ์๋ํ๋ฉฐ 2012 ๊ตญ์ ํ์
์ฑ์ทจ๋ ํ๊ฐ (PISA)์ ์ฒ์ ๋์
ํ ํ๋ณต ๋ฐ ์ฐ๋น ๋ฌธํญ๋ค๋ก ๊ตฌ์ฒดํ๋์ด ์ ์ด ๋์๋ค. ๋ํ๋ฏผ๊ตญ ํ์๋ค์ ๋ฎ์ ์ถ์ ๋ง์กฑ๋์ ๋ํ ์ฌํ์ ๋
ผ๋๊ณผ ๋ถ์ ๋ฝ ๊ต์ก์ ๋ํ ํ์์ด โ๋์ โ์ด๋ผ๋ ์ด๋ฒคํธ์ ๊ฒฐํฉํด โํ๋ณต ๊ต์ก ์ด๋ผ๋ ๋์์ผ๋ก ์ฐจ์ฉ๋์๋ค.
์ต๊ทผ OECD์์๋ โํ๋ณต ๋ฐ โ์ฐ๋น ์ด๋ผ๋ ์ฉ์ด๋ค์ด ๊ต์ก ์ฑ๊ณผ์ ์ฒ๋๋ฅผ ๋์ด์ ๋ฏธ๋ ์ฐ์ ์ธ๋ ฅ์ด ํ์์ ์ผ๋ก ์ง๋
์ผํ ์์ง ๋ฐ ์ญ๋์ผ๋ก ๊ฐ์กฐ๋๋ ๋ฑ ์ธ๋์ ์ ํ์ ์์ฑ๊ฐ ์ง์์ง๊ณ ์๋ค. ํ ๋ฌธ์ฌ์ธ ์ ๋ถ์์๋ ์์ ํ๋
์ ๋ฑ ์ด์ ์ ๋ถ์ ํ๋ณต๊ต์ก ๊ธฐ์กฐ ์๋ ๋ฑ์ฅํ๋ ์ ์ฑ
๊ณผ์ ๋ค์ด ๊ณ์ํด์ ์ด์ด์ง๊ณ ์์ผ๋, ๊ธฐ์กด โํ๋ณต ์ด๋ผ๋ ์์์ด๋ ๋ฏธ๋, ํ์ , ๊ณต์ , ํ๋ฑ ๋ฑ ์๋ก์ด ์ฉ์ด๋ก ๋ณํํ์๋ค. ๊ทธ๋ฌ๋ ํ๋ณต๊ต์ก๊ณผ ๋ง์ฐฌ๊ฐ์ง๋ก, โํ์ , โ๋ฏธ๋ ๋ฑ์ ์ฉ์ด๊ฐ ์๋ฏธํ๋ ๋ฐ์ ๋ํด์๋ ์๋ฏธ๊ฐ ๋ถ๋ถ๋ช
ํ์ฌ ํด์ ๋ฐ ์ฌ์ฉ์ด ์์์ ์ผ๋ก ์ด๋ฃจ์ด์ง๊ณ ์๋ค. ๋ณธ ์ฐ๊ตฌ๋ ์ด๋ฐ ์์์ด๋ค์ด ๊ต์ก์ ์ฑ
๋์
์ ์ ๋นํํ๋ ํ๋์ โ๋ถ์ ๊ธฐํ (floating signifier)๋ก ์์ฉํ๊ณ ์์ผ๋ฉฐ, ์ด์ ๊ฐ์ ์ธ์ด์ ์๋์ ์ค์ฉ ํ์์ ์๋ฌต์ ์ธ ์๋น์ ํฉ์ (bipartisanship)๋ก ๊ฐํ๋์์์ ๋ฐํ๋ค
Prediction of the Chemical Composition and Fermentation Parameters of Fresh Coarse Italian Ryegrass Haylage Using Near Infrared Spectroscopy
Italian ryegrass (Lolium multiflorum) is an annual forage grass species which is widely cultivated in South Korea. It grows extensively in the southern part of the country and is an important component of winter forage for livestock. Each year, in Korea, over one million hectares of Italian ryegrass is converted to round bale haylage. Quality control is an important field in forage utilization research and marketing, and involves the estimation of forage nutrient content. Wet chemistry is the traditional method used to analyze the nutrient content of forage. However, this technique is often destructive, expensive, and time consuming, and it is not suitable for real-time feedstuff analysis. Near infrared spectroscopy (NIRS), on the other hand, is an alternative technique that has several major advantages over traditional methods. The analysis of silage nutrient content, using NIR, conventionally includes the drying and milling of samples. However, these processes can lead to reduction of volatile acids, which are important components of silage. NIRS can be affected by spectral regions, drying and grinding methods, particle size, packing density and the temperature of samples (Reeves and Blosser, 1991). In order to obtain accurate NIRS results, sample preparation, and the measurement conditions of the calibration set and predicted samples, need to match. The objectives of this study were to (1) assess the usefulness of NIRS in determining the nutritional composition and fermentative parameters of fresh coarse samples of Italian ryegrass haylage, (2) assess the predictive value of various NIRS calibration models, and (3) explore cost-effective and time saving methods for forage quality estimation, in field populations
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