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

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 // 행복교육: 교육정책에서의 부유기표와 의도적 언어 오용

Over the past decade, the concept of ‘happiness’ 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 ‘HEP: Happiness Education Policy’ 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 administration’s political and economic visions of ‘creative economy’. 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 ‘happiness’ by ‘innovation’ and ‘future’. Therefore, this study suggests happiness education and, more lately, future education as good examples of ‘floating signifiers’; that is, by lacking a clear referent, they minimize political objections and legitimate the introduction and continuation of contested reforms. // 본 연구는 정책 전이 및 차용 이론에 근거하여 박근혜 정부의 ‘꿈과 끼를 키우는 행복교육 을 중심으로 정책 명칭과 관련된 언어의 의도적 오용 현상에 대해 분석하였다. 행복교육의 경우 OECD가 인도적 전환(humanitarian turn)을 시도하며 2012 국제 학업성취도 평가 (PISA)에 처음 도입한 행복 및 웰빙 문항들로 구체화되어 전이 되었다. 대한민국 학생들의 낮은 삶의 만족도에 대한 사회적 논란과 북유럽 교육에 대한 환상이 ‘대선’이라는 이벤트와 결합해 ‘행복 교육 이라는 대안으로 차용되었다. 최근 OECD에서는 ‘행복 및 ‘웰빙 이라는 용어들이 교육 성과의 척도를 넘어서 미래 우수 인력이 필수적으로 지녀야할 자질 및 역량으로 강조되는 등 인도적 전환의 색채가 지워지고 있다. 현 문재인 정부에서도 자유학년제 등 이전 정부의 행복교육 기조 아래 등장했던 정책과제들이 계속해서 이어지고 있으나, 기존 ‘행복 이라는 수식어는 미래, 혁신, 공정, 평등 등 새로운 용어로 변화하였다. 그러나 행복교육과 마찬가지로, ‘혁신 , ‘미래 등의 용어가 의미하는 바에 대해서는 의미가 불분명하여 해석 및 사용이 자의적으로 이루어지고 있다. 본 연구는 이런 수식어들이 교육정책 도입을 정당화하는 하나의 ‘부유 기표 (floating signifier)로 작용하고 있으며, 이와 같은 언어의 의도적 오용 현상은 암묵적인 양당의 합의 (bipartisanship)로 강화되었음을 밝혔다

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