LOW-JITTER AND LOW-SPUR RING-OSCILLATOR-BASED PHASE-LOCKED LOOPS

Department of Electrical EngineeringIn recent years, ring-oscillator based clock generators have drawn a lot of attention due to the merits of high area efficiency, potentially wide tuning range, and multi-phase generation. However, the key challenge is how to suppress the poor jitter of ring oscillators. There have been many efforts to develop a ring-oscillator-based clock generator targeting very low-jitter performance. However, it remains difficult for conventional architectures to achieve both low RMS jitter and low levels of reference spurs concurrently while having a high multiplication factor. In this dissertation, a time-domain analysis is presented that provides an intuitive understanding of RMS jitter calculation of the clock generators from their phase-error correction mechanisms. Based on this analysis, we propose new designs of a ring-oscillator-based PLL that addresses the challenges of prior-art ring-based architectures. This dissertation introduces a ring-oscillator-based PLL with the proposed fast phase-error correction (FPEC) technique, which emulates the phase-realignment mechanism of an injection-locked clock multiplier (ILCM). With the FPEC technique, the phase error of the voltage-controlled oscillator (VCO) is quickly removed, achieving ultra-low jitter. In addition, in the transfer function of the proposed architecture, an intrinsic integrator is involved since it is naturally based on a PLL topology. The proposed PLL can thus have low levels of reference spurs while maintaining high stability even for a large multiplication factor. Furthermore, it presents another design of a digital PLL embodying the FPEC technique (or FPEC DPLL). To overcome the problem of a conventional TDC, a low-power optimally-spaced (OS) TDC capable of effectively minimizing the quantization error is presented. In the proposed FPEC DPLL, background digital controllers continuously calibrate the decision thresholds and the gain of the error correction by the loop to be optimal, thus dramatically reducing the quantization error. Since the proposed architecture is implemented in a digital fashion, the variables defining the characteristics of the loop can be easily estimated and calibrated by digital calibrators. As a result, the performances of an ultra-low jitter and the figure-of-merit can be achieved.clos

A maximal inequality associated to Schr\{o}dinger type equation.

In this note, we consider a maximal operator $\sup_{t \in \mathbb{R}}|u(x,t)| = \sup_{t \in \mathbb{R}}|e^{it\Omega(D)}f(x)|$, where $u$ is the solution to the initial value problem $u_t = i\Omega(D)u$, $u(0) = f$ for a $C^2$ function $\Omega$ with some growth rate at infinity. We prove that the operator $\sup_{t \in \mathbb{R}}|u(x,t)|$ has a mapping property from a fractional Sobolev space $H^\frac14$ with additional angular regularity to $L_{loc}^2$

The evolution of business ethics in China and the United States: convergence, divergence or crossvergence?

This study presents a cross-temporal comparison of managerial ethics in China and the US. Although it is well established that cross-cultural differences exist in business ethics and that culture and values in a society may evolve over time, little attention has been paid to the longitudinal changes in such cross-cultural differences that might have occurred over time. Building on the three different perspectives on values evolution, namely, convergence, divergence, and crossvergence, we investigate whether and how cross-cultural differences in managerial ethical decision-making and the associated moral philosophy have changed in China and the US over a decade between the mid-1990s and the mid-2000s. Our analysis reveals that the difference in Chinese and American managers’ ethical decision-making evolved in many different directions over the decade, lending support to the crossvergence perspective. Interestingly, however, we discover that the divergence outlook prevails when it comes to the moral philosophies behind their decision-making. These findings provide critical insights into cross-cultural as well cross-temporal evolution in business ethics in a world of increasing cross-cultural and multicultural interactions. 本文对中美两国经理人员的商业伦理决策进行了跨期比较研究。已有研究普遍认为，商业伦理中存在着跨文化差异，且一个社会的文化和价值观会随着时间的推移而演化。但是，相关研究对这种跨文化差异随着时间的推移而发生纵向变化的关注相对较少。基于价值观演化的三种不同视角——趋同、趋异和交叉融合，我们研究了在20世纪90年代中期至21世纪最初十年的中期这一阶段，中美两国经理人员的商业伦理决策和相关道德哲学的跨文化差异的纵向变化。我们的分析表明，在这十年中，中美两国经理人员的商业伦理决策差异在多个不同方向上演化，存在着交叉融合。然而，有趣的是，我们也发现，当涉及到商业伦理决策背后深层次的道德哲学时，相互间的差异点占了上风。这些发现为在全球日益增多的跨文化和多元文化互动中深度认识商业伦理的跨文化和跨时间演化提供了重要见解

Unpacking martial arts pedagogy in sport - based youth development

There has been growing concern regarding youth participation in martial arts programs (Vertonghen & Theeboom, 2013). Previous studies have revealed contradictory findings of youth martial arts programs related to a potential increasing physical aggression and violent behaviors as a negative side of youth martial arts practice (Endresen & Olweus, 2005; Mutz’s, 2012; Sofia & Cruz, 2017) or producing positive youth developmental (PYD) outcomes as positive side of youth martial arts practice (van der kooi, 2020; Vertonghen & Theeboom, 2010). Little attention has been paid to the “black box” of what causes those outcomes. The black box refers to what and how martial arts are being taught to promote positive youth development (PYD). Little information is available in the literature that unpacks the black box of martial arts pedagogy. An embedded multiple case study design (Yin, 2016) was used to unpack the black box of martial arts pedagogical practices employed in three cases: 1) traditional Taekwondo program, 2) afterschool Taekwondo program, and 3) high school physical education (PE) Taekwondo program. Research participants were purposefully selected who were expected to provide-in-depth and detailed information regarding the research topic. In the traditional Taekwondo (case 1), eight (fe)male students, four parents, and two instructors participated in this study. In the afterschool Taekwondo (case 2), five (fe)male students, four parents and an instructor were selected. In the school PE Taekwondo (case 3), four (fe)male students, five program staff, and a PE teacher participated in this study. The average ages of students were 14.5 years old (case 1), 13 years old (case 2), and 15 years old (case 3). Using a mixed method approach, qualitative (interviews, focus groups, lesson reflections, and TARE post-teaching reflection) and quantitative (TARE observation, ToRQ, and PSRQ) data were collected. Qualitative data was analyzed using concept-driven and data-driven approaches to thematic analysis. A descriptive statistical analysis of quantitative raw data was conducted using measures of central tendency (i.e., mean, median, and mode). In phase one (within case analysis), each case was examined in-depth with the qualitative analysis to unpack the black box of martial arts pedagogy and positive youth developmental experiences. In phase two, (cross-case analysis), a pattern-matching and explanation building was carried out to identify the contrasts and similarities through comparing between the cases. Both the quantitative analysis (descriptive statistics) and the qualitative analysis were used for the comparison. Based on the procedures, findings revealed that the particularities of martial arts pedagogy were related to cultural heritage and promoting explicit life skills education in case 1; adaptive Taekwondo teaching, promoting transfer of Taekwondo life skills in case 2; and integrating restorative practices with Taekwondo teaching in case 3. The teaching strategies that characterized their instruction were directed teaching for case 1, promoting peer teaching for case 2, and facilitating collaborative learning for case 3. Results also showed that PYD experiences were characterized differently among the cases that were a) youth taekwondoists’ journey to the black belt that involves systematic goal setting and accomplishment as well as mind-body practices, b) disciplined kids who care about others and their personal life by actively applying the life skills to daily life, and c) recognizing individuals that promotes self-expression in students and positive social interaction. On the other hand, common positive youth developmental outcomes consistently identified across the three cases included a) positive identity (e.g., self-efficacy and sense of belonging), b) cultural competence (e.g., awareness about different cultures), and c) contribution (e.g., personal and community development). Throughout the investigation, it was confirmed that martial arts have potential as a vehicle to promote positive youth developmental outcomes, such as life skills, character development, and social-emotional learning. Martial arts curriculum can be flexible to adapt needs of teachers and students (e.g., afterschool program and physical education). To conclude, more research needs to 1) pay attention to the potential of the martial arts-based youth development programs, 2) identify the positive youth developmental outcomes, and 3) explore the pedagogical processes that foster such outcomes

Convergence in international business ethics? A comparative study of ethical philosophies, thinking style, and ethical decision-making between US and Korean managers

This study investigates the relationship among ethical philosophy, thinking style, and managerial ethical decision-making. Based on the premise that business ethics is a function of culture and time, we attempt to explore two important questions as to whether the national differences in managerial ethical philosophies remain over time and whether the relationship between thinking style and ethical decision-making is consistent across different national contexts. We conducted a survey on Korean managers’ ethical decision-making and thinking style and made a cross-cultural, cross-temporal comparison with the results presented by previous studies that surveyed Korean and US managers with the same questionnaire at different points in time. Our analysis revealed that Korean managers have become more reliant on rule utilitarianism for ethical decision-making over the last two decades, which is dominantly used by US managers, corroborating our convergence hypothesis built on social contracts theory. However, as opposed to previous research, we found that managers with a balanced linear and nonlinear thinking style do not necessarily make more ethical decisions compared to those with a predominantly linear or nonlinear thinking style. This study contributes to international business ethics literature by presenting a theoretical framework that may explain the convergence of ethical philosophies employed by managers in different national contexts over time, and that the relationship between thinking style and managerial ethical decision-making may not be universal, but contingent on contextual factors

Comparative genome analysis of two Cryptosporidium parvum isolates with different host range

Parasites of the genus Cryptosporidium infect the intestinal and gastric epithelium of different vertebrate species. Some of the many Cryptosporidium species described to date differ with respect to host range; whereas some species’ host range appears to be narrow, others have been isolated from taxonomically unrelated vertebrates. To begin to investigate the genetic basis of Cryptosporidium host specificity, the genome of a C. parvum isolate belonging to a sub-specific group found exclusively in humans was sequenced and compared to the reference C. parvum genome representative of the zoonotic group. Over 12,000 single-nucleotide polymorphisms (SNPs), or 1.4 SNP per kilobase, were identified. The genome distribution of SNPs was highly heterogeneous, but non-synonymous and silent SNPs were similarly distributed. On many chromosomes, the most highly divergent regions were located near the ends. Genes in the most diverged regions were almost twice as large as the genome-wide average. Transporters, and ABC transporters in particular, were over-represented among these genes, as were proteins with predicted signal peptide. Possibly reflecting the presence of regulatory sequences, the distribution of intergenic SNPs differed according to the function of the downstream open reading frame. A 3-way comparison of the newly sequenced anthroponotic C. parvum, the reference zoonotic C. parvum and the human parasite C. hominis identified genetic loci where the anthroponotic C. parvum sequence is more similar to C. hominis than to the zoonotic C. parvum reference. Because C. hominis and anthroponotic C. parvum share a similar host range, this unexpected observation suggests that proteins encoded by these genes may influence the host range

Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good