Random singlets and permutation symmetry in the disordered spin-2 Heisenberg chain: A tensor network renormalization group study

We use a tensor network renormalization group method to study random $S=2$ antiferromagnetic Heisenberg chains with alternating bond strength distributions. In the absence of randomness, bond alternation induces two quantum critical points between the $S=2$ Haldane phase, a partially dimerized phase and a fully dimerized phase, depending on the strength of dimerization. These three phases, called ($\sigma$,$4-\sigma$)=(2,2), (3,1) and (4,0) phases, are valence-bond solid (VBS) states characterized by $\sigma$ valence bonds forming across even links and $4-\sigma$ valence bonds on odd links. Here we study the effects of bond randomness on the ground states of the dimerized spin chain, calculating disorder-averaged twist order parameters and spin correlations. We classify the types of random VBS phases depending on strength of bond randomness $R$ and the dimerization $D$ using the twist order parameter, which has a negative/positive sign for a VBS phase with odd/even $\sigma$. Our results demonstrate the existence of a multicritical point in the intermediate disorder regime with finite dimerization, where (2,2), (3,1) and (4,0) phases meet. This multicritical point is at the junction of three phase boundaries in the $R$-$D$ plane: the (2,2)-(3,1) and (3,1)-(4,0) boundaries that extend to zero randomness, and the (2,2)-(4,0) phase boundary that connects another multicritical point in the undimerized limit. The undimerized multicritical point separates a gapless Haldane phase and an infinite-randomness critical line with the diverging dynamic critical exponent in the large $R$ limit at $D=0$. Furthermore, we identify the (3,1)-(4,0) phase boundary as an infinite-randomness critical line even at small $R$, and find the signature of infinite randomness at the (2,2)-(3,1) phase boundary only in the vicinity of the multicritical point.Comment: 13 pages, 14 figure

Empirical Study of Online Auction Seller Switching: The Case of Yahoo vs. Ruten in Taiwan

Most online auction platform providers (OAPPs) agree that the majority of their profits comes from users, i.e., their buyers and sellers. The major concern of OAPPs is how to gain and lock in users in order to maintain and enhance a competitive edge. Customer switching is one of the primary problems of all companies, including OAPPs. This study focused on online auction sellers and attempted to understand their switching behavior. We developed an integrated model that consisted of OAPP strategies (anti-switching and anti-lock-in), value-based factors (platform qualities and switching costs), lock-in factors (network effects), and perceived values to explore the switching intentions of online auction sellers. The model was tested using a field study of 248 sellers from two online auction websites. The results show that OAPP strategies will affect switching costs which affect perceived value which, in turn, impacts a seller’s switching behavior. Our findings indicate that value-based factors directly influence perceived value which could suitably explain a seller’s decision to switch from one OAPP to another. The study suggests that OAPPs should develop strategies and leverage the network effect to avoid customer switching

Vermont Agriculture and Food System Plan 2020 -- A Review of Recommendations (Part One)

Key Findings in reviewing the Vermont Agriculture and Food System Plan: 1. All recommendations in this review have been coded into eight thematic categories to be used more effectively by stakeholders. 2. We identify four clusters of recommendations to assist stakeholders in understanding the relationships between categories and enabling understanding of the various stakeholders and resources necessary to implement recommendations from different briefs 3. 87% of recommendations either request direct funding for an initiative or recommend a capital expenditure. With financial challenges amidst COVID-19, we highlight eight recommendations for a Vermont Food System that could move forward without financial resources. 4. In the future, giving authors a guide for writing recommendations would make them easier to categorize and implement

Ricci-flat cubic graphs with girth five

We classify all connected, simple, 3-regular graphs with girth at least 5 that are Ricci-flat. We use the definition of Ricci curvature on graphs given in Lin-Lu-Yau, Tohoku Math., 2011, which is a variation of Ollivier, J. Funct. Anal., 2009. A graph is Ricci-flat, if it has vanishing Ricci curvature on all edges. We show, that the only Ricci-flat cubic graphs with girth at least 5 are the Petersen graph, the Triplex and the dodecahedral graph. This will correct the classification in Lin-Lu-Yau, Comm. Anal. Geom., 2014, that misses the Triplex

Alcohol Use, Abuse, and Dependency in Shanghai

The use of alcohol for social and ceremonial occasions was recorded in Chinese history as early as 1760 B.C. during the Yin Dynasty (Ci-Hai Encyclopedia, 1979:936). The cultural tradition of ancient China placed alcoholic beverages at the center of social occasions, which presumably was the origin of the adage: Without wine, there is no li (or etiquette). Thus, the use of alcoholic beverages has always been accompanied by the concept of propriety and the discharging of one\u27s role obligations m social functions, rather than that of personal indulgence

Domain-Generalized Face Anti-Spoofing with Unknown Attacks

Although face anti-spoofing (FAS) methods have achieved remarkable performance on specific domains or attack types, few studies have focused on the simultaneous presence of domain changes and unknown attacks, which is closer to real application scenarios. To handle domain-generalized unknown attacks, we introduce a new method, DGUA-FAS, which consists of a Transformer-based feature extractor and a synthetic unknown attack sample generator (SUASG). The SUASG network simulates unknown attack samples to assist the training of the feature extractor. Experimental results show that our method achieves superior performance on domain generalization FAS with known or unknown attacks.Comment: IEEE International Conference on Image Processing (ICIP 2023

Right hepatectomy using Glissonean pedicle transection method with anterior approach (with video)

Right hepatectomy for hepatocellular carcinoma is the most common major operation in liver surgery; therefore, liver surgeons should know the fundamental surgical concept and techniques of the Glissonean pedicle approach. A J-shaped or reversed T laparotomy is performed in the right subcostal area. The Glissonean pedicle approach is performed at the hepatic hilus. In this approach, the right anterior and posterior Glissonean pedicles are encircled and ligated without liver dissection. The right hepatic artery, right portal vein and right hepatic duct in the hepatoduodenal ligament should be divided if the Glissonean pedicles cannot be approached easily. After confirming the border between the right and left liver, the liver parenchyma is dissected from the anterior surface of the liver to the anterior surface of the inferior vena cava (IVC). The V5 and V8 middle hepatic veins are divided and liver dissection is performed along the main middle hepatic vein. Finally, the anterior surface of the IVC and the trunk of the right hepatic vein are identified in the liver. This approach is widely known as the anterior approach described by Lai and Fan (World J Surg 20:314–8, 1996). However, this procedure had already been reported by Takasaki et al. (Shoukakigeka 7:1545–51, 1984) but since they did not report this procedure in English, their pioneering work on the anterior approach has not been recognized. The liver hanging maneuver described by Belghiti et al. (J Am Coll Surg 193:109–111, 2001) is also useful in right hepatectomy. Among the techniques used in right hepatectomy, the Glissonean pedicle approach, the anterior approach and the liver hanging maneuver are considered to be the most important