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We prove some stability and hyperstability results for the well-known Fréchet equation stemming from one of the characterizations of the inner product spaces. As the main tool, we use a fixed point theorem for the function spaces. We finish the paper with some new inequalities characterizing the inner product spaces.

In this paper we give a complete description of the Bieri–Neumann–Strebel–Renz invariants of the Lodha–Moore groups. The second author previously computed the first two invariants, and here we show that all the higher invariants coincide with the second one, which finishes the complete computation. As a consequence, we present a complete picture of the finiteness properties of normal subgroups of the first Lodha–Moore group. In particular, we show that every finitely presented normal subgroup of the group is of type $\\textrm{F}_\\infty$ , answering a question posed in Oberwolfach in 2018. The proof involves applying a variation of Bestvina–Brady discrete Morse theory to the so called cluster complex X introduced by the first author. As an application, we also demonstrate that a certain simple group S previously constructed by the first author is of type $\\textrm{F}_\\infty$ . This provides the first example of a type $\\textrm{F}_\\infty$ simple group that acts faithfully on the circle by homeomorphisms, but does not admit any nontrivial action by $C^1$ -diffeomorphisms, nor by piecewise linear homeomorphisms, on any 1-manifold.

In recent years, plasma treatment technology has attracted more attention in the textile industry, as it seems to be a promising economically and ecologically sound alternative to conventional wet-chemical processing techniques. Plasma surface treatment is a relatively simple process that is clean, solvent-free, time saving, and environmentally friendly. Moreover, plasma treatments offer the possibility to obtain typical textile finishes without changing the key textile properties. The efficiency of plasma treatment depends on several factors including the nature of the substrate and the treatment operating conditions. However, the application of plasma technology to different kinds of textile materials has not been fully exploited. This paper presents a review of the current literature on the surface modification of textiles by low-temperature plasma (LTP) technology. Its main objectives are to (i) investigate the influence of LTP treatment on the surface properties of natural and man made textile materials, (ii) outline the contribution of LTP treatment towards sustainable development, and (iii) examine the hurdles that LTP has to overcome in the textile industry.

The surface finish (SF) becomes a part of the solder joint during assembly and improves the component’s reliability. Furthermore, the SF influences the solder joint’s reliability by affecting the thickness of the intermetallic compound (IMC) layer at the solder interface and copper pads. In this experiment, five different alloys are used and compared with the SAC305 alloy, two of which, Innolot and SAC-Bi, are bi-based solder alloys. This study includes three common SFs: electroless nickel immersion gold (ENIG), immersion silver (ImAg), and organic solderability preserve (OSP). The performance of three surface finishes is examined in terms of component characteristic life. All of the boards were isothermally aged for twelve months at 125 °C. The boards were then exposed to 5000 cycles of thermal cycling at temperatures ranging from −40–+125 °C. Most of the current research considers only one or two factors affecting the reliability of the electronic package. This study combines the effect of multiple factors, including solder paste content, SF, isothermal aging, and thermal cycling, to ensure that the test conditions represent real-world applications. In addition, the electronics packages are assembled using commercialized alloys. The current study focuses on a high-performance alloy already present in the electronic market. The failure data were analyzed statistically using the Weibull distribution and design of experiments (DOE) analysis of variance (ANOVA) techniques. The findings reveal that the micro and uniformly distributed precipitates in solder microstructures are critical for high-reliability solder joints. Re-crystallization of the thermally cycled solder joints promotes the local formation of numerous new grains in stress-concentrated zones. As the fracture spreads along these grain boundaries and eventually fails, these new grains participate in crack propagation. Aging significantly worsens this situation. Finally, although the ENIG surface finish with its Ni layer outperforms other SFs, this does not imply that ENIG is more reliable in all solder paste/sphere/finish combinations.

Balinese cosmological beliefs have become a very important foundation in Balinese lives, including architecture. Balinese architecture does not simply consist of physical and natural materials, it also seeks balance and propriety. It needs to be in a harmonious balance relationship between humans with humans, humans with their natural surroundings, and humans with God or known as Tri Hita Karana. This study tries to apply this concept that is usually used in architecture, within an interior space with a children’s creativity hub in Kuta, Bali as a study case through the qualitative method. The result of this study proposed a design concept ‘ Jelajah Riang ’ a concept that is suitable for the function of the space and can be embedded with Tri Hita Karana as well as Tri Loka concept, with three rooms used as a sample; the break room, dancing studio as well as painting and drawing studio. In these three rooms, not only the activities designed suitable to those concepts but also the interior elements, such as wall and floor finishes, lighting, ventilation, and so on

This review covers state-of-the-art quantum teleportation technologies, from photonic qubits and optical modes to atomic ensembles, trapped atoms and solid-state systems. Open issues and potential future implementations are also discussed. Quantum teleportation is one of the most important protocols in quantum information. By exploiting the physical resource of entanglement, quantum teleportation serves as a key primitive across a variety of quantum information tasks and represents an important building block for quantum technologies, with a pivotal role in the continuing progress of quantum communication, quantum computing and quantum networks. Here we summarize the basic theoretical ideas behind quantum teleportation and its variant protocols. We focus on the main experiments, together with the technical advantages and disadvantages associated with the use of the various technologies, from photonic qubits and optical modes to atomic ensembles, trapped atoms and solid-state systems. After analysing the current state-of-the-art, we finish by discussing open issues, challenges and potential future implementations.

Macro-operators (macros) are a well-known technique for enhancing performance of planning engines by providing “short-cuts” in the state space. Existing macro learning systems usually generate macros by considering most frequent action sequences in training plans. Unfortunately, frequent action sequences might not capture meaningful activities as a whole, leading to a limited beneficial impact for the planning process. In this paper, inspired by resource locking in critical sections in parallel computing, we propose a technique that generates macros able to capture whole activities in which limited resources (e.g., a robotic hand, or a truck) are used. Specifically, such a Critical Section macro starts by locking the resource (e.g., grabbing an object), continues by using the resource (e.g., manipulating the object) and finishes by releasing the resource (e.g., dropping the object). Hence, such a macro bridges states in which the resource is locked and cannot be used. We also introduce versions of Critical Section macros dealing with multiple resources and phased locks. Usefulness of macros is evaluated using a range of state-of-the-art planners, and a large number of benchmarks from the deterministic and learning tracks of recent editions of the International Planning Competition.

Recently, research into the factors that influence the formation and growth of intermetallic compounds (IMCs) layer in lead-free solders has piqued interest, as IMCs play an important role in solder joints. The reliability of solder joints is critical to the long-term performance of electronic products. One of the most important factors which are known to influence solder joint reliability is the intermetallic compound (IMC) layer formed between the solder and the substrate. Although the formation of an IMC layer signifies good bonding between the solder and substrate, its main disadvantage is due to its brittle nature. This paper reviews the formation and growth of IMCs in lead-free solder joints detailing the effect of alloying additions, surface finishes, aging time, aging temperature and solder volume. The formation and growth of the brittle IMCs were significantly affected by these factors and could be possibly controlled. This review may be used as a basis in understanding the major factors effecting the IMC formation and growth and relating it to the reliability of solder joints.

This paper investigated the melting point and surface oxide thickness of Sn58Bi clean solder (non-flux-coated solder with a clean surface). The surface morphology, spreadability, voidage, and interfacial reaction of Sn58Bi clean solder and flux-coated solder welded with three different surface finishes were studied during vacuum welding and atmospheric reflow welding. The surface finishes consisted of pure copper, matte tin, and gold plating. The results indicated that the optimal welding surface finish of Sn58Bi clean solder was gold plating, and the interfacial reaction was sufficient and the average voidage was 7.69%. The interfacial intermetallic compound (IMC) was approximately 0.6-1 um thick, uneven and discontinuous. As for flux-coated solder, the preferable surface finish was matte tin, which had good welding surface morphology and formed a continuous smooth IMC layer with a thickness of about 0.4-0.8 um; spreading ratio and average voidage were 101.64% and 4.03%, respectively. An unknown particle-shaped Au-Sn-Bi phase ɑ with Au:Sn:Bi (wt.%) ≈ 18.5:56.2:24.2 (Au15Sn68Bi17 (at.%)) was discovered in the welding interface of Sn58Bi solder and gold-plated substrate. In addition, another Au-Sn-Bi ternary compound β with Au:Sn:Bi (wt.%) ≈ 27.8:65.5:6.7 (Au19Sn76Bi5 (at.%)) was found in Au18.5Sn56.2Bi24.2 (wt.%) alloy which prepared by smelting. (Au15Sn68Bi17 (at.%) named ɑ and Au19Sn76Bi5 (at.%) named β in the present work).

Wood species can be classified by spectral reflectance. It is unclear whether finish coated on the wood surface affects the accuracy of wood species classification. This paper focused on this issue, using the spectral reflectance of 8 different kinds of finish for wood species classification. The spectral reflectance of wood surface coated with finish was modified by the transfer model in order to reduce the effect of finish on classification accuracy. The experimental results show that it is not feasible to use the spectral reflectance of wood samples coated with finish directly to classify wood species; the best classification accuracy using the eight finishes was 30%. After correcting the spectrum of wood samples coated with finishes with the direct standardization (DS) transfer model, the classification accuracy of the near-infrared (NIR) spectrum was close to that of the original spectrum without finish. However, the visible/near-infrared (VIS/NIR) spectrum did not achieve a good classification effect after correction with the DS transfer model.