Compaction of Church Numerals for Higher-Order Compression

In this study, we address the problem of compacting Church numerals. Church numerals appear as a representation of the repetitive part of data in higher-order compression. We propose a novel decomposition scheme for a natural number using tetration, which leads to a compact representation of $\lambda$-terms equivalent to the original Church numerals. For natural number $n$, we prove that the size of the $\lambda$-term obtained by the proposed method is $O(({\rm slog}_{2}n)^{\log n/ \log \log n})$. Moreover, we quantitatively confirmed experimentally that the proposed method outperforms a binary expression of Church numerals when $n$ is less than approximately 10000

SYNTHESIS OF NIGRICANIN VIA INTRAMOLECULAR BIARYL COUPLING REACTION OF FUNCTIONALIZED PHENYL BENZOATE

A tetracyclic natural product, nigricanin (1), was synthesized through an intramolecular biaryl coupling reaction of the phenyl benzoate derivative which was derived from the corresponding phenol and benzoic acid

Latent trajectory modelling of pulmonary artery pressure in systemic sclerosis: a retrospective cohort study

OBJECTIVES: To visualise the trajectories of pulmonary arterial pressure (PAP) in systemic sclerosis (SSc) and identify the clinical phenotypes for each trajectory, by applying latent trajectory modelling for PAP repeatedly estimated by echocardiography. METHODS: This was a multicentre, retrospective cohort study conducted at four referral hospitals in Kyoto, Japan. Patients with SSc who were treated at study sites between 2008 and 2021 and who had at least three echocardiographic measurements of systolic PAP (sPAP) were included. A group-based trajectory model was applied to the change in sPAP over time, and patients were classified into distinct subgroups that followed similar trajectories. Pulmonary hypertension (PH)-free survival was compared for each trajectory. Multinomial logistic regression analysis was performed for baseline clinical characteristics associated with trajectory assignment. RESULTS: A total of 236 patients with 1097 sPAP measurements were included. We identified five trajectories: rapid progression (n=9, 3.8%), early elevation (n=30, 12.7%), middle elevation (n=54, 22.9%), late elevation (n=24, 10.2%) and low stable (n=119, 50.4%). The trajectories, in the listed order, showed progressively earlier elevation of sPAP and shorter PH-free survival. In the multinomial logistic regression analysis with the low stable as a reference, cardiac involvement was associated with rapid progression, diffuse cutaneous SSc was associated with early elevation and anti-centromere antibody was associated with middle elevation; older age of onset was associated with all three of these trajectories. CONCLUSION: The pattern of changes in PAP over time in SSc can be classified into five trajectories with distinctly different clinical characteristics and outcomes

At-sea experiment of adaptive time-reversal multiuser communication in the deep ocean

An at-sea experiment of multiuser communication in deep water using adaptive time reversal was carried out. In the experiment, two sources and a 20-channel receiver array were deployed at the range of 30 km in an area of 1500-2000 m water depth. One of the sources was moored and the other was suspended at various depths. For processing signals actually transmitted from two sources, it was demonstrated that adaptive time reversal could cancel multiuser interference independently of relative source positions. Additionally, for a more detailed investigation, the analysis of multiuser test signals by synthesizing signals from different depths was performed. As a result, especially in the case of adjacent sources, adaptive time reversal significantly suppressed crosstalk.http://www.godac.jamstec.go.jp/darwin/cruise/kaiyo/ky15-01/

Experimental study on multiple-input/multiple-output communication with time reversal in deep ocean

Multiple-input/multiple-output (MIMO) communication using adaptive time reversal is discussed comparing with orthogonal frequency division multiplexing (OFDM) with simulated MIMO test signals by synthesizing experimental data in deep ocean. The experiment was executed in 1,100-m-depth area at the range of 10 km with the bandwidth of 500 +/- 50 Hz. Although time variance is not included in analysis of OFDM, it is impossible to increase MIMO channels with OFDM. In the meantime, with adaptive time reversal, it is possible to achieve 8 x 20 and 6 x 20 MIMO communication with binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK), respectively, in spite of time variance and input SNRs degradation due to synthesizing signals. Thus, it is demonstrated that adaptive time reversal has much better performance than OFDM in MIMO underwater acoustic communication.http://www.godac.jamstec.go.jp/darwin/cruise/kaiyo/ky15-15/

The effect of water immersion on short-latency somatosensory evoked potentials in human

<p>Abstract</p> <p>Background</p> <p>Water immersion therapy is used to treat a variety of cardiovascular, respiratory, and orthopedic conditions. It can also benefit some neurological patients, although little is known about the effects of water immersion on neural activity, including somatosensory processing. To this end, we examined the effect of water immersion on short-latency somatosensory evoked potentials (SEPs) elicited by median nerve stimuli. Short-latency SEP recordings were obtained for ten healthy male volunteers at rest in or out of water at 30°C. Recordings were obtained from nine scalp electrodes according to the 10-20 system. The right median nerve at the wrist was electrically stimulated with the stimulus duration of 0.2 ms at 3 Hz. The intensity of the stimulus was fixed at approximately three times the sensory threshold.</p> <p>Results</p> <p>Water immersion significantly reduced the amplitudes of the short-latency SEP components P25 and P45 measured from electrodes over the parietal region and the P45 measured by central region.</p> <p>Conclusions</p> <p>Water immersion reduced short-latency SEP components known to originate in several cortical areas. Attenuation of short-latency SEPs suggests that water immersion influences the cortical processing of somatosensory inputs. Modulation of cortical processing may contribute to the beneficial effects of aquatic therapy.</p> <p>Trial Registration</p> <p>UMIN-CTR (UMIN000006492)</p

An Efficient Algorithm for Almost Instantaneous VF Code Using Multiplexed Parse Tree

Almost Instantaneous VF code proposed by Yamamoto and Yokoo in 2001, which is one of the variable-length-to-fixed-length codes, uses a set of parse trees and achieves a good compression ratio. However, it needs much time and space for both encoding and decoding than an ordinary VF code does. In this paper, we proved that we can multiplex the set of parse trees into a compact single tree and simulate the original encoding and decoding procedures. Our technique reduces the total number of nodes into O(2ℓk - k2), while it is originally O(2ℓk), where ℓ and k are the codeword length and the alphabet size, respectively. The experimental results showed that we could encode and decode over three times faster for natural language texts by using this technique

Pattern Matching with Taxonomic Information

In this paper, we study the pattern matching problem with taxonomic information (PMTX, for short), where taxonomy is a partially ordered set of letters describing an IS-A hierarchy. We present an efficient algorithm for PMTX that runs in O(mn/w) time with O(m+mh/w) preprocess and O(mσ/w) extra space, where h, m, t, σ, and w are the size of the taxonomic information H, the length of the pattern P ∈ Σ∗, the length of the text T ∈ Σ∗, the cardinality of the sorted alphabet Σ, and the computer word length, respectively. If the pattern length m is less than w, it runs in O(n) time, O(m + h) preprocess, and O(σ) space, and works very fast in practice. We also discuss various improvements of the algorithms for real world applications