No abstract

A private quantum channel (PQC) in quantum cryptography is one of the most well-known quantum cryptographic protocols using a secret key obtained from the quantum key distribution (QKD) protocol, and it is called a quantum one-time pad or random unitary channel and so on. The reason a PQC is important is that the output state of the channel always gives rise to a maximally mixed state, so the quantum communication can be secured without any external eavesdropping; thus, it preserves information-theoretic security. We explicitly construct five kinds of single-qubit PQCs and try to connect each to a 3-dimensional polyhedron. We expand a corresponding method between four unitary matrices given by Pauli matrices and the regular tetrahedron, and find specific unitary matrices corresponding to another four regular polyhedra. Each unitary matrix is naturally connected to a pre-shared key obtained by using the QKD protocol, which completes a model of five kinds of PQCs for the single-qubit state. Finally, we analyze a trade-off relation between security and efficiency for the PQC.

Purpose: Despite increasing number of reports on Enhanced Recovery After Surgery program (ERAS) and readmission after pancreaticoduodenectomy (PD) from Western countries, there are very few reports on this topic from Asian countries. This study aimed to evaluate the effects of ERAS on hospital stay and readmission and to identify reasons and risk factors for readmission after PD. Methods: This retrospective cohort study included 670 patients who underwent open PD from January 2003 to December 2017. The patients were classified into ERAS (n = 352) and non-ERAS (n = 318) groups. Patients' characteristics, perioperative outcomes, and readmission rates were compared. Results: There were no significant differences in the postoperative complication rates between the groups. The mean postoperative hospital stay was significantly shorter in the ERAS group (24.5 vs. 18.0 days, P < 0.001), but the 90-day readmission rate was similar in the 2 groups (9.1% vs. 8.5%, P = 0.785). Complications associated with pancreatic fistula (42.4%) were the most common cause for readmission. In the multivariate analysis, diabetes mellitus (odds ratio [OR], 1.84; 95% confidence interval [CI], 1.05-3.24; P = 0.034), preoperative non-jaundice (OR, 0.45; 95% CI, 0.25-0.82; P = 0.009) and severe postoperative complications (OR, 4.12; 95% CI, 2.34-7.26; P < 0.001) were identified as risk factors for readmission. Conclusion: The results confirmed that the ERAS program for PD was beneficial in reducing postoperative stay without increasing readmission risks. To decrease readmission rates, prudent discharge planning and medical support should be considered in patients who experience severe complications.

Recently, as the market for SMART TV expands, the camera is embedded for providing various user experience. However, this leads to occurrence of camera failure due to TV power up sequence problem, which are usually not detectable in conventional test equipments. Although the failure-detection can be possible by re-generating control signals for audio interface with new equipment, it is expensive and also requires much time to test. In this paper, for SMART TV, FPGA(Field Programmable Gate Array)-based failure-detection system is proposed which can lead to reduction of both cost and time for test.