In this paper, we propose an adaptive triangular deployment algorithm that can adjust sensor distribution depending on the variation in communication performance in an underwater environment. To predict the distance between sensor nodes, a performance surface model is implemented by estimating the communication performance based on spatio-temporal environment factors affecting the communication performance of the underwater sensor node. Subsequently, the performance surface model is applied to the adaptive triangular deployment algorithm and is used to control the distance between nodes. Therefore, underwater wireless sensor networks deployed with adaptive triangular deployment algorithms can achieve a maximum connectivity rate with an optimal number of nodes.

Background and Purpose The myelin oligodendrocyte glycoprotein (MOG) antibody is detected at a high rate in childhood acquired demyelinating syndrome (ADS). This study aimed to determine the diagnostic value of the MOG antibody in ADS and the spectrum of MOGantibody-positive demyelinating diseases in children. Methods This study included 128 patients diagnosed with ADS (n=94) or unexplained encephalitis (n=34). The MOG antibody in serum was tested using an in-house live-cell-based immunofluorescence assay. Results The MOG antibody was detected in 48 patients (46 ADS patients and 2 encephalitis patients, comprising 23 males and 25 females). Acute disseminated encephalomyelitis (ADEM) (35.4%) was the most-common diagnosis, followed by the unclassified form (17.4%), isolated optic neuritis (ON) (15.2%), neuromyelitis optica spectrum disorder (13.0%), multiple sclerosis (MS) (10.8%), other clinically isolated syndromes [monophasic event except ADEM, isolated ON, or transverse myelitis (TM)] (8.7%), and unexplained encephalitis (4.3%). At the initial presentation, 35 out of the 46 patients with ADS had brain lesions detected in magnetic resonance imaging, and 54% of these 35 patients had encephalopathy. Nine of the 11 patients without brain lesions exhibited only ON. Thirty-nine percent of the patients experienced a multiphasic event during the mean follow-up period of 34.9 months (range 1.4-169.0 months). Encephalopathy at the initial presentation was frequently confirmed in the monophasic group (p= 0.011). Conclusions MOG antibodies were identified in all pediatric ADS phenotypes except for monophasic TM. Therefore, the MOG antibody test is recommended for all pediatric patients with ADS, especially before a diagnosis of MS and for patients without a clear diagnosis.

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In this article, a dual‐polarized double‐slot antipodal Vivaldi antenna (DP‐DsAVA) is proposed to solve the problem of conventional four‐element dual‐polarized antipodal Vivaldi antennas in that the side lobe level increases as frequency increases, and a grating lobe is generated at frequencies above one octave. The DP‐DsAVA comprises two modified double‐slot antipodal Vivaldi antennas (DsAVAs), which are suitable for dual‐polarized implementation through incision and intersection, and each crossed DsAVA implements each polarization separately. Therefore, the proposed antenna does not produce a grating lobe within the operating frequency range, and it has a lower side lobe level compared to that of a conventional antenna. Measurements of the proposed antenna indicate that its impedance bandwidth is 5.4 to 16.4 GHz, and no grating lobe occurs within this bandwidth. At the operating frequency, the gain is 8.4 to 10.6 dBi, and the cross‐polarization level is below −18 dB.

In the conventional dual-slot Vivaldi antenna, the beam is concentrated in the E-plane by the dual-slot structure, thereby reducing the beam width of the E-plane. Therefore, radiation pattern asymmetry of the E-plane and H-plane occurs. In this work, a double-slot Vivaldi antenna with an extended dielectric structure is proposed to improve the radiation pattern symmetry of the double-slot Vivaldi antenna in the E/H-plane. The proposed antenna reduces the beam width by focusing the E-field on the H-plane in the axial direction of the antenna, using the phenomenon of the refraction of the electric field at the interface between the extended dielectric and air, so that the radiation pattern exhibits symmetry. The effects of reducing the beam width in the H-plane when the extended dielectric is present or absent were compared. It was found that the extended dielectric structure has a beam width reduction effect of as much as 25° according to the frequency.