4,448 research outputs found
A characterization of some {2υα+1+υγ+1, 2υα+υγ; k−1, 3}- minihypers and some (n,k, 3k−1 − 2 · 3α − 3γ; 3)-codes (k⩾3, 0⩽α<γ<k−1) meeting the Griesmer bound
No full textAbstractRecently, Hamada and Deza (1988) and Hamada and Helleseth (in a submitted paper) characterized all {υα+1+υβ+1+υγ+1, υα+υβ+υγ; t, q}-minihypers for any integers t, q, α, β and γ such that q⩾5 and 0⩽α⩽β⩽γ<t where q is a prime power and υl = (ql−1)(q−1) for any integer l⩾0. The purpose of this paper is to characterized all {υα+1+υβ+1+υγ+1,υα+ υβ+υγ;t,q}-minihypers for any integers t, q, α, β and γ such that (a) q = 3, 0⩽α = β< γ<t and γ≠α+1 or (b) q = 3 and (α, β, γ) = (2, 2, 3). Using those results, all (n,k,d; 3)-codes meeting the Griesmer bound are characterized for the case k⩾3 and d = 3k−1 −2·3α−3γ
Detection of localized UIS failure on IGBTs with the aid of lock-in thermography
No full textIGBTs with embedded current monitors, i.e. realized by separating a small part of the main device emitter
and using it as the current sense terminal, are currently used to integrate intelligent power modules
(IPMs). In a previous paper [Breglio G, Irace A, Napoli E, Spirito P, Hamada K, Nishijima T, et al. Study
of a failure mechanism during UIS switching of planar PT-IGBT with current sense cell. Microelectron
Reliab 2007;47(9–11):1756–60] we have demonstrated how, during UIS switching in particular circuit
configurations, the interplay between the sense-emitter cell and the rest of the device can lead to
latch-up of the lateral p–n–p bipolar transistor and current focalization in the sense-emitter cell which
finally causes device failure. In this paper, we show how the location of this very localized failure spot
can be very accurately determined with the aid of a very sensitive lock-in thermography setup. The main
advantage of this approach is the direct applicability to the failed device without the need of time consuming
sample preparation as in other failure analysis (FA) techniques
Review of Learning words from reading: A cognitive model of word-meaning inference; Author: Megumi Hamada; Publisher: Bloomsbury Academic, 2021; ISBN: 978-1-3501-5368-4; Pages: 168
No full textBook Review: Learning words from reading: A cognitive model of word-meaning inference. Author: Megumi Hamada. Publisher: Bloomsbury Academic, 2021. ISBN: 978-1-3501-5368-4. Pages: 16
A new species of Enderleina Jewett (Plecoptera, Perlidae) from Amazonas State, Brazil
No full textHamada, N., Silva, J. O., Pedroza, M. K. (2016): A new species of Enderleina Jewett (Plecoptera, Perlidae) from Amazonas State, Brazil. Zootaxa 4098 (2): 392-400, DOI: 10.11646/zootaxa.4098.2.1
Polarities, quasi-symmetric designs, and Hamada\u27s conjecture
No full textWe prove that every polarity of PG(2k - 1,q), where k≥ 2, gives rise to a design with the same parameters and the same intersection numbers as, but not isomorphic to, PGk (2k,q). In particular, the case k = 2 yields a new family of quasi-symmetric designs. We also show that our construction provides an infinite family of counterexamples to Hamada\u27s conjecture, for any field of prime order p. Previously, only a handful of counterexamples were known
Long-term evolution of solar coronal holes
No full textAbstractSolar coronal holes are regions of open magnetic field lines in the solar corona. They are the source region of high-speed solar wind streams that play an important role for geomagnetic activity and are the most important driver of energetic particle precipitation into the Earth’s atmosphere. Understanding the evolution of coronal holes is critical for solar magnetism as well as for accurate space weather forecasts. Historically, coronal holes have been identified visually and hand-traced by experienced observers. In this thesis, we develop a novel automated method to identify coronal holes from the extreme ultraviolet synoptic maps by determining the intensity threshold of coronal hole regions separately for each synoptic map. We quantify the spatio-temporal evolution of coronal hole during solar cycles 23 and 24. We studied geomagnetic storms triggered by two sequences of high-speed streams from persistent low-latitude coronal hole sources, observed in the declining phase of solar cycle 23. We found a systematic change in the Bz(GSM)–Bz(GSE) difference which offers the first detailed analysis of the onset of the Rusell-McPherron mechanism, increasing geomagnetic activity of the negative polarity sequence as we approach the March equinox. We also present a novel homogenized solar extreme ultraviolet synoptic dataset based on full-disk images from Solar and Heliospheric Observatory/Extreme ultraviolet Imaging Telescope and Solar Dynamics Observatory/Atmospheric Imaging Assembly. These maps provide a systematic and homogenous view of the entire solar surface in the extreme ultraviolet wavelengths from 1996 until 2019. Using this long-running homogenized dataset of solar extreme ultraviolet observations together with the coronal hole automated identification algorithm, we prepared a 23-year (1996–2019) coronal hole synoptic dataset. This coronal hole dataset is combined with the MacIntosh Archive (1973–2009) to produce the longest dataset of equatorial coronal hols covering more than four solar cycles.Original papersOriginal papers are not included in the electronic version of the dissertation.Hamada, A., Asikainen, T., Virtanen, I., & Mursula, K. (2018). Automated identification of coronal holes from synoptic EUV maps. Solar Physics, 293(4), 71. https://doi.org/10.1007/s11207-018-1289-2Self-archived versionMunteanu, C., Hamada, A., & Mursula, K. (2019). High‐speed solar wind streams in 2007–2008: Turning on the Russell‐McPherron effect. Journal of Geophysical Research: Space Physics, 124(11), 8913–8927. https://doi.org/10.1029/2019JA026846Self-archived versionHamada, A., Asikainen, T., & Mursula, K. (2020). New homogeneous dataset of solar EUV synoptic maps from SOHO/EIT and SDO/AIA. Solar Physics, 295(1), 2. https://doi.org/10.1007/s11207-019-1563-ySelf-archived versionHamada, A., Asikainen, T., & Mursula, K. (2020). A uniform series of coronal holes in 1973–2018. Manuscript submitted for publication. https://doi.org/10.1007/s11207-021-01781-wSelf-archived versionOsajulkaisutOsajulkaisut eivät sisälly väitöskirjan elektroniseen versioon.Hamada, A., Asikainen, T., Virtanen, I., & Mursula, K. (2018). Automated identification of coronal holes from synoptic EUV maps. Solar Physics, 293(4), 71. https://doi.org/10.1007/s11207-018-1289-2Rinnakkaistallennettu versioMunteanu, C., Hamada, A., & Mursula, K. (2019). High‐speed solar wind streams in 2007–2008: Turning on the Russell‐McPherron effect. Journal of Geophysical Research: Space Physics, 124(11), 8913–8927. https://doi.org/10.1029/2019JA026846Rinnakkaistallennettu versioHamada, A., Asikainen, T., & Mursula, K. (2020). New homogeneous dataset of solar EUV synoptic maps from SOHO/EIT and SDO/AIA. Solar Physics, 295(1), 2. https://doi.org/10.1007/s11207-019-1563-yRinnakkaistallennettu versioHamada, A., Asikainen, T., & Mursula, K. (2020). A uniform series of coronal holes in 1973–2018. Manuscript submitted for publication. https://doi.org/10.1007/s11207-021-01781-wRinnakkaistallennettu versioAcademic Dissertation to be presented, with the assent of the Graduate School of the University of Oulu, for public discussion in the Auditorium IT115, Linnanmaa, on November 6th, 2020, at 12 o’clock noonAbstract
Solar coronal holes are regions of open magnetic field lines in the solar corona. They are the source region of high-speed solar wind streams that play an important role for geomagnetic activity and are the most important driver of energetic particle precipitation into the Earth’s atmosphere. Understanding the evolution of coronal holes is critical for solar magnetism as well as for accurate space weather forecasts. Historically, coronal holes have been identified visually and hand-traced by experienced observers. In this thesis, we develop a novel automated method to identify coronal holes from the extreme ultraviolet synoptic maps by determining the intensity threshold of coronal hole regions separately for each synoptic map. We quantify the spatio-temporal evolution of coronal hole during solar cycles 23 and 24. We studied geomagnetic storms triggered by two sequences of high-speed streams from persistent low-latitude coronal hole sources, observed in the declining phase of solar cycle 23. We found a systematic change in the Bz(GSM)–Bz(GSE) difference which offers the first detailed analysis of the onset of the Rusell-McPherron mechanism, increasing geomagnetic activity of the negative polarity sequence as we approach the March equinox. We also present a novel homogenized solar extreme ultraviolet synoptic dataset based on full-disk images from Solar and Heliospheric Observatory/Extreme ultraviolet Imaging Telescope and Solar Dynamics Observatory/Atmospheric Imaging Assembly. These maps provide a systematic and homogenous view of the entire solar surface in the extreme ultraviolet wavelengths from 1996 until 2019. Using this long-running homogenized dataset of solar extreme ultraviolet observations together with the coronal hole automated identification algorithm, we prepared a 23-year (1996–2019) coronal hole synoptic dataset. This coronal hole dataset is combined with the MacIntosh Archive (1973–2009) to produce the longest dataset of equatorial coronal hols covering more than four solar cycles
INVERSION SPLITTING IN AND ITS J, K-DEPENDENCE
No full text Y. Hamada, A. Y. Hirakawa, K. Tamagake, and M. Tsuboi, J. Mol. Spectroscopy, 35, 420 (1970). M. Tsuboi and J. Overend, J. Mol. Spectroscopy, 52, 256 (1974).Author Institution:In continuation of our of the antisymmetric wagging band , 1020--860 ) of hydrazine, , an examination with resolution has recently been made by the use of infrared diode lasers. The J-structures of the , and clusters have been analyzed, where a, b, c, and d are the components of the inversion splitting in each transition (C-type) (see the figure). It has been found that the inversion splitting becomes smaller with increasing J and with increasing K, both in the state (shown by b-c) and state (shown by a-d). An explanation is given for this finding. [FIGURE
Haliplus regili Benetti & Hamada, 2017, sp. n.
No full textHaliplus regili sp. n. (Figs. 3–4, 13–20) Type locality. Brazil: Roraima state, Alto Alegre county, pond near the RR-205 road (02°59'39.8"N 61°06'46.2"W). Type material. Holotype male (INPA): Brazil: Roraima state, Alto Alegre county, pond near the RR-205 road (02°59'39.8"N 61°06'46.2"W), 05.vi.2015, leg. C.J. Benetti, K. Dias-Silva and B.G. Oliveira. Diagnosis. Haliplus regili sp. n. can be distinguished from other neotropical species of Haliplus by the following combination of characteristics: elytra brown with extensive but not clearly defined maculation consisting of dark patches (Fig. 3); prosternal process gradually widening anteriorly, slightly narrowed in posterior part; about 1.9 times longer than wide at base (Fig. 16); metaventral process with two well-defined impressions on both sides (Fig. 4) and median lobe of aedeagus in lateral view curved, straight in the apical third, with the apex strongly truncated (Fig. 19). Description. Habitus (Fig. 3). Body oval, tapering backwards, widest just behind the shoulders, with very narrow pronotum and shoulders pronounced. Measurements (n=1). TL: 3.36 mm; MW: 2.13 mm; PL: 0.7 mm; PW: 1.45 mm; DE: 0.26; EW: 0.25 mm. Head. Orange-brown with vague darkening near antennae and between eyes; strongly and densely punctured; narrower than pronotum, widest across eyes; width between eyes 0.9 × width of eye. Antennae yellow; placed anterior to eyes; with 11 antennomeres, 1st and 2nd short and broad, 3–11 long, 11th the largest (Fig. 13). Palpi yellow; maxillary palpi with four palpomeres, the last shorter than penultimate. Genal lines behind eyes double. Pronotum. Reddish-brown, with two vague dark spots at base; strongly and densely punctured, more strongly impressed along base; widest at base, narrow towards apex; lateral sides convex, not margined; base without plicae. Elytra. Brown, with extensive but not clearly defined maculation consisting of dark patches; dark marks along suture and base not darkened (Fig. 3). Primary puncture rows strongly impressed at base and finely impressed at apex; about 33 punctures in first row; fifth elytral puncture row not extended along base; secondary puncture rows dense and moderately strong, along suture strong, in two irregular rows; all punctures darkened (Fig. 14). Lateral margin completely bordered; shoulders weakly serrate; apical margin not serrate. Ventral side. Reddish-brown, darkened towards coxae. Epipleura reddish-brown, with double row of strong punctures in anterior part and single row of weaker punctures in posterior narrowed part, reaching to the end of fifth sternite. Prosternum bordered anteriorly, strongly punctured in the middle. Prosternal process gradually widening anteriorly, slightly narrowed in posterior part; about 1.9 times longer than wide at base; anterior edge margined, laterally grooved; moderately strongly and densely punctured (Figs. 4, 16, 17). Metaventral process with two well-defined, but slightly confluent impressions on both sides, not impressed in the middle; moderately punctured (Fig. 16). Metacoxal plates reaching to the fifth sternite, densely punctured. Fifth and sixth sternites densely punctured; last sternite punctured only at base (Fig. 4). Legs. Orange-brown to brown. Fore- and mid legs: femur basally narrowed, medially enlarged, surface covered with dense, coarse micropunctures; tibia with long hairs on inner margin, apically with two equal spurs; tarsi with 5 tarsomeres, the 5th longest, tarsal claws of equal length. Hind legs: coxal plates enlarged covering trochanter and most of the femoral region; femur broadest at apex; tibia slender with unequal apical spurs, setiferous striole on dorsal face of 1/5 × length and longer apical spur as long as the length of first tarsomere (Fig. 15); tarsi with 5 tarsomeres, 1st the longest, with a pair of equal claws. Male. First three tarsomeres of fore- and midlegs widened and ventrally with a tuft of sucker hairs. Aedeagus: Median lobe in lateral view curved, straight in the apical third, wider at base, narrowed towards the apex and slightly widened at tip; apex strongly truncated (Fig. 19). Left paramere in lateral view short and broad, subtriangular, almost as long as wide, with basal process narrow, and with apex angular; with a series of long setae and some sparse setae at the apex (Fig. 18). Right paramere in lateral view slender, moderately curved, base bilobed, apex rounded; inner margin with a series of large setae in the apical two thirds (Fig. 20). Etymology. This species is named in honor of Juan Antonio Régil Cueto, the PhD supervisor of the first author, a good friend and colleague, in gratitude for all the shared moments during our long friendship and in recognition of his contribution to the knowledge of water beetles. Distribution and habitat. Northern Brazil, currently only known in the state of Roraima (Fig. 21). Specimen was collected in a shallow pond with macrophytes covering the entire surface (Fig. 23). Taxonomic comments. Haliplus regili sp. n. can be distinguished from other neotropical species of Haliplus by the combination of characteristics of elytra, prosternal and metaventral processes and the male genitalia shape. The new species resembles H. langleyi Vondel & Spangler, 2008 and H. triplehorni Vondel & Spangler, 2008, but differs from these species in the shape of prosternal process (Fig. 16), gradually widening anteriorly (almost parallel in H. langleyi and H. triplehorni); male median lobe (Fig. 19), shorter and less curved downward in H. langleyi and H. triplehorni and right paramere (Fig. 20), without distal appendage (with distal appendage in H. langleyi and H. triplehorni.Published as part of Benetti, Cesar João & Hamada, Neusa, 2017, Two new species of Haliplus Latreille, 1802 (Coleoptera, Haliplidae) from Northern Brazil, pp. 584-592 in Zootaxa 4282 (3) on pages 587-592, DOI: 10.11646/zootaxa.4282.3.10, http://zenodo.org/record/82787
Rivudiva oxum Cruz & Boldrini & De Lima & Hamada 2022, sp. nov.
No full textRivudiva oxum sp. nov. urn:lsid:zoobank.org:act: 21BF614C-3B80-4307-82BE-F981DE45D244 Figs 8–11 Rivudiva trichobasis – Boldrini & Cruz 2014: 5. — Salles et al. 2020: 49. Diagnosis NYMPH. The combination of the characters: 1) labrum distal margin straight (Fig. 8A); 2) labrum ventral surface with robust, distally bifid, eventually pectinated, setae on distal margin (Fig. 8A); 3) left mandible with incisors fused at middle (Fig. 8B); 4) maxillary palp segment II with inner distal protuberance, outer margin straight, with long distal lobe (Fig. 8D–H); 5) hypopharynx without distomedial projection (Fig. 8I); 6) glossae inner arc of setae following the inner margin at base, curved at apex, outer arc of setae sinuous (Fig. 8J–K); 7) labial palp segment III robust, conical and apically pointed (Fig. 8J); 8) dorsal margin of forefemur with one row of long setae from base to apex (Fig. 9A); 9) anterior surface of forefemur with blunt setae at middle (Fig. 9A); 10) patella-tibial suture absent; 11) distal margin of terga with triangular spines (Fig. 10A). Etymology ʻ Oxum ʼ is a female ʻ orixá ʼ (deity or goddess) from the Ijexá nation, adopted and worshipped in Afro- Brazilian religions. She is the fresh waters ʻ orixá ʼ (lakes, rivers and waterfalls), of wealth, love, prosperity and beauty. Name in apposition. Material examined Holotype BRAZIL • nymph on slide; Rondônia, Alto Alegre dos Parecis, line 24 southbound from RO-370 leaving Alto Alegre to the east, under the bridge; 12°12′57.8″ S, 061°47′18.4″ W; 8 Jul. 2016; P.V. Cruz leg.; INPA. Paratypes BRAZIL • 3 nymphs; same collection data as for holotype; INPA • 3 nymphs; Rondônia, Machadinho do Oeste, RO-133 between Tabajara and 2 de novembro streams; 08°53′10.0″ S, 062°11′21.8″ W; 21 Aug. 2016; P.V. Cruz and N. Hamada leg.; INPA • 1 nymph; Rondônia, Alto Alegre dos Parecis, line 24 southbound from RO-370 leaving Alto Alegre to the east, at the curve at the foot of a hill; 12°14′22.8″ S, 061°47′26.9″ W; 9 Jul. 2016; P.V. Cruz and N. Hamada leg.; INPA • 5 nymphs; Rondônia, Alto Alegre dos Parecis, line 24 southbound from RO-370 leaving Alto Alegre to the east, at the curve at the foot of a hill; 12°14′23.2″ S, 061°47′26.7″ W; 8 Jul. 2016; P.V. Cruz and N. Hamada leg.; INPA • 2 nymphs; same locality as for preceding; 24 Jul. 2016; P.V. Cruz and N. Hamada leg.; INPA • 6 nymphs; Rondônia, Alto Alegre dos Parecis, line 24 southbound from RO-370 leaving Alto Alegre to the east, preserved area of PCH Santa Luzia, small stream; 12°20′37.4″ S, 061°45′26.3″ W; 9 Jul. 2016; P.V. Cruz leg.; INPA • 1 nymph; Rondônia, Nova União, Vale da Cachoeiras, Balneário, access by RO-470 or RO-473, below waterfall, from RO 470 on the left, 13 km; 10°55′18.0″ S, 062°22′34.6″ W; 1 Aug. 2016; P.V. Cruz and N. Hamada leg.; INPA • 4 nymphs; Amazonas, Humaitá, PARNA Campos Amazônicos, Veado stream; 08°26′27.4″ S, 061°39′37.3″ W; 6 Jul. 2018; P.V. Cruz, N. Hamada and G. Desidério leg.; INPA. Description Nymph LENGTH. Body, 3.3–3.5 mm. HEAD.Antenna. Flagellum with minute spines on apex of each segment. Labrum (Fig. 8A). Rectangular, length about 0.6× maximum width; distal margin straight; one row of robust, distally bifid, eventually pectinated, setae from lateral to middle of distal margin; one row of thin bifid setae on distal margin not reaching distolateral margin; dorsal surface with many thin setae over surface. Left mandible (Fig. 8B). Incisors partially cleft in two sets (fused at middle); outer and inner sets of incisors respectively with 4 + 3 denticles, outer incisor with spine-like process; prostheca robust and pectinated; margin between prostheca and mola straight; tuft of spine-like setae at base of mola present; subtriangular process wide; denticles of mola constricted; mola with two large denticles, apex of mola with one simple seta; outer margin convex. Right mandible (Fig. 8C). Incisors fused at base; outer and inner sets of incisors respectively with 3 + 3 denticles, outer incisor with spine-like process; prostheca stout, bifurcated at apex, inner lobe longer; margin between prostheca and mola almost straight; tuft of spine-like setae at base of mola present; denticles of mola not constricted; apex of mola with one simple seta; first process of mola rounded, second expanded and straight; outer margin convex. Maxilla (Fig. 8D–H). Maxillary palpi 1.7× length of galea-lacinia; segment II 0.9× length of segment I; segment II with inner distal protuberance, outer margin straight, with long distal lobe half of width of segment II apex; ventral canine enlarged, not laterally expanded; set of distal setae of the inner-ventral row rounded. Hypopharynx (Fig. 8I). Lingua longer than superlingua, sub-quadrangular, without distomedial projection, with medio-distal tuft of simple setae; superlingua with rounded outer margin; short, thin, simple setae scattered over distal margin of lingua and superlingua. Labium (Fig. 8J–K). Glossa slightly expanded at base, with parallel margins, distal margin slightly rounded, shorter than paraglossa; inner margin without row of setae; ventral surface covered by thin setae; dorsal surface with inner arc of robust pointed setae following the inner margin at base, curved at apex, outer arc of long robust setae following the inner margin at base, sinuous at apex; one small robust blunt seta on apex. Paraglossa curved inward; apex with one row of robust and long spine-like setae; outer margin without setae; dorsal surface with four longitudinal rows of setae, inner row longer than half of length of paraglossa, distally with long robust setae; ventral surface with one row of six setae near to inner margin, apex with one row of robust setae. Labial palp with segment I 0.8× length of segments II and III combined; inner distal protuberance of segment II rounded, covered with thin setae; segment III robust, conical, and apically pointed; outer margin with short thin setae, dorsal surface covered with short spine-like setae, ventral surface with two short spine-like setae, and covered by long thin setae. THORAX. Foreleg (Fig. 9A–C). Femur length about 3.3× maximum width; dorsal margin with one row of long spine-like setae from base to apex; anterior surface with one medial row of blunt setae, one row of long spine-like setae near ventral margin reaching apex, one row of long spine-like setae near dorsal margin; posterior surface with one row of long spine-like setae near ventral margin from base to apex, and one medial row of long spine-like setae from base to apical third. Tibia. Dorsally bare; ventral margin with one row of long spine-like setae at apical half, patella-tibial suture absent. Tarsus. Ventral margin with one row of spine-like setae. Tarsal claws 0.5× length of tarsus, with two rows of small conical denticles not reaching apex. Hind leg (Fig. 9D–E). Femur dorsal margin with one row of long spine-like setae; anterior surface with one row of spine-like setae near dorsal margin, one row of long spine-like setae near ventral margin, one row of spine-like setae near middle; posterior surface with one row of spine-like setae near ventral margin. Tibia. Dorsally bare; ventral margin with two small blunt setae base, patella-tibial suture present. Tarsus. Ventral margin with one row of small blunt setae. Tarsal claws 0.6× length of tarsus, with two rows of small conical denticles reaching apex. ABDOMEN. Terga (Fig. 11) with all segments yellowish or white (color lost in alcohol), terga I–VIII with two small medial dots, sometimes dots absent; terga III and VIII with one large dot on distal margin (eventually absent); tergum IX darker. Posterior margin of terga with triangular spines (Fig. 10A). Gills oblong, longer than next segment, with one medial trachea pigmented. Paraproct (Fig. 10B) with seven to nine marginal spines, posterolateral extension with spines. Cerci (Fig. 10C) with lateral spines on every segment. Paracercus (Fig. 10D) without spines. Comments The variation presented in Fig. 8E–F is related to the slide mount artifact. In Fig. 8E, the maxillary palp is in outer margin view, while in Fig. 8G–H it is in lateral view. The palps presented in Fig. 8G–H are true variations of the segment II and its distal lobe.Published as part of Cruz, Paulo Vilela, Boldrini, Rafael, De Lima, Cláudia R. T. & Hamada, Neusa, 2022, It is a mess! How many species are in Rivudiva trichobasis Lugo- Ortiz & McCafferty, 1998 (Ephemeroptera: Baetidae)?, pp. 153-191 in European Journal of Taxonomy 789 (1) on pages 168-169, DOI: 10.5852/ejt.2022.789.1639, http://zenodo.org/record/596540
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