182,573 research outputs found
Lobellina gladius Hu & Jiang & Jiang 2019, sp. nov.
No full textLobellina gladius sp. nov. Figures 2, 4, 6, 10–14, 16, 18, 20, Tables 4–5 Type material. Holotype: male, China, Hunan, Xinning county, Langshan National Geopark. Coordinates: 26.273767N, 110.732951E, alt. 770m, in forest of bamboo, leg. Ji-Gang Jiang, Cheng Jiang, Li-Ping Duan, 29.iv.2018. Paratypes: 5 females and 2 juveniles, about 30 specimens in alcohol, the same data as holotype, collection number as J2018042904. One female, subadult, and 4 juvenile, Guangxi, Ziyuan county, Langshan National Geopark. Coordinates: 26.274416N, 110.732011E, alt. 685m, in forest of bamboo, leg. Ji-Gang Jiang, Cheng Jiang, Li-Ping Duan, 29.iv.2018 (J2018042903). Female and male, Guangxi, Ziyuan county, Langshan National Geopark. Coordinates: 26.276824N, 110.730528E, alt. 510m, nearby the entrance of the Park, leg. Ji-Gang Jiang, Cheng Jiang, Li-Ping Duan, 29.iv.2018 (J2018042901). One male, Hunan, Xinning county, Shunhuangshang National Nature Reserve, Coordinates: 26.450028N, 111.014716E, alt. 930m, in forest, leg. Ji-Gang Jiang, Cheng Jiang, Li-Ping Duan, 1.v.2018 (J2018050102). Type materials are housed in the Key Laboratory of Zoology, Hunan University of Arts and Science (HUAS), Changde, Hunan Province, China. Diagnosis. Three pigmented eyes on head, mandible with six teeth, cephalic chaeta O present and including in tubercle Fr, cephalic tubercle Di not fused, non-cross type chaetotaxy on posterior area of head, cephalic lateral tubercle Dl, L and So independent respectively, Ant. I with 9 chaetae, Th. I with 4+4 tubercles, VT with 6–8 (usually 7) chaetae. Description. Body length: holotype, male, 4.0 mm. Usually, males: 4.0– 4.4 mm, females: 3.5–4.8 mm, juveniles: 1.5–3.5 mm. Body color. Red while living (Fig. 2) and white in alcohol (Fig. 4). Chaetal morphology (Fig. 6). Dorsal ordinary chaetae of four types: Ml, Mc, Mcc and me. Macrochaetae Ml long, sheathed, smooth and with blunt tip, gladius shaped (Fig. 6j), some Ml not sheathed and with pointed tip, such as F chaetae on head (Fig.6k) and macrochaetae on Abd. VI (Fig. 6l). Macrochaetae Mc similar to Ml morphologically, but shorter (Fig. 6 m–n). Macrochaetae Mcc morphologically similar to Mc and shorter than Mc (Fig. 6o). Mesochaetae similar to ventral chaetae, thin, smooth, and pointed, with various length (Fig. 6 p–r, t). S-chaetae on terga thin, smooth, equal to Mc and longer than Mcc (Fig. 6s). Head (Table 4, Fig. 10). Eyes 3+3, black (Fig. 11). Antenna 4-segmented (Fig. 16). Ant. I with 9 Chaetae. Ant. II with 9–11 Chaetae. Ant. III dorsally fused to Ant. IV. Two guard chaetae sgd and sgv present. Two short rods exposed in separate pit. Ant. IV dorsally with 8 thickened and curved sensilla, apical bulb trilobed. sensory organite (or) present. Ventral chaetotaxy of Ant. IV: ap with 7 bs and 3 miA, ca with 3 bs and 1 miA, cm with 2 bs and 2 miA, cp with 1 miA. On ventral side of Ant. III, Vi, Vc, Ve respectively with 3, 5, 4 chaetae. Buccal cone weakly developed, labrum truncated, chaetal formula as 0/2, 2. Mandible with four apical teeth, one curved middle tooth and one basal tooth (Fig. 12). Maxilla crochet form (Fig. 13). Labium with 11 chaetae and no x (Fig.18). Group Vi with 6+6 chaetae (Fig.18). Groups Vea, Vem and Vep with 5, 2 and 2 chaetae respectively. Dorsal chaetotaxy of head as in Table 4. and Fig. 10. Dorsal central area with 6 separate tubercles: 1 tubercle Cl, 2 An, 1 Fr and 2 Oc. Dorsal posterior area with 4 separate tubercles: 2 Di and 2 De. Line of chaetae Di2–De2 not crosses line Di1– De1 on head (non-cross type, Deharveng, 1983). Dorsal lateral area with 3 separate tubercles: Dl, L and So. Thorax (Table 5 & Fig. 10). Th. I with 4+4 tubercles (Di, De, Dl and L). Th. II and Th. III with 4+4 tubercles respectively. Chaetotaxy of thorax and legs as in Table 2. Unguis with a basal inner tooth, unguiculus absent. Chaeta M present on tibiotarsus. Abdomen (Table 5 & Fig. 10). Abd.I–IV respectively with 4+4 tubercles. Abd. V dorsally with 3+3 tubercles, two tubercles Di separate from each other, tubercle De separate from Dl, tubercle L present, on ventral side. Abd. VI with 1 tubercle on each side. VT with 7+7 chaetae, sometimes 6+6 or 8+8. Furcular remnant with 4 chaetae (Fig. 20). Etymology. The name of the species derives from the “ gladius ” shape of its macrochaetae. Remarks. The new species can be separated from known species by the following characters: Th. I with 4+4 tubercles; tubercle Di with 3 chaetae on Abd. I–III respectively, VT with 6–8 chaetae (usually 7); non-crossed type chaetae on cephalic posterior area. Including the new species, sixteen species of genus Lobellina are known worldwide. Seven of them have O chaeta on cephalic tubercle Fr, of which, 4 with chaeta O free from the tubercle, and three species, i.e. L. nanjingensis, L.fusa and L. gladius sp. nov. with chaeta O included in tubercle Fr. The new species can be easily differentiated from the other two species of the last group by the following key.Published as part of Hu, Ya-Hui, Jiang, Cheng & Jiang, Ji-Gang, 2019, Two new species of Lobellini from Central-South China (Collembola Neanuridae), pp. 77-89 in Zootaxa 4712 (1) on pages 83-88, DOI: 10.11646/zootaxa.4712.1.5, http://zenodo.org/record/358686
Hybrid Iterative Multiuser Detection for Channel Coded Space Division Multiple Access OFDM Systems
No full textSpace division multiple access (SDMA) aided orthogonal frequency division multiplexing (OFDM) systems assisted by efficient multiuser detection (MUD) techniques have recently attracted intensive research interests. The maximum likelihood detection (MLD) arrangement was found to attain the best performance, although this was achieved at the cost of a computational complexity, which increases exponentially both with the number of users and with the number of bits per symbol transmitted by higher order modulation schemes. By contrast, the minimum mean-square error (MMSE) SDMA-MUD exhibits a lower complexity at the cost of a performance loss. Forward error correction (FEC) schemes such as, for example, turbo trellis coded modulation (TTCM), may be efficiently combined with SDMA-OFDM systems for the sake of improving the achievable performance. Genetic algorithm (GA) based multiuser detection techniques have been shown to provide a good performance in MUD-aided code division multiple access (CDMA) systems. In this contribution, a GA-aided MMSE MUD is proposed for employment in a TTCM assisted SDMA-OFDM system, which is capable of achieving a similar performance to that attained by its optimum MLD-aided counterpart at a significantly lower complexity, especially at high user loads. Moreover, when the proposed biased Q-function based mutation (BQM) assisted iterative GA (IGA) MUD is employed, the GA-aided system’s performance can be further improved, for example, by reducing the bit error ratio (BER) measured at 3 dB by about five orders of magnitude in comparison to the TTCM assisted MMSE-SDMA-OFDM benchmarker system, while still maintaining modest complexity
Multiuser MIMO-OFDM for Next-Generation Wireless Systems
No full textThis overview portrays the 40-year evolution of orthogonal frequency division multiplexing (OFDM) research. The amelioration of powerful multicarrier OFDM arrangements with multiple-input multiple-output (MIMO) systems has numerous benefits, which are detailed in this treatise. We continue by highlighting the limitations of conventional detection and channel estimation techniques designed for multiuser MIMO OFDM systems in the so-called rank-deficient scenarios, where the number of users supported or the number of transmit antennas employed exceeds the number of receiver antennas. This is often encountered in practice, unless we limit the number of users granted access in the base station’s or radio port’s coverage area. Following a historical perspective on the associated design problems and their state-of-the-art solutions, the second half of this treatise details a range of classic multiuser detectors (MUDs) designed for MIMO-OFDM systems and characterizes their achievable performance. A further section aims for identifying novel cutting-edge genetic algorithm (GA)-aided detector solutions, which have found numerous applications in wireless communications in recent years. In an effort to stimulate the cross pollination of ideas across the machine learning, optimization, signal processing, and wireless communications research communities, we will review the broadly applicable principles of various GA-assisted optimization techniques, which were recently proposed also for employment inmultiuser MIMO OFDM. In order to stimulate new research, we demonstrate that the family of GA-aided MUDs is capable of achieving a near-optimum performance at the cost of a significantly lower computational complexity than that imposed by their optimum maximum-likelihood (ML) MUD aided counterparts. The paper is concluded by outlining a range of future research options that may find their way into next-generation wireless systems
Iterative multi-user detection for OFDM using biased mutation assisted genetic algorithms
No full textSpace Division Multiple Access (SDMA) aided Orthogonal Frequency Division Multiplexing (OFDM) systems assisted by efficient Multi-User Detection (MUD) techniques have recently attracted intensive research interests. As expected, Maximum Likelihood (ML) detection was found to attain the best performance, although this was achieved at the cost of a high computational complexity. Forward Error Correction (FEC) schemes such as Turbo Trellis Coded Modulation (TTCM) can be efficiently amalgamated with SDMA-OFDM systems for the sake of improving the achievable performance without bandwidth expansion. In this contribution, a MMSE-aided Iterative GA (IGA) MUD is proposed for employment in a TTCM-assisted SDMA-OFDM system, which is capable of achieving a similar performance to that attained by its optimum ML-aided counterpart at a significantly lower complexity, especially at high user loads. Moreover, when the proposed novel Biased Q-function Based Mutation (BQM) scheme is employed, the IGA-aided system’s performance can be further improved by achieving an Eb/N0 gain of about 6dB in comparison to the TTCM-aided MMSE-SDMA-OFDM benchmarker system both in low- and high-throughput modem scenarios, respectively, while still maintaining a modest complexity
Crossodonthina langshanensis Hu & Jiang & Jiang 2019, sp. nov.
No full textCrossodonthina langshanensis sp. nov. Figures 1, 3, 5, 7–9, 15, 17, 19, Tables 1–3 Type material. Holotype: female, China, Hunan, Xinning county, Langshan National Geopark. Coordinates: 26.277054N, 110.730618E, alt. 520m, in forest, leg. Ji-Gang Jiang, Cheng Jiang, Li-Ping Duan, 30.iv.2018 (J2018043002). Paratypes: 2 females, China, Hunan, Xinning county, Langshan National Geopark. Coordinates: 26.276580N, 110.729240E, alt. 470m, in forest, leg. Ji-Gang Jiang, Cheng Jiang, Li-Ping Duan, 30.iv.2018 (J2018043003); 3 juvenile, Guangxi, Ziyuan county, Langshan National Geopark, Coordinates: 26.276824N, 110.730528E, alt. 510m, nearby the entrance of the Park, leg. Ji-Gang Jiang, Cheng Jiang, Li-Ping Duan, 29.iv.2018 (J2018042901). Type materials are housed in the Key Laboratory of Zoology, Hunan University of Arts and Science (HUAS), Changde, Hunan Province, China. Othermaterial. 2females, China, Hunan, Xinningcounty,LangshanNationalGeopark. Coordinates: 26.276986N, 110.736902E, alt. 527m, in forest, leg. Ji-Gang Jiang, Ya-Hui Hu, Wei Hu, 25.vii.2019 (J2019072502). Diagnosis. 2+2 black eyes on head; labral chaetotaxy as 2/4, 2; cephalic chaeta O present; tubercle Dl on Th. II with 3 chaetae (2+s); mandible with 2 prominent basal teeth and 2 fringed rami of quite different sizes; maxilla with marginal filaments on outer lamella; tubercle Di on Abd. V separated; Description. Body length: holotype 2.4 mm, two paratypes 2.3–2.4 mm, three juveniles 1.0– 1.1mm. Color. Red while living (Fig. 1) and white in alcohol (Fig. 3). Chaetal morphology (Fig. 5). Dorsal ordinary chaetae of five types: Ml (Fig. 5 a–b), Mc (Fig. 5c), Mcc (Fig. 5d), me (Fig. 5 e–f) and mi (Fig. 5h). S-chaetae on terga thin, smooth, shorter than Ml and longer than Mc (Fig. 5g). Head. Eyes 2+2, black. Antenna 4-segmented (Fig. 15). Ant. I with 9 chaetae. Ant. II with 11 chaetae. Ant. III and IV dorsally fused. Dorsal sensory guard chaeta (sgd) on Ant. III not migrated distally, two rods exposed in separate pit. Ant. IV dorsally with 8 slightly thickened and blunt sensilla, apical bulb trilobed. sensory organite (or) present. Ventral chaetotaxy of Ant. IV: ap with 8 bs and 3 miA, ca with 2 bs and 3 miA, cm with 3 bs and 1 miA, cp without miA. On ventral side of Ant. III, Vi, Vc, Ve with 3, 4, 4 chaetae respectively. Buccal cone moderately developed. Labrum truncated, chaetal formula as 2/4, 2 (adult) or 4/4, 2 (juvenile). Labium with 11 chaetae and 2 x (Fig. 17). Mandible complicated (Fig. 8), consisting of 2 rami, 2 definite teeth and some spine-like chaetae. Small ramus consisting of one spine-like chaeta and 7–8 slender chaetae, large ramus developed, with 2 rows of marginal chaetae, 4 strong and spine-like chaetae, marginal chaetae on ramus simple, bifurcated or tri-furcated, about 9-12 spine-like chaetae present on the central area of basal part of the large ramus. The longer ramus about 10 times as long as the small one. Maxilla consisting of two lamellae, the inner lamella much shorter than the outer one, with two minute apical teeth, the outer one with marginal filaments on inner side (Fig. 9). On ventral side of head, group Vi with 6+6 chaetae, groups Vea, Vem and Vep with 4, 3 and 2 chaetae respectively. Dorsal tubercles and chaetotaxy of head as in Tab. 1. and Fig. 7. Dorsal central area with 6 separate tubercles; one tubercle Cl, 2 An, one Fr and 2 Oc, chaeta O absent. Dorsal posterior area with 4 separate tubercles: 2 Di and 2 De. Line of chaetae Di2–De2 crosses line Di1– De1 on head (cross-type, Deharveng 1983). Dorsal lateral area with 1 fused tubercle (Dl+L+So). Thorax (Table 2 & Fig. 7). Th. I with 3+3 tubercles (Di, De, Dl). Th. II and Th. III with 4+4 tubercles respectively, ms on tubercle Dl of Th. II present (its form as in Fig. 5i). Chaetotaxy of thorax and legs as in Table 2. Unguis with a basal inner tooth, unguiculus absent. Chaeta M present on tibiotarsus. Abdomen (Table 2 & Fig. 7). Abd. I–IV respectively with 4+4 tubercles. Abd. V dorsally with 2+2 tubercles, two tubercles Di close to each other, but not fused together, tubercle De fused to Dl, tubercle L present on ventral side. Abd. VI with 1 tubercle on each side, no cryptopygy. VT with 4+4 chaetae. Furcular remnant with 3-4 chaetae (Fig. 19). Etymology. The name of the species derives from the locality where it was collected. Ecology. Among decayed leaves in forest. Remarks. So far, 12 species of genus Crossodonthina were reported worldwide, 11 species were from Asia and only one from Oceania, seven species were reported from China (Jiang & Zhang, 2012). In genus Crossodonthina, three species have 2+2 eyes, they are C. bidentata, C. hainana and C. montana, the new species is the fourth one with 2+2 eyes. In general appearance, Crossodonthina langshanensis sp. nov. strongly resembles Chinese species C. bidentata (Luo & Chen, 2009) in the number of mandible basal teeth, the arrangement of body tubercles, the presence of chaeta O of tubercle Fr, the number of chaetae on VT, and the presence of inner tooth on claw. However, these species can be distinguished by the following features: structure of mandible (in C. langshanensis with two fringed rami, in C. bidentata with three fringed rami), structure of maxilla (in C. langshanensis outer lamella fringed, in C. bidentate outer lamella not fringed), whether the tubercle Di fused on Abd. V or not (in C. langshanensis not fused, in C. bidentate fused), the labral chaeta formula (in C. langshanensis 2/4, 2, in C. bidentata 2/5, 2), number of chaetae (besides of ms) on tubercles Dl of Th. II (in C. langshanensis 3, in C. bidentata 4). The new species is also similar to the 2+2-eyed Chinese species C. montana (Lee & Kim, 1990) and C. hainana (Xiong et al., 2005) in the arrangement of body tubercles, the presence of chaeta O of tubercle Fr, the separate tubercle Di of Abd. V and the presence of 4+4 chaetae on VT. The new species can be separated from the above species by the characters listed in Table 3.Published as part of Hu, Ya-Hui, Jiang, Cheng & Jiang, Ji-Gang, 2019, Two new species of Lobellini from Central-South China (Collembola Neanuridae), pp. 77-89 in Zootaxa 4712 (1) on pages 78-82, DOI: 10.11646/zootaxa.4712.1.5, http://zenodo.org/record/358686
Wusong (China), USS Houston on the Wusong Jiang river
No full textWusung [Wusong] village and Whampoa [Wusong Jiang] river, China. USS "Houston" Whampoa [Wusong Jiang river]GrayscalePendleton nitrate negative, Box 26 of 38
Otago Exercise Program in the United States: Comparison of 2 Implementation Models
No full textAuthor(s): Shubert, TE; Smith, ML; Goto, L; Jiang, L; Ory, M
Multiuser MIMO-OFDM Systems using Subcarrier Hopping
No full textRecently space division multiple access (SDMA) assisted multiple-input–multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems invoking multiuser detection (MUD) techniques have attracted substantial research interest, which is capable of exploiting both transmitter multiplexing gain and receiver diversity gain. A new scheme referred to here as slowsubcarrierhopping (SSCH) assisted multiuser SDMA-OFDM, is proposed. It is shown that, with the aid of the so-called uniform SSCH (USSCH) pattern, the multiuser interference (MUI) experienced by the high-throughput SDMA-OFDM system can be effectively suppressed, resulting in a significant performance improvement. In the investigations conducted, the proposed USSCH-aided SDMA-OFDM system was capable of outperforming a range of SDMA-OFDM systems considered, including the conventional SDMA-OFDM system dispensing with the employment of frequency-hopping techniques. For example, at an Eb/N0 value of 12 dB, the proposed USSCH/SDMA-OFDM system reduced the bit error ratio (BER) by about three orders of magnitude, in comparison to the conventional SDMA-OFDM system, while maintaining a similar computational complexity
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