274 research outputs found
A hybrid approach combining Fuzzy AHP and Fuzzy TOPSIS to rank agritourism destinations in Tan Cuong green tea region, Thai Nguyen, Vietnam
No full textAgritourism is recognized as a strategic approach to harness the existing advantages of rural areas, including both on-farm and off-farm attractions. This study, conducted in the Tan Cuong tea region of Thai Nguyen, examines the practical application of the Fuzzy Analytic Hierarchy Process (AHP) and the Fuzzy Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) in ranking agritourism destinations. Five experts, all with experience in agritourism in Tan Cuong, provided data through questionnaires for the analysis. The results indicated that the Hao Dat Tea Cooperative (A1) ranked highest for sustainable agritourism development. Additionally, the transportation system serving agritourism destinations (C9) was identified as the most influential factor based on the empirical findings. Based on these results, policy recommendations are proposed to prioritize the development of agritourism across various destinations, with suggestions for both central and local policy initiatives
The Interactions among the Heavy Metals in Soils and in Weeds and Their Antioxidant Capacity under the Mining Activities in Thai Nguyen Province, Vietnam
No full textIn this study, the relationship between heavy metals (HMs) concentrations in soils and several weeds including Cyclosorus parasiticus, Dicranopteris linearis, Pityrogramma calomelanos, and Pteris vittata in three mining sites (Cam Gia (Thai Nguyen city), Tan Long (Dong Hy district), and Ha Thuong (Dai Tu district)) in Thai Nguyen province, Vietnam, have been investigated. The levels of HMs varied among soil origins and showed the contaminations of As, Cu, and Pb in soil samples collected in Dong Hy and Dai Tu districts. In addition, the HM distribution and cocontamination phenomena in different soils significantly affected the HM residues and transportation abilities into different species as well as tissues. Moreover, based on the analysis of bioaccumulation factor (BF) and translocation factor (TF), C. parasiticus and D. linearis were found potentially for phytoextraction by roots, while P. calomelanos and P. vittata were suitable for hyperaccumulation in shoots and leaves. Consequently, the strongest antioxidant property by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion (SRSA) radical scavenging assays were demonstrated in the methanol root extracts of C. parasiticus and P. vittata, respectively. In conclusion, the correlation among HM in soils and tissues with antioxidant property allows us to hypothesize that the presence of these elements can enhance the antioxidant activity of plant extracts, suggesting to apply the weeds in phytoremediation as well as in phytomedicine
FreGrad: 확산 보코더에 이산 웨이블릿 변환 적용
No full text학위논문(석사) - 한국과학기술원 : 전기및전자공학부, 2025.2,[iii, 22 p. :]The goal of this work is to generate realistic audio with a lightweight and fast diffusion-based vocoder, named FreGrad. Our framework consists of the following three key components: (1) We employ discrete wavelet transform that decomposes a complicated waveform into sub-band wavelets, which helps FreGrad to operate on a simple and concise feature space, (2) We design a frequency-aware dilated convolution that elevates frequency awareness, resulting in generating speech with accurate frequency information, and (3) We introduce a bag of tricks that boosts the generation quality of the proposed model. In our experiments, FreGrad achieves times faster training time and times faster inference speed compared to baseline while reducing the model size by times (only M parameters) without sacrificing the output quality. We provide the synthesized audio samples at: \url{https://mm.kaist.ac.kr/projects/FreGrad/}.한국과학기술원 :전기및전자공학부
Effect of large graphene particle size on structure, optical property and photocatalytic activity of graphene-titanate nanotube composites
No full textAvailable online 19 October 2021In this work we investigate the crystal transformation and optical properties of hydrothermal titania nanotube (TNT) when combining with large size of exfoliated graphene achieved by electrochemical process (EC-Gr). The TNT monoclinic structure has been changed to TiO2 anatase phase when TNT was grown in the presence of graphene dispersion. The effect of graphene on the evolution of TNT crystal could be understood by the interaction of carbon elements in graphene and Ti4+ ions in the titania structure. Due to the carrier separation which reduced recombination rate of excited photoelectrons and holes revealed by photoluminescence characterizations, the visible light photocatalytic activity in degradation of methylene blue in solution of the composite was enhanced. The photocatalytic enhancement was discussed and clarified based on UV–vis diffuse absorption spectra and time-resolved photoluminescence investigation.Vo Cao Minh, Phan Tan Dat, Pham Thi Thuy, Nguyen Xuan Sang, Nguyen Tri Tuan, Tran Thanh Tung, Dusan Losi
Risk - adjusted rates of return for project appraisal
No full textIncorporating risk assessment into public project appraisal makes sense when project risk is significantly correlated with uncertainty about national income. It is especially important in countries that specialize in particular agricultural or resource sectors. This report presents the following conclusions: (a) risk corrections can be substantial; (b) the intuition that risk is great for further investment in a crop or sector that constitutes a large part of a country's GNP is not invalid, but the effect may be offset by other forces in operation; (c) risk corrections can be negative because of a negative correlation between project return and GNP; (d) risk premia vary greatly across countries and sectors - so recognizing the risk correction needed for each project on its own merits makes more sense than including a common general risk premium in the rate of return required for all lending; (e) risk corrections are small for many sectors and countries - so efforts can be concentrated on the other categories, where the proposed treatment of risk makes a big difference; (f) risk affects investment projects in many different, subtle ways; and (g) resource requirements for this are not great.Environmental Economics&Policies,Health Economics&Finance,Banks&Banking Reform,Statistical&Mathematical Sciences,Crops&Crop Management Systems
Metaphire houlleti Perrier 1872
No full textMetaphire houlleti (Perrier, 1872) Perichaeta houlleti Perrier, 1872: 99, Plate 2, Figs 31–44. Pheretima houlleti— Gates 1939: 94; 1972: 190; Pham 1995c: 89; Nakamura 1999: 42; Thai 2000a: 309; Huynh 2005a: 109; Huynh 2005b: 20; Nguyen et al. 2010: 114; Pham 2010: 63; Nguyen T.T. & Tran 2008: 61; Nguyen & Nguyen 2010: 123; Nguyen & Huynh 2011: 1018; Nguyen et al. 2011: 1025; Nguyen et al. 2012: 146; Nguyen 2013: 49; Nguyen 2014: 109. Metaphire houlleti— Sims & Easton 1972: 238; Blakemore 2007a: 48; Blakemore 2008b. Perichaeta campanulata Rosa, 1890b: 115. Pheretima campanulata— Gates 1930: 307, 311; 1939: 83; Thai et al. 2004: 759; Pham 1995c: 89; Nakamura 1999: 41; Thai 2000a: 308; Huynh 2005a: 112; Nguyen V.T. & Tran 2008: 184; Pham 2010: 63; Nguyen & Nguyen 2010: 123; Nguyen & Huynh 2011: 1018; Nguyen et al. 2011: 1025; Nguyen et al., 2012: 146. Metaphire campanulata— Sims & Easton 1972; 238; Blakemore 2007a: 48, treated as synonym of Metaphire houlleti (Perrier, 1872). Type locality. India (Calcutta). Type material. MHNH, France. Examined material. 25 C and 18 A (CTU-EW.006.06) natural forest, Cat Tien NP, Tan Phu, Dong Nai, 13/ 10/2013, coll. Le Van Nhan; 22 C (CTU-EW.006.02) Phung Hiep, Can Tho, 9/10/2009, coll. Ngo Thi Ngan; 13C, 4 A (SORC-V.129.01) deciduous forest, Ealop, Dak Lak, 18/10/1989, coll. Huynh Thi Kim Hoi; 15 C and 5 A (CTU-EW.018.01) Nam Cat Tien, Tan Phu, Dong Nai, 13/10/2013, coll. Le Van Nhan; 11 C (CTU-EW.018.05) Cu Lao Duyen, Cho Moi, An Giang, 9/2009, coll. Ho Minh Thuan. Records from Vietnam. Son La (Moc Chau); Dien Bien (Tuan Giao; Dien Bien); Nghe An (Que Phong); Quang Tri (Huong Hoa); Thua Thien Hue (Huong Tra; Hue; Huong Thuy; Nam Dong); Da Nang (Hoa Vang; Son Tra; Ba Na NP); Quang Nam (Dien Ban; Hiep Duc; Tam Ky; Tien Phuoc; Phuoc Son; Tra My); Quang Ngai (Son Ha); Kon Tum (Dak Glei; Sa Thay); Binh Dinh (Tuy Phuoc; An Nhon); Gia Lai (An Khe; Duc Co); Phu Yen (Tuy An); Dak Lak (Ea Sup; Yok Don NP; Buon Me Thuot); Dak Nong (Ta Dung Mts); Binh Thuan (Tanh Linh); Lam Dong (Duc Trong; Da Lat); Khanh Hoa (Nha Trang); Dong Nai (Vinh Cuu; Xuan Loc; Tan Phu; Dinh Quan; Trang Bom; Thong Nhat; Nhon Trach; Long Thanh; Cam My); Tay Ninh (Ba Den Mt.); Dong Thap (Thanh Binh; Lap Vo; Cao Lanh; Cu Lao Tan Long); Hau Giang (Phung Hiep; Nga Bay); Long An (Vinh Hung; Thanh Hoa); Kien Giang (Phu Quoc Isl.); Tien Giang (Cai Be; Cai Lay; Chau Thanh); Vinh Long (Long Ho); An Giang (Cho Moi: Cu Lao My Hiep; Chau Doc; Tinh Bien; Tri Ton); Kien Giang (Kien Luong; Hon Tre Isl.; Lai Son Isl.; An Son Isl.; Hon Dat); Hau Giang (Phung Hiep); Can Tho; Ben Tre (Binh Dai); Tra Vinh (Duyen Hai; Hoa Minh Isl.; Cau Ke); Soc Trang (Long Phu; Tran De; Ke Sach; Chau Thanh); Bac Lieu (Hoa Binh); Ca Mau (Dam Doi; Cai Nuoc; Ca Mau City) (Do 1994; Nguyen 1994; Pham 1995c, 2010; Huynh 2005a; Thai et al. 2004; Nguyen V.T. & Tran 2008; Nguyen & Nguyen 2010; Nguyen & Huynh 2011; Nguyen et al. 2010; Nguyen et al. 2011; Nguyen et al. 2012). Distribution. Cosmopolitan species, occurring in India, Thailand, Cambodia, Laos, Myanmar, Taiwan, Singapore, China, Australia, USA (Gate 1939, 1972; Easton 1982; Thai & Do 1989; Thai & Samphon 1991; Shen & Yeo 2005; Shen et al. 200 5). Vietnamese name. Giun houllet. Remarks. Gates (1939) noted that the original home of the species is probably somewhere a region comprising eastern Myanmar and Thailand. The species has been known in Vietnam as two different species, Pheretima houlleti and Pheretima campanulata.Published as part of Nguyen, Tung T., Nguyen, Anh D., Tran, Binh T. T. & Blakemore, Robert J., 2016, A comprehensive checklist of earthworm species and subspecies from Vietnam (Annelida: Clitellata: Oligochaeta: Almidae, Eudrilidae, Glossoscolecidae, Lumbricidae, Megascolecidae, Moniligastridae, Ocnerodrilidae, Octochaetidae), pp. 1-92 in Zootaxa 4140 (1) on pages 58-59, DOI: 10.11646/zootaxa.4140.1.1, http://zenodo.org/record/25650
Facial expressions in American sign language: Tracking and recognition
No full textThis paper presents work towards recognizing facial expressions that are used in sign language communication. Facial features are tracked to effectively capture temporal visual cues on the signers face during signing. Face shape constraints are used for robust tracking within a Bayesian framework. The constraints are specified through a set of face shape subspaces learned by Probabilistic Principal Component Analysis (PPCA). An update scheme is also used to adapt to persons with different face shapes. Two tracking algorithms are presented, which differ in the way the face shape constraints are enforced. The results show that the proposed trackers can track facial features with large head motions, substantial facial deformations, and temporary facial occlusions by hand. The tracked results are input to a recognition system comprising Hidden Markov Models (HMM) and a support vector machine (SVM) to recognize six isolated facial expressions representing grammatical markers in American sign language (ASL). Tracking error of less than four pixels (on 640×480 videos) was obtained with probability greater than 90%; in comparison the KLT tracker yielded this accuracy with 76% probability. Recognition accuracy obtained for ASL facial expressions was 91.76% in person dependent tests and 87.71% in person independent tests. © 2011 Elsevier Ltd. All Rights Reserved
Recognizing Continuous Grammatical Marker Facial Gestures in Sign Language Video
No full textIn American Sign Language (ASL) the structure of signed sentences is conveyed by grammatical markers which are represented by facial feature movements and head motions. Without recovering grammatical markers, a sign language recognition system cannot fully reconstruct a signed sentence. However, this problem has been largely neglected in the literature. In this paper, we propose to use a 2-layer Conditional Random Field model for recognizing continuously signed grammatical markers in ASL. This recognition requires identifying both facial feature movements and head motions while dealing with uncertainty introduced by movement epenthesis and other effects. We used videos of the signers' faces, recorded while they signed simple sentences containing multiple grammatical markers. In our experiments, the proposed classifier yielded a precision rate of 93.76% and a recall rate of 85.54%. © 2011 Springer-Verlag Berlin Heidelberg
Peliosanthes luteoviridis Vislobokov, K. S. Nguyen, Kalyuzhny, Nuraliev & N. Tanaka 2022, sp. nov.
No full text<p> <i>Peliosanthes luteoviridis</i> Vislobokov, K.S.Nguyen, Kalyuzhny, Nuraliev & N.Tanaka, <i>sp. nov.</i> (Figs. 1, 2)</p> <p> <b>Diagnosis:—</b> Most similar to <i>P. macrostegia</i>, but differs mainly by shorter and denser inflorescence, terete peduncle, and yellowish green flowers with a somewhat thinner, translucent perigone.</p> <p> <b>Type:—</b> VIETNAM. Dong Nai Province: Tan Phu district, Cat Tien National Park, around the point 11°25.523’N, 107°25.722’E, elev. 127 m, in forest, collected in nature on 6 November 2019 by N.A. Vislobokov, the herbarium specimen prepared from the living cultivated plant on 19 May 2021, <i>N.A. Vislobokov, M.S. Romanov 19203H</i> (holotype MW: MW0595759).</p> <p> <b>Plant</b> herbaceous, evergreen, perennial, entirely glabrous. <b>Rhizome</b> plagiotropic or ascending, about 2 cm long, 4–6 mm in diameter. <b>Cataphylls</b> chartaceous, 3–7.5 cm long, 6–11 mm wide. <b>Roots</b> grey, 1.5–3.5 mm in diameter. <b>Foliage leaves</b> green, petiolate, ascending or arching. Petiole rigid, adaxially sulcate, 17–36 cm long, 1.3–2.6 mm in diameter. Leaf blade elliptic, 14.5–23 cm long, 2.3–5.2 cm wide, base cuneate, apex acuminate, margin entire, with 9–17prominent longitudinal veins and numerous subtransversal secondary veinlets. <b>Inflorescence</b> a raceme (flowers solitary), about 8.5 cm tall. Peduncle yellowish white, erect, smooth, terete (non-ribbed), 2.1–5 cm long, 2.9–3.7 mm in diameter, with 5–6 sterile bracts; sterile bracts greenish white, lanceolate to narrowly lanceolate, 8.5–15 mm long, 1.8–5 mm wide. Rachis yellowish white, 4.2–6 cm long, 2.2–3.6 mm in diameter, bearing about 35–40 flowers. Flower-subtending bracts greenish white, scarious, lanceolate to narrowly lanceolate, 3.9–9 mm long, 1.5–2.8 mm wide. <b>Flowers</b> densely arranged, touching each other with tepals, facing horizontally or ascending, light yellowish green with darker tepal apices and paler androecial corona-like structure. <b>Pedicel</b> 0.7–1.4 mm long, 0.6–1 mm in diameter. <b>Bracteole</b> single, attached at pedicel base, transversal, lanceolate, 1.6–2 mm long, 0.5–1 mm wide. <b>Perigone</b> campanulate, 4.2–5.8 mm long (including hypanthium), 5.4–9.2 mm in diameter when full open; hypanthium (perigone tube) 1.7–2.8 mm long, 3.0– 3.9 mm in diameter; lobes 6, arranged in two whorls, homomorphic, outer lobes slightly overlapping inner lobes, erect to slightly spreading, slightly translucent, ovate, with margins strongly bent longitudinally on abaxial side, 3–3.7 mm long, 1.9–2.6 mm wide. <b>Stamens</b> 6; filaments united forming fleshy broadly dome-shaped corona-like structure 0.9–1.3 mm high, 3.0– 3.9 mm in diameter with obtusely star-shaped orifice 1.2–1.6 mm in diameter; anthers 6, in radii of tepals, sessile, dorsally attached to upper portion of corona (just below orifice), 0.5–0.6 mm long, introrse. <b>Pistil</b> 1.6–2.2 mm high. Ovary semi-inferior to almost superior, rounded and slightly 3-lobed in top view, 3-locular, 1.3–1.6 mm high, 1.6–1.9 mm in diameter, each locule bearing 4 ovules. Style conoid, 0.2–0.8 mm high, bearing at top 3 flat horseshoe-shaped stigmas 0.3–0.4 mm in diameter. <b>Seeds</b> (unripe) pale green, ovoid, 10.6–12.5 mm long, 6.9–7.5 mm in diameter.</p> <p> <b>Additional specimens examined (paratypes):—</b> VIETNAM. Dong Nai Province: Tan Phu District, Cat Tien National Park, in forest, 11°25.523’N, 107°25.722’E, elev. 127 m, 6 November 2019, <i>N.A. Vislobokov 19203</i> (sterile) (MW: MW0595761); Dong Nai Province: Tan Phu District, Cat Tien National Park, forest with <i>Dipterocarpus</i> sp., <i>Calamus</i> sp. and bamboo, 11.47958°N, 107.37956°E, elev. 184 m, 2 February 2021, <i>S.S. Kalyuzhny s.n.</i> (with flowers) (MHA); Dong Nai Province: Tan Phu district, Cat Tien National Park, humid areas under the evergreen broad-leaved forest with <i>Dipterocarpus</i> spp., 11°26’36”N, 107°25’56”E, about 100 m a.s.l., 9 January 2021, <i>Pham Thi Thanh Dat, Nguyen Van Canh PTTD 21</i> (with flowers) (HN); Dong Nai Province: Tan Phu, Dac Lua Commune, Cat Tien National Park, remnants of primary tropical evergreen and semi-deciduous broad-leaved lowland forests on mainly basaltic rocks, 11°30’12”N, 107°17’28”E, 190 m a.s.l., 10 September 2020, <i>Nguyen Sinh Khang, Pham Van The, Pham Thi Thanh Dat NSK 1354B-1</i> (with fruits) (HN); same location, the herbarium specimen prepared from the living cultivated plant on 30 January 2021, <i>Nguyen Sinh Khang NSK 1354B-2</i> (with flowers) (HN); living plant in the Main Botanical Garden of the Russian Academy of Sciences (Moscow), garden number: 2019.15598, collected by N.A. Vislobokov at the type locality on 6 November 2019.</p> <p> <b>Etymology:—</b> The specific epithet refers to the yellowish green floral colour.</p> <p> <b>Phenology:—</b> Flowering from January to February, fruiting in September.</p> <p> <b>Distribution:—</b> The species is known only from Cat Tien National Park (Dong Nai Province, Vietnam). It grows at elevations of 100–200 m a.s.l.</p> <p> <b>Taxonomic relationships:</b> —In having campanulate perigone, androecium forming a dome-shaped corona and semi-inferior to almost superior ovary, the new species is similar to <i>P. macrostegia</i> Hance (1885: 328) and <i>P. crassicoronata</i> K.S.Nguyen, Aver. & N.Tanaka in Nguyen <i>et al.</i> (2020: 41). <i>Peliosanthes luteoviridis</i> differs from <i>P. macrostegia</i> mainly by shorter and denser inflorescence (about 8.5 cm vs. 9–25 cm long), smooth terete (vs. ribbed) peduncle, shorter pedicel (0.7–1.4 mm vs. 5–6 mm long) and entirely yellowish green (vs. green to purple) flower (Chen & Tamura 2000, Averyanov <i>et al.</i> 2016a). The new species is distinguishable from <i>P. crassicoronata</i> chiefly by its shorter petiole (17–36 cm vs. 50–54 cm long), shorter leaf blade (14.5–23 cm vs. 35–38 cm long), shorter inflorescence (about 8.5 cm vs. 11.5–22.5 cm long), shorter pedicel (0.7–1.4 mm vs. 1.5–3 mm long), smaller (5.4–9.2 mm vs. 10–11 mm in diameter) entirely yellowish green (vs. purple to dark violet) flower, and pistil abruptly tapering to a conoid style (vs. with indistinct style) (Nguyen <i>et al.</i> 2020). In addition, the somewhat thinner, translucent perigone distinguishes <i>P. luteoviridis</i> from the two similar species.</p> <p> In its yellowish green flowers forming a dense erect inflorescence, <i>Peliosanthes luteoviridis</i> is superficially somewhat similar to <i>P. cupuliformis</i> Aver., N.Tanaka & K.S.Nguyen in Averyanov <i>et al.</i> (2020b: 2), <i>P. densiflora</i> Aver. & N.Tanaka in Averyanov <i>et al.</i> (2015: 32) and <i>P. separata</i> Vislobokov (2016: 186). However, the new species is readily distinctive from all of them in floral structure. For instance, the stamens of <i>P. luteoviridis</i> form a dome-shaped hemispherical corona partly covering the pistil, whereas the staminal corona of <i>P. cupuliformis</i> is annular and widely open (Averyanov <i>et al.</i> 2020b); the flowers of <i>P. luteoviridis</i> are smaller than those of <i>P. densiflora</i> (5.4–9.2 mm vs. 10–12 mm in diameter) (Averyanov <i>et al.</i> 2015); the staminal corona of <i>P. luteoviridis</i> is only shallowly lobed apically, whereas that of <i>P. separata</i> is dissected nearly to the base (Vislobokov 2016).</p> <p> <i>Peliosanthes luteoviridis</i> inhabits forests of Cat Tien National Park (Dong Nai Province, Vetnam), where it cooccurs with <i>P. curviandra</i> Vislobokov in Vislobokov <i>et al.</i> (2020: 70). Since the vegetative parts of the two species (as well as a significant portion of other species of the genus) look somewhat alike, these species can be confused if encountered in a sterile condition. With respect to the floral characters, <i>P. luteoviridis</i> is clearly distinguished from <i>P. curviandra</i> by semi-inferior to almost superior ovary and a shorter conoid style, whereas the latter species possesses inferior ovary and a long slender tortuous style characteristic of the species complex formerly recognized as the genus <i>Neolourya</i> Rodriguez (1934: 96).</p>Published as part of <i>Ya. Vislobokov, Romanov, Mikhail S., Nguyen, Khang Sinh, Pham, Vanthe, Pham, Thi Thanh Dat, Nguyen, Van Canh, Тanaka, Noriyuki, Kalyuzhny, Sergey S., Kuznetsova, Svetlana P., Kuznetsov, Andrey N. & Nuraliev, Maxim S., 2022, Peliosanthes luteoviridis (Asparagaceae), a new species with yellowish green flowers from southern Vietnam, pp. 234-240 in Phytotaxa 538 (3)</i> on pages 235-238, DOI: 10.11646/phytotaxa.538.3.6, <a href="http://zenodo.org/record/6336796">http://zenodo.org/record/6336796</a>
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