Vol. 13 No. 6 (2015)

The objective of this study was to compare the effects of N, P, K fertilizers in combination with sugarcane filter cake on growth and N, P, K uptake of young and ratoon sugarcaneon alluvial soil. A 22factorial experiment in a randomized complete block including four inorganic fertilizer treatments (O1: N, P, K;O2: N, P;O3: N, K and O4: P, K) and two sugarcane filter cake (SFC) treatments (S1: 10 and S2: 0 tons ha-1) with four replications was conducted in Hau Giang province during 2011 (youngsugarcane crop) and 2012 (ratoon sugarcane crop). The total treatments were O1S1 (N, P, K fertilizers application + 10 tons SFC ha-1), O2S1 (N, P fertilizers application + 10 tons SFC ha-1), O3S1 (N, K fertilizers application + 10 tons SFC ha-1), O4S1 (P, K fertilizers application + 10 tons SFC ha-1), O1S2 (N, P, K fertilizers application), O2S2 (N, P fertilizers application), O3S2 (N, K fertilizers application) and O4S2 (P, K fertilizers application). Results showed that growth and N, P, K uptake decreased both plant and ratoon sugarcane crop as without single N, P, K application. The ratoon sugarcane yield decreased by 25 tons per hectare in comparison with plant sugarcane yield, which result in lower N, P, K uptake. Where, phosphorus uptake reduced the highest value. The sugarcane filter cake application improved N, P, K uptake of ratoon sugarcane, but it increased only phosphorus uptake of plant sugarcane. However, it improved sugarcane yield of two crops. The sugarcane filter cake application improved sugarcane yield, nitrogen and potassium uptake of ratoon sugarcane compared to plant sugarcane.

A study was conducted to assess the effect of organic fertilizerand plantingdensity and their interaction on physiological characteristics and yield of black sticky rice variety DH6. It was found that different levels of organic fertilizerdid not affect plant heightand growth duration. The fertilizerlevel-planting density interaction clearlyinfluenceleaf area index (LAI) and dry matteraccumulationat allgrowth stages. At eachorganic fertilizerlevel and plant density, there was no correlation between productivity and LAI at the maximum tillering stage, but closecorrelation between productivity and LAI at anthesis and ripening stages. At dough grainstage, planting density of 40 seedlings/m2yieldedhighest dry matter accumulation in all organic fertilizer compost levels. Application of of 700 - 900 kg and 900kgorganic fertilizer per spring and autumn crop, respectively, gave highest grain yields.

Oranges grown in Ha Giang areone of the most common citrus products in northern Viet Nam. However,vegetative propagation and selection for adaptation to various growing environments led to deviation from original genotype.Assessinggenetic diversity of indigenous citrus maycontribute to the collection, classification, evaluation and conservation as well as provide genetic information among citrus germplasm, which could be used for the breeding program. RAPD and ISSR analysis combined with the construction of phylogenetic tree revealed the genetic relationship among researched citruses. The results showed that 25 RAPD and 5 ISSR primers generated polymorphic patterns of PCR products (100%), however,the numbers of polymorphic bands detected on each genotype were significant in range. A total of 2157 DNA bands were foundwith an average of 1.80 DNA bands per genotype. RAPD markers (OPAW19andOPAE15)and ISSR markers (T1andT5)yielded highest polymorphism, with 4.48, 4.23 and 3.25, 3.45 bandsper genotype, respectively. The resultsalso indicated that the similarity coefficient of 39 samples ranged from 0.33 to 0.98 and 5 genetic groups were obtained.

The Garra fish group of the genus GarraHamilton, 1822 (Cyprinidae, Cypriniformes) in Viet Nam and in the world was recorded with three species, viz. G. orientalis Nichols, 1925, G. bourretiPellegrin, 1928 distributed in the northern provinces and G. fuliginosaFowler, 1934 distributed in southern provincesand central highlands. Through the fish specimens preserved at the Fish Museum at theResearch Institute for Aquaculture No. I, the authors studied in depth system of morphological characteristics and distribution of fish species in the Garra groupand discovered threenew species: G. songbangensissp.n., in the Bang River of Cao Bang province, G. quangtriensissp.n. in the Dakrong river in Quang Tri and G. centralasp.n. in the streams and rivers of the Quang Tri and Thua Thien - Hue provinces. This article describednew species, scientific name, distribution, biological generalization, its value and establishedkeys for identification.

A feeding trial was carried out to assess the comparative values of Stylosanthes guianensis (stylo) and Leucaeana leucocephala(Leucaeana) as protein supplement for goat based on feedintake, digestibility, nitrogen balance and purine derivatives. A total of 9 male crossbred (Jumnapari x Saanen) goats were used in the experiment with an average initial body weight of 18 ±0,2kg. The goats were randomly divided into 3 groups of 3 each to be fed ad libitumone of three experimental diets in metabolism cages. Three dietary treatments composed of maize stover supplemented with one of two forage legume and ground corn (200 g/day). Results showed that intakes of dry matter, organic matter, protein and digestibility were highest when maize stover was supplemented with Leucaeana except protein digestibility(P<0,05). Goats fed Leucaeana and stylo supplemented diets had positive nitrogen balance, purine derivatives, microbial nitrogen and the efficiency of microbial nitrogen supply wasbetter than those of control group (P<0,05). However, all parameters were lower for goats fed stylocompared to leucaeana(P<0,05). Experimental results suggestedthat leucaeana and stylocan be utilized as source ofprotein supply during the dry season. Leucaeanahad more potential for feeding goats compared to stylo.

Cá trê lai (Clarias macrocephalusx Clarias gariepinus) được nuôi phổ biến ở Việt Nam và có thể thất thoát ra ngoài môi trường tự nhiên. Việc xác định đúng cá thể con lai trở nên quan trọng trong quản lý nguồn lợi cũng như trong nuôi trồng thủy sản. Phân biệt con lai dựa vào hình thái thường không chính xác. Nghiên cứu này sử dụng phương pháp PCR-RFLP đối với gien ti thể (Cytochrome C oxidase subunit I, COI) và gien trong nhân (Rhodopsin, rho) để phân biệt con lai với hai loài bố mẹ. Mười hai mẫu cá (6 mẫu cho mỗi loài) và 3 mẫu cá trê lai nuôi được giải trình tự 2 gien trên. Sau đó, trình tự gien của hai loài được sắp xếp thẳng hàng để tìm enzym cắt giới hạn đặc trưng cho loài. Hai enzym SpeI và XcmI được chọn để cắt hai gien tương ứng, COI và rho. Kết quả khẳng định cá trê vàng C. macrocephaluslà loài cá mẹ của con lai đang được nuôi hiện nay. Chromatogram và phân đoạn gien rho sau khi bị cắt bởi enzym XcmI của con lai thể hiện đặc điểm trung gian của hai loài bố mẹ. Như vậy, phương pháp phân tích PCR-RFLP gien COI và rho là phương pháp hiệu quả và chính xác để xác định từng cá thể cá trê lai.

The implementation of land consolidation work has partially overcome the fragmentation of agricultural land taking place across the country. Nam Dịnh has three of nine districts successfully completedthe land consolidation project, but the rest six districts still encounteredsome difficulties. Thepresentresearch was conducted to identify solutionsto effective land consolidation. The results showedthat after the land consolidation completion, the number of parcelsper households was reduced, resultingin high economic efficiency. However, land consolidation was facing with constraints, i.e. decreasedproduction area anddelayedgrantofland use right certificate, and delayedimprovement of infield traffic system and irrigation. To overcome the above-mentioned weaknesses, the local government should speed up the granting of land use right certificates, complete the traffic system and offer support policies for the households that receive less fertileplots of land.

Nam Dinh is a province that has competitive advantages of marine economy, but is strongly affected by climate change that leads to changes in the land use structure. In addition to surveys, collecting of information and study of land use patterns, map overlay method was used to investigate the change in land and the impact of climate change and to select suitable land use model in response to climate change. Based on analysis of B2 climate change scenario until 2020, it was estimated that flooding land and saline land area increase to 4.667,94 ha and 2.363,91ha, respectively. In order to adapt to to climate change due to flooding and salinization, Nam Dinh province should shift land use pattern of 2,310.59ha and flooded area and 2.216,09 ha salinized area, respectively.

Sử dụng phương pháp lặp theo hàm mũ để giải phương trình truyền neutron trong lò phản ứng hạt nhân với cấu trúc hình học phẳng, một chiều bằng phương pháp mô phỏng Monte Carlo để xác định trị riêng và hàm riêng (tương ứng với sự phân bố của nguồn phân hạch) tồn tại hai vấn đề chính là: (1) sự hội tụ chậm của nguồn phân hạch dự đoán ban đầu về phân bố thực; (2) mối liên hệ giữa các chu kỳ trong mỗi mô phỏng sẽ dẫn đến sai số khi đánh giá độ tin cậy của kết quả thu được. Do đó, nghiên cứu này đã đề cập tới một phương pháp mới, Wielandt, với mục đích tăng tốc quá trình hội tụ của nguồn ban đầu và đưa ra phương án mới để đánh giá mối liên hệ giữa các chu kì liên tiếp trong một mô phỏng độc lập. Ngôn ngữ lập trình hướng đối tượng có tên gọi Python đã được sử dụng để mô tả sự truyền của hạt neutron đơn năng, đồng thời so sánh kết quả thu được bằng hai phương pháp khác nhau. Kết quả cho thấy, phương pháp mới đã giải quyết thành công các vấn đề đặt ra của bài toán Monte Carlo. Tuy nhiên, bài toán về hệ số phẩm chất vẫn cần tiếp tục nghiên cứu thêm.

Bài báo này giới thiệu về một hệ thống tự động nhận dạng hạt thóc giống phục vụ cho quy trình sản xuất thóc giống ứng dụng kĩ thuật xử lý ảnh và thị giác máy tính. Hạt thóc của những giống lúa khác nhau khi nhìn bằng mắt thường là rất giống nhau về màu sắc, hình dáng và kết cấu bên ngoài. Điều đó làm cho việc phân biệt các loại thóc giống khác nhau với độ chính xác cao nhằm đánh giá độ thuần chủng của thóc là một thách thức lớn. Chúng tôi tập trung vào các kĩ thuật khác nhau để trích chọn đặc trưng hình ảnh của hạt thóc giống thông qua ảnh chụp các giống lúa một cách hiệu quả. Sau đó chúng tôi phân tích hiệu năng của các bộ phân loại dựa trên các đặc trưng được trích chọn ở trên để tìm ra một phương pháp phân lớp có độ chính xác cao nhất. Hình ảnh của sáu giống lúa khác nhau đã được thu nhận ở miền Bắc Việt Nam, trong đó mỗi giống có từ 1026-2229 hình ảnh hạt lúa. Những thực nghiệm của chúng tôi đã chỉ ra rằng hệ thống phân lớp đạt độ chính xác cao nhất 90.54% khi sử dụng phương pháp rừng ngẫu nhiên dựa trên bộ đặc trưng cơ bản. Kết quả này có thể sử dụng để phát triển một hệ thống thị giác máy tính hỗ trợ việc đánh giá tự động độ thuần chủng của hạt thóc giống.

Những năm 1970, khái niệm cơ sở dữ liệu quan hệ (rõ) được đềxuất cho phép chúng ta có thể lưu trữ và thao tác với một họ có tổ chức của dữ liệu. Trong một cơ sở dữ liệu quan hệ, tất cả các dữ liệu được lưu trữ và truy cập thông qua các quan hệ. Sự mở rộng của cơ sở dữ liệu quan hệ có thể thực hiện theo nhiều hướng khác nhau. Cơ sở dữ liệu quan hệ mờ là một sự mở rộng của cơ sở dữ liệu quan hệ cổ điển. Bài báo nàyxingiới thiệu một khái niệm mới về cơ sở dữ liệu mờ bức tranh (PFDB), nghiên cứu một vài truy vấn trên một cơ sở dữ liệu mờ bức tranh và đưa ra một ví dụ minh họa cho ứng dụng của mô hình CSDL này.

Spectral clustering algorithms have been the most effective algorithms to divide genes into groups accordingto the degree of their expression similarity. Such a grouping may suggestthat the respective genes are correlated and/or co-regulated, and subsequently indicatesthat the genes could possibly share a common biological role. In this paper,three spectral clustering algorithms were investigated: unnormalized spectral clustering, normalized spectral clustering according to Shi and Malik (2000), and normalized spectral clustering according to Ng, Jordan and Weiss (2002). The algorithms were benchmarked against each other.The performance of the three clustering algorithms wasstudied on time series expressiondata using Dynamic TimeWarping (DTW) distance in order to measure similarity betweengene expression profiles. Four different cluster validation measures were usedto evaluate the clustering algorithms: Connectivity and Silhouette Index for estimatingthe quality of clusters, Jaccard Index for evaluating the stability of a clustermethod and Rand Index for assessing the accuracy. The results were analyzedby Friedman’s test. The performance of normalized spectral clustering according to Ng, Jordan and Weiss (2002)wasdemonstratedto be the best under the Silhouetteand Rand validation indices.

The Software Defined Networking technology promises a bright future to IP network. Many researcheshave beenbeing conducted. However, until now there are only a few frameworks supportingemulation and implementation to verify the research. Mininet is one of the most popular tools because of the openness, cost effectiveness, and full Openflow support. By default, Mininet helps to create a standalone typical SDN network along with lightweight clients. In this paper, we explorethe extended functions of network topology emulation in Mininet based on Virtualbox, such as Internet connection, independent OS clients, standard routing controller, and automatic flow logging. Therefore, it brings about an easier and convenient facility to research and training.

Land pricing and determining the key factors of the land price are useful for land use planning and for the banking. At present, landprice estimation is relied ontraditional methods. These methods largely depend onanalysis and intervention by pricing staff, thus, may not be free of subjective mistakes and non-transparency. In this study, we proposeda method for land pricing based on hedonic model. This model was introduced by Lancaster in 1966 and has many applications in economicsincluding land pricing. Usually, for each region, various particularmathematical models arechosen and tested. In this paper, we investigateda linear model and a secondorder model in combination withpenalty technique to select the key factorsaffecting land price. The optimal parameters were obtained by solving convex optimization problems. A demo software to calculate the optimal parameters and to evaluate the error was developped. Numerical results with data collected from Long Bien district showedthat the proposed method is potentially promising.

Entity extraction is a task of information extraction and element classification in text such as the names of persons, organizations, locations, times, etc. and to find relationship between entities such as the relationship between the names of persons with the organizations. The X.ent tool was built solve this task. It uses dictionaries matching and hand - crafted rules to extract. In extracting the relationship between the entities, we applied two methods: analysis of text structures and unsupervised learning approach called coo – ccurrence analysis. This tool is available on the site of R at the links: http: //cran.r - project.org/web/packages/x.ent/index.html.

For tea producers and tea researchers, counting tender shoots in a samplingarea is usually done to evaluate productivity, recordthe growth of teaor to decide the appropriate time for harvest. However, it is a tedious and time consuming task. In this paper, we proposeda computerized vision - based method for automatically detecting and counting the number of tea shoottips in an image acquired from a tea field. First, we builta parametric model of a tea – shoottipscolor distribution in order to roughly separate Regions - of - Interest (ROIs) from a complicated background. For each ROI, we then extractedsupportive (local) features with expectations that these features will only appear around an apical bud of tea shoots thanks to two measurements: the density of edge pixels and thestatistic of gradient directions. Consequently, the extracted features were put into a mean shift cluster to locate the position of tea shoottips. The proposed method wasevaluated on a set of testing images at different sitesof tea fields and different plant ages. The results showed that the system could recognize tea shoot tips with86% accuracy. It is, therefore, possibleto designacounting-assistedtool for supportingtea producers or tea researchers.

This paper presents a database of rice seeds properties to aid users in the assessment and recognition of seed characteristics of rice varieties based on their apprearance. Inspired by practical demands in quality control and rice seed purity assessment in seed production, we collected rice seeds of different varieties, acquired their images and consulted with experts about the visual properties for rice variety identification. As a result, we built a database of rice seed properties accompanied with their images and the description of the visual features. The database included popular rice varieties in the northern delta of Viet Nam. A database management system (DBMS) was built for managing and searching for rice seeds in the database. A web-based version of the DBMS was also developed. The system can be used to search for different rice varieties based on name and/or the description of the seed appearance. It can help users to learn about rice seed varieties, their visual features for discrimination and recognition. The system is easy to use, especially for non-IT users such as technicians, agronomy students or rice experts of rice seed production companies. This is also the first web-based database of rice varieties in Viet Nam with rice seed images to support rice seed searching and recognition.

NinhBinh province is one of main paddy cultivation areas in theRed River Delta. Mapping paddy rice area by using remote sensing techniques is useful for policy makers to manage and plan for food security and socio - economic development in the province as well as in the region.Multi - temporal eight - day composite MODIS images (MOD09A1, MOD09Q1) and Landsat Thematic Mapper (TM) dataset were used for mapping paddy rice area. MODIS images were classified by using Maximum Likelihood Classification algorithm in testclassificationfollowed bysubpixel classification to increase the accuracy of classification result.Results of testclassification were over 74% (for the image taken on 02 June 2010) and 78% (forthe 14 September 2010 one) of land use classification in MODIS images. These results are acceptable for the moderate spatial resolution images. Result of Sub - pixel classification was over 86% (02 June 2010) and 90% (14 September 2010) of accuracy.

The overall objective of the paper was to describe the existing situation of resources and their effects onincomes of agricultural households in Thanh Hoa province through a casestudy at Ha Trung and Tho Xuan districts. The primary data were collected throughthe survey of 80 agricultural households and analyzed using descriptive statistics and multiple regression. The survey results showedthat labor quality, productive land and capital of the households were quite low. Average income of the households wasabout VND 72 millionper year, especially the income from salary and wages contributes a significant share in the household income. Land size, quantity and educational level of labor, and value of production means werepositively correlated withthe household income, wherebythe land size exerted highest impact. In addition, the accessibilityto credit, gender of household head and geographical location also significantly affected the household income.

This study aimedto identify the technical efficiency and factors affecting the efficiency in organic vegetable production.By usingCobb - Douglas production function with 67 organic vegetable producers in Thanh Xuan commune, Soc Son district, Ha Noi city, the present study indicatedthat the technical efficiencies of organic tomato and cabbage production were 62% and 89%, respectively. Factors affecting the technical efficiencies includedsowing rate, planting area, organic fertilizer, plant protection cost and water., factors causing the technical inefficiencies were age, education and experience of farm households inorganic farming. The expansione of farm size in combination with proper uses of inputs under organic technical procedures can improve organic vegetable yields.