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ติดประกาศ ҷԵ 25 .. 07@ 13:47:29 ICT โดย admin
ҹԨ ʷ.շ7 Ѻ 3(2)
Ѵ


ûԹ¹ŧҾǴdz½觷ѧѴոҪ Ҿ´кʹʵ

Assessing coastal environmental changes in Nakorn Si Thammarat Province using remote sensing and GIS

ͤ

ҭ ز

ǹ §

зѾҡøҵ

ԷʧҹԹ

. Ҵ˭ . ʧ 90112

Abstract

This study aimed to assess coastal environment changes in Nakhon Si Thammarat Province, southern Thailand, using aerial photographs and land satellite images and Geographic Information Systems (GIS). To define changes in coastal land use, 1966/67, 1990 and 2004 land uses were visually interpreted from aerial photographs and Landsat-5 Thematic Mapper (TM) image maps. Results revealed that between 1990 and 2004, the areas devoted to paddy field, nipa palm, marshland and mangrove forests decreased by 6,834 ha, 1,141 ha, 525 ha and 315 ha respectively due to an increase in the land devoted to shrimp farms, which increased from 3,065 ha in 1990 to 12,375 ha in 2004. The rapid expansion of shrimp farm areas along the coastal shores perturbed the coastal environment primarily through the deterioration of soil and water quality and problems of coastal erosion. These processes together with the loss of livelihoods for coastal inhabitants have led to a decline in the quality of life for the coastal population. Management recommendation which would prevent and mitigate environmental

consequences of coastal land use changes are discussed.

Key words: land use changes, shrimp farming, coastal erosion, remote sensing, Geographic Information System

͹Ǣͧһҳ㹺ҡȷҡվ

ҡẺͧᵡҧѹ

Sensitivity of GPS-derived Precipitable Water Vapor Content Using Different Tropospheric models

ʶо Chalermchon Satirapod

Email : chalermchon.s@chula.ac.th

§ ص Samniang Suttara

Email : lookniang @yahoo.com

ҤԪǡǨ Department of Survey Engineering

ǡʵŧóԷ Faculty of Engineering Chulalongkorn University

Abstract

The Precipitable Water Vapor (PWV) content is the main variable for weather forecasting and can be used to study the variation of climate in any season. Normally, the PWV content can be measured directly from Microwave Radiometer. However, the cost of this instrument is still far too expensive to install at any locations. Since the cost of a dual-frequency GPS receiver is about ten times less expensive than the Microwave Radiometer, an alternative way to determine the PWV content is to convert the tropospheric bias contaminated in GPS data to the PWV content. In this study, we used three consecutive months of GPS data starting from August to October, 2001. In order to investigate a sensitivity of GPS-derived PWV values, three standard tropospheric models, namely Saastamoinen model, Modified Hopfield model, and Essen and Froome model were used in the data processing step. It was found that there are no significant differences in the GPS-derived PWV values. Hence, the determination of the PWV content from GPS observations is an attractive method.

KEYWORDS: GPS, Precipitable Water Vapor content, Tropospherice bias

Ѵ

ҳ㹺ҡȶ繵ѡ 㹡þҡóҡ ö֡ҡ¹ͧҾҡĴ١ »Ԥһҳ㹺ҡöѧѴµçҡͧ ǿô ҧáҤҢͧشͧ

ѧѧ٧ҡҡͧ÷еԴ㹷ءʶҹͧ ͧҡҤҢͧͧѺѭҳվẺͧ鹶١ͧǿôҳԺ ѧ鹷ҧ͡աҧ㹡Ҥҳ㹺ҡȤ͡ŧҤҴ͹ͧҡѡ㹪鹺ҡ㹢Ũվҳ㹺ҡ 㹡֡ҹ餳мԨŨվ͹ͧѹ͹ԧҤ ֧͹Ҥ ..2544 ͵ǨҤ͹Ǣͧûҳһҳ㹺ҡȨҡվ 㹢鹵͹ûżŢ͡ẺͧûѺҴ͹㹪鹺ҡҵðҹҧѹẺͧ Ẻͧ Saastamoinen Ẻͧ Modified Hopfield Ẻͧ Essen and Froome ŷʴҤһҳ㹺ҡȨҡվʷդᵡҧѹչӤѭ ѧԸաûҳһҳ㹺ҡȨҡվʶ繷ҧ͡ʹѹ˹

Ӥѭ վ ҳ㹺ҡ ҤҴ͹ͧҡѡ㹪鹺ҡ

Expert Classification for Age Class Identification of Oil Palm Plantation in Krabi Province, Thailand

Jarunya Kitiphaisannon Faculty of Environment and Resources Studies

jarunya@hotmail.com Mahidol University, Thailand

Sura Pattanakiat (Ph.D)

enspt@mahidol.ac.th

Charlie Navanugraha (Ph.D)

encnv@mahidol.ac.th

Abstract

The objective of this study is to apply the Geo-Information Technology including Remote Sensing, Global Positioning System, and Geographic Information System integrated with Expert System in order to generate a knowledge base system for age class identification of oil palm plantation. Rule base under the knowledge base for oil palm classification is generated from the relationship of multiple regressions related with Water Index (WI), Bare Soil Index (BI), Normalized Differential Vegetation Index (NDVI), and Advance Vegetation Index (AVI). These equations are used to define age class stage of oil palm plantation which can be divided into 4 classes: Young stage (1-3 years old), Intermediate stage (4-10 years old), Productive stage (11-20 years old), and Mature stage (more than 20 years old). The percentages of accuracy for each class using expert classification are 92.19, 50.88, 80.00, and 12.50 respectively. Meanwhile, the percentages of accuracy for maximum likelihood classification are 90.63, 42.11, 40.54, and 72.34 respectively. Therefore, the accuracy for each age class stage from the expert classification is higher than the maximum likelihood classification. Furthermore, the overall accuracy of the expert classification is about 63.11%, and the maximum likelihood classification is only about 60.33%. Thus the accuracy of the expert classification is about 2.78% higher than the maximum likelihood classification. In conclusion, application of the Geo-Information Technology and Expert System provides useful information about classification on age class of oil palm plantation.

Keywords: OIL PALM / AGE CLASS / EXPERT CLASSIFICATION / KRABI PROVINCE / THAILAND

ûѺا١ͧͧҵ˹ẺشǷ´٧¨վ ¡Ը MINQUE Ѻûҳԡͧûǹ

Improving the accuracy of GPS Precise Point Positioning using MINQUE Procedure for an Estimation of Variance Covariance Matrix

ʶо Chalermchon Satirapod

Email : chalermchon.s@chula.ac.th

ǹ Mayura Luansan

Email : mara2523@yahoo.com

˹»ԺѵԡԨ෤բҾԧʵ Geo-Image Technology Research Unit

ҤԪǡǨ Department of Survey Engineering

ǡʵ ŧóԷ Faculty of Engineering Chulalongkorn University

Abstract

Nowadays, GPS has become an important tool for high accuracy positioning applications. In order to ensure high accuracy positioning results, both the functional model and the stochastic model must be correctly defined. Data differencing techniques are extensively used for constructing the functional model because they can eliminate many biases. However, some unmodelled biases still remain in the GPS observables that make the coordinate results still have an error. It is still possible to further improve the accuracy and reliability of GPS results through an enhancement of the stochastic model. This research aims to improve the stochastic model used for GPS precise point positioning technique. The MINQUE (Minimum Norm Quadratic Unbiased Estimation) method was selected and used to estimate the variance-covariance matrix. Preliminary results indicate that the accuracy of GPS positioning results is improved when the estimated variancecovariance matrix is used.

KEYWORDS : GPS Precise Point Positioning, Stochastic model, MINQUE

ԵѳԻѭ͡þѲСáШԧʵ

Ҥѹ͡§˹

An Analysis of Wisdom and Skill Products for Development and Their Geographic Distribution in Northeastern Thailand.

óСӸ ٹʹ͡þѲҤѹ͡§˹

ѵ ʴ Է¢͹

Դآ

ѧ ä

ʹ زҧ

ͧ Թ Է෤ù

Ҥ ԭ Էä

ѵĴ ѵԸ ԷغҪҹ

Abstract

The policy of Thai government focuses on strengthening the economic cornmunity of the grass-roots. As a result, the extension of local wisdom, skill of people and ways of living are essential with objectives of transferring knowledge bases and of developing the product sustainability. To accomplish these, the databases of local wisdom and skill were then established with an analysis of those skill products.

The databases of ways of living, wisdom and skill of people in local communities are established, based on the existing products in the communities. The data obtained from interviewing people who were original procedures or their connections. In every province of the Northeast, 5 kinds of products were selected each of which were produced from 3 villages.

The data set were then hierarchically categorized into 4 levels; kind of wisdom, main product, product group and product type. The databases were established and linked to geographic locations. Further analysis of each product was performed, based on local wisdom, skill required on production and market management, with a number of criteria used. The prospect of the products according to the criteria could be classified into 3 levels : high, moderate and low.

The geographic distribution of the information obtained was digitally performed using GIS

The database establishment of the ways of living local wisdom and people skill was performed for 19 provinces in the Northeast. The classification of the products are accounted for 52.78, 45.37 and 1.85% for the applied wisdom, traditional wisdom and innovated wisdom respectively. Of the total products, about 33.23% is the hand weaving products. Moreover, in terms of the prospect of the product. in the Northeast there are 20.68, 70.37 and 8.95% of the total products (314) classified as high, moderate and low prospects respectively.

It is reccommented that the products with high business prospects should be preserved as a local heritage. The product with moderate prospects should be supported with research and development to strengthen the commercial values.

Keyword : local wisdom, skill products , OTOP , GIS , Northeastern Thailand

Ѵ

º¢ͧѰ鹡ҧ ҧɰԨͧдѺҡ˭ ѧ Իѭҷͧ ѡ ԶժԵ֧ͧդ ѵػʧ Ͷ·ʹҹоѲҼԵѳҧ׹ ѵػʧѧ ҹԻѭҷͧзѡТͧ ֧դ㹡þѲ Ѻ秢ͧԵѳѧ ҧҹ¡ǨԵѳҡ㹪¡ɳ ؤҡмǢͧԹüԵѳ 㹷ءѧѴ Ҥѹ͡§˹ ͡Եѳ 5 Դ աüԵҧ 3 ҹ ŷѺ ṡ͡ 4 дѺ ԴͧԻѭ Եѳѡ Եѳ ЪԴͧԵѳ

ҹҧҹ §Ѻ˹觷ҧʵ ԵѳЪԴ Իѭ ѡФӹҭ èѴáõҴ »Сͺ͹䢵ҧ ͧ 秢ͧԵѳ ͹Ѵṡ͡ 3 дѺ

áШ·ҧʵͧҹʴкʹʵ ŷѺҹ ԶժԵ Իҷͧ зѡТͧ 19 ѧѴ Ҥѹ͡§˹ ṡԵѳ͡ 3 Сä Իѭһء ԻѭҴ Իѭ Ҥѹ͡§˹ԻѭҴѧ 52.78, 45.37 1.85 繵 ӴѺ

ҡԵѳ ҳ 33.23 繵 繼Եѳҷ 秢ͧԵѳ դ 20.68, 70.37 8.95 繵 ṡ繤дѺ٧ ҹҧ е ӴѺ

ʹ㹡駹 Եѳդ٧ԧáԨ è׺ʹôͧͧ мԵѳդ移ҹҧèѺþԨóԨ оѲ ҧ秷դسҷҧäҵ

Ӥѭ : Եѳ , кʹʵ



 
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