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Dive into the research topics where Alexius Korom is active.

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Featured researches published by Alexius Korom.


Journal of forest and environmental science | 2014

Estimation of Above-Ground Biomass of a Tropical Forest in Northern Borneo Using High-resolution Satellite Image

Mui How Phua; Zia-Yiing Ling; Wilson Wong; Alexius Korom; Berhaman Ahmad; Normah Awang Besar; Satoshi Tsuyuki; Keiko Ioki; Keigo Hoshimoto; Yasumasa Hirata; Hideki Saito; Gen Takao

Abstract Estimating above-ground biomass is important in establishing an applicable methodology of Measurement, Reporting and Verification (MRV) System for Reducing Emissions from Deforestation and Forest Degradation-Plus (REDD+). We developed an estimation model of diameter at breast height (DBH) from IKONOS-2 image that led to above-ground biomass estimation (AGB). The IKONOS image was preprocessed with dark object subtraction and topographic effect correction prior to watershed segmentation for tree crown delineation. Compared to the field observation, the overall segmentation accuracy was 64%. Crown detection percent had a strong negative correlation to tree density. In addition, satellite-based crown area had the highest correlation with the field measured DBH. We then developed the DBH allometric model that explained 74% of the data variance. In average, the estimated DBH was very similar to the measured DBH as well as for AGB. Overall, this method can potentially be applied to estimate AGB over a relatively large and remote tropical forest in Northern Borneo.Key Words: tree crown delineation, biomass estimation, IKONOS-2


Remote Sensing of Environment | 2016

Evaluation of the similarity in tree community composition in a tropical rainforest using airborne LiDAR data

Keiko Ioki; Satoshi Tsuyuki; Yasumasa Hirata; Mui How Phua; Wilson Wong; Zia Yiing Ling; Shazrul Azwan Johari; Alexius Korom; Daniel James; Hideki Saito; Gen Takao


Proceedings of SilviLaser 2011, 11th International Conference on LiDAR Applications for Assessing Forest Ecosystems, University of Tasmania, Australia, 16-20 October 2011 | 2011

Characteristics of satellite LiDAR waveform in tropical rain forests from the comparison with canopy condition derived from high resolution satellite data

Yasumasa Hirata; Mui How Phua; Hideki Saito; Toshiya Matsuura; Wilson Wong; Alexius Korom; Kanehiro Kitayama


Iforest - Biogeosciences and Forestry | 2017

Seeing trees from space: above-ground biomass estimates of intact and degraded montane rainforests from high-resolution optical imagery

Mui How Phua; Zia Yiing Ling; David A. Coomes; Wilson Wong; Alexius Korom; Satoshi Tsuyuki; Keiko Ioki; Yasumasa Hirata; Hideki Saito; Gen Takao


Sains Malaysiana | 2016

Relationships between crown size and aboveground biomass of oil palms: an evaluation of allometric models.

Alexius Korom; Mui How Phua; Toishiya Matsuura


37th Asian Conference on Remote Sensing, ACRS 2016 | 2016

Aboveground biomass estimation using airborne laser scanning (ALS) and structure from motion (SfM) in tropical montane forest, Northern Borneo

Wilson Wong; Satoshi Tsuyuki; Mui How Phua; Keiko Ioki; Alexius Korom; Yasumasa Hirata; Hideki Saito; Gen Takao


37th Asian Conference on Remote Sensing, ACRS 2016 | 2016

Exploring forest degradation: Tree density and aboveground biomass

Alexius Korom; Mui How Phua; Wilson Wong; Toshiya Matsuura; Hideki Saito; Yasumasa Hirata


35th Asian Conference on Remote Sensing 2014: Sensing for Reintegration of Societies, ACRS 2014 | 2014

Aboveground biomass assessment of degraded rainforest using IKONOS-2: Specific forest cluster analysis

Alexius Korom; Mui How Phua; Yasumasa Hirata; Toshiya Matsuura; Hideki Saito; Wilson Wong


34th Asian Conference on Remote Sensing 2013, ACRS 2013 | 2013

Estimating tree height and above ground biomass of tropical rainforest across different degradation levels in malaysian borneo using airborne lidar data

Keiko Ioki; Satoshi Tsuyuki; Keigo Hoshimoto; Mui How Phua; Zia Yiing Ling; Wilson Wong; Alexius Korom; Berhaman Ahmad; Normah Awang Besar; Yasumasa Hirata; Hideki Saito; Gen Takao


34th Asian Conference on Remote Sensing 2013, ACRS 2013 | 2013

Shadow allometry for mapping biomass of tropical forest in northern Borneo

Mui How Phua; Zia Yiing Ling; Wilson Wong; Alexius Korom; Berhaman Ahmad; Normah Awang Besar; Satoshi Tsuyuki; Keiko Ioki; Yasumasa Hirata; Hideki Saito; Gen Takao

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Mui How Phua

Universiti Malaysia Sabah

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Yasumasa Hirata

National Agriculture and Food Research Organization

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Wilson Wong

Universiti Malaysia Sabah

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Hideki Saito

Forest Research Institute

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Gen Takao

Center for International Forestry Research

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Berhaman Ahmad

Universiti Malaysia Sabah

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Zia Yiing Ling

Universiti Malaysia Sabah

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