Sensitivity of vegetation indices to spatial degradation of RapidEye imagery for paddy rice detection: a case study of South Korea

The purpose of this study is to investigate the influencing factors of parental child abuse by North Korean refugees who are living in South Korea. In-depth interviews were conducted with five parents who escaped from North Korea. The study identified three categories of factors impacting child abuse: the weakening of family functions from past experiences before and after defection, the stress of adapting to the culture of an unfamiliar society, and low parenting self-efficacy. North Korean parents suffered from emotional and functional crises from past traumatic events and, at the same time, experienced additional acculturative stress as a “minority” after entering South Korea, even as they continued to deal with Maternal Parenting Stress. These complex factors have been shown to lead to child abuse in migrant societies. This study contemplated the context of child abuse through specific examples. The results could provide thoughtful insights into child abuse among migrants and refugee parents, and provide evidence-based intervention plans for its prevention.

Download Full-text

Cloud Cover throughout All the Paddy Rice Fields in Guangdong, China: Impacts on Sentinel 2 MSI and Landsat 8 OLI Optical Observations

Remote Sensing ◽

10.3390/rs13152961 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2961

Author(s):

Rui Jiang ◽

Arturo Sanchez-Azofeifa ◽

Kati Laakso ◽

Yan Xu ◽

Zhiyan Zhou ◽

...

Keyword(s):

Cloud Cover ◽

Southern China ◽

Vegetation Indices ◽

Paddy Rice ◽

Rice Fields ◽

Optical Observations ◽

Landsat 8 ◽

Monthly Basis ◽

Satellite Sensors ◽

Sentinel 2

Cloud cover hinders the effective use of vegetation indices from optical satellite-acquired imagery in cloudy agricultural production areas, such as Guangdong, a subtropical province in southern China which supports two-season rice production. The number of cloud-free observations for the earth-orbiting optical satellite sensors must be determined to verify how much their observations are affected by clouds. This study determines the quantified wide-ranging impact of clouds on optical satellite observations by mapping the annual total observations (ATOs), annual cloud-free observations (ACFOs), monthly cloud-free observations (MCFOs) maps, and acquisition probability (AP) of ACFOs for the Sentinel 2 (2017–2019) and Landsat 8 (2014–2019) for all the paddy rice fields in Guangdong province (APRFG), China. The ATOs of Landsat 8 showed relatively stable observations compared to the Sentinel 2, and the per-field ACFOs of Sentinel 2 and Landsat 8 were unevenly distributed. The MCFOs varied on a monthly basis, but in general, the MCFOs were greater between August and December than between January and July. Additionally, the AP of usable ACFOs with 52.1% (Landsat 8) and 47.7% (Sentinel 2) indicated that these two satellite sensors provided markedly restricted observation capability for rice in the study area. Our findings are particularly important and useful in the tropics and subtropics, and the analysis has described cloud cover frequency and pervasiveness throughout different portions of the rice growing season, providing insight into how rice monitoring activities by using Sentinel 2 and Landsat 8 imagery in Guangdong would be impacted by cloud cover.

Download Full-text

Simplification and Detection of Outlying Trajectories from Batch and Streaming Data Recorded in Harsh Environments

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi8060272 ◽

2019 ◽

Vol 8 (6) ◽

pp. 272 ◽

Cited By ~ 1

Author(s):

Iq Reviessay Pulshashi ◽

Hyerim Bae ◽

Hyunsuk Choi ◽

Seunghwan Mun ◽

Riska Asriana Sutrisnowati

Keyword(s):

South Korea ◽

Real World ◽

Experimental Evaluation ◽

Streaming Data ◽

Harsh Environments ◽

Noise Filtering ◽

New Approach ◽

Detection Algorithms ◽

Outlying Point

Analysis of trajectory such as detection of an outlying trajectory can produce inaccurate results due to the existence of noise, an outlying point-locations that can change statistical properties of the trajectory. Some trajectories with noise are repairable by noise filtering or by trajectory-simplification. We herein propose the application of a trajectory-simplification approach in both batch and streaming environments, followed by benchmarking of various outlier-detection algorithms for detection of outlying trajectories from among simplified trajectories. Experimental evaluation in a case study using real-world trajectories from a shipyard in South Korea shows the benefit of the new approach.

Download Full-text