scholarly journals Jakarta Composite Index Model Before and During COVID-19 Using CNN-LSTM

2022 ◽  
Author(s):  
Yogi Anggara ◽  
Epha Diana Supandi
Keyword(s):  
Composite Index ◽  
Index Model

scholarly journals Freeze-Thaw Deformation Cycles and Temporal-Spatial Distribution of Permafrost along the Qinghai-Tibet Railway Using Multitrack InSAR Processing

2021 ◽  
Vol 13 (23) ◽  
pp. 4744
Author(s):  
Jing Wang ◽  
Chao Wang ◽  
Hong Zhang ◽  
Yixian Tang ◽  
Wei Duan ◽  
...  
Keyword(s):  
Time Series ◽  
Large Scale ◽  
Surface Deformation ◽  
Anthropogenic Activities ◽  
Composite Index ◽  
Buffer Zone ◽  
Absolute Error ◽  
Tibet Plateau ◽  
Permafrost Region ◽  
Index Model

The Qinghai-Tibet Railway (QTR) is the railway with the highest elevation and longest distance in the world, spanning more than 1142 km from Golmud to Lhasa across the continuous permafrost region. Due to climate change and anthropogenic activities, geological disasters such as subsidence and thermal melt collapse have occurred in the QTR embankment. To conduct the large-scale permafrost monitoring and geohazard investigation along the QTR, we collected 585 Sentinel-1A images based on the composite index model using the multitrack time-series interferometry synthetic aperture radar (MTS-InSAR) method to retrieve the surface deformation over a 3.15 × 105 km2 area along the QTR. Meanwhile, a new method for permafrost distribution mapping based on InSAR time series deformation was proposed. Finally, the seasonal deformation map and a new map of permafrost distribution along the QTR from Golmud to Lhasa were obtained. The results showed that the estimated seasonal deformation range of the 10 km buffer zone along the QTR was −50–10 mm, and the LOS deformation rate ranged from −30 to 15 mm/yr. In addition, the deformation results were validated by leveling measurements, and the range of absolute error was between 0.1 and 4.62 mm. Most of the QTR was relatively stable. Some geohazard-prone sections were detected and analyzed along the QTR. The permafrost distribution results were mostly consistent with the simulated results of Zou’s method, based on the temperature at the top of permafrost (TTOP) model. This study reveals recent deformation characteristics of the QTR, and has significant scientific implications and applicational value for ensuring the safe operation of the QTR. Moreover, our method, based on InSAR results, provides new insights for permafrost classification on the Qinghai-Tibet Plateau (QTP).

scholarly journals The Analysis of Optimal Portfolio Using Single Index Model, The Case of Stocks Listed In Jakarta Islamic Index 2010-2013

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Doddi Prastuti ◽  
Erti Septina
Keyword(s):  
Stock Price ◽  
Data Use ◽  
Composite Index ◽  
Secondary Data ◽  
Optimal Portfolio ◽  
Expected Return ◽  
Single Index ◽  
Index Model ◽  
Single Index Model ◽  
Data Analysis Methods

The purpose of this study is to apply the single index model in order to make an optimal portfolio for stocks listed in Jakarta Islamic Index (JII). The model is used in order to analyze what stocks to be chosen as components of a portfolio stock and how much proportion to be invested in each stock. This research use stocks that are listed in Jakarta Islamic Index. The reason for choosing stocks listed in JII is because many Indonesians, mostly Muslims, still not familiar with the stock that is accordance with the requirement of Sharia. The data use in this study is secondary data, among others: quarterly stock price data during period of 2010-2013, composite index, interest rate. Sample in this study are 28 companies’ stocks listed in the Jakarta Islamic Index, two companies’ stock did not meet the criteria of the sample because the companies start listed in the index in 2012. Data analysis methods use in this study are: stocks’ return and expected return, stocks’ risk, market’s return and risk, beta and alpha, variance of residual error, rate of excess return to beta, determine the cut off rate, proportion of fund invested in optimal portfolio, and risk of optimal portfolio. Result of this study showed that there are 10 stocks that meet the criteria of optimal portfolio formation. Those stocks and their proportion are: 24,852% stock of JMSR, 16,587% stock of ASRI, 14,721% stock of INDF, 15,398% stock of AKRA, 11,835% stock of LPKR, 5,684% EXCL, 5,184% MAPI, 3,143% CPIN, 1,511% SMGR and 1,086% stock of KLBF. Based on the calculation, the portfolio’s expected return is 10,33% and the risk is 2,74%.

scholarly journals Spatiotemporal Evaluation of Socio-Ecological-Economic System Vulnerability: A County-Level Analysis of Chongqing, China

2020 ◽  
Vol 12 (9) ◽  
pp. 3912
Author(s):  
Chunxia Liu ◽  
Qingqing He ◽  
Yuechen Li
Keyword(s):  
Sustainable Development ◽  
Economic System ◽  
Composite Index ◽  
Vulnerability Index ◽  
Entropy Method ◽  
County Level ◽  
Ecological Economic ◽  
Index Model ◽  
The Social ◽  
Regional Sustainable Development

The research on vulnerability can provide insights into social, economic, and ecological risks. Therefore, the objective of this work was to measure the degree of socio-ecological-economic system (SEES) vulnerability in Chongqing, one of the regions with the high constraint of natural conditions and human activity in the southwest of China. For this, by using three criteria and 40 indices based on the exposure-sensitive-adaptive capacity (ESC) model, an index system was designed. The entropy method was used to determine the weight of the indices. Furthermore, the composite index model and coefficient of variation were applied to evaluate the spatiotemporal characteristics of SEES vulnerability in the study area at the county level. The results showed that the average vulnerability index of SEES from 2005 to 2010 in Chongqing was 0.5735. The development pressure was high, and the ability to resist disturbance from external risks was low. Regional sustainable development was facing challenges. Spatial distribution of SEES vulnerability of Chongqing varied from high (moderately vulnerable or worse) in the western counties to low (mildly vulnerable) in the northeastern and southeastern areas with better ecological bases. The general vulnerability of the ecological and economic subsystems continues to decrease. However, the vulnerability of the social subsystem tended to initially decrease and then increase. Overall, the differences in the pattern of SEES vulnerability of the counties declined. Moreover, economic and social development tended to balance. This study is helpful to understand the overall trend and characteristics of vulnerability change and provides theoretical methods and reference opinions to support regional sustainable development.

scholarly journals Mitigating Spatial Conflict of Land Use for Sustainable Wetlands Landscape in Li-Xia-River Region of Central Jiangsu, China

2021 ◽  
Vol 13 (20) ◽  
pp. 11189
Author(s):  
Yan Sun ◽  
Xiaoping Ge ◽  
Junna Liu ◽  
Yuanyuan Chang ◽  
Gang-Jun Liu ◽  
...  
Keyword(s):  
Land Use ◽  
Socioeconomic Development ◽  
Composite Index ◽  
Reduction Rate ◽  
Index Model ◽  
Land Use Conflict ◽  
Practical Strategy ◽  
River Region ◽  
Natural Wetlands ◽  
Economic Developments

Li-Xia-river Wetlands make up the biggest freshwater marsh in East China. Over the last decades, social and economic developments have dramatically altered the natural wetlands landscape. Mitigating land use conflict is beneficial to protect wetlands, maintain ecosystem services, and coordinate local socioeconomic development. This study employed multi-source data and GIS-based approaches to construct a composite index model with the purpose of quantitatively evaluating the intensity of land use conflict in Li-Xia-river Wetlands from 1978 to 2018. The results showed that the percentage of the wetlands’ area declined from 20.3% to 15.6%, with an overall reduction rate of 23.2%. The mean index of land use conflict increased from 0.15 to 0.35, which suggests that the conflict intensity changed from “no conflict” to “mild conflict.” The number of severe conflict units increased by about 25 times. A conspicuous spatial variation of land use conflict was observed across different periods, although taking land for agricultural activities was the overriding reason for wetlands reduction. However, in recent years, urban sprawl has posed the greatest threat to Li-Xia-river Wetlands. Coordinating land use conflict and formulating a practical strategy are the initial imperative steps to mitigate the threat to wetlands.

scholarly journals Seasonal InSAR Displacements Documenting the Active Layer Freeze and Thaw Progression in Central-Western Spitsbergen, Svalbard

2021 ◽  
Vol 13 (15) ◽  
pp. 2977
Author(s):  
Line Rouyet ◽  
Lin Liu ◽  
Sarah Marie Strand ◽  
Hanne Hvidtfeldt Christiansen ◽  
Tom Rune Lauknes ◽  
...  
Keyword(s):  
Time Series ◽  
Active Layer ◽  
Composite Index ◽  
Ground Surface ◽  
Western Coast ◽  
Thermal Dynamics ◽  
Index Model ◽  
Synthetic Aperture Radar Interferometry ◽  
Freeze And Thaw ◽  
Ground Conditions

In permafrost areas, the active layer undergoes seasonal frost heave and thaw subsidence caused by ice formation and melting. The amplitude and timing of the ground displacement cycles depend on the climatic and ground conditions. Here we used Sentinel-1 Synthetic Aperture Radar Interferometry (InSAR) to document the seasonal displacement progression in three regions of Svalbard. We retrieved June–November 2017 time series and identified thaw subsidence maxima and their timing. InSAR measurements were compared with a composite index model based on ground surface temperature. Cyclic seasonal patterns are identified in all areas, but the timing of the displacement progression varies. The subsidence maxima occurred later on the warm western coast (Kapp Linné and Ny-Ålesund) compared to the colder interior (Adventdalen). The composite index model is generally able to explain the observed patterns. In Adventdalen, the model matches the InSAR time series at the location of the borehole. In Kapp Linné and Ny-Ålesund, larger deviations are found at the pixel-scale, but km or regional averaging improves the fit. The study highlights the potential for further development of regional InSAR products to represent the cyclic displacements in permafrost areas and infer the active layer thermal dynamics.

scholarly journals Comprehensive Utilization Pattern of the Bohai Rim Coastline Using the Restrictive Composite Index Method

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yun Zhang ◽  
Tong Wu ◽  
Yuanzhi Ye
Keyword(s):  
Yellow River ◽  
Composite Index ◽  
Utilization Pattern ◽  
Index Method ◽  
Factors Affecting ◽  
Comprehensive Utilization ◽  
Index Model ◽  
The North ◽  
Ecological Protection ◽  
Bohai Rim

Coastlines play an important role in human activity and economic development. Reasonably allocating shoreline resources and addressing contradictions between ecological protection and development are critical issues. In this study, positive and negative factors affecting the natural, environmental, and socioeconomic status of the coastal zone while considering land and sea effects were comprehensively analyzed using ecological theories and methods, and an improved restrictive composite index model was constructed. We quantitatively analyzed the comprehensive utilization pattern of the Bohai Rim coastline, China, in terms of the coastline utilization type and spatial agglomeration characteristics. The comprehensive utilization pattern of the Bohai Rim coastline is as follows: ecological areas are present in the north and south, and industrial areas are present in the east and west. Industrial production areas along the coastline are mainly distributed in the East Liaodong and Bohai bays, and ecological protection areas are located in the estuaries of the Liaohe and Yellow River. The improved restricted comprehensive index method model weakens the interaction among variables and makes the calculation results closer to the real situation. The results of the comprehensive utilization pattern of Bohai Rim coastline obtained by quantitative evaluation are of great significance for the coordinated development of coastline ecological protection and development and utilization.

Urban environment quality assessment by using composite index model

2015 ◽  
Vol 34 (5) ◽  
pp. 1473-1480 ◽  
Author(s):  
Maryam Robati ◽  
S. M. Monavari ◽  
H. Majedi
Keyword(s):  
Quality Assessment ◽  
Urban Environment ◽  
Composite Index ◽  
Index Model ◽  
Environment Quality

Evaluation of Land Saving Effect for Highway Construction Based on Composite Index Model

2013 ◽  
Vol 361-363 ◽  
pp. 1671-1675
Author(s):  
Xia Li ◽  
Xi Long Ren
Keyword(s):  
Evaluation Method ◽  
Highway Construction ◽  
Composite Index ◽  
Service Level ◽  
Entropy Method ◽  
Index Model ◽  
Standard Value ◽  
Factor Evaluation ◽  
Saving Effect ◽  
Land Saving

In order to realize a comprehensive effect assessment of highway construction of different levels, the thesis builds up a system of evaluating indicators in a meso-level, which consists of three criteria—land saving amount, function and service level and comprehensive return of land usage. Moreover, it nails down the standard value of the land saving index, and determines practical value of each index by taking the actual situation of HengShui-DaMing section in DaQing-GuangZhou expressway into consideration, then carries out non-dimensional treatment to the index and builds a comprehensive index model by employing the multi-factor evaluation method based on entropy method empowerment. Multi-factor composite index model is a feasible approach to assess the land saving effect of a certain highway construction project, thus realizing the definition and comparative evaluation of land saving level.

scholarly journals A Prosperity Index Model of Regional Tourism Industry Based on Composite Index

2021 ◽  
Vol 15 ◽  
pp. 80-91
Author(s):  
Dandan Qi ◽  
Jingwen Fang ◽  
Jiaxin Liu ◽  
Qinglin Zhou ◽  
Ping Han
Keyword(s):  
Turning Point ◽  
Composite Index ◽  
Policy Formulation ◽  
Tourism Industry ◽  
Heilongjiang Province ◽  
Index Model ◽  
Regional Tourism ◽  
Current Economic Situation ◽  
Warning Model ◽  
Prosperity Index

In recent years, the ice and snow tourism industry has developed rapidly, which plays an important role in boosting regional economy. The prosperity index of the ice and snow tourism industry was compiled, and the early warning model of the ice and snow tourism industry in Heilongjiang Province of China was built, which was taken as a comprehensive scale to observe the fluctuation of the ice and snow tourism industry. Combined with the current economic situation, the composite index, the situation of the industry and the turning point of the industry cycle volatility are analyzed, to determine the situation and trend of the industry volatility. This can provide reference for the policy formulation of the ice and snow tourism industry in Heilongjiang province and the micro-management of tourism companies.

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