bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trends and controls on water-use efficiency of an old-growth coniferous forest in the Pacific Northwest
Authors: Jiang Yueyang , Still Christopher J , Rastogi Bharat , Page Gerald F M , Wharton Sonia , Meinzer Frederick C , Voelker Steven , Kim John B 
Published: May 2019

AbstractAt the ecosystem scale, water-use efficiency (WUE) is defined broadly as the ratio of carbon assimilated to water evaporated by an ecosystem. WUE is an important aspect of carbon and water cycling and has been used to assess forest ecosystem responses to climate change and rising atmospheric CO2concentrations. This study investigates the influence of meteorological and radiation variables on forest WUE by analyzing an 18 year (1998–2015) half-hourly time series of carbon and water fluxes measured with the eddy covariance technique in an old-growth conifer forest in the Pacific Northwest, USA. Three different metrics of WUE exhibit an overall increase over the period 1998–2007 mainly due to an increase in gross primary productivity (GPP) and a decrease in evapotranspiration (ET). However, the WUE metrics did not exhibit an increase across the period from 2008 to 2015 due to a greater reduction in GPP relative to ET. The strength of associations among particular meteorological variables and WUE varied with the scale of temporal aggregation used. In general, vapor pressure deficit and air temperature appear to control WUE at half-hourly and daily time scales, whereas atmospheric CO2concentration was identified as the most important factor controlling monthly WUE. Carbon and water fluxes and the consequent WUE showed a weak correlation to the Standard Precipitation Index, while carbon fluxes were strongly dependent on the combined effect of multiple climate factors. The inferred patterns and controls on forest WUE highlighted have implications for improved understanding and prediction of possible adaptive adjustments of forest physiology in response to climate change and rising atmospheric CO2concentrations.
Spatial pattern of paddy fields and rice mills in Mande, Karangtengah and Cilaku Districts, Cianjur Regency, West Java, Indonesia
Authors: Munibah K , Tjahjono B , Hardianto T W , Wijaya H 
Published: May 2019

Abstract
Cianjur Regency is one of granary area in West Java Province which produces an average of 847,741 tons/year and ranks 5-7th at West Java Province during 2010-2015. This rice production should to be supported with rice milling infrastructure to convert paddy to rice. In general, location and number of rice mills are related to location and area of paddy field because they need each other. Objectives are to analysis spatial pattern of paddy fields and rice mills using nearest neighbor distance and relationship between area of paddy fields and number of rice mills using regresion. Results show that spatial pattern of paddy fields in Mande, Karangtengah, Cilaku District are clustered, disparsed, clustered, respectively. This difference is due to topography, where land with hilly or mountainous topography, the spatial pattern of paddy fields is clustered on flat land. The spatial pattern of rice mills in Mande, Karangtengah, Cilaku District are clustered, clustered, disparsed, respectively. This rice mill is located along the road, therefore rice mills are clustered on tight road, flat topography and around the paddy fields. The relationship between area of paddy fields and number of rice mills in Mande and Cilaku Districts are strong (r2 = 0.62, r2 = 0.64), while Cilaku District is sufficient (r2 = 0.37).
Determination of planting crops using satellite data at Shonai Plain in Japan
Authors: Saito Genya , Uto Kuniaki , Yonezawa Chinatsu , Sasaki Yuka , Yoshino Kunihiko , Oda Kunio , Sato Jun , Oyoshi Kei , Mizukami Yosei 
Published: May 2019

Abstract
Shonai Plain is famous paddy area in Japan. As a countermeasure overproduction of rice in Japan, there are many other crops not rice in the paddy fields. We try to determination of planted crops using satellite data. Recently, in Asian countries, GIS is spread widely and agricultural field polygon is commonly used. Crop determination using the polygon is becoming popular. Normally, fields are used without changing, but sometimes, one field is divided two or three fields, and two or three fields are integrated one field. It is necessary to overlay satellite image and the polygon, and to check with fitting or not. In case of mismatch, field polygon must be corrected. Simultaneously with this confirmation work for each field polygon, the optical satellite data were classified as water surface ‘water’, vegetation as ‘vegetation’, bare soil as ‘soil’ and ‘cannot determination’. In the SAR image, we classify 4 degrees, as small scattering of the water surface ‘0’, scattering slightly larger than the water surface ‘1’, larger than the water surface ‘2’, and large scattering ‘3’. The crop determination is performed according to the following standard using to the time series data. (a) Rice: Almost water surface at rice planting time and following several weeks. In summer, there is large vegetation. (b) Wheat: There is large vegetation at rice planting time, and small vegetation at summer. (c) Soybean: There is small vegetation at rice planting time, and large vegetation in summer. Using this evaluation criteria, we performed the crop classifications in Shonai Pain by ALOS2 and Sentinel2 data, and the correct answer rates are more than 95% at both satellite data.
Vertical structure of Convectively Coupled Equatorial Waves (CCEWs) during Boreal Summer and Winter
Authors: Yuni Anggi Riska Elma , Lubis Sandro W , Setiawan Sonni 
Published: May 2019

Abstract
Atmospheric variability in the tropics on the daily to intraseasonal timescale is often related to convectively coupled equatorial waves (CCEWs), including Kelvin, MRG, ER, and TD-type waves. This study aims toanalyze the observed vertical structures of the CCEWsduring boreal summer and winter fromthe NCEP-DOE reanalysis dataset. Consistent with a linear wave theory, the vertical structure of CCEWs is characterized by a distinctive phase tilt, indicatinga distinct direction of wave energy propagation. The vertical structure of Kelvin, MRG and ER waves is signified by westward phase tilts with height, especially in the upper troposphere when the waves become dry (i.e. there is noeffect of moisture), while in the lower troposphere, the phase tiltsdeviatesignificantly from the linear wave theory, whenthe waves become moist. On the other hand, the TD-type waves exhibit a perpendicular, baroclinic structure with height. The vertical structures of the Kelvin, MRG and TD-Type waves are more clearly observed during boreal summer, while ER waves are more observed during boreal winter. This is consistent with the increasing wave amplitudesdue to a stronger wave sourceduring those periods. Future studies are still required in order to understand how the vertical modulation of CCEWs on RH and wind fields can be used to better improve weather predictions in the tropics.
Water Supplying Vegetation Index (WSVI) Analysis for Drought Rate Mapping in Bogor Regency
Authors: Rosalena I R , Rokhmatuloh  , Hernina Revi 
Published: May 2019

Abstract
Bogor dubbed as The City of Rain because of the high rainfall, Bogor is also a water conservation area. But in recent years in 2015, there was drought in several subdistricts in Bogor, consisting of 40 districts and distributed in 59 villages. Drought is closely related to the existing water reserves in the soil, good water to land as well as for everyday human needs. This research aims to map levels of drought that occurred in Bogor Regency from 2005 to 2015 using the Water Supplying Vegetation Index (WSVI). Research with Water Supplying Vegetation Index (WSVI) is to map the level of drought is still not much done in Indonesia. Methodology this research is to analyze the data of remote sensing technology and geographic information system (GIS) using the Water Supplying Vegetation Index (WSVI) prepared from Landsat 8 OLI/TIRS and Landsat 5 TM. Obtained that areas with a very high level of drought are Cariu Subdistrict, Babakanmadang Subdistrict, Jonggol Subdistrict, Ciampea Subdistrict, and Cibungbulang Subdistrict. The level of drought can be indicated by the level of humidity. If there is a decrease in vegetation, it can reduce the level of moisture which later can also increase the potential for drought.
Influence of the positive Indian Ocean Dipole in 2012 and El Niño-southern oscillation (ENSO) in 2015 on The Indonesian Rainfall Variability
Authors: Mareta Lesi , Hidayat Rahmat , Hidayati Rini , Alsepan Givo 
Published: May 2019

Abstract
Indian Ocean Dipole (IOD) and El Niño-southern oscillation (ENSO) are coupled ocean – atmosphere variability in the Indo – Pacific Oceans that play important roles to the Indonesian rainfall variability. This study is focused on the influence of the positive IOD in 2012 and El Niño in 2015 on the rainfall in Indonesia using satellite-derived precipitation data. Sea surface temperature (SST), rainfall and wind components, are analyzed to evaluate the detailed evaluation of those events. The results show that, in 2012, the positive IOD develops in July - October and reaches its peak in September. During the positive IOD in 2012, there is a negative SST anomaly in the eastern Indian Ocean (western Sumatra). This causes a shift in the warm water pool to the western Indian Ocean. This shifted warm pool is accompanied by a shift in the convective region, leading to deareased rainfall in the western Sumatra. Mean while, in 2015, El-Niño started to develop from July to November. Negative anomalies of rainfall in the transition period II and the east monsoon season are in line with the SST elevation in the eastern and central Pacific Ocean. So that the eastern and central of the Pacific Ocean become to center of low pressure which causes the air in the eastern Pacific Ocean to upward (convection) which will form a clouds that contain water, so that the eastern and central of the Pacific Ocean will experience an increase in the amount of rainfall while in the western of the Pacific Ocean or the eastern of Indonesia will experience a rainfall deficit.
Simulation of two-dimensional currents to the depth and suspended sediment concentration in Aceh Besar Waters
Authors: Setiawan I , Yuni S M , Purnawan S , Ilhamsyah Y , Wafdan R 
Published: May 2019

Abstract
Aceh Besar Waters are geographically located at 5.3° - 5.7°N and 95.1° - 95.6°E which border Indian Ocean, Andaman Sea, and Malacca Strait in the West, North, and East, respectively. The purpose of this study was to simulate the circulation of current and suspended sediment transport driven by southwest and northeast monsoon. Model discretization cover 0.5 x 0.5 arcminutes (925 x 925 m) of spatial resolution with time interval of 9 seconds. The parameters of the model are wind friction Cd = 1.285x10−3, bottom friction r = 0.0025, lateral eddy viscosity = 2500 m2/s. The primary data of estuary suspended sediment concentrations were collected in the coastal waters of Lhok Nga, Ulee Lheue, Lampulo, Alue Naga and Krueng Raya as input for the suspended sediment distribution model. The results of the study show that during southwest monsoon, the current in the western part of Aceh Besar Waters move northward and during northeast monsoon in the western and eastern part of the region, the current move toward south and west. Thus, the distribution of suspended sediments follows the direction of the current, where sediment concentrations are reduced when they are away from the coast.
Characteristics study and robustness comparison of various star pattern recognition algorithm for star sensor using digital simulation
Authors: Ardi Nugraha Setya , Poetro Ridanto Eko , Arif Saifudin M , Fathurrohim Luqman , Courie Ilham Akbar 
Published: May 2019

Abstract
The last few years the use of star sensor, which is the most accurate sensor on satellites, began to penetrate into micro satellites and nano satellites, previously used only on high-end satellites. Hence we need to develop star sensor according to the specific needs of microsatellite and nano satellites. One of star sensor’s aspect is star pattern recognition algorithm. A good star pattern recognition algorithm must have a high level of matching success when there are a lot of disturbances (robust) and fast processing time. There are different types of star pattern recognition algorithms, which have their respective advantages and disadvantages, so it is necessary to characterize and compare the various algorithms. In this paper, the characterization and comparison of robustness in different types of star pattern recognition algorithm are done using digital simulation. The simulation results show that the success rate does not always rise with the number of stars used for matching because it depends on how the algorithm works. In addition, the more the number of stars are used, the longer processing time, and vice versa. The best algorithm in terms of success rate is an algorithm that uses a combination pattern of all possible triangles, in other words most robust, but has the longest processing time. This long processing time can be overcome by optimizing GSC (Guide Star Catalogue). From the results the multitriangles 2 algorithm has the best success rate compared to the other algorithms, with success rate for 5, 6, and 7 stars configuration are 97.8%, 98.7%, and 99.8% respectively.
Comparison of LISAT and Landsat imagery for estimating chlorophyll-a (case study: Jatiluhur Reservoir)
Authors: Permatasari P A , Muslimah S , Utomo B A 
Published: May 2019

Abstract
Jatiluhur Reservoir located in Purwakarta Regency, West Java is one of the largest reservoirs in Indonesia. Various studies have been done to determine the quality of water in the reservoir. The presence of locally made satellites, LISAT, can be a tool for monitoring the reservoir’s water constituent using satellite imagery. Our purpose here is to define the spectral reflectance properties on Jatiluhur Reservoir and determine the water column constituents that correlate with the observed lake color. In addition, this study also aims to compare the spatial, temporal, and spectral resolutions of LISAT imagery and Landsat imagery in the Jatiluhur Reservoir region. Based on the table of the relationship between TSI with chlorophyll a parameter, the TSI value is in the range of 80 - 90. TSI 80 value> falls into the category of hypereutrophic waters. The estimated result from Landsat and LISAT imageries still show different results. Chlorophyll-a value from image processing also show significance differences from Chlorophyll-a value derived from laboratory analysis.
Quarter orbit maneuver using magnetorquer to maintain spacecraft angular momentum
Authors: Utama S , Hakim P R , Mukhayadi M 
Published: May 2019

Abstract
LAPAN-Tubsat, angular momentum is maintained by using magnetorquer in right ascension direction and gravity gradient in declination direction. Declination correction using gravity gradient in LAPAN-Tubsat only produce 1.5 °/day corrections for 5° gravity gradient. Must be noted that gravity gradient achieved by tilting the satellite, or require off-nadir attitude, this condition is not ideal for imaging mission. This paper introduces new method for angular momentum vector correction in declination direction by using magnetorquer. In this method certain coil current in y direction is set to produce magnetic torque. From previous research certain y coil current for one orbit will effectively change angular momentum’s right ascension. In this research y coil current is only set for a quarter orbits, hence torque resultant will only affect angular momentum’s declination. LAPAN-A3 satellite, 7° declination correction can be achieved by setting y coil current 30 mA for a quarter orbits or 23.5 minutes. Furthermore, by varying y coil current direction for each quarter orbit, 28° declination correction can be achieved in one full orbit. From this research can be seen that the new method is more efficient than the gravity gradient and also have advantage where the spacecraft will always in near nadir pointing.
Channel adaptive diversity handover with multiple queueing models for LEO equatorial satellites
Authors: Pratama R , Fadilah N 
Published: May 2019

Abstract
The development of satellite communication constellation in various countries has developed rapidly over the past decade. The satellite constellation in LEO orbit is chosen because of several advantages such as low power consumption, lower delay time, simple ground station, and high spectrum efficiency. Behind all the advantages in Low Earth Orbit, the main problem in LEO constellation is the mobility. Because of that, a handover is applied in LEO Constellation. The variation of satellite handover is Hard Handover, CASD Handover, or DDBHP handover. In this paper, the CASD model is used because it only uses one orbital plane and this model suppresses blocked and dropped calls. The modification is done by varying the queue model in this scheme, and which queuing model gives the best results. The best results of the research are in the FIFO model were carried out using the dual diversity scheme are 0.94% for blocked calls, 5.86% for dropped calls, and 93.2% for successful calls, and a total delay of 2.04 second of total simulation time for 30 seconds, caused incoming calls will be served sequentially so that no calls are served randomly and have more priority than other calls.
Power produced analysis of solar arrays in nadir pointing mode for low-earth equatorial micro-satellite conceptual design
Authors: Ribah A Z , Ramayanti S 
Published: May 2019

Abstract
We analyse the power produced by solar arrays in low-earth equatorial Micro-satellite conceptual design. The micro-satellite will be designed to be operated in nadir pointing mode, 1200 km of altitude, and equatorial orbit with 0 degree of inclination. Based on the profile, the mission of the satellite is operated suitably as LEO type communication satellite. To support the mission, the satellite needs to consider how much power provided from power resource; in this case, the satellite has solar arrays to obtain the power. Furthermore, the micro-satellite also has the body mounted solar array configuration, and these arrays are installed at the Z-, X+, and X- side of the satellite. However, to estimate the power output from the arrays, there are some problems that must be concerned, the first is the nadir pointing mode that makes the satellite must be pointed to nadir, and it causes the sunlight vector do not perpendicularly come into the solar arrays surface. The second problem is the sun position (equinox and solstice) that changes periodically throughout the year. Then, both can produce losses in producing power from the solar arrays. In this paper, the differences in produced power are analysed. Then the power produced in the Z-, X+, and X- sides in the two specific sun position become estimated. After that, we determine and analyse the ratio between average produced power and the maximum power produced.
Uniqueness of embeddings of the affine line into algebraic groups
Authors: Feller Peter , van Santen Immanuel 
Published: May 2019

Let

Y
Y

be the underlying variety of a complex connected affine algebraic group. We prove that two embeddings of the affine line

C

\mathbb {C}

into

Y
Y

are the same up to an automorphism of

Y
Y

provided that

Y
Y

is not isomorphic to a product of a torus

(

C

∗

)
k

(\mathbb {C}^\ast )^k

and one of the three varieties

C

3

\mathbb {C}^3

,

SL
2

\operatorname {SL}_2

, and

PSL
2

\operatorname {PSL}_2

.
Impacts of the MHC class I-like XNC10 and innate-like T cells on tumor tolerance and rejection in the amphibian Xenopus
Authors: Banach Maureen , Edholm Eva-Stina , Gonzalez Xavier , Benraiss Abdellatif , Robert Jacques 
Published: May 2019

AbstractThe conditions that lead to antitumor or protumor functions of natural killer T (NKT) cells against mammalian tumors are only partially understood. Therefore, insights into the evolutionary conservation of NKT and their analogs—innate-like T (iT) cells—may reveal factors that contribute to tumor eradication. As such, we investigated the amphibian Xenopus laevis iT cells and interacting MHC class I-like (XNC or mhc1b.L) genes against ff-2 thymic lymphoid tumors. Upon ff-2 intraperitoneal transplantation into syngeneic tadpoles, two iT cell subsets iVα6 and iVα22, characterized by an invariant T-cell receptor α chain rearrangement (Vα6-Jα1.43 and Vα22-Jα1.32 respectively), were recruited to the peritoneum, concomitant with a decreased level of these transcripts in the spleen and thymus. To address the hypothesize that different iT cell subsets have distinct, possibly opposing, roles upon ff-2 tumor challenge, we determined whether ff-2 tumor growth could be manipulated by impairing Vα6 iT cells or by deleting their restricting element, the XNC gene, XNC10 (mhc1b10.1.L), on ff-2 tumors. Accordingly, the in vivo depletion of Vα6 iT cells using XNC10-tetramers enhanced tumor growth, indicating Vα6 iT cell-mediated antitumor activities. However, XNC10-deficient transgenic tadpoles that also lack Vα6 iT cells were resistant to ff-2 tumors, uncovering a potential new function of XNC10 besides Vα6 iT cell development. Furthermore, the CRISPR/Cas9-mediated knockout of XNC10 in ff-2 tumors broke the immune tolerance. Together, our findings demonstrate the relevance of XNC10/iT cell axis in controlling Xenopus tumor tolerance or rejection.
Towards a Semantic Framework for Lifelong Integrated Competency Management and Development
Authors: Rezgui Kalthoum , Mhiri Hédia 
Published: May 2019

Abstract
In the domain of technology-enhanced competency-based learning and training, there is an increased interest in the integration of competency-related information for supporting competency-driven decision-making purposes. Indeed, since competency development draws upon several related areas, including teaching subjects, instructional design, learning resource annotation, e-Portfolios and motivated by the need for an integrated and semantic-based approach to competency management and development, a series of ontological structures have been formalized and developed for each of these areas. This paper aims to provide a framework specification for lifelong competency management and development, called LCMDF. The main advantage of this framework lies in its ability to provide a unifying semantic foundation in the form of a set of controlled vocabularies for describing competencies and their related details within the contexts of technology-enhanced competency-based learning and training. Moreover, this framework provides a novel integrated model to support a wide range of use cases. The proposed framework results from reusing widespread international standards for competency modeling which helps designing and implementing interoperability architecture of semantically-enhanced competency-based learning/human resource (HR) systems.