Characterizing and Diagnosing Architectural Degeneration of Software Systems from Defect Perspective

The architecture of a software system is known to degrade as the system evolves over time due to change upon change, a phenomenon that is termed architectural degeneration. Previous research has focused largely on structural deviations of an architecture from its baseline. However, another angle to observe architectural degeneration is software defects, especially those that are architecturally related. Such an angle has not been scientifically explored until now. Here, we ask two relevant questions: (1) What do defects indicate about architectural degeneration? and (2) How can architectural degeneration be diagnosed from the defect perspective? To answer question (1), we conducted an exploratory case study analyzing defect data over six releases of a large legacy system (of size approximately 20 million source lines of code and age over 20 years). The relevant defects here are those that span multiple components in the system (called multiple-component defects - MCDs). This case study found that MCDs require more changes to fix and are more persistent across development phases and releases than other types of defects. To answer question (2), we developed an approach (called Diagnosing Architectural Degeneration - DAD) from the defect perspective, and validated it in another, confirmatory, case study involving three releases of a commercial system (of size over 1.5 million source lines of code and age over 13 years). This case study found that components of the system tend to persistently have an impact on architectural degeneration over releases. Especially, such impact of a few components is substantially greater than that of other components. These results are new and they add to the current knowledge on architectural degeneration. The key conclusions from these results are: (i) analysis of MCDs is a viable approach to characterizing architectural degeneration; and (ii) a method such as DAD can be developed for diagnosing architectural degeneration

Integration or Predictability? A Further Specification of the Functional Role of Gamma Oscillations in Language Comprehension

Gamma-band neuronal synchronization during sentence-level language comprehension has previously been linked with semantic unification. Here, we attempt to further narrow down the functional significance of gamma during language comprehension, by distinguishing between two aspects of semantic unification: successful integration of word meaning into the sentence context, and prediction of upcoming words. We computed event-related potentials (ERPs) and frequency band-specific electroencephalographic (EEG) power changes while participants read sentences that contained a critical word (CW) that was (1) both semantically congruent and predictable (high cloze, HC), (2) semantically congruent but unpredictable (low cloze, LC), or (3) semantically incongruent (and therefore also unpredictable; semantic violation, SV). The ERP analysis showed the expected parametric N400 modulation (HC < LC < SV). The time-frequency analysis showed qualitatively different results. In the gamma-frequency range, we observed a power increase in response to the CW in the HC condition, but not in the LC and the SV conditions. Additionally, in the theta frequency range we observed a power increase in the SV condition only. Our data provide evidence that gamma power increases are related to the predictability of an upcoming word based on the preceding sentence context, rather than to the integration of the incoming word’s semantics into the preceding context. Further, our theta band data are compatible with the notion that theta band synchronization in sentence comprehension might be related to the detection of an error in the language input

A computational model for path loss in wireless sensor networks in orchard environments.

A computational model for radio wave propagation through tree orchards is presented. Trees are modeled as collections of branches, geometrically approximated by cylinders, whose dimensions are determined on the basis of measurements in a cherry orchard. Tree canopies are modeled as dielectric spheres of appropriate size. A single row of trees was modeled by creating copies of a representative tree model positioned on top of a rectangular, lossy dielectric slab that simulated the ground. The complete scattering model, including soil and trees, enhanced by periodicity conditions corresponding to the array, was characterized via a commercial computational software tool for simulating the wave propagation by means of the Finite Element Method. The attenuation of the simulated signal was compared to measurements taken in the cherry orchard, using two ZigBee receiver-transmitter modules. Near the top of the tree canopies (at 3 m), the predicted attenuation was close to the measured one-just slightly underestimated. However, at 1.5 m the solver underestimated the measured attenuation significantly, especially when leaves were present and, as distances grew longer. This suggests that the effects of scattering from neighboring tree rows need to be incorporated into the model. However, complex geometries result in ill conditioned linear systems that affect the solver's convergence

Effect of water content on backscattering parameters

Water content is one of the parameters that used to determine fruit quality. In this study, the effect of water content on the changes of backscattering parameters was investigated. The experiment was conducted on 240 bananas which vary from ripening stages 2 to 4. About half of the samples were stored at 6°C to induce chilling injury symptoms while the other were stored at 13°C and used as a control samples. The water content values were measured destructively on each sample based on the wet basis method. The results were compared with backscattering data that acquired using backscattering imaging. Results indicated there were significant differences (P<0.05) on the water content values and backscattering parameters as ripening stages increased. Results also revealed there were significant differences on the collected data as chilling injury developed. Hence, backscattering imaging is potentially useful for determining water content values and textural properties of fresh produce

Evaluation on the Efficiency of Crop Insurance in China's Major Grain-Producing Area

AbstractIn China, crop insurance is just a pilot program characterized by material cost-based coverage level and government-subsidized premium. To identify the efficiency of the crop insurance, we use the nonparametric density function model and estimate the probability of yield loss rate at 3 proposed levels for grain crop, wheat, corn, rice and cotton respectively from 13 provinces in the Major Grain-Producing Area. Besides, we point out some unfavorable factors for crop insurance management based on the Second National Agricultural Census data (2006). Our finding is: the coverage level is on average no larger than 50% of the per hectare crop production value while the probability of yield loss for each crop approaches to zero if the proposed yield loss rate is larger than 40%, so the yield damage compensations are not necessary unless the huge catastrophes occur with the yield loss rate over 50%. Farmers could buy crop insurance to avoid big crop failure other than to maximize their returns. Therefore, the current crop insurance coverage level under normal years could not create an effective inducement for farmers to purchase insurance contracts. To expand crop insurance participation, we consider that it is necessary to carry out positive and conditional forced insurance, provide a larger portion of premium subsidy to the Major Grain-Producing Area by central government and improve the basic agricultural production conditions

Spectral shift as advanced index for fruit chlorophyll breakdown

The decline of fruit chlorophyll is a valuable indicator of fruit ripeness. Fruit chlorophyll content can be nondestructively estimated by UV/VIS spectroscopy at fixed wavelengths. However, this approach cannot explain the complex changes in chlorophyll catabolism during fruit ripening. We introduce the apparent peak position of the red band chlorophyll absorption as a new qualitative spectral indicator. Climacteric fruit (apple: n = 24, mango: n = 38, tomato: n = 48) were analysed at different ripeness stages. The peak position and corresponding intensity values were determined between 650 and 690 nm of nondestructively measured fruit spectra as well as of corresponding spectra of fruit extracts. In the extracts, individual contents of chlorophyll a, chlorophyll b, pheophytin a and carotenoids were analysed photometrically, using an established iterative multiple linear regression approach. Nondestructively measured peak positions shifted unimodal in all three fruit species with significant shifts between fruit ripeness classes of maximal 2.00 ± 0.27 nm (mean ± standard error) in tomato and 0.57 ± 0.11 nm in apple. Peak positions in extract spectra were related to varying pigment ratios (Rmax = −0.91), considering individual pigments in the pool. The peak intensities in both spectral readings, nondestructive and fruit extracts, were correlated with absolute chlorophyll contents with Rmax = −0.84 and Rmax = 1.00, respectively. The introduced spectral marker of the apparent peak position of chlorophyll absorbance bears the potential for an advanced information gain from nondestructive spectra for the determination of fruit ripeness

Seasonal changes in dendrometer-derived stem variation in apple trees grown in temperate climate

Studies of daily changes in tree trunk diameter provide valuable information concerning growth patterns and their relationships with varying environmental conditions. To date, very few experiments with fruit trees evaluated the effects of climate variation on trunk shrinkage and the duration of the contraction and recovery phases and of growth. In this study, electronic dendrometers continuously monitored trunk diameter and trunk water storage dynamics of drip-irrigated ‘Gala’ apple trees (Malus x domestica Borkh.) during three growing seasons, which differed significantly in temperature, precipitation, air humidity and solar irradiation. It was found that trunk diameter and meteorological variables were closely related, even when excluding the effects of soil water limitations. During each growing season, the durations of the daily contraction phase began to increase with increasing water vapour partial pressure deficit, and decreased again in autumn, when vapour partial pressure decreased. Throughout the season, the duration of the growth phase tended to change inversely to that of both contraction and recovery phase. The relationship between maximum trunk shrinkage and vapour partial pressure was higher post than pre harvest for all years studied. The duration of contraction, recovery, and growth phases may provide valuable information concerning seasonal changes and environmental drivers of water storage dynamics in apple trees

Tree Water Status in Apple Orchards Measured by Means of Land Surface Temperature and Vegetation Index (LST–NDVI) Trapezoidal Space Derived from Landsat 8 Satellite Images

In this study, the split window (SW) method was applied for land surface temperature (LST) retrieval using Landsat 8 in two apple orchards (Glindow, Altlandsberg). Four images were acquired during high demand of irrigation water from July to August 2018. After pre-processing images, the normalized difference vegetation index (NDVI) and LST were calculated by red, NIR, and thermal bands. The results were validated by interpolated infrared thermometer (IRT) measurements using the inverse distance weighting (IDW) method. In the next step, the temperature vegetation index (TVDI) was calculated based on the trapezoidal NDVI/LST space to determine the water status of apple trees in the case studies. Results show good agreement between interpolated LST using IRT measurements and remotely sensed LST calculation using SW in all satellite overpasses, where the absolute mean error was between 0.08 to 4.00 K and root mean square error (RMSE) values ranged between 0.71 and 4.23 K. The TVDI spatial distribution indicated that the trees suffered from water stress on 7 and 23 July and 8 August 2018 in Glindow apple orchard with the mean value of 0.69, 0.57, and 0.73, whereas in the Altlandsberg orchard on 17 August, the irrigation system compensated the water deficit as indicated by the TVDI value of 0.34. Moreover, a negative correlation between TVDI and vegetation water content (VWC) with correlation coefficient (r) of −0.81 was observed. The corresponding r for LST and VWC was equal to −0.89, which shows the inverse relation between water status and temperature-based indices. The results indicate that the LST and/or TVDI calculation using the proposed methods can be effectively applied for monitoring tree water status and support irrigation management in orchards using Landsat 8 satellite images without requiring ground measurements

Preface to the FRUTIC- 2019 Symposium

Fresh fruit and vegetables are the major source of essential vitamins and minerals, which are needed for human health and well-being. They are, however, perishable living products that request continuous measures for quality keeping by growers, storage operators, processors, and retailers. Sampling of fresh produce for assessing appearance, texture, flavour, and nutritional value have been established quality criteria, whereas non-invasive measurements on each individual product pre- and postharvest with traceability along the supply chain are becoming important for all role players. The FRUTIC-2019 provided a platform for researchers and practitioners to engage in technical discussions about innovations and new technologies, and explore further areas of research needed in the industry to promote quality and safety of fruit and vegetables. The first symposium of the FRUTIC series took place in Israel 1983, followed by USA, Spain, Japan, France, Germany, Italy and Chile. In 2017 and 2018 FRUTIC was organized in cooperation with FRUIT LOGISTICA in Berlin, Germany, in September 2019 FRUTIC was held in Hong Kong in cooperation with ASIA FRUIT LOGISTICA. Scientists presented their topics at the site of the ASIA FRUIT LOGISTICA trade fair at the AsiaWorld-EXPO of Hong Kong, in industry-oriented sections. Some of the selected talks are now published as full articles in this Special Issue. The FRUTIC-2019 event provided a concerted action that brought together academic scientists and the role players from fresh produce industry, to interact with each other for the purpose of information dissemination, sharing practical experience and developing road maps for the most effective way to reach the common goals. We would like to thank all participants for their contributions to the symposium program and for their contributions to this special issue. We also express our sincere thanks to the Journal of Applied Botany and Food Quality team for publishing this special issue on time