Rapid Visual Survey Research Articles

Engineering surveys of Sri Lankan schools exposed to tsunami

The 2004 Indian Ocean tsunami affected 5% of Sri Lanka’s schools, severely damaging 108 and destroying 74. The catastrophe highlighted the critical role of schools in providing educational continuity during community recovery. Sri Lanka has since rehabilitated and rebuilt most of the destroyed schools along the coastline. However, there is a limited understanding of current levels of school exposure to tsunami. This hampers preparedness and risk reduction interventions that can improve community and educational tsunami resilience. This paper presents a multi-disciplinary school exposure database relevant to both vulnerability and loss modelling. The repository includes data on 38 schools and 86 classroom buildings, surveyed across the coastal districts of Ampara, Batticaloa and Galle in Sri Lanka, which were heavily affected by the 2004 tsunami. A new engineering rapid visual survey tool is presented that was used to conduct the physical assessment of schools for the exposure repository. School damage mechanisms observed in past tsunami inform the survey forms, which are designed to capture information at both school compound and building levels. The tsunami engineering survey tools are universally applicable for the visual assessment of schools exposed to tsunami. The surveys show that most Sri Lankan school buildings can be classified into three building archetypes. This means that future risk assessments can be conducted considering a small number of index buildings that are based on these archetypes with differing partition arrangements and structural health conditions. The surveys also raise three significant concerns. Firstly, most schools affected by the 2004 tsunami remain in the same exposed locations without any consideration for tsunami design or strengthening provisions. Secondly, Sri Lankan schools are fragile to tsunami loading and many of the schools in the Galle district suffer from severe corrosion, which will further affect their tsunami vulnerability. Thirdly, schools do not appear prepared for tsunami, and do not have adequate tsunami warnings nor evacuation protocols in place. These observations raise the urgent need to mitigate tsunami risk, including a holistic plan for tsunami retrofitting and for interventions to improve the tsunami preparedness of schools in Sri Lanka.

Damage Assessment of Historical Masonry Churches Subjected to Moderate Intensity Seismic Shaking

An earthquake of magnitude 4.3 MW struck Cosenza (Calabria region, South Italy) and its immediate area on 24 February 2020. Although no damage was reported to ordinary masonry buildings, the ancient masonry churches suffered widespread damage. The herein article presents an analysis of the failures suffered by monumental buildings (e.g., churches) following a moderate seismic action. The contribution is based on the in situ damage observation of 14 churches, with a dating ranging from the 12th to 20th century. The study consists of a first phase, in which the different damage modes are identified, describing their causes and effects, and a second phase that correlates the damage detected to the main parameters that influence the seismic response of the churches (geometric characteristics, boundary condition, masonry and floor organization, past interventions, etc.), regardless of the state of conservation that was discrete for all buildings before the telluric event. From the rapid visual survey, the “weight” of each seismic parameter on the type of damage detected was then established. The past “retrofitting” interventions were decisive in the response of the ancient structure, with particular regard to those that made an aggravation of seismic mass and an increase in stiffness.

Seismic risk assessment of reinforced concrete buildings in Koyna-Warna region through EDRI method

The Koyna-Warna region of Maharashtra, India, is one of the most significant worldwide examples for reservoir-induced seismicity. The area is highly vulnerable to earthquakes, and it has experienced over 1 lakh number of shocks since 1963. The largest known earthquake of magnitude 6.5 (Richter scale) occurred on 10th December 1967. Many low and moderate earthquake events have occurred over the past 50 years. A structured survey using rapid visual screening was carried out for existing RC buildings. The seismic risk index depends on three parameters, viz. hazard, exposure, and vulnerability. Many existing RC buildings in the Koyna-Warna region are designed to resist the gravity loads only without any seismic resistant provisions. Hence, there is a need to study the risk index of these RC buildings to assess future serious risks. In this study, the rapid visual survey of 120 existing RC buildings has been done through a modified EDRI method (Earthquake Disaster Risk Index) to evaluate the seismic risk index of the Koyna-Warna region (Zone-IV as per IS: 1893–2016). The results depict that the risk index of RC buildings in the Koyna-Warna region is in severe damage condition and hence there is a need to take an initiatives for earthquake preparedness plan, with emphasis on retrofitting measures, to reduce the loss of human life and damage to physical infrastructure in future seismic events.

Historical masonry churches diagnosis supported by an analytic-hierarchy-process-based decision support system

<p class="Abstract"><span lang="EN-GB">The structural and anti-seismic performances of historical masonry churches are related not only to structural damage and masonry quality but also to other criticalities that can jeopardise the connections, wooden elements, and non-structural elements. As such, the technical and scientific communities are interested in the development of fast visual-survey approaches for assessing these issues and for performing exhaustive diagnostics by considering all the parameters affecting the building performance.</span></p><p class="Abstract"><span lang="EN-GB">In this paper, a new procedure for performing rapid visual surveys and the diagnostics of masonry buildings using a set of condition ratings is proposed. The proposed novel approach includes three synergistically related techniques: i) the analytic hierarchy process method for measuring and analysing both qualitative and quantitative data during a visual survey, ii) a suitable survey form to perform a rapid visual inspection implementable in a decision support system (DSS), and iii) a DSS procedure to provide a powerful computerised tool that would be useful in large-scale data acquisition. Finally, to demonstrate the potential of the proposed approach, the Romanesque masonry church SS. Salvatore in Capurso, Italy,</span><span lang="EN-GB">is analysed. A comparison with a standard diagnostic workflow is also presented to validate the procedure and to emphasise the advantages of the novel diagnostics.</span></p><p class="Abstract"> </p>

A comparative study of different rapid visual survey methods used for seismic assessment of existing buildings

Determination of seismic safety of existing buildings is a time consuming and challenging process. Instead, rapid survey methods were developed which identify deficient structures from a large building stock in a city or town. This paper presents a comparison and critical review of existing rapid visual survey methods used for seismic assessment of existing reinforced concrete buildings. The study focuses on rapid visualsurveymethods developed for the safety assessment of reinforced concrete buildings in the Indian subcontinent and a widely used method in the United States.Comparison is carried out in various ways. Initially, a direct comparison is made based on vulnerable parameters and damage grades proposed by each method. Later, a scoring system is developed to highlight the differences and rank the selected methods. This system considers the general description, physical parameters, and damage description. Finally, as a case study, a rapid visual survey was conducted on 100 reinforced concrete buildings in each of the three cities (i.e., Pithoragarh, Gangtok, and Agartala) in India. These cities have different seismic, geological, and topographical conditions. The results show that all five methods give different outputs for the same sample surveyed buildings in each city. It was observed that there are many uncommon vulnerability parameters amongst each selected method. The results show a considerable variation in the weights assigned to each vulnerable parameter in all five methods.

A multi-hazard risk prioritisation framework for cultural heritage assets

Abstract. Multi-hazard risk assessment of building portfolios is of primary importance in natural-hazard-prone regions, particularly for the prioritisation of disaster risk reduction and resilience-enhancing strategies. In this context, cultural heritage assets require special consideration because of their high vulnerability to natural hazards – due to ageing and types of construction – and their strong links with communities from both an economic and a historical–sociocultural perspective. This paper introduces a multi-hazard risk prioritisation framework specifically developed for cultural heritage assets. The proposed framework relies on a multilevel rapid-visual-survey (RVS) form for the multi-hazard exposure data collection and risk prioritisation of case-study assets. Because of the multilevel architecture of the proposed RVS form, based on three levels of refinement and information, an increasing degree of accuracy can be achieved in the estimation of structural vulnerability and, ultimately, structural risk of the considered assets. At the lowest level of refinement, the collected data are used for the computation of seismic-risk and wind-risk prioritisation indices, specifically calibrated in this study for cultural heritage assets with various structural and non-structural features. The resulting indices are then combined into a unique multi-hazard risk prioritisation index in which the intangible value of cultural heritage assets is also considered. This is achieved by defining a score expressing the cultural significance of the asset. The analytic hierarchy process is extensively used throughout the study to reduce the subjectivity involved in the framework, thus obtaining a simplified yet robust approach which can be adapted to different building typologies. The proposed framework is applied to 25 heritage buildings in Iloilo City, Philippines, for which innovative, non-invasive techniques and tools for improved surveying have also been tested. Thermal and omnidirectional cameras have helped in the collection of structural data, together with drones for the inspection of roofs. Results of the study are presented and critically discussed, highlighting advantages and drawbacks of the use of new technologies in this field.

A multi-criteria-based procedure for the robust definition of algorithms aimed at fast seismic risk assessment of existing RC buildings

After emergency events like severe earthquakes, the structural performance targets and civil protection provisions require that existing strategic buildings must be fully operational, whereas common buildings must avoid collapse and ensure correct evacuation.The observation of post-earthquakes damages has shown that the performance of existing buildings and their functionality after an earthquake are related not only to structural damage but also to damage that occurs to nonstructural elements, systems, installations and furniture. In addition, if adequate guidelines, training and evacuation procedures are provided, the emergencies can be better faced safeguarding the users health.To this aim for a large-scale mapping of the seismic risk in existing building the performance of non-structural elements and equipment should be taken into account in new fast seismic risk evaluation procedure.In this paper, an Analytic Hierarchy Process based procedure is applied to indirect risk assessment method for reinforced concrete structures such as the Rapid Visual Surveys, to obtain a robust Risk Index. The main novelty of this approach regards the application of a Multi-Criteria Analysis in order to take into account qualitative and quantitative data, including the effectiveness of guidelines, training and evacuation procedures, involved in the index evaluation (more than 80 parameters). Moreover, a state-of-the-art sensitivity analysis is applied to overcome the robustness issue of the Risk Index by exploiting the theory of Multi-Criteria methods. Finally, in order to test the effectiveness of the method, the resulting Index is compared with the RVS method and a TOPSIS-based risk assessment through the application to 4 case studies.

Earthquake Vulnerability Assessment of High-Rise Buildings in Surabaya using RViSITS Android Application

This article presents about vulnerability assessment of high-rise building in Surabaya, the second largest city in Indonesia. In 2007, the Earthquake National Research Center -Indonesia’s Ministry of Public Works released the latest earthquake fault map. Include the discovery of Surabaya fault and Waru fault that across Surabaya. According to that new discovered fault, it is possible that there is a higher potential earthquake hazard for buildings structures in Surabaya. Therefore, the efforts to assess the vulnerability of buildings towards the earthquake need to be conducted, especially for the high-rise buildings. An android based RViSITS (Rapid Visual Survey by Institut Teknologi Sepuluh Nopember) is an application that has been developed based on FEMA 154. That application helps the vulnerability assessments of buildings can be conducted quickly and efficiently. Since, it does not require a lot of personnel, quite short research time and cheaper cost than having to use a manual form that is considered less effective for a large number of buildings. This research itself is conducted to assess the vulnerability of high-rise buildings (8-15 floors) throughout Surabaya city using the RViSITS android application. Based on the results of this study on 98 high rise buildings, it is found that 21 buildings (21.43%) are in the prone category since they had an index value < 2, while 77 buildings (78.57%) are in the safe category with an index ≥ 2. The result obtained in this research can be used as a database of local government institution for mapping the vulnerability of high rise buildings and initial input for mitigation plan toward the higher possibility of an earthquake hazard in Surabaya.

AHP-based methodology integrating modern information technologies for historical masonry churches diagnosis

Surveys conducted in the aftermath of recent earthquakes have shown that the structural and anti-seismic performances of historical masonry churches are related not only to structural damages and masonry quality but also to other key features such as effectiveness of connections, damages of wooden elements or criticalities related to humidity. Technical and scientific communities are interested in developing or improving existing procedures for the fast-visual survey and diagnostics in order to measure and analyze all the parameters affecting the building performance. In this paper a new procedure, that can be implemented in a Decision Support System (DSS) based on the Analytic Hierarchy Processes (AHP), is developed to perform a rapid visual survey and diagnostics of masonry building through a set of condition ratings. The originality of the presented work is fourfold: 1) the AHP allows to include in the analysis qualitative and quantitative data such as the quality of masonry and connections effectiveness; 2) the proposed survey and diagnostics performed by suitable condition ratings allow an extensive application in order to identify the most damaged buildings that require more detailed structural investigations; 3) the proposed AHP-based approach is integrated in a DSS to provide a powerful computerized tool, useful to large scale data acquisition; 4) the comparison with a standard diagnostics is performed to validate the procedure and emphasize the advantages of the novel diagnostics.

Resilient communities through safer schools

Access to education is a basic human right. It is the 4th of the 17 Sustainable Development Goals (SDGs) and education is strongly associated with poverty reduction. Providing facilities to educate children requires construction of school buildings and rapid expansion of curricula. However, in the rush to fulfil the right to education, are children being put at risk? What attention is being given to structural safety during the construction of new school facilities? The growing consensus among stakeholders is that public school infrastructure in developing countries worldwide is particularly susceptible to natural hazards. This highlights a compelling need for developing and implementing effective, integrated, and ‘ground-real’ strategies for assessing and radically improving the safety and resilience of schools across those countries.To this aim, the paper explores two main issues: effectiveness at scale and the relevance of multiple hazard effects on the resilience of school infrastructure. Specifically, the paper first discusses the challenges associated with the World Bank Global Program for Safer School (GPSS) and the development of its Global Library of School Infrastructure (GLOSI), highlighting the issues associated with producing a tool which can be effective at scale and support nationwide risk models for school infrastructure across the world, so that fairness and relevance of investment can be achieved. This is followed by the illustration of a number of specific tools developed by the authors to expand the risk prioritization procedures used for seismic hazard, to other hazards such as flood and windstorm and to quantify the reduction in seismic fragility obtained by implementing specific strengthening strategies. Rapid visual survey forms, a mobile app, a multi-hazard risk prioritization ranking, and numerical fragility relationships are presented and their application discussed in relation to a case study in the Philippines. The proposed tools represent a first step toward a detailed multi-hazard risk and resilience assessment framework of school infrastructure. The aim is to allow stakeholders and decision-makers to quickly identify the most vulnerable structures among the surveyed stock, to guide more detailed data collection campaigns and structural assessment procedures, such as analytical vulnerability approaches, and ultimately to plan further retrofitting/strengthening measures or, if necessary, school replacement/relocation.

From rapid visual survey to multi-hazard risk prioritisation and numerical fragility of school buildings

Abstract. Regional seismic risk assessment is paramount in earthquake-prone areas, for instance, to define and implement prioritisation schemes for earthquake risk reduction. As part of the Indonesia School Programme to Increase Resilience (INSPIRE), this paper proposes an ad hoc rapid-visual-survey form, allowing one to (1) calculate the newly proposed INSPIRE seismic risk prioritisation index, which is an empirical proxy for the relative seismic risk of reinforced concrete (RC) buildings within a given building portfolio; (2) calculate the Papathoma Tsunami Vulnerability Assessment (PTVA) index, in any of its variations; (3) define one or more archetype buildings representative of the analysed portfolio; (4) derive detailed numerical models of the archetype buildings, provided that the simulated design is used to cross-check the model assumptions. The proposed INSPIRE index combines a baseline score, calibrated based on fragility curves, and a performance modifier, calibrated through the analytic hierarchy process (AHP) to minimise subjectivity. An attempt to define a multi-hazard prioritisation scheme is proposed, combining the INSPIRE and PTVA indices. Such a multi-level framework is implemented for 85 RC school buildings in Banda Aceh, Indonesia, the most affected city by the 2004 Indian Ocean earthquake–tsunami sequence. As part of the proposed framework, two archetype buildings representative of the entire portfolio are defined based on the collected data. Their seismic performance is analysed by means of non-linear static analyses, using both the analytical simple lateral mechanism analysis (SLaMA) method and numerical finite-element pushover analyses to investigate the expected plastic mechanisms and derive displacement/drift thresholds to define appropriate damage states. Finally, non-linear dynamic analyses are performed to derive fragility curves for the archetype buildings. This paper demonstrates the effectiveness of the INSPIRE data collection form and proposed index in providing a rational method to derive seismic risk prioritisation schemes and in allowing the definition of archetype buildings for more detailed evaluations/analyses.

Seismic vulnerability assessment of earthquake-prone mega-city Shillong, India using geophysical mapping and remote sensing

ABSTRACTThe concept of seismic vulnerability is a yard-stick of damage estimation from a probable earthquake considering physical cum social dimension and enables a basis for decision-makers to develop preparedness and mitigation strategies. We aim at vulnerability assessment of the typical urban system of capital city Shillong situated on hilly terrain. High-resolution satellite imagery of Shillong facilitates analysis of building footprints, communication network, and open ground. Different building typologies are identified taking into account the building’s structural configuration assessed through a rapid visual survey of more than 15% of total residential households. Slope map demarcates the landslide-prone area through discrete elevation modelling. A methodology incorporating several parameters e.g. building typology, slope angle, shear wave velocity characteristics, geomorphology, and the number of occupants in correlation with a physical measurement of vulnerability is presented and is applied to estimate the dimension of vulnerability. Additionally, MASW survey indicates lithology up to 30 m deep along with the existence of stiff soil and rocks at different depths whereas resonant frequency is identified to be in the range of 6–8 Hz through H/V ratio. Integrating all, it is observed that more than 60% of Shillong city falls under moderate to higher vulnerability and the rest is less vulnerable.

Different damage observed in the villages of Pescara del Tronto and Vezzano after the M6.0 August 24, 2016 central Italy earthquake and site effects analysis

&lt;p&gt;The authors have surveyed many damaged villages located at the epicentre of the ML=6.0 earthquake which occurred on August 24, 2016 in central Italy. Some unexpected anomalies were discovered such as very different levels of damage in Vezzano and Pescara del Tronto villages (Arquata del Tronto Municipality, Ascoli Piceno province). The two villages are situated just 1300 meters from each other. Pescara del Tronto suffered very heavy damage with many masonry building collapses and 48 fatalities, while Vezzano suffered only light damage to few buildings. This paper provides a preliminar analysis from an engineering and geophysics perspective. Particularly, rapid visual surveys were carried out in the two villages in order to detect possible significant differences in the vulnerability of their building stocks and site geophysical investigations were performed to detect possible local amplification effects.&lt;/p&gt;

Emerging coral diseases in Kāne'ohe Bay, O'ahu, Hawai'i (USA): two major disease outbreaks of acute Montipora white syndrome.

In March 2010 and January 2012, we documented 2 widespread and severe coral disease outbreaks on reefs throughout Kāne'ohe Bay, Hawai'i (USA). The disease, acute Montipora white syndrome (aMWS), manifested as acute and progressive tissue loss on the common reef coral M. capitata. Rapid visual surveys in 2010 revealed 338 aMWS-affected M. capitata colonies with a disease abundance of (mean ± SE) 0.02 ± 0.01 affected colonies per m of reef surveyed. In 2012, disease abundance was significantly higher (1232 aMWS-affected colonies) with 0.06 ± 0.02 affected colonies m(-1). Prior surveys found few acute tissue loss lesions in M. capitata in Ka¯ne'ohe Bay; thus, the high number of infected colonies found during these outbreaks would classify this as an emerging disease. Disease abundance was highest in the semi-enclosed region of south Kāne'ohe Bay, which has a history of nutrient and sediment impacts from terrestrial runoff and stream discharge. In 2010, tagged colonies showed an average tissue loss of 24% after 1 mo, and 92% of the colonies continued to lose tissue in the subsequent month but at a slower rate (chronic tissue loss). The host-specific nature of this disease (affecting only M. capitata) and the apparent spread of lesions between M. capitata colonies in the field suggest a potential transmissible agent. The synchronous appearance of affected colonies on multiple reefs across Kāne'ohe Bay suggests a common underlying factor. Both outbreaks occurred during the colder, rainy winter months, and thus it is likely that some parameter(s) associated with winter environmental conditions are linked to the emergence of disease outbreaks on these reefs.

First record of vase tunicate, Ciona intestinalis (Linnaeus, 1767) in coastal Newfoundland waters

Vase tunicate, Ciona intestinalis (Linnaeus, 1767) Type B (sensu Sato et al. 2012), was first recorded in Newfoundland (Canada) in Burin, Placentia Bay, by SCUBA divers conducting rapid visual surveys for invasive species on 19 September 2012. Follow-up surveys of Burin and adjacent communities were conducted in October and November 2012. Ciona intestinalis was present in relatively low abundance in Burin, but a well-established population was located in Little Bay, approximately 15 km north of Burin. Little Bay is located within Mortier Bay, an area of high vessel traffic and the possible introduction source of C. intestinalis. Further surveys are recommended to delineate the present distribution and monitor future dispersal of C. intestinalis in coastal Newfoundland waters. Due to the demonstrated high ecological and economic impacts of this species in other previously invaded regions, options for mitigating population growth and dispersal should be examined to minimize effects of this non-indigenous species.

Spatial and temporal pattern in seagrass community composition and productivity in south Florida

We document the distribution and abundance of seagrasses, as well as the intra-annual temporal patterns in the abundance of seagrasses and the productivity of the nearshore dominant seagrass (Thalassia testudinum) in the south Florida region. At least one species of seagrass was present at 80.8% of 874 randomly chosen mapping sites, delimiting 12,800 km2 of seagrass beds in the 17,000-km2 survey area. Halophila decipiens had the greatest range in the study area; it was found to occur over 7,500 km2. The range of T. testudinum was almost as extensive (6,400 km2), followed by Syringodium filiforme (4,400 km2), Halodule wrightii (3,000 km2) and Halophila engelmanni (50 km2 ). The seasonal maxima of standing crop was about 32% higher than the yearly mean. The productivity of T. testudinum was both temporally and spatially variable. Yearly mean areal productivity averaged 0.70 g m−2day−1, with a range of 0.05–3.29 g m−2 day−1. Specific productivity ranged between 3.2 and 34.2 mg g−1 day−1, with a mean of 18.3 mg g−1 day−1. Annual peaks in specific productivity occurred in August, and minima in February. Integrating the standing crop for the study area gives an estimate of 1.4 × 1011 g T. testudinum and 3.6 × 1010 g S. filiforme, which translate to a yearly production of 9.4 × 1011 g T. testudinum leaves and 2.4 × 1011 g S. filiforme leaves. We assessed the efficacy of rapid visual surveys for estimating abundance of seagrasses in south Florida by comparing these results to measures of leaf biomass for T. testudinum and S. filiforme. Our rapid visual surveys proved useful for quantifying seagrass abundance, and the data presented in this paper serve as a benchmark against which future change in the system can be quantified.

The UA5 Streamer Chamber Experiment at the SPS pp̄ Collider

A multiparticle detector based on two large (6 m long) streamer chambers triggered by surrounding scintillation hodoscopes and viewed by cameras via image intensifiers is being assembled at CERN and tested at the ISR. Its purpose is to perform a first rapid visual survey of the new energy region afforded by the SPS pp̄ collider. Charged tracks can be observed down to 3/4°, and hence over most of the pseudorapidity range (|η| ≲ 5.0) covered by high multiplicity events. Lead glass plates are being placed within each chamber to convert gammas produced within the same η range. The apparatus is hence particularly appropriate for the detection with high efficiency of the so-called Centauro events, thought to be characterized by very large multiplicities (⟨nch⟩ ∼ 100) and by very few accompanying neutral particles.

Densitometry of miniature thin-layer chromatograms : Approximate results based on flying spot scanning with a newly developed apparatus

An alternative circuit for the output from the author's flying spot scanner has been developed so that transmission in the two dimensions may be presented continuously as a negative logarithm on a flat-bed recorder. Thus, a rapid visual survey of all the detectable information present in as many as six chromatograms on one 75 × 75 mm plate can now be made. The proportion of each resolved zone can be estimated approximately from manual calculations based on the sum of peak heights. In a binary mixture scanned at 330 nm the coefficient of variation found was about 4%. The chromatography, recording and manual calculation of, for example, twelve impurities in terms of two standards occupy about 2 h. When scanning at wavelengths below 280 nm, a reduction in layer thickness to 0.14 mm is made to reduce the increase in light absorption of silica gel G. In the examples shown, −log T recordings in the UV are more sensitive than visual or visualisation methods for testing the resolution of mixtures. The effect of tailing of standards in the estimation of impurities in a manufactured intermediate product is also discussed.

The F rth Microphotometer and its Application in Physics

The Furth microphotometer, by the application of electronic principles, depicts instantly on the fluorescent screen of a cathode-ray oscillograph the densigram record. It provides for a rapid visual survey of the whole photographic plate under examination and of any particular part of the plate in fine detail. Magnifications along the line of traverse (or scan) of the order of 1000 or more may be obtained which are much greater than those for existing types and no elaborate gearing mechanism is necessary. The use of photocells or electron multipliers whose maximum photoelectric sensitivity lies within the visible part of the spectrum, permits the use of ordinary incandescent filament projector lamps, and at the same time enables an optical system to be built up from readily obtainable lens systems. The instantaneous operation obviates the necessity for incorporating compensating photoelectric elements and for stringent constancy of the analysing light source. The resolving power is adequate for the majority of practical applications.