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The effect of ionospheric delay on the ground-based augmentation system under normal conditions can be mitigated by determining the value of the nominal ionospheric gradient (σvig). The nominal ionospheric gradient is generally obtained from Continuously Operating Reference Stations data by using the spatial single-difference method (mixed-pair, station-pair, or satellite-pair) or the temporal single-difference method (time-step). The time-step method uses only a single receiver, but it still contains ionospheric temporal variations. We introduce a corrected time-step method using a fixed-ionospheric pierce point from the geostationary equatorial orbit satellite and test it through simulations based on the global ionospheric model. We also investigate the effect of satellite paths on the corrected time-step method in the region of the equator, which tends to be in a more north–south direction and to have less coverage for the east–west ionospheric gradient. This study also addresses the limitations of temporal variation correction coverage and recommends using only the correction from self-observations. All processes are developed under simulations because observational data are still difficult to obtain. Our findings demonstrate that the corrected time-step method yields σvig values consistent with other approaches.

The Multi-Carrier Modulation (MCM) technique in the Near Vertical Incidence Skywave (NVIS) propagation mode poses a challenge due to the ionosphere’s dynamic behavior. The selection of the main bandwidth and transmission frequency in the MCM-NVIS system should consider the different ionospheric refraction indexes within each available frequency of the ionosphere channel. This ensures that all transmitted sub-carriers arrive at the receiver at an acceptable time. It is important to note that not all transmission frequencies may reach the receiver, and the propagation time of each received frequency may differ significantly. Using sub-carrier frequencies with varying propagation times in the MCM technique may negatively impact the system’s performance. Therefore, information on the NVIS propagation mode frequency window with homogeneous Time of Flight (ToF) values is crucial for successfully implementing the MCM technique. In this paper, we explore the frequency window with homogeneous ToF values for NVIS propagation based on ionograms. The width of the frequency window and its center frequency variation can be used to determine the main bandwidth and transmission frequency of the MCM-NVIS system. Our numeric simulation with the inputs of the widest frequency window based on the ionograms at Kupang in 2022 shows that the maximum value of ergodic capacity is up to $10^{6}$ bps at 20 dB SNR during the daytime.

Vehicles involved in platoon formation may experience difficulties in obtaining full-state information that can be exchanged and used for controller synthesis. Therefore, a distributed controller based on a model reference and designed utilizing a cooperative observer is proposed for vehicle platoon synchronization. The proposed controller is composed of three main blocks, namely, the reference model, the cooperative observer and the main controller. The reference model is developed by using a homogeneous vehicle platoon that utilizes cooperative full-state information. The cooperative observer is a state estimator which is constructed based on the cooperative output estimation error. It provides state estimates to be used by the main controller. The main controller is constructed from a nominal control and a synchronization input. The nominal control has the main task of tracking the lead vehicle, while in order to reduce the synchronization error, the synchronization input is added by utilizing the cooperative disagreement error. Stability analysis is focused on the vehicle platoon when it is subjected to completely periodical intermittent information. The condition on the information rate is derived for guaranteeing the synchronization of the platoon. Numerical simulation of a vehicle platoon consisting of one leader and five followers is used to examine the performance of the controller.

Abstract The occurrence of equatorial spread F (ESF) has the potential to detrimentally impact space-based technological systems. This study investigates the utility of ionosondes in forecasting the incidence of post-sunset ESF in the zonal direction, utilizing observational data obtained from four ionosondes located near the magnetic Equator in Southeast Asia. Data were collected during the equinox seasons (March–April and September–October) between 2003 and 2020. To establish a relationship between the probability of post-sunset ESF occurrence and the evening vertical plasma drift (v), a logistic regression model was employed. Post-sunset ESF occurrence is defined as the presence of ESF during the time window between 19:00 and 21:00 LT, while v is derived from the average time derivative of virtual heights during the interval from 18:30 to 19:00 LT. Results indicate that the probability of post-sunset ESF occurrence approaches zero, signifying that ESF is unlikely to develop when v is negative. Conversely, when v exceeds 30 m/s, the probability of post-sunset ESF occurrence surpasses 0.87, indicating that ESF occurs almost invariably. The likelihood of post-sunset ESF occurrence reaches 1 when v equals or exceeds 40 m/s. Utilizing this model, the study determined that a single ionosonde positioned at the Equator can effectively forecast the incidence of post-sunset ESF up to a longitudinal distance of 30° from its location. The accuracy of ionosondes in predicting post-sunset ESF occurrence above their respective locations is approximately 0.80, with a 10% decrease in accuracy when forecasting ESF occurrence at longitudinal distances of 30°. In conclusion, this study enhances our understanding of the link between the evening vertical plasma drift and the manifestation of post-sunset ESF by leveraging ionosonde data. Furthermore, it provides valuable insights into the recommended coverage range of ionosondes for predicting post-sunset ESF occurrence in the zonal direction, which can be employed to fortify regional space weather services. Graphical Abstract

Arlina Nurhapsari,1,2 Risya Cilmiaty,3 Adi Prayitno,3 Bambang Purwanto,4 Soetrisno Soetrisno5 1Doctoral Degree of Medical Science, Faculty of Medicine, Sebelas Maret University, Surakarta, Central Java, Indonesia; 2Department of Conservative Dentistry, Faculty of Dentistry, Islam Sultan Agung University, Semarang, Central Java, Indonesia; 3Department of Oral Disease, Faculty of Medicine, Sebelas Maret University, Surakarta, Central Java, Indonesia; 4Department of Internal Medicine, Faculty of Medicine, Sebelas Maret University, Surakarta, Central Java, Indonesia; 5Department of Obstetrics and Gynaecology, Faculty of Medicine, Sebelas Maret University, Surakarta, Central Java, IndonesiaCorrespondence: Arlina Nurhapsari, Department of Conservative Dentistry, Faculty of Dentistry, Islam Sultan Agung University, Semarang, Jawa Tengah, 50112, Indonesia, Email arlina@unissula.ac.idPurpose: Acute dental pulp inflammation necessitates early treatment to alleviate inflammation and pain. In the inflammatory phase, a substance is required to lower the inflammatory mediators and reactive oxygen species that play a crucial role in that phase. Asiatic acid is a natural triterpene obtained from the Centella asiatica plant with a high antioxidant value. This study examined the effect of Asiatic acid’s antioxidant, anti-inflammatory, and antinociceptive properties on dental pulp inflammation.Methods: The research is an experimental laboratory, with a post-test only with a control group design. The study utilised 40 male Wistar rats weighing 200– 250 grams and aged 8– 10 weeks. Rats were divided into five groups (control, eugenol, Asiatic Acid 0.5%; 1%; 2% group). Dental pulp inflammation was created in the maxillary incisor after six hours of administration of lipopolysaccharides (LPS). The dental pulp treatment then continued with the administration of eugenol and three different Asiatic acid concentrations (0.5%, 1% and 2%). In the next 72 hours, the teeth were biopsied, and the dental pulp was analysed using the enzyme-linked immunosorbent assay (ELISA) to measure the level of MDA, SOD, TNF-α, beta-endorphins and CGRP. Histopathological examination and the Rat Grimace Scale were utilised to determine the level of inflammation and pain, respectively.Results: The effect of Asiatic Acid on MDA, TNF-α, and CGRP levels decreased significantly compared to the control group (p=< 0.001). On the SOD and beta-endorphin levels, Asiatic acid treatment resulted in a considerable rise (p =< 0.001).Conclusion: Due to its antioxidant, anti-inflammatory, and antinociceptive characteristics, Asiatic acid can reduce inflammation and pain in acute pulp inflammation due to its ability to decrease MDA, TNFα, and CGRP levels while raising SOD and beta-endorphin levels.Keywords: pulp inflammation, Asiatic acid, MDA, TNF-α, SOD, beta endorphins, CGRP

Abstract Ground-Based Augmentation System (GBAS) is a GNSS augmentation system that meets International Civil Aviation Organization (ICAO) requirements to support precision approach and landing. GBAS is based on local differential GNSS technique with reference stations located around an airport to provide necessary integrity and accuracy. The performance of the GBAS system can be affected by gradient in the ionospheric delay between aircraft and reference stations. A nominal ionospheric gradient, which is bounded by a conservative error bound, is represented by a parameter σ vig. The parameter σ vig is commonly determined using station pair to GNSS Continuous Operating Reference Station (CORS) data. The station-pair method is susceptible to doubling of the estimation error of receiver inter-frequency bias (IFB) and is not suitable with the CORS conditions in Indonesia. We propose a satellite-pair method that is found to be more suitable for the CORS network over Indonesia which is centered in Java and Sumatra islands. An overall value of σ vig (5.21 mm/km) was obtained using this method along with preliminary results of a comparison of σ vig from Java and Sumatra islands. Graphical Abstract

Observation of wireless channel using channel sounder method is needed in order to obtain the channel characteristics in the form of delay spread (Tm) and doppler spread (fD) parameters for optimizing the design of digital communication systems. This also applies to the ionosphere channels which are known to have dynamic properties in the time and place domains. The Sliding Correlator Channel Sounder technique known as a popular technique due to the advantage in the low level of complexity and relatively low cost. Similar to the advantages of the sliding correlator technique, Software Define Radio (SDR) device is one of the popular inexpensive platforms for implementing the communication system into the real world. The implementation of the sliding correlator channel sounder technique in the SDR platform will increase the advantages of the ionosphere channel measurement system that needed as an effort to obtain the dynamic of ionospheric channel characteristic information. However, the process of implementing a sliding correlator channel sounder system into the SDR device requires precise calculations to guarantee the designed system able to works according to the specifications of the SDR device and also meet the system performance targets. This paper discusses the design of a sliding correlator channel sounder system for observing the characteristics of ionosphere channels using SDR devices. The system design starts with the process of calculating the clock frequency generator bit (fchirp) based on the system performance target which refers to the recommendation of the ionospheric channel characteristics based on ITU-R F.1487 documents. Parallel with the calculation of the fchirp, the calculation of the Pseudo Noise (PN) bit length (L) based on the Dynamic Range (DR) value that meets with the specifications of the SDR hardware also carried out. Based on the obtained fchirp and L values, the calculation of other sliding correlator channel sounder parameters is performed with a limitation of a hardware specification and the target system performance. MATLAB simulation results show that the expected system performance can be met. This systems can also be realized significantly through the results of real signal transmission experiments conducted in a closed room laboratory

An animation-based drawing learning model involves simple animation from the beginning to the end of the drawing, with the teacher acting as a facilitator and guide. The research is based on the fact that there are still many children who have difficulty expressing themselves through their drawings due to low imagination. The goal of this study is to develop a practical drawing learning model based on animation for children. 153 children aged 5-6 years participated in this study. An observation sheet was used to collect data on the shape and color of objects in children's drawings. Both qualitative and quantitative data analysis was utilized. The results revealed that limited trial, large scale trials, and wide-scale trials have a positive effect on children. The impact has been observed to exhibit a rising pattern. The results showed that the animation-based drawing learning model can be implemented in children 5-6 years old to stimulate drawing artworks.

Development of scientific explanation abilities in students is an important aspect in science education. However, traditional learning methods such as textbooks and PowerPoint presentations are often less effective in improving skills due to lack of student interactivity and involvement in the learning process. This study aimed to analyze the effectiveness of using augmented reality media based on problem-solving frameworks to empower scientific explanation. The research design was used a Nonrandomized Control Group, Pretest-Posttest Design. The study used a quasi-experimental method with a factorial design of 2 x 2. The research sample was 72 students, one of senior high school in Indonesia. The sample was divided into two groups: the control group using two-dimensional learning media based on books, PowerPoints, and videos. The treatment group used augmented reality learning media based on problem-solving frameworks. The material used in the study is the human circulation system in biology subjects. The instrument used to obtain scientific explanation data is an essay test developed from scientific explanation indicators adapted from McKneill et al. Data analysis using ANCOVA (p=0.05%) with pre-test values as covariates. The results showed that augmented reality media based on problem-solving frameworks could empower and more significantly improve the ability of scientific explanation, this is evidenced by the average value of scientific explanation skills in the experimental class is higher than the control class.

The Sustainable Development Goals (SDGs) are global action plans that aim to address various problems globally in the social, economic, cultural, energy, and environmental fields. One of the global problems is the significant open unemployment rate due to the gap between graduates and available jobs. Therefore, we need an innovation in learning to train students to develop their competencies. Competency development can be done through chemoentrepreneurship-based chemistry learning (CEP). CEP-based learning is chemistry learning through projects in product manufacturing and marketing. This study aims to measure students' social and vocational skills through CEP learning. This research was conducted at Islamic Senior High School in Rembang, Indonesia. The research subjects were 47 students. The results of the N-gain test showed that the social skills of the experimental and control groups experienced an increase in the low/effective less category. The N-gain value of the experimental group's social skills was 50.06, while the control group was 41.32. The results of the N-gain test for vocational skills in the experimental group were better than those in the control group. The increase in the vocational skills of the experimental group was in the medium/quite effective category (58.32), while the control group experienced a very low/ineffective increase in the category (33.47). [Note: The issue number (1) shown on the PDF is incorrect. The correct issue number is 2.]

The eruption of Mount Anak Krakatau occurred on December 22, 2018, in the Sunda Straits, Indonesia, causing a tsunami that affected the coastal area of Banten Province. We use COMCOT 1.7 to make a tsunami model based on flank collapse caused by a landslide tsunami. The aim of study is to remodel past events to anticipate the mechanism and impact of the damage in the future. Bathymetry and topography are integrated to become high resolution data with a grid area of 49.8 meterss. The flank collapse scenario is applied with slide dimensions of 2000 meters long, 1500 meters wide, and 228 meters thick following previous study. The tsunami model consists of the initial tide model and the coastal model. The highest tsunami run-up of the tide model is in Carita of 1.9 meters height. The fastest arrival time of the tide model is in Sumur of 19 minutes. which is slightly different from previous studies due to different modeling applications and different initial tide locations. The highest tsunami run-up of the coastal model is in Lesung and Sumur of 2.5 meters height which almost matches the results of field observations.

Mataram City, West Lombok and Central Lombok Regencies are areas that have a high level of infrastructure development. This high level of infrastructure development has indirectly increased the risk of lightning strikes in the city of Mataram and its surroundings. This study aims to determine the level of threat, susceptibility, and vulnerability to lightning strikes in the city of Mataram and its surroundings, and to find a correlation between the increase in land use as buildings and settlements with the increase in the number of lightning strikes. The lightning data was obtained from the monitoring results of the Mataram Geophysics Station in the 2017-2021 period which was processed using the Simple Additive Weighting method. From the processing results, the level of vulnerability to lightning in the very high category is in Selaparang and Mataram sub-districts. The results of the Pearson correlation calculation in an increase in the number of areas used as buildings and settlements to an increase in the number of lightning, obtained 14 districts with high Pearson correlation index values and 3 districts with very high Pearson correlation index values which included Batukliang, Sekotong, and Jonggat Districts.

The Horizontal to Vertical Spectral Ratio (HVSR) is a seismic analysis method used to obtain information about subsurface geological characteristics. This method is based on the spectral ratio analysis between the horizontal and vertical components of earthquakes or other vibration sources. HVSR has proven to be an effective tool in evaluating rock layers, layer thickness, rock hardness, and geological hazard potential. In the HVSR method, seismic data are measured using three-component seismometers, the N-S (North-South), E-W (East-West), and vertical components. In this study, the HVSR method is used for Vs30 inversion to estimate shear wave velocity at a depth of 30m. The southern and western regions of Sulawesi have various geological conditions and high seismicity levels. The results of this inversion can be used for mapping soil vulnerability indices. The obtained soil vulnerability index values indicate high vulnerability near the Palu-Koro fault, with A0 9.27 at F0 3.2 Hz. This method can also estimate shear wave velocity values at a depth of 30 m. Vs30 values range from 200 m/s to 500 m/s at various measurement points, indicating variability. According to the SNI 1726:2012 and NEHRP classifications, the research area has soil conditions ranging from medium to soft.

The occurrence of post-sunset equatorial spread-F (ESF) could have detrimental effects on trans-ionospheric radio wave propagation used in modern communications systems. This problem calls for a simple but robust model that accurately predicts the occurrence of post-sunset ESF. Logistic regression was implemented to model the daily occurrence of post-sunset ESF as a function of the evening upward plasma drift (v). The use of logistic regression is formalized by y^=1/[1+exp(−z)], where y^ represents the probability of post-sunset ESF occurrence, and z is a linear function containing v. The value of v is derived from the vertical motion of the bottom side of the F-region in the evening equatorial ionosphere, which is observed by the ionosondes in Southeast Asia. Data points (938) of v and post-sunset ESF occurrence were collected in the equinox seasons from 2003 to 2016. The training set used 70% of the dataset to derive z and y^ and the remaining 30% was used to test the performance of y^. The expression z=−2.25+0.14v was obtained from the training set, and y^≥0.5 (v ≥ ~16.1 m/s) and y^<0.5 (v < ~16.1 m/s) represented the occurrence and non-occurrence of ESF, respectively, with an accuracy of ~0.8 and a true skill score (TSS) of ~0.6. Similarly, in the testing set, y^ shows an accuracy of ~0.8 and a TSS of ~0.6. Further analysis suggested that the performance of the z-function can be reliable in the daily F10.7 levels ranging from 60 to 140 solar flux units. The z-function implemented in the logistic regression (y^) found in this study is a novel technique to predict the post-sunset ESF occurrence. The performance consistency between the training set and the testing set concludes that the z-function and the y^ values of the proposed model could be a simple and robust mathematical model for daily nowcasting the occurrence or non-occurrence of post-sunset ESFs.

This study has three aims: (1) test the effectiveness of using an ebook based on the Collegiate Learning Assessment (CLA) Task to empower critical explanatory ability; (2) examine the influence of problem-solving style differences on critical explanatory ability; and (3) assess the interaction between the use of CLA Task-based Ebooks and problem-solving styles on critical explanatory ability. This study used a quasi-experimental design and 4×3 factorial design. The instrument was an essay test and Problem Solving Style Questionnaire (PSSQ). ANCOVA was used for data analysis (p = 0.05). This study concludes that: (1) CLA Task-based ebooks are more effective at empowering critical explanatory capabilities than PowerPoint-based CLA Tasks and PowerPoint-based conventional media; (2) Students with the problem-solving Assimilator type have a higher critical explanatory ability value than Diverger, Converger, and Accommodator types; and (3) The interaction between students who use CLA Task-based Ebook media with the problem-solving style Assimilator type has a higher average value of critical explanatory ability than other combinations.

Creative thinking skills are crucial to current generations dealing with 21st-century challenges. However, studies on higher-order thinking skills remain limited. CTS can be easily empowered if students have good metacognitive abilities. This study analysed the effect of STEM-based online learning lesson plans on the CTS of students and metacognitive abilities on the inheritance of living things through online learning. The pretest-posttest research designs with a non-equivalent control group were used. The treatment given in the experimental class was the implementation of a STEM-based online learning lesson plan, while the control class was taught through traditional methods used by the teachers. The results of this study indicated that the CTS and metacognitive abilities of students in the experimental class were significantly higher than that of the control class [F(1,54) = 105.287, p = 0.000 and F(1,54) = 103.943, p = 0.000, respectively]. In conclusion, the STEM-based online learning lesson plan is effective in improving the CTS and metacognitive abilities of students.

Language politeness is considered one of the defining characteristics of Indonesian society. In the age of global communication and computing, moderate politeness, centered on politeness of opinion, politeness in deliberation, and politeness in respecting the opinions of others, is an important factor. However, progressive politeness in Urban Muhammadiyah Primary School is becoming a growing concern that requires special attention. The purpose of this study was to examine this violation in the interactions between learners, teachers, and principals in Yogyakarta, Indonesia. This study adopts a qualitative approach with a case study design. The data were collected from interviews, observations, and documentation. Interviews were conducted with classroom teachers, principals, and learners, while observations were recorded through field notes and reflections. Moreover, audio-visual documentation in the form of photographs, videos, and recordings during the learning processes and interactions between learners or teachers were utilized. Data collection was based on four strategies: observation, interview, documents, and audio-visual, as outlined in Creswell's theory. Validity was examined using data triangulation, member checking, prolonged duration of data collection, repeated observations in the study location, and peer examination. The findings of the study include a) There was a violation of the politeness through bullying, body shaming, and verbal abuse, which violated the principles of appreciation and sympathy. b) Urban Muhammadiyah Primary School helped promote language politeness through several methods, including performing Duha prayers, morning recitation with assistance from the teacher and principal, and teacher role modelling by arriving at school at 06.15 and reciting Asmaul Husna together. Importantly, these efforts positively affected the politeness of the learners. This study provides an update on the assistance given to learners to address impoliteness, including Duha prayers, morning recitation, and memorization of Al-Qur'an and Asmaul Husna assisted by teachers. Moreover, the school has a well equipped School Health Unit (SHU) to promote a healthy, clean, disciplined, and polite lifestyle. Appeals are made through persuasive and affectionate books and direct assistance from teachers as role models. The study of the Quran and Asmaul Husna demonstrates children's moderate politeness in expressing their opinions. The agreement to develop a joint discipline demonstrates the children's moderate politeness in deliberation.

This study aims to test the effectiveness of using environment-oriented e-books based on Problem-Based Learning (PBL) to empower problem-solving skills. The research design used is a Nonrandomized Control Group, Pretest-Posttest Design. The study used a quasi-experimental method with a 2 x 2 factorial design. The research sample was 70, grade X students of Colomadu State High School. The sample was divided into two groups: the control group using powerpoint media and conventional learning models and the treatment group using PBL-based environment-oriented e-books. The material used in the research is ecosystems in biology subjects. The instrument used to obtain data on problem-solving skills is an essay test. Data analysis using ANCOVA (p = 0.05%) with pretest value as a covariate. The results showed that PBL-based environment-oriented e-books had the most significant increase in problem-solving skills scores compared to the control class.

Student study service is a community service, education and research activity that is carried out in an interdisciplinary and intra-curricular by dividing students into each group in certain location. Its group and location were determined by applications that produce alternative choices in making decisions on the distribution of student study service groups evenly through certain methods and criteria. The research applied the analytic hierarchy process method, where problems were simplified in a hierarchy including 3 components, such as goals, assessment criteria and alternative choices. The criteria were gender, department, and location potential. Applications of system builder were Visual Basic .NET, SQL Server and Crystal Report. The results were to facilitate distribution according to the criteria balanced and time of student study service efficiently. By the application, it assisted administration staff to determine student study service distribution and was able to be developed into various features and criteria.

Sign language is a language formed by a combination of finger, hand, body movements and facial expressions used by persons with disabilities such as deaf and speech impaired. One of these sign language recognitions is recognition using Leap Motion Controller (LMC) sensor technology. In addition to the sign language that is formed has diversity such as folded fingers, hidden fingers, indonesian sign forms also have characteristics and shapes that are almost similar to one another. The LMC sensor is not always able to recognize all forms of signs properly. In this study, optimization is proposed at the feature level where optimization aims to provide more detailed features and characteristics of each sign language formed. The stages of the process are designing the layout of the sensors, adding features and combining feature data from each sensor. The test of the feature optimization on this dual LMC sensor can provide an increase in the recognition accuracy of the given Indonesian sign language. The Indonesian sign language can be recognized well with an average accuracy of 87.24% and the optimization carried out is able to produce an increase in accuracy of up to 2.88%.

Synthesis, magnetic, and structural properties and adsorption study of magnetic particles of Fe3O4 have been carried out. Magnetic particles were synthesized from natural iron sand of Kata Beach Pariaman West Sumatera using ball milling method. The structural properties of the samples were determined using X-Ray Diffractometer (XRD) technique. Magnetic properties such as magnetization were measured based on hysteresis loop using vibrating sample magnetometer (VSM). Mass susceptibility of the sample was measured using Pasco magnetic probe. It was found that the mass susceptibility of magnetic particles increased significantly as ball milling time increased. Based on VSM results, the magnetic particle of Fe3O4 has magnetization value of 32.26 emu/g with small coercivity of 174 Oe. Moreover, the results showed that ball milling method has succeeded to obtain magnetic particles. The increase of ball milling time resulted in an increase of magnetic moment of the sample. In this research, the magnetic particle of Fe3O4 was added to a solution of methyline blue performed using shaker method. Atomic Adsorption Spectroscopy (AAS) method was used to study the methylene blue degradation.

Semantic is associated with the relationship between symbol, reference, and the problem's context involved in the problem-solving process which also involves reasoning and decision-making. Hence, this study describes the characteristics of students' semantic reasoning to solve the double discounts problem. 51 high school students in Sidoarjo participated in this qualitative study. The data were collected through 15-20 minutes problem-solving tests. The students' answers were grouped into correct and wrong answers. The correct answers were then regrouped once more based on the strategies used by the students to answer the test and to identify their semantic reasoning characteristics. The data were analyzed by reducing, classifying the think-aloud and also by observing. Then the similarity of characteristics of students' semantic reasoning when solving the double discount problem was identified. To test the accuracy of the data, a triangulation method was used. This semantic reasoning was identified by (1) giving the problem situation, (2) stating the keywords and their meaning, (3) stating the relationship, (4) transforming it into a mathematics statement, (5) calculating based on their strategies, (6) decision making, and (7) completing the answer interpretation. This study contributes to developing basic knowledge in interpreting each process of solving ill-structured problems until finding a solution.

This study attempts to describe characteristics of graph thinking in solving a mathematical problem. Three students at the 10th grade of senior-high schools were involved as the subject. The data was collected from the result of an optimization problem task (OPT), video recording, interviews, and field notes. The results showed two major characteristics of graph thinking were found in solving the problem. First, students used the concept of graph theory to create a problem modelling. They were able to represent the information given in the problem in the form of graph. Second, students also used the concept of graph theory to create a problem modelling and search algorithm. The problem modelling was created as the students interpreted the problem by making connection between the objects in the form of an adjacency matrix and connectivity. In devising a plan, the students referred to the problem modelling to develop search algorithms. However, the algorithms were not entirely efficient. Some of them required the students to initially describe all answer possibilities. The algorithms constructed by the students referred to sequential and conditional algorithms. This study argues that graph-thinking skill can be developed through a learning process which involves students in the solving of open-ended problem to stimulate ideas of problem solving. By developing graph thinking ability, students will be able to analyse and reason information, express mathematical ideas, and have flexibility in solving a problem. These skills are urgently needed in the 21st century where rapid and continuous changes occur.

The limitations of inquiry-based teaching modules impact the low critical thinking skills of students. The research objective is to develop an inquiry-based module to improve students' critical thinking skills. This development research uses the Borg and Gall model in designing and testing the module. The development was carried out in February-November 2020 at Batik Senior High School 1 of Surakarta, Central Java. The subjects of this study were students of class XI-Science Batik Senior High School 1 of Surakarta. The assessment of the feasibility and effectiveness of the module uses a validation instrument by linguists, material experts, and learning experts. Assessment of students' critical thinking skills using HOTS questions. The effectiveness of the module was tested using the Z test. The results concluded that the module was feasible to use in learning with a feasibility score of 3.83 (linguistic aspect), 3.92 (material aspect), and 3.80 (learning aspect). Furthermore, this module effectively improves students' critical thinking skills as indicated by the results of the Z test ([alpha]<0.05). This study recommends the development of inquiry-based modules in improving students' critical thinking skills

This study aims at creating an integrated design of a building material laboratory for Teacher Education Institutes (TEIs) in higher education of vocational and academic programs to support the effective and efficient learning processes. Development of a building materials laboratory design in the form of a 2-story floor plan with a capacity of 20 students. This research belongs to development research using the ADDIE model. The research design was prepared through a Focus Group Discussion (FGD) consisting of 10 respondents involving (1) the coordinator of the TEI building materials lab; (2) the construction industry; and (3) the architecture expert. The collecting data using a questionnaire with an assessment of 2 aspects, namely the completeness of communicating spatial drawings. Data analysis using descriptive statistics to assess the feasibility of the layout drawings of the building materials laboratory was assessed by 2 building planning experts. Data analysis using descriptive statistics to assess the feasibility of the layout drawings of the building materials laboratory was assessed by 2 building planning experts. The results of the feasibility assessment of building materials laboratory drawings obtained 80.4% in the very feasible category. The research results revealed that (1) the practice course contents of building materials in the TEIs of Vocational and Academic program were testing sand, gravel, cement, bricks, light bricks, paving blocks, wood, concrete reinforcing steel, light steel, and concrete technology; (2) the 2-story laboratory floor plan that was developed has a total area of 387 m[superscript 2], all of which are integrated into one area.

The determination of work competence according to industrial needs that are expected by employers of new graduates in the department of architectural engineering in vocational high schools will help graduates to transit smoothly from the academic education environment to the real conditions of the construction industry in the workplace. This research identifies which group of competencies attributes that graduates should have in explaining appropriate competencies according to construction industry standards in Indonesia. The survey was conducted in 47 building construction companies consisting of 56 respondents using a questionnaire method. Multivariate analyses using the CB-SEM method used to validate the evaluation model. The research analysis used quantitative descriptive and factor analysis with the Explanatory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA) methods. The EFA test shows ten factors so that it consists of 30 items of competency measurement. Overall, the CFA test has met the criteria for the goodness of fit statistics. The results of the study concluded that the instrument developed met good validity and reliability and two model frameworks for measuring the level of achievement of student competence in architectural techniques were feasible to use.

The COVID-19 pandemic has forced an immediate transition from face-to-face learning in classrooms to online learning, including math learning. Mathematics with abstract working objects is not easy to learn online. So, an excellent self-regulated learning ability is required. So far, many efforts have been made to improve self-regulated learning in mathematics learning. However, there are still gaps in improving students' self-regulated learning ability in online mathematics learning, especially in relation to the integration of GeoGebra into the Flipped Learning approach. The purpose of this study is to examine the effectiveness of integrating GeoGebra into the Flipped Learning approach to improve students' self-regulated learning ability in learning mathematics online during the COVID-19 pandemic. This research is a quasi-experimental study with a pretest-posttest control group design to compare the effectiveness of a GeoGebra-integrated Flipped Learning approach. A conventional Flipped Learning approach and a conventional learning approach increase students' self-regulated learning level in constructing their understanding of mathematical concepts during online learning in the COVID-19 pandemic. The study involved 60 students randomly selected from one of Indonesia's private universities. They were divided into three groups representing each approach. Pretest and posttest results were quantitatively analyzed using Normalized Gain (N-Gain) Score, Cohen's d effect size, and statistical descriptive. The analysis results revealed that GeoGebra-integrated Flipped Learning is more effective in increasing students' self-regulated learning level in online mathematics learning than the other two approaches. It is expected that the results of this study can provide insights into alternative solutions for improving the quality of online mathematics learning by increasing the level of self-regulated learning of students.