Telkom University

Abstract The irregularities of ionospheric plasma bubbles (EPBs) sequentially generated over wide longitudes are expected to share similar lifetime under normal conditions. In this study, we report a special case where the EPB irregularity lifetime over wide longitudes showed a quasi‐wavelike undulation pattern with wavelength of ∼3,000 km, that is, the lifetime of EPB irregularities sequentially generated at different longitudes experienced several gradually decreasing/increasing cycles. Irregularities with longer (shorter) lifetime corresponded to the EPBs with larger (smaller) development in latitude/altitude. Further observations revealed that smaller‐scale (hundred‐kilometer) and larger‐scale (thousand‐kilometer) waves may coexist at the bottomside of ionosphere around sunset. The former acted as the seeding source for EPB generation, whereas the latter superimposed on PRE and modulated EPB development in altitude over different longitudes, leading to the wavelike undulation morphology in irregularity lifetime ultimately. This study provides implications on how the complex wave structures influence EPB morphology over wide longitudes.

In an era of rapid change, businesses must undergo constant evolution to maintain competitiveness while mitigating the potential for exacerbating social inequality and environmental harm. Failure to implement and transparently communicate corporate social responsibility (CSR) initiatives can jeopardize not only a company's reputation and market position, but also its legal standing and long-term viability. Consequently, this investigation aims to inspect the concurrent and partial effects of firm size, gender diversity, and profitability on the CSR disclosure level in food and beverage sub-sector businesses registered on the Indonesia Stock Exchange (IDX) from 2014 to 2023. This investigation employs quantitative, descriptive, and analytical techniques. This investigation utilized panel data regression as the analytical method. The purposive sampling technique yielded 8 data points annually on food and beverage sub-sector companies registered on the IDX between 2014 and 2023. The investigation's findings indicate that gender diversity, business size, and profitability simultaneously impact CSR disclosure, while the firm size variable solely influences CSR disclosure, not gender diversity or profitability. The practical implications of prioritizing CSR implementation in the food and beverage sub-sector are significant. Firms must ensure that CSR practices are effectively disclosed to stakeholders and integrate CSR considerations into their overall business strategy. This study provides new insights into the drivers of sustainable agrifood systems by identifying corporate and institutional drivers of CSR disclosure in Indonesia's food and beverage industry, a key sector of the agricultural economy.

Missing and incomplete observations in Environmental IoT sensor networks reduce data reliability and disrupt analyses, especially for temperature and humidity time series exhibiting strong diurnal seasonality. This study develops and evaluates a seasonal imputation method to address missing data in IoT-based environmental monitoring, using a workflow of anomaly detection, outlier removal, time-of-day-aware imputation, and performance evaluation under varying missing-rate scenarios. Key challenges include sensor noise, connectivity issues, and intermittent hardware failures, which degrade data integrity and affect trend analysis, forecasting, and anomaly detection. To mitigate these, the method uses hourly and minute-level seasonal patterns after filtering out physically unrealistic values. Experimental results show high accuracy and robustness in reconstructing temperature and humidity data: temperature imputation achieves MAE values of approximately 0.86–0.87°C, and humidity yields MAE values of 3.92–4.01%RH, with no performance drop even at 50% data loss. The imputed series preserves natural diurnal dynamics without introducing distortions, effectively restoring continuity and structural consistency in environmental IoT time series for reliable modeling, feature extraction, and decision support.

The COVID-19 pandemic has significantly disrupted Malaysia's tourism industry, as well as highlighted many vulnerabilities in its resilience and governance. While government interventions were mounted, undetermined challenges continued to be faced. While post-pandemic recovery has been one of the most commonly analyzed issues, the study of the operational and strategic obstacles faced by Malaysian tourism practitioners remains very limited. Using a summative content analysis of tourism reports and academic literature, supplemented by in-depth interviews, this study uncovers the strategic post-pandemic challenges in Malaysia's tourism and hospitality industry from the industry's perspective. Our findings offer practical insights for policymakers and industry stakeholders in the development of effective policies, operational strategies, and travel packages that strengthen the 'Malaysia Truly Asia' image, enhance resilience, and ensure a sustained competitiveness again in this region.

Pengelolaan pemakaman bersejarah di Yayasan Sajarah Timbanganten Bandung masih menghadapi permasalahan administrasi, inkonsistensi data, dan keterbatasan pengelolaan lahan makam. Kegiatan pengabdian kepada masyarakat ini bertujuan mengembangkan dan mengimplementasikan Sistem Informasi Manajemen Pemakaman TIMGRAVID sebagai solusi digital terintegrasi. Metode yang digunakan adalah Participatory Action Research (PAR) dan User-Centered Design (UCD) dengan keterlibatan aktif mitra. Sistem berbasis web dikembangkan secara modular dengan basis data terpusat untuk mendukung layanan publik, pengelolaan operasional, keuangan, serta pengawasan. Hasil evaluasi menunjukkan peningkatan akurasi dan transparansi pengelolaan serta tingkat kepuasan mitra yang sangat baik dengan nilai rerata di atas 4,5 (skala 1–5). Temuan ini menunjukkan bahwa sistem TIMGRAVID efektif mendukung efisiensi pengelolaan pemakaman sekaligus pelestarian warisan budaya melalui dokumentasi digital.

Abstract Hemiparesis affects 80% of stroke survivors, causing significant limitations in upper-extremity motor function and activities of daily living. Traditional clinical assessment methods rely on subjective evaluation scales, creating the need for objective biomarkers for rehabilitation monitoring. This study developed an EMG-based assessment approach using time-domain features Root Mean Square (RMS) and Mean Absolute Value (MAV) from biceps brachii and deltoid medialis muscles for quantitative characterization of post-stroke hemiparesis. Surface EMG signals were recorded from one hemiparesis patient and two healthy control subjects during three contraction conditions: relaxation, mild contraction (functional movement), and high-intensity contraction (maximum voluntary effort). Results showed progressive RMS values in biceps brachii increased from relaxation (2.06 ADC) to mild contraction (6.14 ADC) to high-intensity contraction (23.56 ADC), with contraction ratios of 2.98 and 11.44. MAV showed similar patterns with high correlation to RMS (r > 0.95). Perfect separability between contraction conditions without overlap provides ideal discrimination capability for machine learning applications. The consistent biceps/deltoid activation ratio (∼1.11) across conditions indicates similar impairment levels in both muscles, supporting the use of RMS and MAV as reliable biomarkers for objective hemiparesis assessment and rehabilitation monitoring.

Abstract This study investigates the underwater soundscape in the perimeter of the 2MW Bhimasena steam power plant at the very shallow Java Sea, Indonesia. Marine traffic is very low with tug, tanker, fishing, including traditional fishing vessels, being dominant vessel types. A passive acoustic monitoring consisting of an affordable device stored inside self-fabricated housing is deployed to measure the underwater ambient sound. Analysis on ambient sound focuses on the omni-present natural wind-driven and anthropogenic sounds. However, the high levels threshold of the instrument makes it unable to explore the wind-noise levels dependency. The dynamics of ambient sound are prominent particularly when the vessels approaching then elevate the sound levels at 500 Hz to 100 dB. Statistical spectra analysis demonstrates that vessel noise exceeds around 10% of the monitoring duration along with the possible signatures of traditional fishing vessel’s engines. No signatures of repeating resonant noise indicating the decent performance of the system.

Penelitian ini bertujuan untuk, memahami dan menganalisis serta mengungkapkan simbol-simbol yang ada pada pertunjukan Pari Perang Centong dalam tradisi ngasa Kampung Adat Jalawastu Brebes. Tari Perang Centong yang menjadi rangkaian pada persembahan pada tradisi Ngasa ini merupakan representasi cerita rakyat masyarakat Kampung Adat Jalawastu di mana terjadi konflik antara dua saudara yang bertentangan untuk menerima masuknya agama Islam ke wilayah Kampung Adat Jalawastu Brebes. Diceritakan tokoh Gandasari menolak masuknya Islam, sementara Gandawangi, saudaranya, menerima ajaran tersebut. Penelitian ini menggunakan metode kualitatif dengan pendekatan etnografi. Teknik pengumpulan data penelitian ini melalui obervasi pada pertunjukan Tari Perang Centong secara langsung dan melakukan wawancara mendalam dengan informan yang berperan sebagai Ketua Adat Kampung, Kepala Desa, Kepala Dusun, penari dan masyarakat Kampung Adat Jalawastu Brebes. Data didapatkan dari teknik pendokumentasian, baik berupa video maupun foto pertunjukan. Teori dalam penelitian tentang simbol dan makna Tari Perang Centong, dalam tradisi ngasa Kampung Adat Jalawastu sebagai pelestarian budaya menggunakan teori semiotika Denotatif dan Konotatif dari Roland Barthes. Hasil penelitian menemukan bahwa pertunjukan Tari Perang Centong dalam tradisi ngasa memiliki simbol-simbol yang mempunyai makna melalui elemen-elemen yang ada dalam tari tersebut seperti, gerak, musik, kostum, tempat pertunjukan, dan properti yang mendukung pertunjukan tari tersebut. Kata Kunci: Tari Perang Centong ; Simbol, Makna Denotatif-Konotatif, Nilai Budaya

This study discusses the integration of rapid prototyping and user experience testing in the development of the MEYKE A.01 modular mechanical keyboard. Rapid prototyping is applied to produce prototypes quickly and iteratively through 3D modeling and additive manufacturing, enabling early evaluation of the physical design, casing structure, and modular system. User experience testing is then conducted to assess typing comfort, switch responsiveness, keycap stability, and overall ergonomics. This research employs a qualitative approach involving concept development, prototype fabrication, user testing, and evaluation analysis. The results indicate that integrating these methods enhances the alignment of the design with user needs and accelerates the identification and refinement of design issues. Thus, this approach is effective in producing a modular keyboard that is functional, ergonomic, and user-experience oriented.