Ruki Harwahyu

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Verified

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• Doctor of Philosophy
• Professor (Associate) at University of Indonesia

Implementing Zero Trust Architecture (ZTA) requires a comprehensive understanding of network assets as a fundamental step in implementing security policies. This study proposes ZTscan, an automated tool to increase the efficiency of network asset resource discovery. This proposed tool is then made open source in Github for anyone to evaluate and ex...

Network security is crucial for protecting organizational information in the rapidly evolving digital era. Threats to networks do not only come from external sources, such as malware or hacking, but also from within the organization, known as insider threats. These threats can cause significant losses, whether due to intentional or unintentional ac...

According to the annual report by the National Encryption Agency in 2023, Indonesia had the highest number of cyber-attack sources, with over 1 million attacks, which has increased quite rapidly compared to the last 3 years. Several online media platforms have reported incidents of this nature over the past three years. Among the 10 institutions im...

The rapid development of information and communication technology has also led to a significant increase in cybercrime activities. According to the Annual Cybersecurity Monitoring Report by the National Cyber and Cryptography Agency, there were 495 million instances of traffic anomalies or attempted attacks in 2020, which rose to 1.6 billion in 202...

Massive Machine-type Communication (mMTC) is one of the main service scenarios in 5G. At the time of initializing the connection to the base station, the MTC machines will make a connection request via the random access procedure. One of the schemes of random access procedure for handling this connection request is similar to how multichannel slott...

SQL Injection attacks are still one type of attack that often occurs in web-based applications. The causes and ways to prevent SQL Injection have been widely explained in various sources. Unfortunately, until now, SQL Injection vulnerabilities are still often found in multiple applications. Web-based application frameworks that already have functio...

SQL Injection masih menjadi salah satu jenis kerentanan yang paling sering ditemukan pada aplikasi berbasis web. Pengujian terhadap aplikasi sebelum dirilis ke production harus dilakukan semaksimal mungkin agar kerentanan ini tidak muncul saat aplikasi tersebut rilis ke production. Salah satu jenis pengujian yang harus dilakukan adalah Static Appli...

Semakin meningkatnya ancaman dan serangan yang mengakibatkan kebocoran data di Indonesia sejalan dengan pesatnya perkembangan teknologi dan informasi. Menjawab tantangan tersebut instansi ABC mengembangkan aplikasi XYZ sebagai salah satu solusi dalam pengamanan data dan informasi. Oleh karena itu, untuk memastikan kemampuan aplikasi tersebut dalam...

This paper aims to contribute in outlining the latest findings and formulating a simple practice in providing sufficient air circulation for classroom activities in preparation for the post-pandemic era. During this pandemic, remote learning over the internet has been a viable solution everywhere, including adopted by education institution to keep...

In digital computing, cryptographic methods considers performance in both speed and security. This study aims to explore and improve a permutation-based symmetric chaotic cryptography technique called Chaotic Permutation Multicircular (CPMC). In this study, a method is proposed to implement asymmetric key system from CPMC technique by generating a...

Research, development, knowledge, and creativity have always been the fuel for advancing humanities and answering the challenges of the current and next era. Sustainable future is vocal point where substantial works can pivot on it and contribute to the society, environment, as well as the science itself. Digital Futures International Congress (DIF...

Today we are facing the era of the industrial revolution 4.0, which brings many changes in all fields. In this era, there are massive changes in various fields through the combination of technology that reduces the barriers between the physical and digital worlds. In addition, various problems in making this earth better is also a task that must be...

IEEE 802.11ax defines a new channel access scheme of OFDMA-based random access (UORA) for varying number of associated stations (STAs) to send their requests or data to the access point (AP) in a contention manner. This paper presents an analytical model to investigate the performance of UORA in transient condition under bursty arrivals with arbitr...

Innovative digital technologies—supported by humanistic societies—are required to balance our economic advancement and environmental regeneration. The well-being of our future will depend on how well we can produce technologies that can improve our climate, health, social equity, and stability. New technologies have been used to enhance productivit...

The COVID-19 pandemic is still affecting many aspects of human life. Many efforts have been carried out by many parties in the fields of health and demographics, food security, secure and clean water, green and efficient energy sources, climate change, quality education and secure communities. The response of many scientists and technologists durin...

Over the past two years, the COVID-19 pandemic has significantly affected all aspects of human life. The pandemic has become an issue of serious global concern in both developing and developed countries, with impacts including rapidly changing health and demographic conditions, threatened food security, declining quality of education at all levels,...

Natural disasters have harmful effects on human lives and the economy, as well as physical damage to the environment. Previous research has discussed technological and social perspectives to cope with disaster events, but limited evidence was found on the communication between victims and rescuers and mobile applications' impact as the means of com...

Bulk metallic glass (BMG) has good mechanical strength, high hardness, wear resistance, and corrosion resistance with promising application in various industries. However, for the industrial production of BMG, the main issue is how to overcome limitations of joining with other materials. The present study focuses on solder processing at low operati...

The Internet of Things (IoT) interconnects “things” and autonomously exchanges data between them. It is expected that there are more than seven billion of connections interconnected by low-power wide-area (LPWA) networks to support IoT services before 2025. Several LPWA technologies are gaining popularity recently, such as LoRa and NB-IoT. Despite...

Utilizing Industry 4.0 technologies to create a sustainable energy industry enables a decentralized energy system in which energy can be effectively produced, managed, and controlled from local resources. Furthermore, the technologies also enable data capture and analysis to improve energy performance. As digital energy is being developed and incre...

The current need to reduce dependence on non-renewable fuels has contributed a lot to the rapid growth of renewable energy systems and electric vehicles. One of the exciting sources of energy storage is the battery. The development of lithium-based batteries is an exciting trend and is continuously being developed for long life and high-level batte...

The diffusion of innovations during the fourth industrial revolution reshaped economic systems and caused structural changes in different economic sectors. These innovations have become the basis of the new digital infrastructure of society. Digital technology is used to manage integrated product whole-life cycles and enhance efficient, reliable, a...

The outbreak of SARS-CoV-2 or COVID-19 is attacking societies in all regions. The speed and scale of the outbreak have been accelerating fatalities and causing social and economic disruption. We need coordinated and comprehensive actions on the national and international level in creating a shared responsibility and human solidarity to suppress the...

Cellular Internet of Things (C-IoT) is a new term referring to access technology introduced by 3GPP to support IoT applications. C-IoT has several advantages compared to unlicensed Low Power Wide Area (LPWA) technology. However, C-IoT’s random access (RA) procedure is easily overloaded by massive access from IoT applications. This work proposes a n...

Narrowband Internet of Things (NB-IoT) is a new technology developed to support low-power wide area networks (LPWAN) services. To extend its coverage and decrease its transmission power, devices in one NB-IoT cell are divided into several coverage enhancement (CE) levels with different random access configuration. This potentially results in unfair...

Shortly after the invention of the steam engine, which revolutionized industry at the end of the nineteenth century, technology was perceived as having only two possible roles: technology was created to comply with market demand or was generated to create markets. These two roles mark the first- and second-generation innovation models that changed...

Simultaneous random access attempts from massive machine-type communications (mMTC) devices may severely congest a shared physical random access channel (PRACH) in mobile networks. This paper presents a novel two-phase random access (TPRA) procedure to deal with the congestion caused by mMTC devices accessing the PRACH. During the first phase, the...

This work mainly compares Android Runtime (ART) and Dalvik in the Android-based app. To compare we create native-based app and test in four version of Android: 4.1 (Jelly Bean), 4.2 (Jelly Bean), 4.4 (Kit Kat), 6.0 (Marshmallow) and 7.0 (Nougat). The test conducted by running three different algorithms which are running on the native-based platform...

Next generation wireless communication technology of Internet of Things (IoT) nowadays is already used in many use cases. In 2016 3GPP (3rd Generation Partnership Project) started introducing a new technology called Narrowband Internet of Things (NB-IoT). Targeting to serve the market of IoT devices, NB-IoT is designed to be better in dealing with...

Narrowband Internet of Things (NB-IoT) is a cellular standard supporting Internet of Things (IoT) applications in wide area. NB-IoT utilizes ‘repetition’ to extend the coverage of the base station. The repetition value in NB-IoT physical random access channel (NPRACH) is set to ensure 99% detection probability without considering the inherent ‘retr...

UI GreenMetric as sustainability-based university rankings has received a worldwide acceptance since its initiation in 2010. One of the criteria for this ranking is the annual electricity consumption of participating Universities. There are some challenges in evaluating the overall data, i.e. some electricity consumption information is missing or m...

Narrowband Internet of Things (NB-IoT) is a new access technology introduced by 3GPP. This paper presents an analytical model to estimate the access success probability and average access delay of the random access channels by considering maximum number of preamble transmissions, size of backoff windows, and number of sub-carriers in each coverage...

Narrowband Internet of Things (NB-IoT) is a new access technology introduced by 3GPP. It aims to support massive machine-type communications services in wide area. This work presents an analytical model to estimate access success probability and average access delay of random access (RA) procedure for three coverage enhancement (CE) levels in NB-Io...

Long-term evolution (LTE)-based vehicular-to-everything (V2X) service is one of the promising technologies for supporting intelligent transportation systems (ITSs). LTE adopts a request-grant approach for allocating wireless resources. Each user follows a contention-based random access (RA) procedure to transmit its request. However, this procedure...

The purpose of the research is to implement a device that functions as a real-time display of the estimated arrival time of the yellow bus in University of Indonesia. The device uses an 8-bit Atmel AVR microcontroller based on Arduino platform as its main controller, and utilizes GPRS-based connection to transmit the data to the server. The system...

The widely-used cellular system, such as LTE, has a large potential to serve vehicle-related connectivity which is one of the potential IoT market in the near future. However, the connection-oriented nature of LTE Random Access procedure remains the challenge. The RA procedure in LTE is prone to be overloaded with simultaneous access request from l...

The increasing trend of Internet of Things brings new challenges to efficiently manage the resource in the access network. As a prominent solution to serve IoT services, LTE incorporates a small data transmission scheme for this reason. In this scheme, the overall system performance is greatly influenced by its random access procedure. Hence, study...

This paper presents an iterative contending-user estimation method to analyze the normalized throughput, the packet-dropping probability, the average access delay, and the variance of the access delay for finite-population slotted ALOHA system supporting multiple access-class traffic. We demonstrate the way to extend the model to accurately predict...

For LTE-A TDD systems supporting DL heavy asymmetry traffic, the number of downlink (DL) subframes are much higher than that of uplink (UL) subframes. The HARQ feedbacks of multiple DL tranport blocks may be transmitted in one UL subframe. Time-bundling is a technique proposed to reduce the HARQ signaling overhead by combining multiple ACK/NACKs in...

Group paging can simultaneously activate hundreds of user equipments (UEs) using a single paging message. Upon receiving the group paging message, all UEs should immediately transmit their paging response messages through the random access channels (RACHs). Simultaneous channel access from a huge group of UEs may result in severe collisions of the...

The ability to provide handset tracking or positioning system independent from the available commercial mobile network is required in emergency. In some cases, it is possible that the commercial mobile networks are suspended due to the natural disaster, terrorist attack or other emergency condition. The commercial mobile networks might also unavail...

This paper reviews node failure detection method in ZigBee loop network. ZigBee network was popularly used for low power and low cost implementation of wireless data transmission. Node failure detection is needed in order to maintain the network reliability. Common node failure detection methods are based on ZigBee mesh networking capability. But i...

This paper explains about data logging on LTE handover simulation for QoS provisioning. Handover event is where user equipment change its source node because the signal strength of another node higher than current node. Monitoring the service quality during user's handover is important for telecommunication operators to ensure user's satisfaction....

Mobile IP is a feature of IPv6 which enables mobile node to be identified by using a single IP even though the connection is moved from its home network to foreign network without intruding the communication. Proxy Mobile is a feature in IPv6 which enables mobile node to receive connectivity with its best performance where the connection is regulat...

In this paper, we present a new concept of ZigBee backbone by utilizing ZigBee technology for the use of low-rate wireless medium-distance link. The backbone is mainly used for connecting sensor devices around the backbone location to the gateway device. Non-beacon enabled ZigBee operation mode is considered in this backbone with ring topology enha...

Several research effort in recent years has shown its significant interest in the development of security measure in the routing of Mobile Ad-hoc Network (MANET). Ad-hoc On-demand Distance Vector (AODV) routing protocol has been one of the basic protocol that is modified to cope with security demands. This paper present an analytical model to evalu...

AODV routing protocol facilitates changing and simple-to-setup network environment. It helps setting up a network without sufficient infrastructure, such as in disaster area. Development of AODV protocol has gathered a worldwide research interest. However, not many researches implement AODV routing protocol in real mobile nodes and real MANET. In a...

AODV routing protocol facilitates changing and simple-to-setup network environment. It helps setting up a network without sufficient infrastructure, such as in disaster area. Development of AODV protocol has gathered a worldwide research interest. However, not many researches implement AODV routing protocol in real mobile nodes and real MANET. In a...

Group paging is one of the mechanisms proposed to resolve the radio access network (RAN) overload problem resulted from simultaneous channel access from huge machine devices [1]. This paper presents a consecutive group paging to enhance the performance of group paging. In consecutive group paging, the base station reserves multiple paging cycles to...

Group paging is one of the most promising mechanisms to alleviate the Radio Access Network (RAN) overload problem in Long Term Evolution (LTE) network supporting Machine-type Communication (MTC). This work presents two enhancement schemes for group paging namely consecutive group paging and group paging with pre-backoff. Both schemes use the analyt...

Color-blind is a physical defect causing patient loses the ability to recognize colors either particular or the whole of them. This disability is problematic in daily life, moreover in some specific areas that require carefulness eyesight. We propose a vision aid kit with improved user experience, such as finger pointer and voice command-and-respon...

A node in Mobile Ad-hoc Network (MANET) solely depends on neighbor nodes for its connectivity to the outer networks. It is completely different with fixed network connection where a central infrastructure is providing connectivity to the outside network for all mobile nodes there. This kind of situation makes MANET easier to build rather than fixed...

Speech feature can be an alternative interaction model for embedded device that is designed without many buttons for control. In this work, we create colorblind aid system. This paper compares speech feature created using SAPI5.1 with speech feature created manually using phoneme concatenation and DTW, and assess their performance in WinCE6 and WES...

People with color blindness often have difficulty in distinguishing certain colors. People with total color blindness can only see things in black, white, and gray. Deficiency of color perception is causing many problems for people with color blindness, from daily activities to educational issue. One solution to help this problem is to build an aid...