Budi Rahardjo
Institut Teknologi Bandung, STEI, Faculty Member
The tender process is a long and complex business process to produce a series of legal obligations related to business contracts. The purpose of conducting a tender in government is to support the work program by finding the right tender... more
The tender process is a long and complex business process to produce a series of legal obligations related to business contracts. The purpose of conducting a tender in government is to support the work program by finding the right tender (provider of goods and services) in the government procurement program so that it can be the basis of their decision to choose the most suitable tender. At the government in Indonesia, the tender process has been carried out using an e-tendering system with the use of internet technology through LPSE. The purpose of e-tendering is to facilitate the procurement process with related parties to increase productivity, effectiveness, and transparency in the tender process. However, problems in the e-tendering system are currently centralized, so that the local LPSE organization has full control of the database and the system which can pose a threat of vulnerability to fraud, collusion, and manipulation practices. The tender selection process that is full of competition must be supported by effective and transparent technology so that it does not cause fraud and suspicion among bidders. Blockchain technology is one of the solutions that allow integrated systems without a third party because it adheres to the decentralized nature of distributed databases so that it has a copy of many users. By adopting blockchain e-tendering can reduce the source of fraud, namely database manipulation. This research will explore the process of developing a blockchain-based system with e-tendering case studies on LPSE.
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Verifiability is one of the parameters in e-voting that can increase confidence in voting technology with several parties ensuring that voters do not change their votes. Voting has become an important part of the democratization system,... more
Verifiability is one of the parameters in e-voting that can increase confidence in voting technology with several parties ensuring that voters do not change their votes. Voting has become an important part of the democratization system, both to make choices regarding policies, to elect representatives to sit in the representative assembly, and to elect leaders. the more voters and the wider the distribution, the more complex the social life, and the need to manage the voting process efficiently and determine the results more quickly, electronic-based voting (e-Voting) is becoming a more promising option. The level of confidence in voting depends on the capabilities of the system. E-voting must have parameters that can be used as guidelines, which include the following: Accuracy, Invulnerability, Privacy and Verifiability. The implementation of the simple verifiability metric to measure the degree of verifiability in the e-voting protocol, the researchers can calculate the degree of verifiability in the e-voting protocol and the researchers have been able to assess the proposed e-voting protocol with the standard of the best degree of verifiability is 1, where the value of 1 is is absolutely verified protocol.
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Graph based modelling is common in many implementation areas involving combinatorics relationship such as in social network. The data explosion produced from user generated content in online social network services trigger the emergence... more
Graph based modelling is common in many implementation areas involving combinatorics relationship such as in social network. The data explosion produced from user generated content in online social network services trigger the emergence of large-scale social network. Having large graph at our disposal gives us many opportunity but at the same time increase the complexity problem, especially in several graph metric computations and also at graph visualization. A fast summarization methods is needed to reduce the graph size into the only most important pattern. This summarize sub-graph should represent the property or at least converge to the value of the original graph property. Social Network is characterized by scale free degree distributions, which have fat-head less important nodes that can be removed. Graph Pruning method is introduced to remove less important nodes in certain graph context, thus reduce the complexity of large-scale social network while still retain the original...
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The theory of finite fields has important applications in coding theory and cryptography. Two type of basis of finite field
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Protokol komunikasi yang saat ini digunakan pada perangkat IoT ada cukup banyak. Salah satu protokol yang telah memiliki standard ISO adalah protokol MQTT (sesuai standard ISO/IEC 20922:2016). Protokol MQTT ini telah digunakan oleh banyak... more
Protokol komunikasi yang saat ini digunakan pada perangkat IoT ada cukup banyak. Salah satu protokol yang telah memiliki standard ISO adalah protokol MQTT (sesuai standard ISO/IEC 20922:2016). Protokol MQTT ini telah digunakan oleh banyak pengembang perangkat IoT disebabkan karena protokol ini membutuhkan bandwidth yang sangat kecil dan menggunakan sedikit memory ketika beroperasi. Dalam penggunaanya, perangkat IoT terkadang mengirimkan data-data rahasia yang hanya boleh diakses oleh orang tertentu. Protokol MQTT secara default tidak mengenkripsi data-data yang dikirimkan. Protokol MQTT ini baru memiliki mekanisme keamanan berupa autentikasi, walaupun proses autentikasinya secara default belum terenkripsi. Mekanisme autentikasi yang ada juga masih belum efektif, disebabkan penggunaan pasangan user dan password yang sama untuk tiap device yang terhubung dengan broker yang sama. Selain itu, protokol ini juga belum memiliki mekanisme authorization untuk device yang terhubung ke broker,...
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Sistem pemungutan suara elektronik (e-voting) telah berkembang pesat dan menggantikan sistem pemungutan suara konvensional yang menggunakan kertas. Ada beberapa aspek yang mempengaruhi kepercayaan terhadap sistem pemungutan suara... more
Sistem pemungutan suara elektronik (e-voting) telah berkembang pesat dan menggantikan sistem pemungutan suara konvensional yang menggunakan kertas. Ada beberapa aspek yang mempengaruhi kepercayaan terhadap sistem pemungutan suara elektronik. Salah satu aspek vital yang harus diperhatikan dalam membuat sistem pemungutan suara elektronik adalah aspek verifikasi. Aspek verifikasi dikatakan vital sebab rendahya tingkat kepercaryaan pemilih dan kandidat yang rendah terhadap sistem pemungutan suara elektronik. Ada beberapa jenis verifikasi dalam sistem pemungutan suara elektronik yaitu individual verifiability, universal verifiability, dan elegibility verifiability. Penerapan jenis-jenis verifikasi tersebut pada sistem pemungutan suara JCJ/Civitas dan Helios yang telah dikembangkan akan direview dalam paper ini.
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A very significant increase in the spread of malware has resulted in malware analysis using signature matching approaches and heuristic methods that are no longer suitable for malware analysis. Recently the approach to using machine... more
A very significant increase in the spread of malware has resulted in malware analysis using signature matching approaches and heuristic methods that are no longer suitable for malware analysis. Recently the approach to using machine learning has been proposed by many researchers. Machine learning is considered a more effective and efficient approach to detect malware compared to conventional approaches. At the same time, researchers proposed a honeypot as a device capable of gathering malware information. Honeypot is designed as a malware trap and is stored on the system provided. Then record events that detect and gather information about the attacker's activities and identity. This paper aims to investigate the use of honeypot in machine learning to detect malware. The Systematic Literature Review (SLR) method was used to identify 684 papers in the IEEE Xplore database and ACM Digital Library based on automatic searches and predefined strings. Then 11 papers were selected to be investigated based on inclusion and exclusion criteria. From the results of the literature, it can be concluded that the trend of honeypot use in malware detection-based learning has increased from 2017 to 2019. The techniques used by most researchers are utilizing available honeypot datasets. Meanwhile, based on the type of malware analyzed, honeypot in machine learning is mostly used to collect IoT-based malware.
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People counting systems can provide statistical trend information used for human behavior analysis. Intuitively people counting system works based on sequence detection, tracking, and counting. However, with active research activities in... more
People counting systems can provide statistical trend information used for human behavior analysis. Intuitively people counting system works based on sequence detection, tracking, and counting. However, with active research activities in Artificial Intelligence in Computer Vision, there are many alternatives available for implementing a people counting system. A systematic literature review is used to obtain the latest research information that accurately following the requirements of the system being designed as well as the gap areas that arise in implementation. The gap areas found are in the design of an implementation that suits your needs and increases the accuracy of the counters who enter or leave the frame. Several strategies can be done to achieve this goal by conducting head detection and training with a pretrained model in the object detection and tracking framework. This strategy is expected to increase accuracy through stabilizing object detection and tracking.
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Data plays a vital role particularly in mining enterprises to foster innovation and business performance through precise decision-making. Scientists have created many kinds of database technology to support them, such as big data, data... more
Data plays a vital role particularly in mining enterprises to foster innovation and business performance through precise decision-making. Scientists have created many kinds of database technology to support them, such as big data, data cloud, etc. Meanwhile business is always facing a fluctuant situation in using those various database technologies. Unfortunately, there is still hard to use database technology in a proper way because there are no model rules in making a perfect planning so that they can choose suitable tools for its own case. Therefore, this paper aims to design an agile enterprise data architecture model rules (blueprint) in mining company based on various frameworks, tools and methods/techniques so that managers can govern their data asset for sustainably business-IT alignment. This data architecture reference models can be easily adopted by CIOs in order to move toward an integrated mining enterprises as well as guide user in producing a precise decision-making.
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Elliptic Curve Cryptography (ECC) is a public key cryptosystem with a security level determined by discrete logarithm problem called Elliptic Curve Discrete Logarithm Problem (ECDLP). John M. Pollard proposed an algorithm for discrete... more
Elliptic Curve Cryptography (ECC) is a public key cryptosystem with a security level determined by discrete logarithm problem called Elliptic Curve Discrete Logarithm Problem (ECDLP). John M. Pollard proposed an algorithm for discrete logarithm problem based on Monte Carlo method and known as Pollard Rho algorithm. The best current brute-force attack for ECC is Pollard Rho algorithm. In this research we implement modified Pollard Rho algorithm on ECC over GF (241). As the result, the runtime of Pollard Rho algorithm increases exponentially with the increase of the ECC key length. This work also presents the estimated runtime of Pollard Rho attack on ECC over longer bits.
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Abstrak Salah satu ancaman besar terhadap suatu perusahaan adalah kejahatan penyelewengan keuangan / financial fraud. Terdapat beberapa aktivitas yang termasuk ke dalam kategori kejahatan ini yaitu: corruption, asset misappropriation dan... more
Abstrak Salah satu ancaman besar terhadap suatu perusahaan adalah kejahatan penyelewengan keuangan / financial fraud. Terdapat beberapa aktivitas yang termasuk ke dalam kategori kejahatan ini yaitu: corruption, asset misappropriation dan fraudulent statements. Pencegahan bisa dilakukan dengan hanya mengawasi aktor aktor tertentu di dalam jaringan perusahaan yang mempunyai nilai centrality yang besar. Jika kejahatan sudah dilakukan, maka tantangan yang dihadapi adalah bagaimana mendeteksi aliran hasil kejahatan menggunakan metode penelusuran ego-centric network dan community detection. Metoda metoda yang disebutkan diatas merupakan bagian dari metodologi Social Network Analysis (SNA), yang memodelkan hubungan antar manusia di dalam jaringan sosial. SNA menyediakan metrik metrik untuk kuantifikasi hubungan hubungan tersebut. Dalam paper ini akan dijelaskan kemungkinan skenario financial fraud dan bagaimana menggunakan metrik di dalam metodologi SNA untuk pencegahan dan penelusuran fin...
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Cryptography is an important tool in e-commerce because it allows the cryptographic protection of electronic information in an e-commerce. The effectiveness of this protection depends on many variables such as length of the key,... more
Cryptography is an important tool in e-commerce because it allows the cryptographic protection of electronic information in an e-commerce. The effectiveness of this protection depends on many variables such as length of the key, cryptographic protocols and the selection of passwords. This paper specifically discusses the selection of the keylength for elliptic curve cryptosystems. Selection of keylength is an important factor in determining the security level of the cryptography used. In this paper we discuss the determination of the key length for public key cryptography based on a set of parameters which are explicitly formulated. Another factor that determines the key length is also discussed in this paper such as the effort and costs incurred for the attack against elliptic curve cryptosystem.
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ABSTRACT In Social Network Analysis (SNA), community structure is an important feature of complex network. There are many researches on detecting community or cluster in graph with the objective to understand functional properties and... more
ABSTRACT In Social Network Analysis (SNA), community structure is an important feature of complex network. There are many researches on detecting community or cluster in graph with the objective to understand functional properties and community structures. Community detection early researches require global knowledge of network, which is not realistic to most real world network. Due to the increase of online social network, the new challenges are to develop methods to support community detection based on local information-only and network modularity. This paper present state of the art of methods in community detection research and propose the direction of future community detection research.
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Elliptic Curve Cryptography (ECC) adalah salah satu kriptografi kunci publik yang membutuhkankomputasi tinggi karena membutuhkan perhitungan aritmetika khusus yang kompleks. Di sisi lain,semakin panjang jumlah bit yang digunakan sebagai... more
Elliptic Curve Cryptography (ECC) adalah salah satu kriptografi kunci publik yang membutuhkankomputasi tinggi karena membutuhkan perhitungan aritmetika khusus yang kompleks. Di sisi lain,semakin panjang jumlah bit yang digunakan sebagai kunci, semakin tinggi tingkat keamanannya. Hal iniberimplikasi dalam implementasi ECC dalam bentuk perangkat keras. Semakin panjang jumlah bit yangdigunakan, semakin besar area (semakin banyak jumlah komponen) yang dibutuhkan. Dalamimplementasi perangkat lunak, semakin panjang jumlah bit yang digunakan semakin besar memori yangdibutuhkan. Optimasi yang perlu dilakukan adalah memperkecil luas area dan/atau meningkatkankecepatan. Salah satu solusi yang ditawarkan adalah mengimplementasikan perhitungan aritmetikadengan menggunakan composite field (lapangan composite). Pendekatan ini dapat memperkecilkebutuhan area (dalam implementasi perangkat keras) atau memori (dalam implementasi perangkatlunak). Pada makalah ini akan disampaikan rancangan arsitektur unit aritmetika composite field.
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Voting is an activity organized within a country on which the population is obliged to exercise the right to vote and to be elected. Voting is generally done in the traditional way, how the inhabitants go directly to the voting booths,... more
Voting is an activity organized within a country on which the population is obliged to exercise the right to vote and to be elected. Voting is generally done in the traditional way, how the inhabitants go directly to the voting booths, but there are also some countries and local governments that have polled electronically using information technology or called e-voting. The voting has become an important part of the democratic system. Poll result data can show effectively in predicting election results. AHP is one of the techniques used to support decision making. In this paper we used AHP algorithm modification with Double-track - Most Significant Operation First (DT-MSOF) concept to help determine voter candidate recommendation during polling. AHP algorithm modification is performed in order to reduce the number of operations that need to be done, where based on the results of experiments the use of the concept of DT-MSOF on AHP can reduce the number of operations that need to be done to get the results (decisions) similar to that obtained by conventional AHP. In this paper we have applied AHP algorithm modification on candidate selection polls compared with AHP algorithm, where the result of poll recommendation for candidate selection shows the same result and has succeeded to reduce the number of operation.
The development of industrial revolution 4.0 in industrial sector opened a cyber gap for outsiders to pose a threat to the system. Industrial control systems initially designed to meet SRA (Safety, Reliability, and Availability)... more
The development of industrial revolution 4.0 in industrial sector opened a cyber gap for outsiders to pose a threat to the system. Industrial control systems initially designed to meet SRA (Safety, Reliability, and Availability) priorities are now beginning to be pressed to consider security aspects related to the magnitude of the impact that can be caused due to external attacks. In making a safe Cyber Physical System (CPS) based automation, risk assessment will be used to determine the level risk of threat. Mini distillation column batch based CPS will be implemented as the approach of CPS in industrial sector. Anomaly detection based data-driven model and data recovery method is proposed to lower the impact of attack on this system.
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The lack of coordination in the integration of information systems between government agencies that issue identity numbers causes replication and redundancy of population information data. Another problem is the emergence of citizens'... more
The lack of coordination in the integration of information systems between government agencies that issue identity numbers causes replication and redundancy of population information data. Another problem is the emergence of citizens' concerns over data integrity and security due to national identification records is also used by the private sector. In this paper, one of the solutions offered to overcome the above problem is to build an integrated national identification database system between government agencies by applying the concept of Single Identity Number (SIN) using blockchain technology. Blockchain is a secure and robust system for keeping a record of the identities of all citizens and also able to facilitate data integration between institutions. This paper uses the strengths of blockchain to possess characteristics of immutability that it is possible to store national identification records.
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Kebutuhan akan keamanan sistem informasi merupakan hal yang sangat penting bagi suatu perusahaan dalam menjamin kesuksesan proses bisnisnya. Hal ini mempunyai hubungan yang signifikan apabila dikaitkan dengan meningkatkannya jumlah... more
Kebutuhan akan keamanan sistem informasi merupakan hal yang sangat penting bagi suatu perusahaan dalam menjamin kesuksesan proses bisnisnya. Hal ini mempunyai hubungan yang signifikan apabila dikaitkan dengan meningkatkannya jumlah insiden keamanan komputer serta kerugian yang ditimbulkannya. Dewasa ini, konsep keamanan yang merupakan sebuah proses manajemen yang berkelanjutan dan melibatkan seluruh komponen dari suatu perusahaan, telah meninggalkan cara konvensional yang hanya mengandalkan keamanan pada kemampuan perangkat lunak atau perangkat keras. Salah satu alternatif solusi manajemen keamanan tersebut adalah dengan membentuk CSIRTs (Computer Security Incident Response Teams) pada organisasi atau perusahaan. Penelitian tentang Model Organisasi CSIRTs telah dirintis oleh CMU/SEI (Carnegie Mellon University/Software Engineering Institute) sejak tahun 1998. Pada tesis ini, akan dilakukan suatu studi kelayakan salah satu model organisasi CSIRTs tersebut, yang disegmentasikan pada p...
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Nowadays, Windows is an operating system that is very popular among people, especially users who have limited knowledge of computers. But unconsciously, the security threat to the windows operating system is very high. Security threats... more
Nowadays, Windows is an operating system that is very popular among people, especially users who have limited knowledge of computers. But unconsciously, the security threat to the windows operating system is very high. Security threats can be in the form of illegal exploitation of the system. The most common attack is using malware. To determine the characteristics of malware using dynamic analysis techniques and static analysis is very dependent on the availability of malware samples. Honeypot is the most effective malware collection technique. But honeypot cannot determine the type of file format contained in malware. File format information is needed for the purpose of handling malware analysis that is focused on windows-based malware. For this reason, we propose a framework that can collect malware information as well as identify malware PE file type formats. In this study, we collected malware samples using a modern honey network. Next, we performed a feature extraction to dete...
GSM voice security improvement is more difficult due to lossy GSM compression. Conventional voice encryption cannot pass through the GSM compression. This study proposes a novel method to improve the GSM voice security that can pass... more
GSM voice security improvement is more difficult due to lossy GSM compression. Conventional voice encryption cannot pass through the GSM compression. This study proposes a novel method to improve the GSM voice security that can pass through the GSM Compression. Using the steganography technique to hide the message voice, noise is added before being sent over the GSM network. It is found that ambience noise, white noise, and 500Hz sine wave can hide the message voice and the original message can be restored properly when received.
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This paper presents the application of SPIN to verify a hardware design. A hazardoues circuit is modelled in PROMELA and verified with SPIN. SPIN shows the presense of hazard. The circuit was corrected and verified.
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The role of ICT in the organization will continue to experience growth in line with business growth. However, in reality, there is a gap between ICT initiatives with the development (needs) of company business that is caused by yet... more
The role of ICT in the organization will continue to experience growth in line with business growth. However, in reality, there is a gap between ICT initiatives with the development (needs) of company business that is caused by yet inadequate of ICT strategic alignment. Therefore this study was conducted with the aim to create an agile enterprise architecture model rules, particularly in mining company, by using TOGAF framework. The results from the design development phase of the mining enterprise architecture meta model represents the domain of business, applications, data, and technology. The results of the design as a whole were analyzed from four perspectives, namely the perspective of contextual, conceptual, logical and physical. In the end, the quality assessment of the mining enterprise architecture is conducted to assess the suitability of the design standards and architectural principles.
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Flashcrowd and Distributed Denial of Service (DDoS) almost has similar symptom across network and server. But security element such Intrusion Detection System (IDS) must handle both differently. If IDS cannot differentiate flashcrowd and... more
Flashcrowd and Distributed Denial of Service (DDoS) almost has similar symptom across network and server. But security element such Intrusion Detection System (IDS) must handle both differently. If IDS cannot differentiate flashcrowd and DDoS attack, Quality of Service of legal user traffic in flashcrowd will degraded. So it is important for IDS to differentiate between flashcrowd and DDoS. Many earlier comparison method could sense the anomalous event, but not pay much attention to identify which flow was the anomaly. We presented residual calculation between windowed aggregate traffic statistical value combination. With residual calculation among statistical percentile 10th and mean, a high accuracy of flashcrowd and DDoS differentiation of synthetic anomalous event gained. This method could directly identify the anomalous flow and perform visual analysis to detect the start to end of both event.
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In Social Computing, Social Network Analysis (SNA) provides models and techniques for analysing social and economic network based on graph theory. SNA can help us to understand the real-world network application such as knowledge... more
In Social Computing, Social Network Analysis (SNA) provides models and techniques for analysing social and economic network based on graph theory. SNA can help us to understand the real-world network application such as knowledge management, market segmentation, viral marketing, customer behavior, competitive advantage and many other applications. The ability to quantify complex network can greatly give an advantage for decision support. There are three approaches in current SNA study: Graph Representation, Content Mining, and Semantic Analysis. In this paper, we focus on graph representation approach which has been used for analyzing social network topology, structural modeling, tie-strength, community detection, group cohesion, visualization, and metrics computations. Many research contribute to the development of SNA, they are based from various idea and sometimes is difficult to track the development of this field. This paper provides SNA taxonomy based on its graph representation.
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This paper describes various challenges and opportunities facing academic institutions specifically in Asia Pacific region.
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ABSTRACT Network administrators must rely on labour-intensive processes for tracking network configurations and vulnerabilities, which requires a lot of expertise and error prone. Organizational network vulnerabilities and... more
ABSTRACT Network administrators must rely on labour-intensive processes for tracking network configurations and vulnerabilities, which requires a lot of expertise and error prone. Organizational network vulnerabilities and interdependencies are so complex to make traditional vulnerability analysis become inadequate. Decision support capabilities let analysts make tradeoffs between security and optimum availability, and indicates how best to apply limited security resources. Recent work in network security has focused on the fact that a combination of exploitation is the typical way in which the invader breaks into the network. Researchers have proposed various algorithms to generate graphs based attack tree (or graph). In this paper, we present a framework, Architecture and Approach to Vulnerability Analysis. I. INTRODUCTION While we cannot predict the origin and timing of attacks, we can reduce their impact by knowing the possible attack paths through our networks. Reliance on manual processes and mental models is inadequate. Automated tools are needed for analysing and visualizing vulnerability dependencies and attack paths, for understanding overall security posture [1]. Attack graphs are constructed by starting an adversary at a given network location and, using information about the network topology and host vulnerabilities, examining how the attacker can progressively compromise vulnerable hosts that are reachable from already compromised hosts. Vulnerability scanners and analyses of filtering performed by firewalls and routers are used to obtain information about host vulnerabilities and to determine host-to-host reachability in a network. Almost all approaches have a method of generating recommendations to patch critical vulnerabilities or make firewalls more restrictive. In addition, most of the existing implementations provide some type of attack graph display. However, the abstract nature of attack graphs has proven to be a serious practical weakness in creating an effective display [2]. Recently, in order to analyse the vulnerabilities in a network of hosts, many methods have been proposed. One significant method is attack graph analysis [1,2,3]. The attack graph depicts the attack paths of a potential attacker, for a
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In this research a brief explanation about basic theory of security metrics is given. Implementation of security metrics are also explained. A future work of security metrics fields are given as a guide to other researcher to make an... more
In this research a brief explanation about basic theory of security metrics is given. Implementation of security metrics are also explained. A future work of security metrics fields are given as a guide to other researcher to make an advanced research in the future. A description of security metrics with global taxonomy and classification are discussed.
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The problem of the recognition of Bulgarian words by means of HMM (hidden Markov models) is discussed. The speech signal was low-pass filtered up to 4 kHz, sampled at 10 kHz, and pushed directly into the computer's memory (IBM... more
The problem of the recognition of Bulgarian words by means of HMM (hidden Markov models) is discussed. The speech signal was low-pass filtered up to 4 kHz, sampled at 10 kHz, and pushed directly into the computer's memory (IBM PC/XT). Unvoiced segments were separated, and the pitch period was evaluated. For every voiced and unvoiced segment 12 LPC (linear predictive coding) coefficients were computed. These segments were used as states q/sub i/ in HMM and their LPC coefficients-an acoustic vector y/sub t/. On the basis of the training set a HMM for every word was generated. A modified Bayesian decision rule is proposed. As a result, if the decision rule is satisfied, the classification is simple; otherwise, the classification is given in the form of ordered couples. The proposed approach shows higher accuracy and is appropriate for word, command and expression recognition.>
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Big data phenomenon arises from the increasing number of data collected from various sources, including the internet. Big data posses characteristics that make it difficult to manage from security point of view. This paper looks at NIST... more
Big data phenomenon arises from the increasing number of data collected from various sources, including the internet. Big data posses characteristics that make it difficult to manage from security point of view. This paper looks at NIST risk management guidance and determines whether it is applicable to big data.
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In Social Network Analysis (SNA), community structure is an important feature of complex network. There are many researches on detecting community or cluster in graph with the objective to understand functional properties and community... more
In Social Network Analysis (SNA), community structure is an important feature of complex network. There are many researches on detecting community or cluster in graph with the objective to understand functional properties and community structures. Community detection early researches require global knowledge of network, which is not realistic to most real world network. Due to the increase of online social network, the new challenges are to develop methods to support community detection based on local information-only and network modularity. This paper present state of the art of methods in community detection research and propose the direction of future community detection research.
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Online social media provides platform for social interactions. This platform produce large-scale data generated mostly from online conversations. Network analysis can help us to mine knowledge and pattern from the relationship between... more
Online social media provides platform for social interactions. This platform produce large-scale data generated mostly from online conversations. Network analysis can help us to mine knowledge and pattern from the relationship between actors inside the network. This approach has been crucial in supporting prediction and decision-making process. In marketing context such as branding effort, using large-scale conversation data is cheaper, faster and reliable comparing mainstream approaches such as questionnaire and sampling.
Social network analysis provides several metrics, which was built with no scalability in minds, thus it is computationally exhaustive. Some metrics such as centrality and community detections has exponential time and space complexity. With the availability of cheap but large-scale data, our challenge is how to measure social interactions based on those large-scale data. In this paper, we present our approach to reduce the computational complexity of social network analysis metrics based on graph compression method to solve real world brand awareness effort.
Social network analysis provides several metrics, which was built with no scalability in minds, thus it is computationally exhaustive. Some metrics such as centrality and community detections has exponential time and space complexity. With the availability of cheap but large-scale data, our challenge is how to measure social interactions based on those large-scale data. In this paper, we present our approach to reduce the computational complexity of social network analysis metrics based on graph compression method to solve real world brand awareness effort.
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Salah satu ancaman besar terhadap suatu perusahaan adalah kejahatan penyelewengan keuangan / financial fraud. Terdapat beberapa aktivitas yang termasuk ke dalam kategori kejahatan ini yaitu: corruption, asset misappropriation dan... more
Salah satu ancaman besar terhadap suatu perusahaan adalah kejahatan penyelewengan keuangan / financial fraud. Terdapat beberapa aktivitas yang termasuk ke dalam kategori kejahatan ini yaitu: corruption, asset misappropriation dan fraudulent statements. Pencegahan bisa dilakukan dengan hanya mengawasi aktor aktor tertentu di dalam jaringan perusahaan yang mempunyai nilai centrality yang besar. Jika kejahatan sudah dilakukan, maka tantangan yang dihadapi adalah bagaimana mendeteksi aliran hasil kejahatan menggunakan metode penelusuran ego-centric network dan community detection. Metoda metoda yang disebutkan diatas merupakan bagian dari metodologi Social Network Analysis (SNA), yang memodelkan hubungan antar manusia di dalam jaringan sosial. SNA menyediakan metrik metrik untuk kuantifikasi hubungan hubungan tersebut. Dalam paper ini akan dijelaskan kemungkinan skenario financial fraud dan bagaimana menggunakan metrik di dalam metodologi SNA untuk pencegahan dan penelusuran financial fraud berdasarkan topologi jaringan.
Research Interests:
In Social Computing, Social Network Analysis (SNA) provides models and techniques for analysing social and economic network based on graph theory. SNA can help us to understand the real-world network application such as knowledge... more
In Social Computing, Social Network Analysis (SNA) provides models and techniques for analysing social and economic network based on graph theory. SNA can help us to understand the real-world network application such as knowledge management, market segmentation, viral marketing, customer behavior, competitive advantage and many other applications. The ability to quantify complex network can greatly give an advantage for decision support. There are three approaches in current SNA study: Graph Representation, Content Mining, and Semantic Analysis. In this paper, we focus on graph representation approach which has been used for analyzing social network topology, structural modeling, tie-strength, community detection, group cohesion, visualization, and metrics computations. Many research contribute to the development of SNA, they are based from various idea and sometimes is difficult to track the development of this field. This paper provides SNA taxonomy based on its graph representation
Research Interests:
Graph based modelling is common in many implementation areas involving combinatorics relationship such as in social network. The data explosion produced from user generated content in online social network services trigger the emergence... more
Graph based modelling is common in many implementation areas involving combinatorics relationship such as in social network. The data explosion produced from user generated content in online social network services trigger the emergence of large-scale social network. Having large graph at our disposal gives us many opportunity but at the same time increase the complexity problem, especially in several graph metric computations and also at graph visualization. A fast summarization methods is needed to reduce the graph size into the only most important pattern. This summarize sub-graph should represent the property or at least converge to the value of the original graph property. Social Network is characterized by scale free degree distributions, which have fat-head less important nodes that can be removed. Graph Pruning method is introduced to remove less important nodes in certain graph context, thus reduce the complexity of large-scale social network while still retain the original graph properties. The method is based on k-core graph properties. The paper show how is the effect of graph pruning to the several most used social network properties.