Danang Triantoro Murdiansyah | Telkom University (original) (raw)

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Papers by Danang Triantoro Murdiansyah

In this paper, thermal performance of various phase change materials (PCMs) used as thermal energ... more In this paper, thermal performance of various phase change materials (PCMs) used as thermal energy storage in a solar cooker has been investigated numerically. Heat conduction equations in cylindrical domain are used to model heat transfer of the PCMs. Mathematical model of phase change problem in the PCM storage encompasses heat conduction equations in solid and liquid region separated by moving solid-liquid interface. The phase change problem is solved by reformulating heat conduction equations with emergence of moving boundary into an enthalpy equation. Numerical solution of the enthalpy equation is obtained by implementing Godunov method and verified by analytical solution of one-dimensional case. Stability condition of the numerical scheme is also discussed. Thermal performance of various PCMs is evaluated via the stored energy and temperature history. The simulation results show that phase change material with the best thermal performance during the first 2.5 hours of energy extraction is shown by erythritol. Moreover, magnesium chloride hexahydrate can maintain temperature of the PCM storage in the range of 110-116.7°C for more than 4 hours while magnesium nitrate hexahydrate is effective only for one hour with the PCM storage temperature around 121-128°C. Among the PCMs that have been tested, it is only erythritol that can cook 10 kg of the loaded water until it reaches 100°C for about 3.5 hours.

Jurnal Nasional Teknik Elektro dan Teknologi Informasi (JNTETI), 2016

The trend of financial transactions using mobile phone or mobile payment is increasing. Using the... more The trend of financial transactions using mobile phone or mobile payment is increasing. Using the mobile payment service, user can save money on the mobile phone and separate the money from prepaid bills. In order to protect the user, provider must equip the mobile payment service with transaction security, such as secure mobile payment application. This paper offers a safety feature which is used for mobile payment application based on Android operating system. A new method, Dynamic Rule Encryption (DRE), is created. In DRE, the encryption is ruled dynamically. By encrypting data with dynamic rules, DRE can protect the data. DRE also has a function as a token for authentication. DRE Token is generated using dynamic time-based rules. The time reference used in DRE is based on the order of the day in the year (day of the year). Performance measurement in this research is based on the Hamming distance. The test results show that the system performs quite good. The average distance among outputs is about 258 bits of 512 bits input. The results also show that the DRE program's execution time is quite fast, i.e. not more than 24 ms.

2016 4th International Conference on Information and Communication Technology (ICoICT), 2016

Teacher have an important role in Indonesia's education as professional educator in all grade... more Teacher have an important role in Indonesia's education as professional educator in all grade. Teacher certification held to select teacher who fullfil basic competence as educator. Indonesia used scoring method with several assesment to make the decision about teacher certification. In this research, we applied the alternative method using Fuzzy Inference System (FIS). Hybrid algorithm with Evolutionary Programming (EP) algorithm was used to optimize the membership function and rules of FIS. The result from hybrid fuzzy-EP is compared with result from scoring method using confusion matrix. Fuzzy hybrid with EP have accuracy is 78.8% with accuracy of testing 85.6%.

2016 4th International Conference on Information and Communication Technology (ICoICT), 2016

Currently, the data storage medium in digital form are widely applied in various fields, includin... more Currently, the data storage medium in digital form are widely applied in various fields, including in the medical world. The excessive size of the digital medical image digital poses problems in terms of storage and the time to transmit these images through the Internet. To overcome these problems, a digital image compression can be conducted. This procedure is conducted to maintain the image quality therefore it does not affect the outcome of a medical image diagnosis. In [1], it has carried out and examined the implementation of the wavelet-based image compression SVD, where the quantity process using graph coloring and for entropy encoding using Arithmetic Coding. In this paper, the data used is a medical image. Furthermore, it has been designed an image compression system based on Integer Wavelet Transform (IWT) and SVD. Graph-based quantization used still refers to [1], but entropy encoding used is adaptive Huffman coding. In addition, IWT used in this system because it is reversible. Performance compression system designed to produce an average PSNR value in the range of 50-53 dB and the compression ratio ranges from 78-85%.

A set of vertices S resolves a graph G if every vertex is uniquely determined by its vector of di... more A set of vertices S resolves a graph G if every vertex is uniquely determined by its vector of distances to the vertices in S. The metric dimension of G is the minimum cardinality of a resolving set of G. Let {G 1 , G 2 ,. .. , G n } be a finite collection of graphs and each G i has a fixed vertex v 0 i or a fixed edge e 0 i called a terminal vertex or edge, respectively. The vertexamalgamation of G 1 , G 2 ,. .. , G n , denoted by V ertex − Amal{G i ; v 0 i }, is formed by taking all the G i 's and identifying their terminal vertices. Similarly, the edgeamalgamation of G 1 , G 2 ,. .. , G n , denoted by Edge − Amal{G i ; e 0 i }, is formed by taking all the G i 's and identifying their terminal edges. Here we study the metric dimensions of vertex-amalgamation and edge-amalgamation for finite collection of regular graphs: complete graphs and prisms.

In this paper, thermal performance of various phase change materials (PCMs) used as thermal energ... more In this paper, thermal performance of various phase change materials (PCMs) used as thermal energy storage in a solar cooker has been investigated numerically. Heat conduction equations in cylindrical domain are used to model heat transfer of the PCMs. Mathematical model of phase change problem in the PCM storage encompasses heat conduction equations in solid and liquid region separated by moving solid-liquid interface. The phase change problem is solved by reformulating heat conduction equations with emergence of moving boundary into an enthalpy equation. Numerical solution of the enthalpy equation is obtained by implementing Godunov method and verified by analytical solution of one-dimensional case. Stability condition of the numerical scheme is also discussed. Thermal performance of various PCMs is evaluated via the stored energy and temperature history. The simulation results show that phase change material with the best thermal performance during the first 2.5 hours of energy extraction is shown by erythritol. Moreover, magnesium chloride hexahydrate can maintain temperature of the PCM storage in the range of 110-116.7°C for more than 4 hours while magnesium nitrate hexahydrate is effective only for one hour with the PCM storage temperature around 121-128°C. Among the PCMs that have been tested, it is only erythritol that can cook 10 kg of the loaded water until it reaches 100°C for about 3.5 hours.

Jurnal Nasional Teknik Elektro dan Teknologi Informasi (JNTETI), 2016

The trend of financial transactions using mobile phone or mobile payment is increasing. Using the... more The trend of financial transactions using mobile phone or mobile payment is increasing. Using the mobile payment service, user can save money on the mobile phone and separate the money from prepaid bills. In order to protect the user, provider must equip the mobile payment service with transaction security, such as secure mobile payment application. This paper offers a safety feature which is used for mobile payment application based on Android operating system. A new method, Dynamic Rule Encryption (DRE), is created. In DRE, the encryption is ruled dynamically. By encrypting data with dynamic rules, DRE can protect the data. DRE also has a function as a token for authentication. DRE Token is generated using dynamic time-based rules. The time reference used in DRE is based on the order of the day in the year (day of the year). Performance measurement in this research is based on the Hamming distance. The test results show that the system performs quite good. The average distance among outputs is about 258 bits of 512 bits input. The results also show that the DRE program's execution time is quite fast, i.e. not more than 24 ms.

2016 4th International Conference on Information and Communication Technology (ICoICT), 2016

Teacher have an important role in Indonesia's education as professional educator in all grade... more Teacher have an important role in Indonesia's education as professional educator in all grade. Teacher certification held to select teacher who fullfil basic competence as educator. Indonesia used scoring method with several assesment to make the decision about teacher certification. In this research, we applied the alternative method using Fuzzy Inference System (FIS). Hybrid algorithm with Evolutionary Programming (EP) algorithm was used to optimize the membership function and rules of FIS. The result from hybrid fuzzy-EP is compared with result from scoring method using confusion matrix. Fuzzy hybrid with EP have accuracy is 78.8% with accuracy of testing 85.6%.

2016 4th International Conference on Information and Communication Technology (ICoICT), 2016

Currently, the data storage medium in digital form are widely applied in various fields, includin... more Currently, the data storage medium in digital form are widely applied in various fields, including in the medical world. The excessive size of the digital medical image digital poses problems in terms of storage and the time to transmit these images through the Internet. To overcome these problems, a digital image compression can be conducted. This procedure is conducted to maintain the image quality therefore it does not affect the outcome of a medical image diagnosis. In [1], it has carried out and examined the implementation of the wavelet-based image compression SVD, where the quantity process using graph coloring and for entropy encoding using Arithmetic Coding. In this paper, the data used is a medical image. Furthermore, it has been designed an image compression system based on Integer Wavelet Transform (IWT) and SVD. Graph-based quantization used still refers to [1], but entropy encoding used is adaptive Huffman coding. In addition, IWT used in this system because it is reversible. Performance compression system designed to produce an average PSNR value in the range of 50-53 dB and the compression ratio ranges from 78-85%.

A set of vertices S resolves a graph G if every vertex is uniquely determined by its vector of di... more A set of vertices S resolves a graph G if every vertex is uniquely determined by its vector of distances to the vertices in S. The metric dimension of G is the minimum cardinality of a resolving set of G. Let {G 1 , G 2 ,. .. , G n } be a finite collection of graphs and each G i has a fixed vertex v 0 i or a fixed edge e 0 i called a terminal vertex or edge, respectively. The vertexamalgamation of G 1 , G 2 ,. .. , G n , denoted by V ertex − Amal{G i ; v 0 i }, is formed by taking all the G i 's and identifying their terminal vertices. Similarly, the edgeamalgamation of G 1 , G 2 ,. .. , G n , denoted by Edge − Amal{G i ; e 0 i }, is formed by taking all the G i 's and identifying their terminal edges. Here we study the metric dimensions of vertex-amalgamation and edge-amalgamation for finite collection of regular graphs: complete graphs and prisms.