• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.2
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• pp.1064-1079
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• 2019

Information security has become increasingly important with the rapid development of mobile devices and internet. An efficient encryption system is a key to this end. In this paper, we propose an image encryption method based on the cross diffusion of two chaotic maps. We use two chaotic sequences, namely the Logistic map and the Chebyshev map, for key generation which has larger security key space than single one. Moreover, we use these two sequences for further image encryption diffusion which decreases the correlation of neighboring pixels significantly. We conduct extensive experiments on several well-known images like Lena, Baboon, Koala, etc. Experimental results show that our algorithm has the characteristics of large key space, fast, robust to statistic attack, etc.

• Journal of Internet Technology
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• v.22 no.6
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• pp.1287-1297
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• 2021

Data aggregation is the significant process in which the information is gathered and combines data to decrease the amount of data transmission in the WSN. The sensor devices are susceptible to node attacks and security issues such as data confidentiality and data privacy are extremely important. A novel technique called Ruzicka Index Regressive Homomorphic Ephemeral Key Benaloh Cryptography (RIRHEKBC) technique is introduced for enhancing the security of data aggregation and data privacy in WSN. By applying the Ruzicka Index Regressive Homomorphic Ephemeral Key Benaloh Cryptography, Ephemeral private and public keys are generated for each sensor node in the network. After the key generation, the sender node performs the encryption using the receiver public key and sends it to the data aggregator. After receiving the encrypted data, the receiver node uses the private key for decrypting the ciphertext. The key matching is performed during the data decryption using Ruzicka Indexive regression function. Once the key is matched, then the receiver collects the original data with higher security. The simulation result proves that the proposed RIRHEKBC technique increases the security of data aggregation and minimizes the packet drop, and delay than the state-of-the- art methods.

• Information and Communications Magazine
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• v.19 no.7
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• pp.56-71
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• 2002

Third generation mobile radio systems (3G) are currently being deployed in different regions of the world. Future systems beyond 3G are already under discussion in international bodies and forums such as ITU, WWRF and R&D programs of the European Union and in other regions. These systems will determine the research and standardization activities in mobile and wireless communication in the next years. Based on the experience of 3G future systems will be developed mainly from the user perspective with respect to potential services and applications including traffic demands. Therefore, the Wireless World Research Forum (WWRF) was launched in 2001 as a global and open initiative of manufacturers, network operators, SMEs, R&D centers and the academic domain. WWRF is focused on the vision of such systems the Wireless World - and potential key technologies. This paper describes the international context of activities on systems beyond third generation, the goals, objectives and structure of WWRF, the user perspective as the starting point for a future system design and the key enabling technologies for the Wireless World.

• Journal of Advanced Navigation Technology
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• v.16 no.2
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• pp.330-339
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• 2012

In this paper, we define and design the Streaming as a Service (StraaS) to support streaming service based on cloud computing. And we describe the various function and security to StraaS service. Specially, we introduce KS-MMA(Key-generation System for Multilateral Matching Authentication) and SIES(Searchable Image Encryption System) as security function for streaming service and cloud computing.

• Phonetics and Speech Sciences
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• v.4 no.1
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• pp.77-87
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• 2012

Interest in music recognition has been growing dramatically after NHN and Daum released their mobile applications for music recognition in 2010. Methods in music recognition based on audio analysis fall into two categories: music recognition using audio fingerprint and Query-by-Singing/Humming (QBSH). While music recognition using audio fingerprint receives music as its input, QBSH involves taking a user-hummed melody. In this paper, research trends are described for music recognition using audio fingerprint, focusing on two methods: one based on fingerprint generation using energy difference between consecutive bands and the other based on hash key generation between peak points. Details presented in the representative papers of each method are introduced.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.914-916
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• 2003

Most current 3D digital maps are 2.5 dimension models based on DEM, which can only be recognized, browsed and operated by a special software, far from meeting the needs of a modern digital city (global) with the distributed, isomerous and multiple application on the real 3D representation and open sharing models. In this paper, a new generation digital city oriented 3D digital map is studied. Firstly, a real 3D digital map representation is presented. And then, some key techniques and methods for browser-based 3D digital map’s representation, display and operation are introduced, which can realized the open sharing of 3D map in distributed, isomerous and multiple application environment. Furthermore, the scale driving technique of proposed 3D digital map is also studied. And currently, some developments based on some of the above methods are being carried to provide key and general platform for other application software’s development.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.6161-6176
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• 2018

Pseudorandom numbers are useful in cryptographic operations for using as nonce, initial vector, secret key, etc. Security of the cryptosystem relies on the secret key parameters, so a good pseudorandom number is needed. In this paper, we have proposed a new approach for generation of pseudorandom number. This method uses the three dimensional combinational puzzle Rubik Cube for generation of random numbers. The number of possible combinations of the cube approximates to 43 quintillion. The large possible combination of the cube increases the complexity of brute force attack on the generator. The generator uses cryptographic hash function. Chaotic map is being employed for increasing random behavior. The pseudorandom sequence generated can be used for cryptographic applications. The generated sequences are tested for randomness using NIST Statistical Test Suite and other testing methods. The result of the tests and analysis proves that the generated sequences are random.

• Journal of the Ergonomics Society of Korea
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• v.26 no.1
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• pp.103-109
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• 2007

Representative human models (RHMs), a group of digital human models which represent the people of the target population within a designated percentage (e.g., 95%), are used for ergonomic design and evaluation in virtual environments. The present study evaluated the grid approach, a RHM generation method, in terms of accommodation percentage. RHMs generated from the grid approach dramatically decreased the accommodation percentage of the target population as the number of anthropometric dimensions under consideration increased. For example, the accommodation percentages by RHMs generated by the grid approach were 95% for 3 key dimensions (selected among 10 anthropometric dimensions), 45% for 5 dimensions, and 10% for 10 dimensions. A standardized multiple regression analysis found that this decreasing accommodation percentage was caused by low correlations between key dimensions and other dimensions. The accommodation evaluation process used in the present study is applicable to evaluation of other RHM generation methods.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.2
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• pp.27-32
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• 2005

This paper presents the optimization of expanding velocity for tube expanding process in the manufacturing of a heat exchanger. In specific, the expanding velocity has a great influence on the performance of a heat exchanger because it is a key variable determining the quantity of tube expending at assembly stage as well as a key Parameter determining overall production rate. The simulation showed that the genetic algorithm used in this paper resulted in the optimal tube expanding velocity by performing the following series of iteration; the generation of arbitrary population for tube expanding parameters, consequently the generation of tube expanding velocities, the evaluation of tube expanding quantity using the pre-trained data of plastic deformation by means of a neural network and finally the generation of next population using a penalty faction and a Roulette wheel method.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2211-2220
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• 2015

This paper analyzes multiple active management (AM) techniques of active distribution network (ADN), and proposes an optimal coordination model of intermittent distributed generation (IDG) accommodation considering the timing characteristic of load and IDG. The objective of the model is to maximize the daily amount of IDG accommodation under the uncertainties of IDG and load. Various active management techniques such as IDG curtailment, on-load tap changer (OLTC) tap adjusting, voltage regulator (VR) tap adjusting, shunt capacitors compensation and so on are fully considered. Genetic algorithm and Primal-Dual Interior Point Method (PDIPM) is used for the model solving. Point estimate method is used to simulate the uncertainties. Different scenarios are selected for the IDG accommodation capability investigation under different active management schemes. Finally a modified IEEE 123 case is used to testify the proposed accommodation model, the results show that the active management can largely increase the IDG accommodation and penetration.