• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.1
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• pp.1-11
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• 1999

In this paper, we proposed a design method of parameterized viterbi decoder, which automatically synthsizes the diverse viterbi deciders used in the digital mobile communication systems. It is designed to synthesize a viterbi decoder specified by user-provided parameters. Those parameters are constraint length, code rate generator polynomials of teh convolutional encoder, data rate and bits/frame of the data transmission, and soft decision bits of viterbi decoder. For the design of the parameterized viterbi decoder, we designed a user interface module C-language, and a viterbi decoder module in a hierarchical atructure using VHDL language and its generic statement. For the verification of the parameterized viterbi decoder, we compared our synthesized viterbi decoder with the conventional viterbi decoder which is designed for the IS-95 CDMA system. The proposed design method of the viterbi decoder will be a new method to obtain a required viterbi decoder in a very short time only by supplying the design parameters.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.1
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• pp.476-496
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• 2018

With the advancement and deployment of wireless communication techniques, wireless body area network (WBAN) has emerged as a promising approach for e-healthcare that collects the data of vital body parameters and movements for sensing and communicating wearable or implantable healthful related information. In order to avoid any possible rancorous attacks and resource abuse, employing lightweight ciphers is most effective to implement encryption, decryption, message authentication and digital signature for security of WBAN. As a typical lightweight cryptosystem with an extended sponge function framework, the PHOTON family is flexible to provide security for the RFID and other highly-constrained devices. In this paper, we propose a differential fault analysis to break three flavors of the PHOTON family successfully. The mathematical analysis and simulating experimental results show that 33, 69 and 86 random faults in average are required to recover each message input for PHOTON-80/20/16, PHOTON-160/36/36 and PHOTON-224/32/32, respectively. It is the first result of breaking PHOTON with the differential fault analysis. It provides a new reference for the security analysis of the same structure of the lightweight hash functions in the WBAN.

• Science of Emotion and Sensibility
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• v.13 no.4
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• pp.777-788
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• 2010

Early diagnosis of autism and intervention of medical treatment are very significant to develop specific social communication skill for children with autistic spectrum disorders (ASDs). But they have difficulties in medical treatment because of lack of a public welfare institution and special medical system. In particular, few children can access such treatment and the existing single-therapist clinics are inefficient with regard to cost and time. Therefore, new methods should be studied for developing various products, services, and systems for autistic children. This study discusses the potential use of an interactive design as assistive technology for such children. We utilize the experience gained in the collaborative design of the interactive therapy system (ITS). The key methods include a collaborative design with rapid interactive prototyping, heuristic evaluation, user-centered process, VR technology, tangible interface, and scenario-based contents. We applied these methods to the ITS and proved the efficiency of interactive design as an assistive technology through clinical experimentation.

• Korean Institute of Interior Design Journal
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• no.22
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• pp.61-68
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• 2000

This paper illustrates what the reality of architectural concepts, materials, notions and phenomena are as central questions of contemporay space design. These issues form the goal of modern space design which should attain to the reality of an era when non-real values prevail. Despite the trends of an everchanging and ephemeral dominating quality in architecture for the last ten years, architects still aim to contruct everlasting space on earth. The trends of dematerialization in today's space design can be substantiated in spatial-temporal dimensions as follows. First of all, ephemeral architecture with concepts of hypothetical temporality, everchanging architecture in fluidity, and the transparent architecture with the floating and overlapping image can be analyzed in the dimension of 'time'. In terms of 'space', void quality for the expression of emptiness, neutral space by the simplified and summarized forms, expanded space through ambiguous boundaries and spatial repetition can becharacterized and also be intended strategies for lightness, state of flux, ambiguity, paradox etc., lead modern space design along that path. As this point, we need to pay attention to the so-called 'hypersurface' concept proposed by Stephen Perella. Hypersurface is a sort of cladding sheathing existence independent from the primary structure. With it, the integration between form and image can be achieved. Sometimes hypersurface can be a strategical screen for image projection, a cognitive receptor for surroundings as well as a catalyst for information and communication systems. When the situation dematerializes more and more as the years go on, the concept of hypersurface can be an inclusive method between the phenomenological form in architecture and its self recipient image. Permissive atmospheres created between them in contemporary space design and new paradigms emerged with digital technology will further reinforce the human space's dynamism.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.200-212
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• 2004

Electronic Navigational Chart is a sophisticated digital chart which contains navigational information such as coastline, depth of water, and nautical mark. It contains high levels of textual, spatial and graphical data, and rapidly replaces traditional paper charts. Although Electronic Navigational Chart has been successfully applied to the navigation of ships, the specific data format, S-57, requires some specialized systems. Furthermore its usage may be limited to specific domains and experts with restrictions. To overcome these limitations resulting from the specific data format, S-57, of Electronic Navigational Chart, more general data format such as XML will be preferred. If Electronic Navigational Chart is transformed into the form of XML, it can be easily accessed and exchanged on the internet. Therefore it may be used for more users and applications. In this paper, we propose an XML. Schema to equivalently represent XML for the S-57 format of Electronic Navigational Chart and develop a program translating the S-57 Electronic Navigational chart to XML document according to the proposed XML schema.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.18-27
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• 2004

In this paper, we presents an analytical simulation procedure for evaluation in baseband digital modulated signals distortions in the present of RF power amplifier(SSPA) nonlinear behavior and backoff operations of OFDM wireless transmission system. we obtained the optimum nonlinear transfer function of designed SSPA with the SiGe HBT bias currents of OFDM multi-channel wireless transmission system and compared this transfer function to SSPA nonlinear modeling functions mathematically, we finds optimum bias conditions of designed SSPA. With the derived nonlinear modeling function of SSPA, We analysed the PSD characteristics of in-band and out-band output powers of SSPA EVM measurement results of distorted constellation signals with the input power levels of SSPA. The results of paper can be applied to find the SSPA linearly with optimum bias currents and determine the SSPA input backoff bias for AGC control circuits of SSPA.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.1
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• pp.43-50
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• 2013

File identification and analysis is an important process of computer forensics, since the process determines which subjects are necessary to be collected and analyzed as digital evidence. An efficient file classification aids in the file identification, especially in case of copyright infringement where we often have huge amounts of files. A lot of file classification methods have been proposed by far, but they have mostly focused on classifying malicious behaviors based on known information. In copyright infringement cases, we need a different approach since our subject includes not only malicious codes, but also vast number of normal files. In this paper, we propose an efficient file classification method that relies on undocumented information in the header of the PE format files. Out method is useful in copyright infringement cases, being applied to any sort of PE format executable file whether the file is malicious, packed, mutated, transformed, virtualized, obfuscated, or not.

• KIPS Transactions on Computer and Communication Systems
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• v.7 no.5
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• pp.111-118
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• 2018

The effects of the Fourth Industrial Revolution on manufacturing are spreading by policies to secure or strengthen the manufacturing competitiveness of each country. Strengthening policies on manufacturing necessitate nurturing manpower for smart manufacturing. This study examines the difference of the experts' perception about the educational curriculum to develop the knowledge of Product Lifecycle which covers the whole knowledge area of product development among the knowledge areas aimed at fostering the manpower of smart manufacturing for the $4^{th}$ Industrial Revolution Era. Experts were aware that future developments in digital development, production, and new product development are most important, and that they feel that the whole knowledge area is generally weak. In this study, the implications for the development of educational curriculum in the future are derived from the perception difference of knowledge on Product Lifecycle obtained through expert survey.

• Journal of Biosystems Engineering
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• v.40 no.3
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• pp.165-177
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• 2015

Purpose: Accurate monitoring of soil strength is a key technology applicable to various precision agricultural practices. Soil strength has been traditionally measured using a cone penetrometer, which is time-consuming and expensive, making it difficult to obtain the spatial data required for precision agriculture. To improve the current, inefficient method of measuring soil strength, our objective was to develop and evaluate an in-situ system that could measure horizontal soil strength in real-time, while moving across a soil bin. Methods: Multiple cone-shape penetrometers were horizontally assembled at the front of a vertical plow blade at intervals of 5 cm. Each penetrometer was directly connected to a load cell, which measured loads of 0-2.54 kN. In order to process the digital signals from every individual transducer concurrently, a microcontroller was embedded into the measurement system. Wireless data communication was used between a data storage device and this real-time horizontal soil strength (RHSS) measurement system travelling at 0.5 m/s through an indoor experimental soil bin. The horizontal soil strength index (HSSI) measured by the developed system was compared with the cone index (CI) measured by a traditional cone penetrometer. Results: The coefficient of determination between the CI and the HSSI at depths of 5 cm and 10 cm ($r^2=0.67$ and 0.88, respectively) were relatively less than those measured below 20 cm ($r^2{\geq}0.93$). Additionally, the measured HSSIs were typically greater than the CIs for a given numbers of compactor operations. For an all-depth regression, the coefficient of determination was 0.94, with a RMSE of 0.23. Conclusions: A HSSI measurement system was evaluated in comparison with the conventional soil strength measurement system, CI. Further study is needed, in the form of field tests, on this real-time measurement and control system, which would be applied to precision agriculture.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.925-938
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• 2010

Depending on network conditions, a communication network could be overloaded when media are transmitted. Research has been carried out to lessen network overloading, such as by filtering, load distribution, frame dropping, and other methods. Among these methods, one of the most effective is frame dropping, which reduces specified video frames for bandwidth diminution. In frame dropping, B-frames are dropped and then I- and P-frames are dropped, based on the dependency among the frames. This paper proposes a scheme for protecting copyrights by encryption, when frame dropping is applied to reduce the bandwidth of media based on the MPEG-4 file format. We designed two kinds of frame dropping: the first stores and then sends the dropped files and the other drops frames in real time when transmitting. We designed three kinds of encryption methods using the DES algorithm to encrypt MPEG-4 data: macro block encryption in I-VOP, macro block and motion vector encryption in P-VOP, and macro block and motion vector encryption in I-, P-VOP. Based on these three methods, we implemented a digital rights management solution for MPEG-4 data streaming. We compared the results of dropping, encryption, decryption, and the quality of the video sequences to select an optimal method, and found that there was no noticeable difference between the video sequences recovered after frame dropping and the ones recovered without frame dropping. The best performance in the encryption and decryption of frames was obtained when we applied the macro block and motion vector encryption in I-, P-VOP.