• Korean Journal of Human Ecology
• /
• v.22 no.3
• /
• pp.455-471
• /
• 2013

The purpose of this study was to investigate on what kinds of consumer confusion exist and how much confusion consumers experience during their information search process. In-depth interviews and a questionnaire survey with college students were conducted to figure out the type and the level of consumer confusion. Results showed that college students were somewhat confused when they chose information channel and when they understood and used the chosen information. It was found that confusion was due to partly because of too many information and partly because of the lack of consumer searching skill.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.29A no.10
• /
• pp.49-56
• /
• 1992

A new global routing algorithm which dynamically adjusts its cost parameters depending on the given routing poroblem to find a near optimum solution has been developed. The proposed algorithm efficiently performs global routing on general area in which all the pin positions are given. This algorithm is composed of two phases`In the first phase, it routes each net by searching a minimum cost path while ignoring the channel capacity. In the second iterative phase, it rips up nets which pass the channel at which the horizontal or vertical routing density exceeds the capacity and then it reroutes them using a modified set of cost parameters. Applying the above phases, paths for nets are found such that routing density doesn't exceed the capacity in each channel and that nets are routed with minimum cost. Experimental results for several benchmark examples including difficult-4, difficult-8, difficult-16, Primary1 and Primary2 show that our method generates better results than other published ones.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.13 no.5
• /
• pp.2718-2731
• /
• 2019

Conjunctive keyword search encryption is an important technique for protecting sensitive data that is outsourced to cloud servers. However, the process of searching outsourced data may facilitate the leakage of sensitive data. Thus, an efficient data search approach with high security is critical. To solve this problem, an efficient conjunctive keyword search scheme based on ciphertext-policy attribute-based encryption is proposed for cloud storage environment. This paper proposes an efficient mechanism for removing the secure channel and resisting off-line keyword-guessing attacks. The storage overhead and the computational complexity are regardless of the number of keywords. This scheme is proved adaptively secure based on the decisional bilinear Diffie-Hellman assumption in the standard model. Finally, the results of theoretical analysis and experimental simulation show that the proposed scheme has advantages in security, storage overhead and efficiency, and it is more suitable for practical applications.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.29 no.5
• /
• pp.961-971
• /
• 2019

Isolation between virtual machines in a cloud computing environment is an important security factor. The violation of isolation between virtual machines leads to interferences of shared resources and the implementation of covert channels. In this paper, the structure of Hyper-V hypervisor is analyzed to implement covert channels between virtual machines. Hyper-V uses a mutex technique for mutual exclusion between virtual machines. It indicates that isolation of virtual machines is violated and covert channels can be implemented due to mutex. We implemented several covert channels by designing a method for searching mutex resources applicable to Hyper-V with complex architectures. The mutex-based covert channel is not hardware dependent. If the covert channel is detected or defended, the defensive technique can be avoided by using the other covert channel among several covert channels.

• Journal of Korea Multimedia Society
• /
• v.10 no.10
• /
• pp.1284-1294
• /
• 2007

In this paper, a blind nonlinear channel equalization is implemented by using a Modified Fuzzy C-Means (MFCM) algorithm. The proposed MFCM searches the optimal channel output states of a nonlinear channel from the received symbols, based on the Bayesian likelihood fitness function instead of a conventional Euclidean distance measure. Next, the desired channel states of a nonlinear channel are constructed with the elements of estimated channel output states, and placed at the center of a Radial Basis Function (RBF) equalizer to reconstruct transmitted symbols. In the simulations, binary signals are generated at random with Gaussian noise. The performance of the proposed method is compared with that of a hybrid genetic algorithm (GA merged with simulated annealing (SA): GASA), and the relatively high accuracy and fast searching speed are achieved.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 2007.05a
• /
• pp.382-388
• /
• 2007

In this paper, a modified Fuzzy C-Means (MFCM) algorithm is presented for nonlinear blind channel equalization. The proposed MFCM searches the optimal channel output states of a nonlinear channel from the received symbols, based on the Bayesian likelihood fitness function instead of a conventional Euclidean distance measure. Next, the desired channel states of a nonlinear channel are constructed with the elements of estimated channel output states, and placed at the center of a Radial Basis Function (RBF) equalizer to reconstruct transmitted symbols. In the simulations, binary signals are generated at random with Gaussian noise. The performance of the proposed method is compared with that of a hybrid genetic algorithm (GA merged with simulated annealing (SA): GASA), and the relatively high accuracy and fast searching speed are achieved.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.9A
• /
• pp.714-721
• /
• 2005

In this parer, we analyze the preamble model in the OFDMA/TDD(OFDM-FDMA/Time Division Duplexing). Besides, under AWGN, ITU-R M.1225 Ped-B and Veh-A channel environments, we analyze capabilities of symbol timing & carrier frequency offset and performance of cell searching capabilities applied to OFDM/TDD system through computer simulation. The performance using Detection Probability, False Alarm Probability, Missing Probability, Mean Acquisition Time and MSE(Mean Square Error) is analyzed. Especially, in the case of symbol timing offset estimation, the preamble structure and its algorithm with enhanced performance are proposed and then compared with existing ones.

• Annals of Clinical Neurophysiology
• /
• v.8 no.1
• /
• pp.44-47
• /
• 2006

Background: The present study used magnetoencephalography (MEG) to investigate the neural substrates for modified version of Treisman's visual search task. Methods: Two volunteers who gave informed consent participated MEG experiment. One was 27- year old male and another was 24-year-old female. All were right handed. Experiment were performed using a 306-channel biomagnetometer (Neuromag LTD). There were three task conditions in this experiment. The first was searching an open circle among seven closed circles (open condition). The second was searching a closed circle among seven uni-directionally open circles (closed condition). And the third was searching a closed circle among seven eight-directionally open circles (random (closed) condition). In one run, participants performed one task condition so there were three runs in one session of experiment. During one session, 128 trials were performed during every three runs. One participant underwent one session of experiment. The participant pressed button when they found targets. Magnetic source localization images were generated using software programs that allowed for interactive identification of a common set of fiduciary points in the MRI and MEG coordinate frames. Results: In each participant we can found activations of anterior cingulate, primary visual and association cortices, posterior parietal cortex and brain areas in the vicinity of thalamus. Conclusions: we could find activations corresponding to anterior and posterior visual attention systems.

• The Journal of Korea Robotics Society
• /
• v.16 no.4
• /
• pp.291-298
• /
• 2021

In this study, we present a multi-sensor module for snake robot searching survivors in a narrow space. To this end, we integrated five sensor systems by considering the opinions of the first responders: a gas sensor to detect CO₂ gases from the exhalation of survivors, a CMOS camera to provide the image of survivors, an IR camera to see in the dark & smoky environment, two microphones to detect the voice of survivors, and an IMU to recognize the approximate location and direction of the robot and survivors. Furthermore, we integrated a speaker into the sensor module system to provide a communication channel between the first responders and survivors. To integrated all these mechatronics systems in a small, compact snake head, we optimized the positions of the sensors and designed a stacked structure for the whole system. We also developed a user-friendly GUI to show the information from the proposed sensor systems visually. Experimental results verified the searching function of the proposed sensor module system.

• Journal of the Korean Home Economics Association
• /
• v.37 no.10
• /
• pp.11-26
• /
• 1999

As the social change has been occured by industrialization and urbanization, making valuable family culture has come to be a social task. The development of family culture education program is required to create future - oriented family culture. This study aims at searching for the direction of family culture education program in Korea development to sere creating desirable family culture. For this study the concepts of family culture and family culture education were defined and the characteristics and problems of Korean family culture were discussed. Based on these discussion, the direction of family culture educational program was proposed. The directions of Korean family culture education program were suggested promotion communitarian consciousness, balancing between traditional and modern value, creating democratization among generations and genders, eqyipping with constructive communication channel, and encouraging autonomy and creativity. To work out these directions, appropriate and educational model should be mobilized to incilude whole family.