• Journal of Internet Computing and Services
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• v.19 no.5
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• pp.55-66
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• 2018

Since existing server-based authentications use vulnerable password-based authentication, illegal leak of personal data occurs frequently. Since this can cause illegal ID compromise, alternative authentications have been studied. Recently token-based authentications like OAuth 2.0 or JWT have been used in web sites, however, they have a weakness that if a hacker steals JWT token in the middle, they can obtain plain authentication data from the token, So we suggest a new authentication method using the verification token of authentic code to encrypt authentication data with effective time. The verification is to compare an authentication code from decryption of the verification-token with its own code. Its crypto-method is based on do XOR with ECDH session key, which is so fast and efficient without overhead of key agreement. Our method is outstanding in preventing the personal data leakage.

• The KIPS Transactions:PartC
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• v.11C no.1
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• pp.31-38
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• 2004

In mobile agent environments, migration of an agent occurs continuously due to the mobility of agents. So cascaded delegation can occur among places for delegating the privilege to execute the agent. Because the existing delegation scheme considers only the delegation between two places that participate in migration of an agent, it does not support secure cascaded delegation. In this paper, we propose a cascaded delegation scheme that provides agents with secure cascaded delegation in mobile agent environments. Depending on the trust-relationship among places, the proposed scheme achieves the goal by nesting each delegation token or by nesting only initial token signed by creator of the agent within the signed part of the next immediate delegation token. And we prove that the proposed scheme is secure against the attack of replaying a message and the attack of substituting a delegation token.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.5
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• pp.35-42
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• 2008

In this paper, we propose a fast coeff_token decoding method based on the re-constructed VLCT. Since the conventional decoding method is still based on large memory accesses, it is not suitable for the multimedia services such as PMP, PMB, DVH-H where fast decoding and low power consumption are required. Based on the analysis for the codeword structure, new structure of the codeword and the corresponding memory architecture are developed in this paper. The simulation results show that the proposed algorithm achieves memory access saving from 10% to 57%, compared to the conventional decoding method. This meant that the issues of tow power consumption and high speed decoding can be resolved without video-quality and coding efficiency degradation.

• Child Health Nursing Research
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• v.5 no.3
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• pp.318-327
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• 1999

Oral medication is one of the most frequent treatment in clinical care. and frequently refused by children. Children's refusal spends unuseful time and require nurses'Patience. So this study was attempted to develop token economy Program which Promote children's medication. and to evaluate its' effect to construct the experimental ground. This study was a quasi experimental study under the nonequivalent control group non-synchronized design. The subjects of this study were 48 children who were aged 3-12 years and admitted pediatric ward because of their respiratory disease. Token economy program was consisted of cartoon record paper with stickers which expresses the better medication is taken the more germs die, and gift was given for back up reinforcer. To evaluate this Program. time spent for oral medication was measured six time to both experimental group and control group. and measured the perceived effectiveness of this program by nurses. To determine the effect of the program, the data were analyzed by the SAS 6.12 Program with t-test and mean, standard deviation. The results of this study were as follows: 1 In experimental group, time spent for oral medication was significantly shorter than in control group(t=5.24. p=0.0001). Therefore, the hypothesis of this study was strongly accepted. 2. Nurses perceived this program as an effective one(mean=3.125～3.792). The effectiveness occurred before. during and after medication as well as in parental responses, especially in using verbal dissatisfaction after medication. In conclusion. it was found that the token economy program for admitted children was effective in inducing the children's behavior of oral medication. There was no effectiveness in very highly anxious children Whereas, it is recommended that this program should not be used for such children until they settle down. If the token economy program was made in various situation with creative thinking, it will be very useful nursing measurement, especially in caring for children. To improve the qualify of nursing care, the various programs, which can give joyfulness to stressed patients should be developed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.1976-1985
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• 2015

The amount of packets in palyout buffer of video streaming receiver can be changed by network condition, and saturated and exhausted by the delay and jitter. Especially, if the amount of incoming video traffic exceeds the maximum allowed playout buffer, buffer overflow problem can be generated. It makes the deterioration of video image and the discontinuity of playout by skip phenomenon. Also, if the incoming packets are delayed by network confusion, the stop phenomenon of video image is made by buffering due to buffer underflow problem. To solve these problems, this paper proposes the video streaming receiver with token bucket scheme which automatically establishes the important parameters like token generation rate r and bucket maximum capacity c adapting to the pattern of video packets. The simulation results using network simulator-2 (NS-2) and joint scalable video model (JSVM) show that the proposed token bucket scheme with automatic establishment parameter provides better performance than the existing token bucket scheme with manual establishment parameter in terms of the generation number of overflow and underflow, packer loss rate, and peak signal to noise ratio (PSNR) in three test video sequences.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.2
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• pp.377-391
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• 2019

Recently, system studies using tokens and block chains for authentication, access control, etc in IoT environment have been going on at home and abroad. However, existing token-based systems are not suitable for IoT environments in terms of security, reliability, and scalability because they have centralized characteristics. In addition, the system using the block chain has to overload the IoT device because it has to repeatedly perform the calculation of the hash et to hold the block chain and store all the blocks. In this paper, we intend to manage the access rights through tokens for proper access control in the IoT. In addition, we apply the Tangle to configure the P2P distributed ledger network environment to solve the problem of the centralized structure and to manage the token. The authentication process and the access right grant process are performed to issue a token and share a transaction for issuing the token so that all the nodes can verify the validity of the token. And we intent to reduce the access control process by reducing the repeated authentication process and the access authorization process by reusing the already issued token.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.1
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• pp.63-70
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• 2009

Recently, in the security token based authentication system, there is an increasing trend of using fingerprint for the token holder verification, instead of passwords. However, the security of the fingerprint data is particularly important as the possible compromise of the data will be permanent. In this paper, we propose an approach for secure fingerprint verification by distributing both the secret and the computation based on the fuzzy vault(a cryptographic construct which has been proposed for crypto-biometric systems). That is, a user fingerprint template which is applied to the fuzzy vault is divided into two parts, and each part is stored into a security token and a server, respectively. At distributing the fingerprint template, we consider both the security level and the verification accuracy. Then, the geometric hashing technique is applied to solve the fingerprint alignment problem, and this computation is also distributed over the combination of the security token and the server in the form of the challenge-response. Finally, the polynomial can be reconstructed from the accumulated real points from both the security token and the server. Based on the experimental results, we confirm that our proposed approach can perform the fuzzy vault-based fingerprint verification more securely on a combination of a security token and a server without significant degradation of the verification accuracy.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.11
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• pp.1206-1218
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• 1992

Token ring systems which control to switch the data stream of networks by passing the token have been widely used to medium access controls in many ring or bus topology LANs. The system could be modeled for analysis as single-server-multi-queue system of the cyclic service method. These concepts could be expanded to multi-token ring systems interconnected with single ring consisting of bridges implemented simply to be stored and transmitted. In the proposal for the performance analysis of the interconnected token ring system, in has been assumed M/G/1 queueing model that frame arrivals are the Poisson process at each station queue and frame sizes are independently and identically distributed. And the average time delays were analyzed mathematically for arbitrary frame transferred from source station to destination area. The time delay of the frame transmission could be explained as the sum of the average time which the token passed from arbitrary position to source station, such as the waiting time in the source station transferring the previous arrival frames, and the propagation time from source station to interdestinated point. These delays were given as the sum of the duration from inner and outer bridge queues, the time delays from inner and outer bridge queues, and the time from outer bridge queue to destination station. These results were investigated by varing parameters effected to total time delays. In the results, those factors to be effected to dominant the total time delays were increased were in the cases of the high arrival rates and the high ration of destination of the other outerring. The system were shown the time delays increased exponentially in spite of the priority service policy. In order to decreasing the number of outerrings and increasing the number of nodes in backbone relatively, so the systems could be decreased the total delay in the interconnected token ring system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.23-30
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• 2009

This paper addresses the design of trTCM (Two Rate Three Color Marker) described in RFC2698. It has proposed for trTCM to be used in Differentiated Service network that provides AF PHB (Assured Forwarding Per Hop Behavior). trTCM is the marker with the metering function, and consists of the token updating function and the marking function. The token updating function uses the dual token bucket. The marking function compares the token values with the length of input packet and then marks the result into IP QoS field (ToS field). In this paper, we design trTCM function and then addresses the scheme to implement it using FPGA technology.

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.4
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• pp.40-46
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• 1999

This paper introduce a Koran-Japanese machine translation system which is a module in the spoken language interpreting system It is implemented based on the TDMT(Transfre Driven Machine Translation). We define a new unit of translation so called TOKEN. The TOKEN-based translation method resolves nonstructural feature in Korean sentences and increases the quaity of translating results. In our system, we get rid of useless effort for traditional parsing by performing semi-parsing. The semi-parser makes the dependency tree which has minimum information needed generating module. We constructed the generation dictionaries by using the corpus obtained from ETRI spoken language database. Our system was tested with 600 utterances which is collected from travel planning domain The success-ratio of our system is 87% on restricted testing environment and 71% on unrestricted testing environment.