• Journal of Internet Computing and Services
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• v.9 no.2
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• pp.83-88
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• 2008

Session initiation protocol (SIP) is an application-layer prolocol to initiate and control multimedia client session. When client ask to use a SIP service, they need to be authenticated in order to get service from the server. Authentication in a SIP application is the process in which a client agent present credentials to another SIP element to establish a session or be granted access to the network service. In 2005, Yang et al. proposed a key exchange and authentication scheme for use in SIP applications, which is based on the Diffie-Hellman protocol. But, Yang et al.'s scheme is not suitable for the hardware-limited client and severs, since it requires the protocol participant to perform significant amount of computations (i.e., four modular exponentiations). Based on this observation. Huang and Wei have recently proposed a new efficient key exchange and authentication scheme thor improves on Yang et al.'s scheme. As for security, Huang and Wei claimed, among others, that their scheme is resistant to offline dictionary attacks. However, the claim turned out to be untrue. In this paper, we show thor Huang and Wei's key exchange and authentication scheme is vulnerable to on offline dictionary attack and forward secrecy.

• The Journal of the Acoustical Society of Korea
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• v.43 no.2
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• pp.200-206
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• 2024

Computing music similarity is an indispensable component in developing music search service. This paper proposes a relevance weight of each chromagram vector for cover song identification in computing a music similarity function in order to boost identification accuracy. We derive a music similarity function using the relevance weight based on the probabilistic relevance model, where higher relevance weights are assigned to less frequently-occurring discriminant chromagram vectors while lower weights to more frequently-occurring ones. Experimental results performed on two cover music datasets show that the proposed music similarity improves the cover song identification performance.

• The Journal of the Acoustical Society of Korea
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• v.29 no.1
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• pp.34-40
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• 2010

As internet spread widely, various service which use the internet have been provided. One of the service is a internet phone. Its usage is increasing by the advantage of cost. But it has a falling off in quality of speech. because it use packet switching method while existing telephone use circuit switching method. Although vocoder use PLC (Packet Loss Concealment) algorithm, it has a weakness of continuous packet loss. In this paper, we propose methods to improve a lowering in quality of speech under continuous loss of packet by using PLC algorithm used in advanced G.729 and G.711. The proposed methods are LP (Linear Prediction) parameter interpolation, excitation signal reconstruction and excitation signal gain reconstruction. As a result, the proposed method shows superior performance about 11%.

• Management & Information Systems Review
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• v.3
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• pp.257-285
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• 1999

Korea Postal Service(KPS) nowadays lies in competitive environment with alternative business such as door-to-door delivery service. Customers began to complain about postal service quality and ask the government to reform a public firm through management innovation. But, Korea Postal Service has not met the break-even point between it's revenue and expenditure because the service is under the government system and cannot independently make major decisions on products, pricing, services, personnel management, financial policies and etc. The objective of this study is to provide marketing planners and practitioners with some guidelines when they establish marketing strategies and to help marketers on theories and practical instructions about postal service marketing when they interact with customers. I. A field survey on both customer satisfaction and internal staff satisfaction was conducted to get some ideas for the marketing strategy planning. II. Practical guidelines and instructions were made for marketers to communicate with customers in various areas such as pricing, product, service demand, marketing channel, promotion, and etc. III. Some suggestions on marketing policies for planners and mangers in the marketing strategy were described including personnel resource as well as physical resource. IV. Special issues on small packet market and direct mail market were discussed and some alternative solutions were proposed. V. Database marketing strategy was emphasized to get new business opportunities such as direct mail, and to provide differential services to customers as much as their contribution into the profitability for KPS. VI. Cyber Post Office should be constructed on Internet to provide new services which are combined with physical material flow and information technologies.

• Journal of the Korea Society of Computer and Information
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• v.4 no.2
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• pp.46-60
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• 1999

Recently, CTI (Computer Telephony Integration) technology has been widely applied to various area such as video conference, file transfer, voice mail, automatic message transfer and automatic redial, integrated messaging and network fax. In this paper, an administrative affairs supporting system using call control mode of CTI is designed. To improve inefficient processing of job due to heavy calling from entrance candidates during entrance examination of a college, the system is developed. The database of the system is desigend using object modeling technique. Also, the automatic calling and response system using CTI call control mode is implemented. Especially, to interface with voice of candidates who ask whether they pass or fail the entrance examination of the college, TTS(Text To Speech) module is developed.

• Physical Therapy Korea
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• v.7 no.1
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• pp.64-78
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• 2000

As in house care is develops and becomes part of the health care delivery system in Korea, it is necessary to quantify the viewpoints of in-patients and outpatients. The purposes of this study are to analyze the utilization of house visits by physical therapist and to investigate the viewpoint of in- and out-patients who had rehabilitation treatment at 3 general hospitals in Wonju, Korea. Two hundred and fifty-eight questionnaires were analyzed and the major findings are as follows: 1. Sixty-five point seven percentage of respondents showed their willingness to utilize house visits by physical therapist if an in house physical therapy program were established. 2. The questionnaire used a Likert-type scale to ask the respondents their viewpoints on in house physical therapy services. Most respondents showed a positive attitude, answering 'I agree'. The findings show that house visits by physical therapists should be introduced as an integral system for the delivery of health care in Korea.

• Journal of Digital Contents Society
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• v.7 no.3
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• pp.169-174
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• 2006

In recent years, RFID is widely used in industrial applications including factory, material flow, logistics and defense areas. In this paper, The convolutional encoding and viterbi decoding is also implemented to improve the system performance. in an FPGA chip. The used convolution code is constraint length K=3 and rate R=1/2. The length of command frame and response frame is total of 48bits consisting of SOF 8 bits, command 16 bits, CRC 16 bit, and EOF 8 bits. And also the frame error rates are measured under the channel of line-of-sight and non line-of-sight, respectively. The performances are analyzed with FSK modulation only and FSK modulation added with convolutional encoding. These two measured results are compared with that of a RFID system with ASK modulation.

• Journal of Korean Society of Rural Planning
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• v.24 no.3
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• pp.63-71
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• 2018

The comparison of demand and supply is needed for efficient ecosystem services planning. However, the gap between them cannot be analyzed as existing studies mainly dealt with only the supply of ecosystem services. This study compares the demand and supply of ecosystem services in Shiheung using environmental complaints and urban planning by semantic network analysis. As a result, 'air' and 'water' quality are magnified in demand, 'energy' and 'water' are crucial in supply. This result presents that citizen ask for the improvement of air quality in regulation services, although local government has plans for energy support in provisioning services. Periodic ecosystem services demand and supply monitoring will be the base of effective ecosystem services planning, which reduce insufficiency and surplus.

• Korean Journal of Health Education and Promotion
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• v.25 no.5
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• pp.21-38
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• 2008

Objective: This study examined the use of mental health helping systems among college students in Korea. A behavioral model of health service utilization was applied to examine factors influencing different types of helping systems. Methods: A total of 454 college students from four universities participated in the survey. A self-administered questionnaire measuring help-seeking behaviors including formal health and mental health services, informal helping system, peer group, and family support was used. Results: Respondents frequently turn to family members and peer group when in need, and age, sex, mental Health status, and attitude and knowledge on mental illness were significant factors affecting help-seeking behaviors of Korean students. While older students and those with more severe symptoms were more likely to seek help from formal resources, students with more severe symptoms were less likely to seek help from informal resources. Male students and those with negative attitude toward mental illness were less likely to ask peer groups for help. Conclusions: Study results indicate that informal resources and peer groups can be significant sources of social support for individuals in their late adolescence and young adulthood, however, their role as gateways to professional help is limited. Student counseling centers should take on a more active role in reaching out; implications for developing peer leaders as counselors and self-help groups are discussed.

• Journal of Digital Convergence
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• v.17 no.6
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• pp.417-426
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• 2019

This researched is an investigation about the youths runaways street life experienced, the crimes committed through the influenced living in the street by looking into the effectiveness of the youth welfare and make an observation of their direction. The survey was conducted on young people who met in the youth shelter and outreach program, and finally analyzed 259 copies. The results of the study are as follows. First, When comparing the ages of the runaway youths if not properly given a support, services and prevention after running away from home, these youth will live their life in the street until their adolescents. Second, Runaway youth shelter has been providing the needs of those runaway youth who came in the shelter. However, it needs necessary new policy and services that will augment the support in solving problems of the youths when they visit youth shelter to ask for help and support. Third, It can be seen that the flight behavior after the street life is increased. They are in a situation where they have no choice but to join the juveniles for street life. Finally, Street life Youth self-reliance, support for living expenses, housing facilities, job opportunities, technical and job skill training were highly desired by the youths. Eventually, the intervention of youth living in street life requires a multifaceted support such as housing, labor, education, and welfare.