• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.199-203
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• 2015

With the development of industry these days, the demand for electric power increases and the larger capacity for power transfer is required. The scales of facilities should become larger; and the relative systems are required to operate with a higher degree of reliability. Therefore, stabilization of electric power systems is an important issue. The high degree of reliability required in the process of production and supply of electric power is an essential part of industrial society. Accident such as blackouts causes a hugh amount of economic losses to the high-tech industrial society dependent upon electric power. This paper is about the basic study of the relations between the load current and lifetime of power cables in operation. In order to do the research, we installed a current transformer and an equipment for measuring temperature at the 6.6. kV cables in operation. The two equipments have been installed on the cable systems in operation for the last 20 years. Since the insulation resistance of most of the cables showed the value larger than the threshold, it was not easy to tell the remaining lifetime of cables. The load current of the cables was almost constant. The surrunding temperature was $15{\sim}25^{\circ}C$, little variation of temperature values.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.4
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• pp.19-25
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• 2017

In the reality that the use of the web is becoming commonplace, the general people are complaining about the inconvenience because they are not standardized when using the web site. Especially, the disabled people such as the social underprivileged classes people suffer from the inconvenience due to the web site that is not accessible. The purpose of this study is to conduct an authentication audit to obtain web accessibility certification mark on the homepage of a specific public institution. Through these practical cases, it is possible to improve the recognition of web accessibility by practitioners or managers, And suggest ways to improve the Aging existing public institution web sites. Although there are a lot of existing literature and previous researches, it is still not being newly produced because of lack of awareness of web accessibility, As a result, the users who access the web site of the public institution for the first time are much inconvenienced. In order to solve this problem, this paper compares the Korean web content accessibility guideline 2.1, revised in April 2015, and verified the effectiveness of the guidelines through web accessibility evaluation of specific public institution sites.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.463-472
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• 2018

The aim of this pilot survey was to investigate the presence status, usage problems, and improvement needs of the upper extremity rehabilitation equipment(: UERE) in the department of occupational therapy(: OT) of hospital setting in Korea. The authors received a questionnaires of clinicians working in a department of OT hospital setting through a social network service. Responses of 72 were analyzed in the first questionnaire, and 47 were analyzed in the second questionnaire. In the first questionnaire, the presence status of 16 UERE was confirmed to be 29.2~97.2%, and the usage experience of 9 UERE in the second questionnaire was 36.2~97.9%. In the second questionnaire, UERE's usage problems were reported discomfort in 15(31.9%) of 47 therapists, and improvement needs were 23(49%). The usage problems of the 9 UERE questioned by open-ended questionnaire were uninteresting, easily damaged, level unadjustable, direction unadjustable, and inconvenient installation. The improvement needs were classified into digitization, durability, level adjustable, adjustable function, convenience. The present pilot survey identified the presence status and usage experience of UERE in the department of OT and could be used as a basis for the development of closed-ended questionnaire on usage problems and improvement needs of UERE.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.331-339
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• 2008

Nowadays with advancement in technology and aging society, the number of disabled citizens is increasing. The disabled citizens always need a caretaker for daily life routines especially for mobility. In future, the need is considered to increase more. To reduce the burden from the disabled, various devices for healthcare are introduced using computer technology. The power wheelchair is an important and convenient mobility device. The demand of power wheelchair is increasing for assistance in mobility. In this paper we proposed a robotic wheelchair for mobility aid to reduce the burden from the disabled. The main issue in an autonomous wheelchair is the automatic detection and avoidance of obstacles and going to the pre-designated place. The proposed algorithm detects the obstacles and avoids them to drive the wheelchair to the desired place safely. By this way, the disabled will not always have to worry about paying deep attention to the surroundings and his path. User has a handheld bio-sensor monitoring system for get user's bio-signal. If user detects unusual signal, alarm send to protector.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.8
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• pp.1567-1576
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• 2015

This paper proposes a reliable real-time data dissemination protocol for mitigating transmission failure of real-time data in WSNs. The re-transmission is well-known for recovery of transmission failure, but this may violate the real-time requirement by transmission delay. To solve this problem, the proposed protocol exploits broadcasting nature and temporal opportunity allocation. In a radio-range of sending node, there may be neighbors satisfying the real-time requirement. The neighbors of specific node could receive data simultaneously by broadcasting, and decide their priority using temporal opportunity allocation method. The method uses time slot and tolerable time. The time slot specifies the priority and transmission deadline for each neighbors, and the tolerable time is the real-time requirement at the sending node. By giving the priority to the node with shorter tolerable time in each slot, we may get more opportunities to forward toward the destination. In other words, even if a node have the longer tolerable time, it still has a chance to forward with the real-time requirement. Simulation results show that the proposed protocol is superior to the existing protocols.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.3
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• pp.175-180
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• 2015

With progress in industrialization, facilities for generating, delivering, and receiving high levels of electric power are in great demand. The scale of electric power equipment is increasing in both size and complexity. This has contributed to the development of our modern, high-tech and information-based society. However, if the generation of electric power is suspended due to unexpected accidents at power facilities or power stations, a range of equipment the operations of which are dependent on electric power can be damaged, causing substantial socioeconomic losses in an industrial society. A great deal of time and money would be expended to repair damaged facilities at a power station, causing enormous economic loss.In order to detect the deterioration processes of power cables, and to prevent the destruction of power cables, the operation status of power cables should be monitored on a regular basis. We have installed equipment at Korea Western Power Co., Ltd., located in Taean, in order to predict and prevent the destruction of power cables. This is an entirely new installation: a set of equipment invented specifically to measure the insulation resistance of power cables. Installation of the equipment does not cause the flow of earth fault current. This ensures accurate measurement of insulation resistance values by the equipment. We have been studying this equipment in order to develop preventive technology that would show the deterioration processes of power cables.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1197-1210
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• 2017

This study aimed to compare premature ejaculation and erectile function according to penile characteristics. 99 adult men responded to a questionnaire on penile characteristics, premature ejaculation and erectile function. In the questionnaire survey, 69 questionnaires were analyzed except missing or incomplete answers. All collected data were analyzed by independent t test, Chi-square test using SPSS 22. Glans > penis type showed significant differences in subjective premature ejaculation and objective premature ejaculation compared to Glans ${\frac{._-}{.}$ penis type (p <.05). Men with subjective premature ejaculation showed significant differences in objective premature ejaculation, treatment intent, and satisfaction compared to men without subjective premature ejaculation (p <.05). Presence of objective premature ejaculation, presence of treatment intent, and marital status were significantly different in satisfaction (p <.05). In economic status, high was significantly different in confidence for erectile function compared to middle or low (p <.05). The results of this study suggest that the premature ejaculation and erectile function according to the penile characteristic may be different and may be used as a basis for the development of an intervention program for sexual rehabilitation of men with premature ejaculation and erectile dysfunction.

• Korean Journal of Construction Engineering and Management
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• v.17 no.4
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• pp.49-56
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• 2016

Recent research has been ongoing for modular buildings in the country and interest increases. However, the activation of modular building projects is obstructed in the construction industry. There are many reasons to identity for this obstruction but one issue should be focussed. Modular buildings require to change the existing construction production system to a new construction production system, which is factory production - transportation - erection. However, the existing project delivery system in the public sector could not be adapted for this new construction production system due to the obligation of multi prime contract use, such as electrical, communication, fire fighting contracts by Law. Therefore, modular buildings in the existing project delivery system are separately contracted by multi prime contracts and modular units composed of the buildings are contracted by an architectural prime contractor as a commodity. As results, construction costs are increased, potential quality problems are raised and the existing project delivery system is finally an obstacle not to maximize benefits of the modular buildings. In this paper, we propose a new project delivery system for the modular buildings to adapt then ew construction production system.

• The KIPS Transactions:PartD
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• v.9D no.4
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• pp.587-602
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• 2002

Replicated database system was emerged to resolve the problem of reduction of the availability and the reliability due to the communication failures and site errors generated at centralized database system. But if update transactions are many occurred, the update is equally executed for all replicated data. Therefore, there are many problems the same thing a message overhead generated by synchronization and the reduce of concurrency happened because of delaying the transaction. In this paper, I propose a new concurrency control algorithm for enhancing the degree of parallelism of the transaction in fully replicated database designed to improve the availability and the reliability. To improve the system performance in the replicated database should be performed the last operations in the submitted site of transactions and be independently executed update-only transactions composed of write-only transactions in all sites. I propose concurrency control method to maintain the consistency of the replicated database and reflect the result of update-only transactions in all sites. The superiority of the proposed method has been tested from the respondence and withdrawal rate. The results confirm the superiority of the proposed technique over classical correlation based method.

• The KIPS Transactions:PartC
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• v.15C no.4
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• pp.281-288
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• 2008

Recently, the advance of multimedia hardware has fostered the development of wireless multimedia sensor network which is able to ubiquitously obtain multimedia content such as image or audio from the environment. The multimedia data which has several characteristics such as large size and correlation between the data requires reliability in transmission. However, the existing solution which take the focus on the efficiency of network mainly, is not appropriate to transmit the multimedia data. In the paper, we proposes a reliable asynchronous image transfer protocol, RAIT. RAIT applies double sliding window method in node-to-node image tansfer to prevent the packet loss caused by network congestion. The double sliding window consists of one sliding window for the receiving queue, which is used for prevention of packet loss caused by communication failure between nodes and the other sliding window for the sending queue which prevents the packet loss caused by network congestion. the routing node prevents the packet loss and guarantees the fairness between the nodes by scheduling the packets based on the image non-preemptively. The RAIT implements the double sliding window method by cross layer design between RAIT layer, routing layer, and queue layer. The experiment shows that RAIT guarantees the reliability of image transmission compared with the existing protocol.