• Journal of KIISE:Computing Practices and Letters
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• v.12 no.3
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• pp.192-207
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• 2006

Today, the SSL protocol has been used as core part in various computing environments or security systems. But, the SSL protocol has several problems, because of the rigidity on operating. First, SSL protocol brings considerable burden to the CPU utilization so that performance of the security service in encryption transaction is lowered because it encrypts all data which is transferred between a server and a client. Second, SSL protocol can be vulnerable for cryptanalysis due to the key in fixed algorithm being used. Third, it is difficult to add and use another new cryptography algorithms. Finally. it is difficult for developers to learn use cryptography API(Application Program Interface) for the SSL protocol. Hence, we need to cover these problems, and, at the same time, we need the secure and comfortable method to operate the SSL protocol and to handle the efficient data. In this paper, we propose the SSL component which is designed and implemented using CBD(Component Based Development) concept to satisfy these requirements. The SSL component provides not only data encryption services like the SSL protocol but also convenient APIs for the developer unfamiliar with security. Further, the SSL component can improve the productivity and give reduce development cost. Because the SSL component can be reused. Also, in case of that new algorithms are added or algorithms are changed, it Is compatible and easy to interlock. SSL Component works the SSL protocol service in application layer. First of all, we take out the requirements, and then, we design and implement the SSL Component, confidentiality and integrity component, which support the SSL component, dependently. These all mentioned components are implemented by EJB, it can provide the efficient data handling when data is encrypted/decrypted by choosing the data. Also, it improves the usability by choosing data and mechanism as user intend. In conclusion, as we test and evaluate these component, SSL component is more usable and efficient than existing SSL protocol, because the increase rate of processing time for SSL component is lower that SSL protocol's.

• Korea Journal of Hospital Management
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• v.8 no.4
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• pp.59-75
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• 2003

This study was conducted to investigate the degree of utilization of outsourcing in large hospitals in Korea. We also investigated the outcome and the level of satisfaction for adopting outsourcing in these hospitals. Types of work areas that were currently operated by outsourcing and were planned to adopt outsourcing in the future were identified. A total of 83 hospitals were eligible for this study, which had more than 500 beds, and were identified from the 2003 National Hospital List published by the Korean Hospital Association. A self-administered Questionnaire survey was conducted between April 25th and May 20th in 2003 with a personnel being charged of arrangement of outsourcing in each hospital. Among the 58 hospitals responding the survey(response rate=69.9%), 49 hospitals(84.5%) utilized outsourcing in at least one work field in their organizations. The largest proportion of the hospitals(85.7%) using outsourcing responded that the biggest outcome after introducing outsourcing were cost reduction(49.0%), followed by improved efficiency in operating the organization or human resources(34.7%) and the improved quality of the work(6.1%). The degree of satisfaction for outsourcing among the hospital managers(3.43) was significantly higher than that among the employees(3.l4) on a S-point Likert-type scale(p<0.05). Among the 7 work areas, the hospitals used outsourcing most frequently in facility management(housekeeping, building maintenance, hospital security and parking management), followed by non-medical profit business(funeral, convenient store, and cafeteria), logistics(provision of patient meal, in-house delivery, and purchasing), and information and computing system(hospital information system, maintenance of personal computers and printers). The work areas that the hospitals planned to adopt or expand the outsourcing in the future most frequently were facility management, non-medical profit business, logistics, and information and computing systems. In conclusion, outsourcing was highly diffused in large Korean hospitals, particularly in the work field of facility management and non-medical profit business. The satisfaction for outsourcing was not high yet in Korean hospitals.

• KIPS Transactions on Software and Data Engineering
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• v.7 no.6
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• pp.221-228
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• 2018

With an increase in demand for the high added value of shipbuilding and marine industry based on the information and communications technology (ICT), software technology has become more important than ever in the industry. In this paper, we present the result of our preliminary investigation on the current software development environment in the shipbuilding and marine industry in order to develop reusable software component, which can enhance the competitiveness of software development. The investigation is performed based on the survey answers from 34 developers who are working in different shipbuilding and marine companies. The questionnaire is composed of items to gather the information of each company such as the number of employees and product domain, and actual software development environment such as operating system, programming languages, deployment format, obstacles for developing components, and the adoption of software development methods and tools. According to the results of the survey, the most important consideration to select their development platform was the number of available utilities and the technical supports, followed by performance, price and security problems. In addition, the requirements of various platforms supporting and the higher reliability, and the limitations of low development cost and manpower made it difficult for them to develop reusable software components. Finally, throughout the survey, we find out that only 15% of developers used software development processes and managed the quality to systematically develop their software products, therefore, shipbuilding and marine companies need more technical and institutional support to improve their ability to develop high qualified software.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.5B
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• pp.385-394
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• 2012

The tactical mobile communication network, which comprises a part of the next-generation Tactical Information and Communication Network (TICN), provides means of communication and control for Tactical Multi-Functional Terminals (TMFT) belonging to a Mobile Subscriber Access Point (MSAP). The next-generation of MSAP is capable of constructing a backbone network via LCTR and HCTR directional antennas. At the same time, WMN modules are used to create and manage a wireless mesh backbone. When directional antennas are used in mobile environments, seamless services cannot be efficiently supported as the movement of the node prevents the angle of the antenna to constantly match. Therefore, data communication through the wireless mesh networks is required to provide direct communication between mobile MSAPs. Accordingly, mutual authentication and data encryption mechanisms are required to provide reliable data transmission in this environment. To provide efficient mutual authentication between MSAP devices, the process of verifying a certificate of the other MSAP device through its own authentication server is required. This paper proposes mutual authentication mechanisms where the MSAP requiring authentication and the MSAP that permits it initiates low-cost and efficient authentication in a distributed way. More specifically, we propose a method of applying EAP-ELS (Extensible Authentication Protocol-Transport Layer Security) in the next-generation TICN.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.10
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• pp.40-48
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• 2008

Security of self organized mobile ad hoc networks is an important issue because administration information in the networks is managed by the constituent nodes. Especially authentication mechanism is necessary for trust setup between newly joining nodes and the network. The authentication models and protocols which are based on the wireline infrastructure could not be practical for mobile ad hoc network. Although public key algorithm-based method is widely used for authentication, it is not easy to be applied to mobile ad hoc networks because they do not have infrastructure such as centralized CA which is needed for certificate verification. In this paper, we consider the public key based random CA group method proposed in [1] to provide efficient authentication scheme to mobile ad hoc networks and analyze the performance of the method, which is then compared to the home CA method. From the analysis results, we see that the random CA method where the function of CA is distributed to some mobile nodes and the authentication information is propagated to randomly chosen CAs shows higher reliability and lower cost than home CA method.

• Journal of KIISE:Computing Practices and Letters
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• v.9 no.1
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• pp.1-12
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• 2003

Recently, many researches into distributed processing on Internet, and multimedia data processing have been performed. Rapid and convenient multimedia services supplied with high quality and high speed are to be needed. In this paper, we design and implement clip-based video retrieval system on the Web enviroment in real-time. Our system consists of the content-based indexing system supporting convenient services for video content providers, and the Web-based retrieval system in order to make it easy and various information retrieval for users in the Web. Three important methods are used in the content-based indexing system, key frame extracting method by dividing video data, clip file creation method by clustering related information, and video database construction method by using clip unit. In Web-based retrieval system, retrieval method ny using a key word, two dimension browsing method of key frame, and real-time display method of the clip are used. In this paper, we design and implement the system that supports real-time display method of the clip are used. In this paper, we design and implement the system that supports real-time retrieval for video clips on Web environment and provides the multimedia service in stability. The proposed methods show a usefulness of video content providing, and provide an easy method for serching intented video content.

• Korean Journal of Occupational Health Nursing
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• v.7 no.2
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• pp.164-176
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• 1998

This study deals with the current medical utilization for migrant workers and the characteristics of them. The purpose of this study is to provide the basic information to establish proper medical policy. For the study self-made questionnaire was used, which was answered by 453 migrant workers working in the area of manufacturing and non-technical work in 10 cities like Seoul, Inchon, Namyangju, Sungnam, Kwangju, Pyungchon, Kunpo, Kimpo, Masuk in Kyungki-do and Chunan in Chungchungnam-do. Besides, 303 medical records of those who had visited free medical check-up center were analyzed. The period of accumulating data is 6 months, from November 1st, 1996 to April 30th, 1997. The characteristics of migrant workers and current medical utilization are analyzed by percentage and the relation between characteristics and current medical utilization were analyzed using ${\chi}^2$-test, t-test, ANOVA. The finding of this study was as follows : 1) The number of nationality was 16. The first majority was Philippians as 32.0%. Among 16 nationalities Southeastern and Northern Asians were 48.9%, Southwestern Asian was 46.5%, the rest was 7.3%. Men were 81.0%, those who are aged from 26 to 30 were 39.0%, Graduatee from high school 92.7%, Christians 56.3%, unmarried 55.4% and salary from 600,000 Won to 800,000 Won 53.8% averaging monthly payment 669,810 Won. As for their residence, those who resided over 3 years were 31.9% and the illegal residence reached 77.4%. As for Korean language, those who speak in middle level were 5.6%. 2) As for kind of work and circumstances, manufacturing was 81.1%, 4 off-days per month 72.2% and 9-10 working hours per day 42.1%. As for accommodation, residence in fabric was 62.6% and one or two members as roommate 40.2%. 3) The characteristics of health behavior showed that 89.4% of migrant workers had 3 meals, 70.9% of them did not drink alcohol, 73.5% of them did not smoke. 4) As a characteristic of health status, 71.8% of them perceived of their health. 76.1% thought that they had no illness before coming Korea. Among them who recognized their illness, those who had problem in circulatory system was 35.3%, respiratory system ENT 19.1% and nervous system 19.1%.66.2% of those having illness had already had sickness when coming to Korea. 5) During last one month, 79.2% of them were known as ones having no illness. Among the sick, those who had problem in circulatory system was 31.6%, nervous system 23.7% and respiratory system 21.1%. 60.3% of the sick were not cured at that time. 6) Sorting the symptom of those who visited free medical check up, dental care was 24.2%, orthopedic 14.0% and digestive system 13.8%. Teethache was 34.4%, stomach problem 11.6%, upper respiratory inflammation 10.2% and back pain 5.9%. Averagely they visited free medical check up 1-2 times. According to symptom, epilepsy 25.5 times, heart and vascular disease 9 times, constipation 2.8%, neurosis 2.38 times and stomach problem 2.34 times. 7) The most frequently visited medical service by migrant workers was hospital. The most mentioned reason was good healing as 36.3%. The medical service satisfied migrant workers mostly was hospital as 64.3%. The reason of satisfaction was also good healing as 45.9%. 8) 77.2% of respondents did not spend money for medical check. Average monthly medical cost was 25,100 Won, 3.7% of income. Those who had no medical security was 73.4%. In their case, 67.7% got discount from hospital or support from working place and religious organization. 9) As for the difference of medical utilization according for the characteristics of migrant workers, legal workers and no-Korean speaker used hospital more frequently. 10) Those who were satisfied most of all with the service of hospital were female workers, hinduists and buddhists, legal workers or manufacture workers. 11) Christians, those who have 3 meals or recognize themselves as healthy ones mostly had no illness. As a result, the most of migrant workers in Korea are from Asia. They are good educated but are working in manufacturing and illegal. Their average income is under 700,000 Won which in not enough for medical cost. They have no medical security and medical fee is supported by religious organization or discounted. Considering these facts the medical policy by government is to be established.

• Journal of the Korea Society of Computer and Information
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• v.18 no.9
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• pp.79-89
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• 2013

Recently, the need for outsourcing sensitive data has grown due to the wide spreading of cost-effective and flexible cloud service. However, there is a fundamental concern in using such service since users have to trust external servers. Therefore, searchable encryption can be a very valuable tool to meet the security requirements of data outsourcing. However, most of work on searchable encryption focus only on privacy preserving search function and relatively lacks research on encryption mechanism used to actually encrypt data. Without a suitable latter mechanism, searchable encryption cannot be deployed in real world cloud services. In this paper, we analyze previously used and possible data encryption mechanisms for multi-user searchable encryption system and discuss their pros and cons. Our results show that readily available tools such as broadcast encryption, attribute-based encryption, and proxy re-encryption do not provide suitable solutions. The main problem with existing tools is that they may require separate fully trusted servers and the difficulty in preventing collusion attacks between outsiders and semi-trusted servers.

• Journal of the Korea Society of Computer and Information
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• v.28 no.8
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• pp.103-109
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• 2023

In this paper, we propose a smart wall switch based on IEEE 802.11b/g/n standard 2.4GHz band communication. As the 4th industrial era evolves, smart home solution development is actively underway, and application cases for smart wall switches are increasing. Most of the Chinese products that preoccupy the market through price competitiveness use Bluetooth and Zigbee communication switches. However, while ZigBee communication is low power, communication speed is slower than Bluetooth and network configuration through a separate hub is additionally required. The Bluetooth method has problems in that the communication range and speed are lower than Wi-Fi communication, the communication standby time is relatively long, and security is weak. In this study, an IEEE 802.11b/g/n smart wall switch applied with Wi-Fi communication technology was developed. In addition, through the two-wire structure, it is designed so that no additional cost is incurred through the construction of a separate neutral line in the building. The result of the study is more than 30% cheaper than the existing wall switch, so it is judged that it will be able to preoccupy the market not only in terms of technological competitiveness but also price competitiveness.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.12
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• pp.471-480
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• 2016

Recently, the damage of cyber attack toward infra-system, national defence and security system is gradually increasing. In this situation, military recognizes the importance of cyber warfare, and they establish a cyber system in preparation, regardless of the existence of threaten. Thus, the study of Intrusion Detection System(IDS) that plays an important role in network defence system is required. IDS is divided into misuse and anomaly detection methods. Recent studies attempt to combine those two methods to maximize advantagesand to minimize disadvantages both of misuse and anomaly. The combination is called Hybrid IDS. Previous studies would not be inappropriate for near real-time network environments because they have computational complexity problems. It leads to the need of the study considering the structure of IDS that have high detection rate and low computational cost. In this paper, we proposed a Hybrid IDS which combines C4.5 decision tree(misuse detection method) and Weighted K-means algorithm (anomaly detection method) hierarchically. It can detect malicious network packets effectively with low complexity by applying mutual information and genetic algorithm based efficient feature selection technique. Also we construct upgraded the the hierarchical structure of IDS reusing feature weights in anomaly detection section. It is validated that proposed Hybrid IDS ensures high detection accuracy (98.68%) and performance at experiment section.