• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.110-117
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• 2018

Recently, as weapon systems have become more complex and multi-functional, the difficulty of the operation and maintenance of weapon systems in the military have become increasingly difficult. On the other hand, the service period of operations and maintenance workers who perform operations and maintenance has been shortened, and the skill of system operation and maintenance has been lowered. This complexity and multi-functionality of equipment cause malfunctions and errors of users and maintenance personnel, and degradation of the reliability affects availability and combat readiness. In addition, life cycle costs have been gradually increasing. Therefore, I would like to suggest an improvement plan of the design of weapon systems and ILS (Integrated Logistics Support) in order to examine the implications of failure in the military. The weapon system is operated in the ROK Navy. Data from 730 cases of failure of weapon systems was collected, and analyzed. The results of the analysis are classified into failures that can be prevented in advance and failures that cannot be prevented. This shows the portion of preventable failures in weapon systems and proposes measures to minimize failures.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.5
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• pp.139-150
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• 2018

This paper aims to elaborate the role and availability of the community enterprise as a form of methodology in local regeneration, dealing with urban social problems generated in the process of urban development. In a situation of the increasing skepticism in the capitalism, the instability in public welfare system and disintegration of community, social economy has come to the fore as an alternative. The community enterprise, especially, has shown the potential to form a virtuous cycle in local regeneration system; residents recognize local problems by themselves; discover and utilize the local resources and assets in the process of solving the problems as an entrepreneurial form; and consequently create social and economic capital which can be reinvested in the local community. Given these aspects, Korean government has implemented supporting policies for the promotion of community enterprises, and new government's "Urban Regeneration New Deal Project" are putting more importance on the role of social and community enterprises as a propulsion unit. In this regard, this paper first explores the concept and features of community enterprise in economic and social aspects, whereby it analyzes the capacity of community enterprises as principal agencies or implements in local development. Then, the development status and institutional supports for community enterprises in the UK is revealed, and investigates case studies which are playing a revolutionary role in urban regeneration or local economic revitalization. Based on this analysis, it draws the main factors for the sustainable and autogenous community enterprise as follows: flexibility in legal forms, community owned assets, diverse fund streams and invigorating social investment market, active partnership between public and private sectors, ardent enterprisers and intermediate support organizations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.7
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• pp.2257-2285
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• 2022

Cyber-physical systems (CPS) have been growing exponentially due to improved cloud-datacenter infrastructure-as-a-service (CDIaaS). Incremental expandability (scalability), Quality of Service (QoS) performance, and reliability are currently the automation focus on healthy Tier 4 CDIaaS. However, stable QoS is yet to be fully addressed in Cyber-physical data centers (CP-DCS). Also, balanced agility and flexibility for the application workloads need urgent attention. There is a need for a resilient and fault-tolerance scheme in terms of CPS routing service including Pod cluster reliability analytics that meets QoS requirements. Motivated by these concerns, our contributions are fourfold. First, a Distributed Non-Recursive Cloud Model (DNRCM) is proposed to support cyber-physical workloads for remote lab activities. Second, an efficient QoS stability model with Routh-Hurwitz criteria is established. Third, an evaluation of the CDIaaS DCN topology is validated for handling large-scale, traffic workloads. Network Function Virtualization (NFV) with Floodlight SDN controllers was adopted for the implementation of DNRCM with embedded rule-base in Open vSwitch engines. Fourth, QoS evaluation is carried out experimentally. Considering the non-recursive queuing delays with SDN isolation (logical), a lower queuing delay (19.65%) is observed. Without logical isolation, the average queuing delay is 80.34%. Without logical resource isolation, the fault tolerance yields 33.55%, while with logical isolation, it yields 66.44%. In terms of throughput, DNRCM, recursive BCube, and DCell offered 38.30%, 36.37%, and 25.53% respectively. Similarly, the DNRCM had an improved incremental scalability profile of 40.00%, while BCube and Recursive DCell had 33.33%, and 26.67% respectively. In terms of service availability, the DNRCM offered 52.10% compared with recursive BCube and DCell which yielded 34.72% and 13.18% respectively. The average delays obtained for DNRCM, recursive BCube, and DCell are 32.81%, 33.44%, and 33.75% respectively. Finally, workload utilization for DNRCM, recursive BCube, and DCell yielded 50.28%, 27.93%, and 21.79% respectively.

• Korean Institute of Interior Design Journal
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• v.24 no.6
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• pp.202-211
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• 2015

This study attempts to deduce the necessity and validity of complexation, and suggests complexation through complexation suitability evaluations as follows. First, the concept and current state of leisure facilities for the elderly and elementary facilities and architectural complexation were investigated through theoretical considerations. Second, the target schools for complexation of 'elementary school-leisure facility for the elderly' were selected. The aspects of facility introduction of an elementary school, teacher support facility, convenience facility for the disabled, safety and security facilities as well as school facility accessibility were investigated on the basis of the data attained from theoretical considerations. Third, the feasibility of complexation of leisure facilities for the elderly was reviewed, based on the investigated data on complexation-targeted elementary school. Regarding school building and support facilities, with a focus on leisure programs for the elderly, the availability and number of rooms, extra numbers of regular classrooms and the room condition were assessed on the basis of the analysis of operational perspective of each facility. The convenience facilities for the disabled were examined by classifying them into interventional facility in consideration of facilities for the elderly, pursuant to the provisions in the convenience promotion assurance act for the disabled, elderly and pregnant women. Safety and security facilities were evaluated in an effort to assess the safety issue of the elderly and children. The result of the evaluation of the 6 elementary schools in Seong-buk county based on the above-mentioned four measurement standards shows that they scored 107~124 points out of the total 155 points, with the average of 118.5 points. This is more than the medium score and shows the possible complexation of the elementary school facilities as the leisure facilities for the elderly, and at the same time it may lead each school to find out the elements conducive to enhancing the complexation as a result of the evaluation. Through the evaluation data, I expect that we contribute to promoting the process of the evaluation of the appropriateness of complexation and the efficient complexation.

• Journal of the Korea Society of Computer and Information
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• v.20 no.2
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• pp.99-112
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• 2015

Datum point for displaying location and altitude of point has being advantage usefully in various measurement parts. However, datum point has been increasing loss cases owing to weather changes and stratum changes and neglecting meaninglessly. In this paper, we design and implement a multi electronic measurement system monitoring software with functions such as include maximize utilization of existing measurement datum system as well as collected various environment data and detection stratum changes of surround area. Proposed software is implemented to support that reusability and extensibility of software using object oriented modeling method. Our software supports a GUI for electronic measurement datum point administrator as well as for web user and mobile user. Our system can support a graph GUI for various data analysis and reposition in realtime to database that measured location information and various sensing information to prevent loss of electronic measurement datum point and to detected stratum changes. In addition, we include a QR code and RFID recognition function. Finally, we suggest performance evaluation result to confirm stratum changes detection and GPS location error rate.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.9
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• pp.1575-1583
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• 2008

Wireless sensor network has merit of low-power, low-cost and self-organization network, so there are many researches substituted for existing wire network. As structure reinforcement work need a high accuracy, many sensors are installed in structure and connected with data logger for monitoring. However this wire data logger method takes a long time to install wires and installed wires obstruct to work. Additionally, wire data logger method represent sensor data by only numeric and graph, it is not able to support a rapid decision-making for working. To resolve wiring problem and support decision-making, we designed and implemented the monitoring system based in wireless sensor network. For verifying performance, accuracy and availability, we simulated and tested our system in real field. Consequently, wireless sensor network method is easier to install and deploy than wire data logger method, user is able to monitor instinctively and overall by 3D representation of structure and sensors, and it show not only accuracy but also performance for many sensors.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.228-237
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• 2021

In those day, the Busan local government had instituted a rule to support and enhance competition as well as improve respect for the ship management industry. This study aims to extract the cause factors to enhance such competition using intuitionistic decision making trial and evaluation laboratory (DEMATEL) and interpretive structural modeling (ISM) methods. First, eight factors were extracted from the specifications in the Ship Management Industry Development Act. Second, the intuitionistic fuzzy number was converted to a crisp number using the standard fuzzy number. Third, the influence relationship was analyzed using DEMATEL, and the priority ranks for the factors are determined using ISM. From the results of the impact relationship analysis, the three main cause factors were determined as improvement of technical ship management capability, improvement of expertise of manpower for onshore management, and improvement of the quality of the Korean seafarer. The priorities under the ISM method, in descending order, were as follows: improvement of the quality of Korean seafarers, improvement of professionalism among the manpower for shore management, improvement of technical ship management capability, improvement of commercial ship management capability, establishment of a comprehensive information system, improvement of the working conditions and employment environment for seafarers, financial support such as overseas orders, and strengthening the availability of foreign seafarers. Therefore, it is necessary to prioritize policy promotion based on these factors, especially the top three, as these have the highest impact.

• Journal of Chest Surgery
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• v.29 no.11
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• pp.1218-1222
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• 1996

The reported incidence of postcardiotomy cardiogenic shock not responding to conventional therapy is still 0.1 to 0.8%. For this group of patients, more aggressive form of circulatory support must be employed. Centrifugal pumps are a ventricular assist device most commonly used on this purpose, due to low cost and easy availability. Currently, however, clinical experience of centrifugal pumps as a ventricular assist device is rarely reported in Korea. From January 1992 to January 1996, 2986 patients underwent cardiac operations on cardiopulmonary bypass at Seoul National University Hospital. Refractory postcardiotomy cardiac failure requring ventricular support with a Biomedicus centrifugal pump developed in ten of these patients. There were eight men and two women, ranged in age from nine years to 77 years with a mean of 50$\pm$20 years. The primary surgical procedures consisted of isolated coronary revascularization in four patients, combined coronary revascularization and aortic valve replacement in two, aortic dissection repair in two, pulmonary embolectomy in one, and heart transplantation in one. Of the ten patients, five had left ventricular assistance, one had right ventricular assistance, and four had biventricular assistance. Duration of ventricular assistance ranged from 24 to 175 hours, with a mean of 76$\pm$51 hours. Seven patients were weaned from ventricular assistance, and four of them discharged. The causes of death for nonsurvivors were progressive cardiac failure in two patients and multiorgan failure, intractable ventricular fibrillation, irreversible brain injury, and mechanical problem, respectively, in the other four. Survival was not predicted by time on cardiopulmonary bypass, aortic cross-clamp time, or duration of ventricular support. Major complications included bleeding(7), renal failure(6), infection(3) and neurologic complication(2). These results indicate that a centrifugal pump can provide reasonably satisfactory short-term circulatory support.

• Journal of Broadcast Engineering
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• v.20 no.1
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• pp.110-121
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• 2015

The digital app-book is an advanced form of the electronic book (e-book), which attracts a lot of interests by the help of video, sound, sensors and a variety of interactions. As mobile devices have evolved, the demand of digital app-books is also rising substantially. However, the distribution of digital app-book contents is hard to meet the demand because the digital app-book requires a lot of programming cost for the interaction. To resolve this problem, Was verified and implementation as a library function of the interaction between device and user. The proposed library consists of three parts (user action recognition, device action, and content action) and provides various user-device interaction functions by combining methods of each part, which can support source code reusability, easy understanding and availability, and wide expandibility. The library was used in the development of natural science education app-book contents. As a result, it could reduce a lot of code lines and facilitate more rapid app-book development.

• Journal of Internet Computing and Services
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• v.3 no.5
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• pp.31-39
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• 2002

A rapid growth of internet and sudden increase of multimedia data demands for high-speed transfer media and if optimizec usage from the interface system. To achieve this level of network bandwidth, multiple NICs for support of high-speed network bandwidth have been developed and studied. Furthermore, the use of multiple NICs can provide high-speed LAN environment without large network environment modification, supports backward compatibility of current system and reduce overhead. However. if system failure is caused by SPOF(Single Point of Failure) fault of large-capacity multiple NICs, incredible loss will be met because it services large capacity of multimedia data, Therefore, to prevent loss coming from faults, we describe 'Fault tolerance of multiple NICs', which use the fault prevention mechanism. Considering inefficiency of availability and serviceability that is occurred with existing TMR, Primary-Standby approach and Watchdog time mechanism, we propose and design the efficient fault tolerance mechanism, which minimize down time as changing of detection period dynamically. Consequently, the fault tolerance mechanism proposed for reducing overhead time when the fault is occurred, should minimize system downtime overall.