• Journal of Advanced Marine Engineering and Technology
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• v.40 no.2
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• pp.96-101
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• 2016

The thermal management of high-power LED components in an assembly structure is crucial for the stable operation and proper luminous function. This study employs numerical tools to determine the optimum thermal design in LEDs with a heat sink consisting of a crevice-type vapor-chamber heat pipe. The effects of the MCPCB are investigated in terms of the substrate thicknesses on which the LEDs are mounted. Further, different placement configurations in a system module are considered. This study found that for a confined area, a power of 40 W/LED is applicable to a high-power package. Furthermore, the thermal conductivity of dielectric layer materials should ideally be greater than 0.9 W/m.K. The temperature conditions of the vapor chamber in a heat pipe greatly affect the thermal performance of the system. At an offset distance of 9.0 mm and a $2^{\circ}C$ increase in the temperature of the heat pipe, the resulting maximum temperature increase is approximately $1.9^{\circ}C$ for each heat dissipation temperature. Finally, at a thermal conductivity of 0.3 W/m.K, it was found that the total thermal resistance changes dramatically. Above 1.2 W/m.K, the resistance change reduces exponentially.

• Smart Structures and Systems
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• v.16 no.4
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• pp.607-621
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• 2015

Wireless sensor technology has been opened up numerous opportunities to advanced health and maintenance monitoring of civil infrastructure. Compare to the traditional tactics, it offers a better way of providing relevant information regarding the condition of building structure health at a lower price. Numerous domestic buildings, especially longer-span buildings have a low frequency response and challenging to measure using deployed numbers of sensors. The way the sensor nodes are connected plays an important role in providing the signals with required strengths. Out of many topologies, the dense and sparse topologies wireless sensor network were extensively used in sensor network applications for collecting health information. However, it is still unclear which topology is better for obtaining health information in terms of greatest components, node's size and degree. Theoretical and computational issues arising in the selection of the optimum topology sensor network for estimating coverage area with sensor placement in building structural monitoring are addressed. This work is an attempt to fill this gap in high-rise building structural health monitoring application. The result shows that, the sparse topology sensor network provides better performance compared with the dense topology network and would be a good choice for monitoring high-rise building structural health damage.

• International journal of advanced smart convergence
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• v.9 no.3
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• pp.227-231
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• 2020

Recently, the importance of user experience (UX) has been rapidly increasing. Its utilization is emphasized for development of systems, products, and services. User experience is widely used across industries including services, products, processes, society, and culture. Therefore, if it is unsatisfactory, it is likely to have a direct negative impact on the corresponding system, product, or service. The failure to analyze user experience causes significant damage to the project, which may lead to its failure or redevelopment; it is hence necessary to prioritize the verification of UX in the earliest stages of development. The requirements development stage, which is a preceding stage, is an appropriate stage for the verification of user experience because the identification of user needs is completed and prototypes can be implemented. In this paper, we proposed a systematic requirements development stage; it adds user experience verification activities to the requirements development stage, using the Honeycomb model, which is a widely used tool for verifying the overall UX. User experience verification was added to the existing requirements development activities, which consisted of three steps: model definition and requirements placement, discussions between external and internal stakeholders, and review by internal stakeholders. By easily validating the user experience through this systematic requirements development stage, we expect to minimize the damage to the project due to the failure of the user experience analysis and increase the possibility of success.

• The Journal of Advanced Prosthodontics
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• v.7 no.5
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• pp.380-385
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• 2015

PURPOSE. The aim of this study was to determine the frequency of significant panoramic radiographic findings and eventual treatment requirements before conventional or implant supported prosthetic treatment in asymptomatic edentulous patients. MATERIALS AND METHODS. A total of 743 asymptomatic edentulous patients were retrospectively evaluated using a digital panoramic system. We analyzed the radiographic findings, including impacted teeth, retained root fragments, foreign bodies, severe atrophy of the posterior maxillary alveolar bone, mucous retention cysts, soft tissue calcifications and radiopaque-radiolucent conditions. RESULTS. Four-hundred-eighty-seven (65.6%) patients had no radiographic finding. A total of 331 radiographic findings were detected in 256 (34%) patients. In 52.9% (n=175) of these conditions, surgical treatment was required before application of implant-supported fixed prosthesis. However, before application of conventional removable prosthesis surgical treatment was required for 6% (n=20) of these conditions. CONCLUSION. The edentulous patients who will have implant placement for implant-supported fixed prosthesis can frequently require additional surgical procedures to eliminate pathological conditions.

• The Journal of Advanced Prosthodontics
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• v.13 no.2
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• pp.117-125
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• 2021

PURPSE. The aim of this study was to evaluate the labio-lingual alterations of the alveolar bone where the implant was placed immediately after tooth extraction. MATERIALS AND METHODS. Implants were placed immediately after tooth extraction on anterior alveolar ridges in the maxilla and mandible. The pinguide system was used to help determine the location and path of implants during the surgical process. The horizontal distance from implants to the outer border of alveolar bone was measured at the rim and middle of the implants in the cone beam computed tomography images. The alteration of alveolar bone was evaluated comparing the horizontal distances measured immediately after surgery and 3 months after surgery. RESULTS. The results show that more resorption occurred towards the labial bone than the lingual bone in the maxilla. A similar amount of labial and lingual bone resorption was observed in the mandible. CONCLUSION. Considering the horizontal alteration of alveolar bone, labio-lingual positioning of the implant towards the lingual bone in the maxilla and at the center of the alveolar ridge in the mandible is recommended when it is placed immediately after tooth extraction.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.3
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• pp.360-368
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• 2010

A SCR catalytic filter system is used for reducing $NO_x$ and soot emissions simultaneously from diesel combustors. The amount of ammonia (as a reducing agent) must be controlled with the amount of $NO_x$ to obtain an optimal $NO_x$ conversion. Hence, gas mixing between ammonia and exhaust gases is vital to ensure that the SCR catalyst is optimally used. If ammonia mass distribution is not uniform, slip potential will occur in rich concentration areas. At lean areas, on the other hand, the catalyst is not fully active. The better mixing is indicated by the higher uniformity of ammonia mass distribution which is necessary to be considered in SCR catalytic filter system. The ammonia mass distributions are depended on the flow field of fluids. In this study, the velocity field of gaseous flow is investigated to characterize the transport of ammonia in SCR catalytic filter system. The influence of different injection placements on the ammonia mass distribution is also discussed. The results show that the ammonia mass distribution is more uniform for the injector directed radially perpendicular to the main flow of inlet at the gravitational direction than that at the side wall for both laminar (Re = 640) and turbulent flows (Re = 4255). It is also found that the mixing index decreases as increasing the heating temperature in the case of ammonia injected at the side wall.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.1
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• pp.61-70
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• 2020

In this study, the IOT-based desk layout method was proposed to complement the existing seating method and to improve the work efficiency. The IoT system for the desk layout needs determining the function, type and network protocol of the sensor to find out the working status of the desk to reasonably assist the worker's seat placement. A collection method was proposed. The algorithm used in Block Stacking was used when deciding how to allocate seats using the acquired data. As a result, we could suggest an arithmetic basis for rational desk layout in IoT environment and show that it can be applied to an advanced flexible seating system based on working type in addition to the preferences of employees in the future.

• Journal of Periodontal and Implant Science
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• v.35 no.2
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• pp.449-460
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• 2005

Objectives Aim of this study was to evaluate the clinical use and the efficacy of Frialit-2 implant system. Experimental Methods Fifty nine patients received placement of Frilalit-2 implants(137 implants) in their maxillary anterior and posterior sites(40 and 97 implants). Intraoral & clinical examination, chart review and radiographs were taken from each patient. Results 1. The total implant survival rate was 92.7% after a mean follow-up period of 19.9 months. 2. The implant survival rate placed in anterior region was 97.5%. 3. The implant survival rate placed in posterior region was 90.7%. 4. The implant survival rate placed in atrophic posterior maxilla with advanced technique (GBR, Sinus elevation) was 87.2%. 5. The implant survival rate placed in type N(D4) bone was 82%, while 95.7% in type III (D3), and 100% in type II(D2) bone. 6. Most of the failed implants(7 of 10) were removed during the maintenance stage after prosthodontic treatment. Conclusion It was concluded that Frialit-2 implant could be used satisfactorily in the esthetic anterior region, but the use in the posterior region, especially with poor bone quality and quantity, further studies are needed.

• The Journal of Korean Academic Society of Nursing Education
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• v.6 no.2
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• pp.327-344
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• 2000

The purpose of this survey study is to guide the direction of the RN-BSN program in Korea by analyzing (1) the philosophy and objectives (2) curriculum (3) and appraisal method, achievement test and self-directed learning. In this study, subjects consisted of 20 department of nursing in University and 20 RN-BSN programs in Korea. The Survey was conducted from September 1999 through May 2000 by mail and FAX. 1) Educational philosophy and objectives of 5 RN-BSN programs have curricular based philosophy. Most popular philosophies were revealed that nursing is oriented role function, human relation, and integrated application. 9 RN-BSN programs have curricular based objectives. There are including of knowledge, applying the new technology, under-standing of human being family community, application of nursing process, leadership, nursing ethics, and participation in research. 2) In RN-BSN programs, total mean credits through general college courses for earning the degree of BSN is 21.5 and total mean credits through the nursing area for earning the degree of BSN is 71.4. In RN-BSN programs, total mean credits through clinical practice for earning the degree of BSN is 5.94. 25.00 of mean credits was earned through achievement test(6.00~37.00). Therefore, this research suggests some recommendation for the development of curriculum of RN-BSN program that was required to do some alterations. And the various and other methods of earning credit should be developed. That is, the students will earn credits, accredited examination of University, advanced placement examination, case study, self-report, self-directed learning and achievement tests, portfolio review session and so on. And the RN-BSN courses are delivered to many areas by teleconferencing system, computer network(EdNet or Internet etc), CD-ROM Title, VOD (video on demand) and other methods.

• Journal of Advanced Navigation Technology
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• v.21 no.3
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• pp.306-311
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• 2017

In the future ubiquitous network, information will collect data from various sensors in the field. Since the sensor nodes are equipped with small, often irreplaceable, batteries with limited power capacity, it is essential that the network be energy-efficient in order to maximize its lifetime. In this paper, we propose an effective network routing method that can operate with low power as well as the transmission of data and information obtained from sensor networks, and identified the number of sensors with the best connectivity to help with the proper placement of the sensor. These purposes of this research are the development of the sensor middle-ware to integrate the maritime information and the proposal of the routing algorithm for gathering the maritime information of various sensors. In addition, for more secure ship navigation, we proposed a method to construct a sensor network using various electronic equipments that are difficult to access in a ship, and then construct a communication system using NMEA(the national marine electronics association), a ship communication standard, in the future.