• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.5
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• pp.1662-1681
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• 2015

The efficient send and receive of information in VANET improves the efficiency of the safety and traffic services advertisment and discovery. However, if the V2V is the only communication system used, the restrictions of the urban environment and network drop the performance of VANET. In order to improve the performance of the network, it is necessary to use V2I communication as well as V2V communication. Therefore, RSUs must be placed in the environment. However due to the high costs of placement, the full coverage of the environment would not be possible. Therefore, it is necessary to optimally install a limited number of RSUs in the environment.

• Proceedings of the Korean Society of Computer Information Conference
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• 2020.07a
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• pp.369-370
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• 2020

최근 크로스 미디어 이용의 확대로 일방적으로 제품의 정보를 받아들이던 수동적인 소비자는 직접 정보를 찾아보는 능동적 소비자로 바뀌었다. 따라서 대중들은 단순히 방송을 시청만 하는 것이 아니라 방송 중에 나오는 인물, 스토리, 제품 등에 대한 다양한 정보를 함께 소비하고 있다. 하지만 시청에 사용되는 디바이스와 검색에 사용되는 디바이스가 달라 불편함이 있고 방송과 검색의 시점의 차이로 대중들은 간접광고를 접한 후 대상제품의 구체적인 정보를 얻는데 어려움이 있다. 또한 제품회사는 간접광고를 접한 시청자들의 반응을 통한 간접광고의 효과를 입증하기 어렵다. 이 논문에서는 간접광고에서 제품 정보의 즉각적 검색을 지원하는 인터렉티브 동영상 플랫폼을 제안하고자 한다. 이를 통해 시청자는 본 방송을 시청하는 도중 관심이 가는 제품이 나왔을 때, 이벤트를 주어 화면 속 제품의 구체적인 정보를 빠르게 제공받을 수 있고 제품회사에서는 인터렉티브한 시청자의 반응을 제공받아 간접광고에 대한 효과를 확인할 수 있도록 한다.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.11a
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• pp.136-160
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• 2002

Most important to financial institutions is to provide well designed and built services to the customers by accessing their core bank systems and affiliated systems in their partners. This will be essential to introduce new products and services and still be able to count on legacy and collaborative affiliated systems. Winning the war on such service competitions among financial institutions is attainable by seizing the "e-bank" opportunities in B2Bi and CRM (Customer Relationship Management). Such application integrations among systems and "e-bank" services need to be available in the new IT environment. In this article, an If and service architecture adopting unified e-business services platform is proposed. This architecture is able to achieve application integrations among legacy, affiliated, and e-business systems and services. We derive an architecture in unified e-business services platform by investigating current and future e-business services platforms involved in domestic and global international banks. Several financial interchange standards which are involved in B2B business of e-procurement, e-placement, e-payment are also investigated.

• Journal of Korean Neurosurgical Society
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• v.58 no.1
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• pp.9-13
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• 2015

Objective : To improve pedicle screw placement accuracy with minimal radiation and low cost, we developed specially designed K-wire with a marker. To evaluate the accuracy of thoracolumbar pedicle screws placed using the novel guide-pin and portable X-rays. Methods : Observational cohort study with computerized tomography (CT) analysis of in vivo and in vitro pedicle screw placement. Postoperative CT scans of 183 titanium pedicle screws (85 lumbar and 98 thoracic from T1 to L5) placed into 2 cadavers and 18 patients were assessed. A specially designed guide-pin with a marker was inserted into the pedicle to identify the correct starting point (2 mm lateral to the center of the pedicle) and aiming point (center of the pedicle isthmus) in posteroanterior and lateral X-rays. After radiographically confirming the exact starting and aiming points desired, a gearshift was inserted into the pedicle from the starting point into the vertebral body through the center of pedicle isthmus. Results : Ninety-nine percent (181/183) of screws were contained within the pedicle (total 183 pedicle screws : 98 thoracic pedicle screws and 85 lumbar screws). Only two of 183 (1.0%) thoracic pedicle screws demonstrated breach (1 lateral in a patient and 1 medial in a cadaver specimen). None of the pedicle breaches were associated with neurologic or other clinical sequelae. Conclusion : A simple, specially designed guide-pin with portable X-rays can provide correct starting and aiming points and allows for accurate pedicle screw placement without preoperative CT scan and intraoperative fluoroscopic assistance.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.7
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• pp.51-58
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• 2010

Wireless Mesh Network has drawn much attention due to wide area service coverage with low system cost. However, there is a bottleneck problem in wireless mesh network since the traffic is aggregated into a gateway. Placement of multi-radio can easy the bottleneck problem, but without careful design it results in unnecessary system cost increasement. In this paper, we propose a system cost minimization through differential antenna placement where optimum antenna placement is determined by the required wireless link capacity. With CPLEX program, optimum number of antennae is determined as a function of local user traffic and gateway capacity. From numerical analysis, it is confirmed that our proposed model can solve bottleneck problem, and at the same time save the system cost.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.5
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• pp.26-37
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• 2009

This paper suggests a sensor's placement method for detecting the dilemma zone problem when real-time driver's safety service is provided at signalized intersections by multiple pointed traffic sensors using USN environments. For detecting the dangerous situations from vehicles accelerating through yellow intervals, red-light running and stopping abruptly like as dilemma zone problem, VISSIM(microscopic, behavior-based multi-purpose traffic simulation program) is used to perform a real-time multiple detection situation by changing the input data like as various inflow-volume, design speed change, driver perception and response time. As a result, the optimal interval of traffic sensors is 20~27m, and the initialized sensor location from stop-line is different according to road design speed. Moreover, the pattern of detection about dilemma zone is also different according to inflow-volumes. This paper shows that the method is useful to evaluate the sensor's placement problem based on micro-simulation and the results can be used as the basic research for USN services.

• Journal of Periodontal and Implant Science
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• v.52 no.3
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• pp.194-205
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• 2022

Purpose: This study aimed to determine the long-term outcomes after peri-implantitis treatment and the factors affecting these outcomes. Methods: This study included 92 implants in 45 patients who had been treated for peri-implantitis. Clinical data on the characteristics of patients and their implants were collected retrospectively. The change in the marginal bone level was calculated by comparing the baseline and the most recently obtained (≥3 years after treatment) radiographs. The primary outcome variable was progression of the disease after the treatment at the implant level, which was defined as further bone loss of >1.0 mm or implant removal. A 2-level binary logistic regression analysis was used to identify the effects of possible factors on the primary outcome. Results: The mean age of the patients was 58.7 years (range, 22-79 years). Progression of peri-implantitis was observed in 64.4% of patients and 63.0% of implants during an observation period of 6.4±2.7 years (mean±standard deviation). Multivariable regression analysis revealed that full compliance to recall visits (P=0.019), smoking (P=0.023), placement of 4 or more implants (P=0.022), and marginal bone loss ≥4 mm at baseline (P=0.027) significantly influenced the treatment outcome. Conclusions: The long-term results of peri-implantitis treatment can be improved by full compliance on the part of patients, whereas it is impaired by smoking, placement of multiple implants, and severe bone loss at baseline. Encouraging patients to stop smoking and to receive supportive care is recommended before treatment.

• Korean Journal of Mathematics
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• v.29 no.2
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• pp.371-386
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• 2021

This paper investigates two discrete time queueing inventory models with positive service time and lead time. Customers arrive according to a Bernoulli process and service time and lead time follow geometric distributions. The first model under discussion based on replenishment of order upto S policy where as the second model is based on order placement by a fixed quantity Q, where Q = S - s, whenever the inventory level falls to s. We analyse this queueing systems using the matrix geometric method and derive an explicit expression for the stability condition. We obtain the steady-state behaviour of these systems and several system performance measures. The influence of various parameters on the systems performance measures and comparison on the cost analysis are also discussed through numerical example.

• Korean Institute of Interior Design Journal
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• v.26 no.3
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• pp.121-129
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• 2017

The study is to identify the status of the ward of public hospital for integrated nursing care service. Integrated nursing service has expanded nationwide from 2016 but 10 out of 34 public hospitals are currently unable to operate as nurses due to the shortage. Analyze each floor plan and space program of ward and provide the basic data for the construction of the architecture plans for Integrated nursing care service. For this study, selecting 14 wards of public hospital in Korea and then analyzes space organization, distance from NS to bedroom and NS to core(Elevator) and spatial hierarchy of them. Among the 14 public hospitals, there are 7 types of double-loaded corridor, 4 types of double corridor and 3 types of single corridor. If NS is placed centrally, the control of the outsider and the patient's control would be efficient, but most of NS are lean on one side of floor. the placement of NS should be independent of individual arrangements, but it should be smooth alignment with patient spaces, staff spaces, and public spaces. This study could serve as basic research for the architectural plan for future integrated nursing care in ward of public hospital.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.26 no.1
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• pp.17-23
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• 2017

Purpose: This retrospective study is to evaluate whether the timing of implant placement and the result of esthetic outcomes are related. Materials and Methods: Among the patients who had undergone single implant surgery on anterior area from 2010 to 2013 in Veterans Health Service Medical Center, 34 implants in 27 patients (24 male and 3 female) were selected and categorized into 3 groups according to the timing of placement, which are group D (Delay), group E (Early) and group I (Immediate). Aesthetic indices used included the Pink Esthetic Score (PES). It has 7 variables scores, such as mesial papilla, distal papilla, a level of soft-tissue margin, soft-tissue contour, alveolar process, soft-tissue color, and soft-tissue texture. Each variable ranges from 0 to 2, therefore total 14 points are highest. All patients were received by regular follow-up at least 1-year. One examiner measured PES on the intraoral photos. Each patient was considered as a statistical unit for statistical analysis. Statistical analyses were performed using a commercially available statistical software (SPSS Statistics 21.0, IBM Corp., Armonk, NY, USA). Kruskal-Wallis test was used for inter-group comparisons. Statistical significance was set at P<0.05. Result: Mean score in Group D, Group I, and Group E were $11.5{\pm}1.5$, $11.4{\pm}1.8$, and $11.3{\pm}1.8$ respectively. In Kruskal-Wallis test, there are no differences (P=0.989). Conclusion: In this limited study suggests that clinical aesthetic results can be achieved with all treatment protocols. Finally, various factors can be considered to produce the esthetic results.