• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.11
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• pp.1294-1302
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• 2008

A design approach for a radiation element of dual polarization, which can be implemented in the waveguide structure, is proposed. For minimization of the radiating element, the ridged waveguide type is used and for dual polarization, the microstrip type of printed dipole structure is additionally installed inside the waveguide. In order to validate the design approach, $1{\times}4$ array antenna is fabricated and its performances such as return loss, co-polarization coupling between adjacent channels, and radiation patterns are investigated. Theory and experiment are observed to be in good agreement. The radiating structure is thought to be a useful one in an application to the phased array antenna system, in particular, requiring dual polarization characteristics.

• Journal of Korean Foot and Ankle Society
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• v.11 no.1
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• pp.86-90
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• 2007

Purpose: We evaluated the results of operative treatment with F or H plates and screws using extensile lateral approach in intraarticular calcaneal fractures. Materials and Methods: From August 2003 to July 2006, twenty intraarticular calcaneal fractures which were operated with open reduction and internal fixation with F or H plates and screws were evaluated retrospectively. According to the Essex-Lopresti classification, 3 cases were tongue type and 16 were joint depression type. With the Sanders classification, 2 cases were IIA type, 7 were IIB, 5 were IIIAB, 2 were IIIAC and 3 were IV. We have analysed the $B{\ddot{o}}hler$ angle, Gissane angle, and calcaneal width in radiologic evaluation, and evaluated clinical result according to the Creighton-Nebraska Health Foundation Score. Results: Radiologic changes showed as follows: $B{\ddot{o}}hler$ angle improved from $5.8^{\circ}$ to $25.9^{\circ}$, Gissane angle from $119.0^{\circ}$ to $113.3^{\circ}$, and calcaneal width from 50.4 mm to 37.8 mm. In the clinical results, excellent cases were noted in 8 cases, good in 8 cases, fair in 2 cases, poor in 1 case. Conclusion: Operative treatment with F or H plates and screws using extensile lateral approach in intraarticular calcaneal fractures was thought to be a useful operative method allowing anatomical reduction.

• Journal of Chest Surgery
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• v.50 no.4
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• pp.275-280
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• 2017

Background: Video-assisted thoracoscopic surgery (VATS) anatomic lung resections are gradually becoming the standard surgical approach in early-stage non-small cell lung cancer (NSCLC). The technique is being applied in cases of larger tumors depending on the experience of the surgical team. The objective of this study was to compare early surgical and survival outcomes in patients undergoing anatomic pulmonary resections using VATS and thoracotomy techniques for clinical T2 NSCLC during the adaptation period of the surgical team to the VATS approach. Methods: The data of all patients who underwent anatomic pulmonary resection for NSCLC using VATS and open techniques since April 2012 were recorded to create a prospective lung cancer database. Clinical T2 NSCLC patients who underwent VATS anatomic lung resection were identified and compared with cT2 patients who underwent open resection. Results: Between April 2012 and August 2014, 269 anatomical resections for NSCLC were performed (80 VATS and 189 thoracotomy). Thirty-four VATS patients who had clinical T2 disease were identified and stage-matched to thoracotomy patients. The average tumor diameter was comparable ($34.2{\pm}11.1{\times}29.8{\pm}10.1mm$ vs. $32.3{\pm}9.8{\times}32.5{\pm}12.2mm$, p=0.4). Major complications were higher in the thoracotomy group (n=0 vs. n=5, p=0.053). There was no 30-day mortality, and the 2-year survival rate was 91% for VATS and 82% for thoracotomy patients (p=0.4). Conclusion: VATS anatomic resections in clinical T2 NSCLC tumors are safe and have perioperative and pathologic outcomes similar to those of thoracotomy, while remaining within the learning curve.

• Environmental and Resource Economics Review
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• v.12 no.1
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• pp.75-90
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• 2003

In this paper we have shown that a Pigouvian tax is an adequate resolution of congestion externality to attain Pareto optimality using utility maximization. For this objective, taking an open access freeway as an example, we not only derived both marginal private benefit and marginal social benefit, but also assessed the divergence between marginal private benefit and marginal social benefit. As a result, we identified that the amount of a Pigouvian tax should be the same amount as the external time cost, which is the value of the marginal time cost to Individual a incurred by Individual b through freeway congestion. This Pigouvian tax coincides with the profit or wealth maximizing toll suggested by literature on the basis of profit maximization. In addition, because an open access freeway is accounted as common property resource, we proved that average social congestion cost is essentially equal to marginal private congestion cost in our model. Finally, we showed that the optimal value of trip derived in our model is the same as that generated on profit maximization approach.

• International journal of advanced smart convergence
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• v.5 no.3
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• pp.66-71
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• 2016

Smart building gate security control system using smartphone integrated with near field communication (NFC) has become part of daily life usage these days. The technology change in replacing RF NFC device using visible light communication technology based approach growing faster in recent days. This paper propose a design and development of gate security control system using color code based user authentication ID generation as part of an intelligent access control system to control automatic door open and close. In this approach gate security access control use the recent visible light communication technology trends to transfer the user specific authentication code to door access control system using color code on smartphone screen. Using a camera in the door access control system (ACS), color codes on smartphone screens are detected and matched to the database of authenticated user to open the door automatically in gate security system. We measure the visual light communication technology efficiency as a part of the research and the experiments have revealed that more than 95% users authenticated correctly at the suggested experiment environment on gate security control system.

• The KIPS Transactions:PartB
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• v.15B no.6
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• pp.603-608
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• 2008

In this paper an approach to building fuzzy model to predict daily open, close, high, and low stock prices is presented. One of prior problems in building a stock prediction model is to select most effective indicators for the stock prediction. The problem is overcome by the selection of information used in the analysis of stick-chart as the input variables of our fuzzy model. The fuzzy rules have the premise and the consequent, in which they are composed of trapezoidal membership functions, and nonlinear equations, respectively. DE(Differential Evolution) searches optimal fuzzy rules through an evolutionary process. To evaluate the effectiveness of the proposed approach numerical example is considered. The fuzzy models to predict open, high, low, and close prices of KOSPI(KOrea composite Stock Price Index) on a daily basis are built, and their performances are demonstrated and compared with those of neural network.

• The Journal of the Korea Contents Association
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• v.19 no.6
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• pp.58-71
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• 2019

The purpose of this study is to explore the multi-dimensionality and the differences of the career success that is revealed by the employee's perception. In order to fulfill the research purpose, LDA topic modeling has applied to extract latent topics of career success from 126 Korean employees' open-end survey questionnaires. The extracted latent topics are social recognition, continuing service within an organization, expertise, financial rewards, and pursuing personal meaning. The occurrence probability of each topic was different by individual characteristics such as gender, education, position. Study findings showed there is multi-dimensionality in career success, and there are differences of topic occurrence probability by demographic characteristics. Additionally, this study showed how to apply the recently developed machine learning approach in order to reduce the researcher's bias by adapting the LDA topic modeling to the qualitative open-ended survey data.

• Journal of the Korean Society of Radiology
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• v.84 no.4
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• pp.846-854
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• 2023

Vascular injuries of the extremities are associated with a high mortality rate. Conventionally, open surgery is the treatment of choice for peripheral vascular injuries. However, rapid development of devices and techniques in recent years has significantly increased the utilization and clinical application of endovascular treatment. Endovascular options for peripheral vascular injuries include stent-graft placement and embolization. The surgical approach is difficult in cases of axillo-subclavian or iliac artery injuries, and stent-graft placement is a widely accepted alternative to open surgery. Embolization can be considered for arterial injuries associated with active bleeding, pseudoaneurysms, and arteriovenous fistula and in patients in whom embolization can be safely performed without a risk of ischemic complications in the extremities. Endovascular treatment is a minimally invasive procedure and is useful as a simultaneous diagnostic and therapeutic approach, which serve as advantages of this technique that is widely utilized for vascular injuries of the extremities.

• The Journal of the Convergence on Culture Technology
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• v.4 no.3
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• pp.105-111
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• 2018

This study aims to investigate Youth Culture in the Stream of Popular Culture by 'The Relation-Approach'. For this, the relations between the two were reviewed, through which the meaning and practical actions were identified as main finding of the fact that youth culture has cultural meaning with possibility. Namely, youth culture is not the culture of passive culture, addressee culture and consumer culture but the culture of active culture, addresser culture and producer culture. Further more, the practical actions as the culture of having new possibility in the stream of popular culture were found to be approached by epistemological and institutional practical actions. The importance of epistemological practice of youth culture is revealed as the importance of perspective. As far as youth culture is approached in the view of exclusive standpoint, there will be accompanied of limitation of closed youth culture. Thus, the possibility of open youth culture could be obtained by taking of the inclusive standpoint. Accordingly, the open possibility of youth culture will have the new possibility in the concept of open culture with open standpoint. That will be realized by the grand broad culture concept, not by the small narrow culture concept.

• Korean Journal of Social Welfare Studies
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• v.41 no.2
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• pp.5-33
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• 2010

The purpose of this study is to understand the open adoption experience of adoptive families. For this purpose, the data were collected through diverse data collection methods including in-depth interviews with adoptive families who had experiences of open adoption and analyzed using a qualitative case study approach. Data collected from six adoptive families were employed for within-case analysis and cross-case analysis. Each case was carefully examined and summarized using story-telling style in the within-case analysis and major issues for open adoption appeared in each case were described and compared one by one. In the cross-case analysis, all the cases were re-examined keeping the issues appeared in the within-case analysis in mind and eight integrated themes were emerged from it. The eight integrated themes are 'the crucial meeting', 'a clear arrangement', 'an uneasy parallel', 'the other mom', 'who are the real parents?', 'the words never to say', 'the hidden characters', and 'the center of relations or the outsider'. Based on the results of the study, the policies and practical guidelines related to open adoption were suggested. Also, the suggestions for the further studies were made to obtain more abundant information beyond the limitations of the study.